1
|
Gholipour S, Nikaeen M, Mohammadi F, Rabbani D. Antibiotic resistance pattern of waterborne causative agents of healthcare-associated infections: A call for biofilm control in hospital water systems. J Infect Public Health 2024; 17:102469. [PMID: 38838607 DOI: 10.1016/j.jiph.2024.102469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND In recent years, the global spread of antimicrobial resistance has become a concerning issue, often referred to as a "silent pandemic". Healthcare-associated infections (HAIs) caused by antibiotic-resistant bacteria (ARB) are a recurring problem, with some originating from waterborne route. The study aimed to investigate the presence of clinically relevant opportunistic bacteria and antibiotic resistance genes (ARGs) in hospital water distribution systems (WDSs). METHODS Water and biofilm samples (n = 192) were collected from nine hospitals in Isfahan and Kashan, located in central Iran, between May 2022 and June 2023. The samples were analyzed to determine the presence and quantities of opportunistic bacteria and ARGs using cultural and molecular methods. RESULTS Staphylococcus spp. were highly detected in WDS samples (90 isolates), with 33 % of them harboring mecA gene. However, the occurrences of E. coli (1 isolate), Acinetobacter baumannii (3 isolates), and Pseudomonas aeruginosa (14 isolates) were low. Moreover, several Gram-negative bacteria containing ARGs were identified in the samples, mainly belonging to Stenotrophomonas, Sphingomonas and Brevundimonas genera. Various ARGs, as well as intI1, were found in hospital WDSs (ranging from 14 % to 60 %), with higher occurrences in the biofilm samples. CONCLUSION Our results underscore the importance of biofilms in water taps as hotspots for the dissemination of opportunistic bacteria and ARG within hospital environments. The identification of multiple opportunistic bacteria and ARGs raises concerns about the potential exposure and acquisition of HAIs, emphasizing the need for proactive measures, particularly in controlling biofilms, to mitigate infection risks in healthcare settings.
Collapse
Affiliation(s)
- Sahar Gholipour
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Mahnaz Nikaeen
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Farzaneh Mohammadi
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Davarkhah Rabbani
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| |
Collapse
|
2
|
Waegenaar F, García-Timermans C, Van Landuyt J, De Gusseme B, Boon N. Impact of operational conditions on drinking water biofilm dynamics and coliform invasion potential. Appl Environ Microbiol 2024; 90:e0004224. [PMID: 38647288 PMCID: PMC11107155 DOI: 10.1128/aem.00042-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/27/2024] [Indexed: 04/25/2024] Open
Abstract
Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality by causing water discoloration and deterioration and can be a reservoir for unwanted microorganisms. In this study, we investigated whether indicator organisms for drinking water quality, such as coliforms, can settle in mature drinking water biofilms. Therefore, a biofilm monitor consisting of glass rings was used to grow and sample drinking water biofilms. Two mature drinking water biofilms were characterized by flow cytometry, ATP measurements, confocal laser scanning microscopy, and 16S rRNA sequencing. Biofilms developed under treated chlorinated surface water supply exhibited lower cell densities in comparison with biofilms resulting from treated groundwater. Overall, the phenotypic as well as the genotypic characteristics were significantly different between both biofilms. In addition, the response of the biofilm microbiome and possible biofilm detachment after minor water quality changes were investigated. Limited changes in pH and free chlorine addition, to simulate operational changes that are relevant for practice, were evaluated. It was shown that both biofilms remained resilient. Finally, mature biofilms were prone to invasion of the coliform, Serratia fonticola. After spiking low concentrations (i.e., ±100 cells/100 mL) of the coliform to the corresponding bulk water samples, the coliforms were able to attach and get established within the mature biofilms. These outcomes emphasize the need for continued research on biofilm detachment and its implications for water contamination in distribution networks. IMPORTANCE The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.
Collapse
Affiliation(s)
- Fien Waegenaar
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Cristina García-Timermans
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Josefien Van Landuyt
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Bart De Gusseme
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
- Farys, Department R&D – Innovation Water, Ghent, Belgium
| | - Nico Boon
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| |
Collapse
|
3
|
Li G, Chen Q, Zhou Y, Su Y, Wu B, Yu J, Yang M, Shi B. Manganese and iron oxides on pipe surface promote dissolved aluminum accumulation in drinking water distribution systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171606. [PMID: 38492600 DOI: 10.1016/j.scitotenv.2024.171606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 03/18/2024]
Abstract
Aluminum-containing deposits are pervasive in drinking water distribution systems (DWDSs). However, the mechanisms driving dissolved Al transformation to pipe deposits remain elusive. This study investigated dissolved Al accumulation in DWDSs by batch experiments and long-term pipe experiments using actual finished water. PVC pipe experiments showed that dissolved Al hardly deposited on clean PVC pipe walls at alkaline pH. However, it could be substantially anchored by the pipe surface covered with Mn and Fe deposits formed from Mn(II) oxidation and Fe(III) precipitation. Batch experiments verified that the synthesized Mn and Fe oxides exhibited a strong capacity for dissolved Al uptake at pH 7.7 and 9.0 (dissolved Al was the dominant form). Biofilms on pipe walls also enhanced dissolved Al accumulation. Iron pipe experiments showed that corroded iron pipes with abundant iron corrosion products readily accumulated Al. Compared to chlorination and chloramination, non-disinfected conditions were more favorable for particulate Al deposition on iron pipe surface, probably due to Al immobilization by biofilms. In addition, continuous Al accumulation in iron pipes enhanced Fe release to pipe water. This study highlighted the important role of metal oxides in dissolved Al accumulation in DWDSs with abundant Mn and Fe solids, which provided new insights into deposit formation and control strategies.
Collapse
Affiliation(s)
- Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qi Chen
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yue Zhou
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuliang Su
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, Guangdong 519000, China
| | - Bin Wu
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, Guangdong 519000, China
| | - Jianwei Yu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
4
|
Zhang H, Zhang S, Liu Y, Yang M, Zhou X, Abbas G, Wang L, Lu J. Effects of chloride on corrosion scale compositions and heavy metal release in drinking water distribution systems. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133452. [PMID: 38198869 DOI: 10.1016/j.jhazmat.2024.133452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/16/2023] [Accepted: 01/03/2024] [Indexed: 01/12/2024]
Abstract
Variations in water chemistry may lead to the release of harmful heavy metals in drinking water distribution systems (DWDSs). In this study, the effects of chloride on the release of heavy metals such as Fe, Mn, As, Cr, Mo, V, Sr, and Co were examined using steel and cast iron pipe loops. After chloride was added, the relative contents of goethite (α-FeOOH), lepidocrocite (γ-FeOOH), and siderite (FeCO3) in pipe scales increased, but the contents of magnetite (Fe3O4) decreased. The most prevalent compounds were α-FeOOH and γ-FeOOH. When the chloride levels were increased, the effluent concentrations of Fe, Mn, As, Cr, Mo, V, Sr, and Co significantly increased. These heavy metals were released presumably because of the destabilization and dissolution of corrosion scales induced by chloride and adsorption site competition. Strong positive correlations were also observed between Fe&Mn, Fe/Mn&As, Fe/Mn&Cr, Fe/Mn&Mo, Fe/Mn&V, Fe/Mn&Sr, and Fe/Mn&Co, indicating the co-release of Fe, Mn, and other metals. This study may be helpful for the potential strategies on avoidance of heavy metal release and improvement of water supply security.
Collapse
Affiliation(s)
- Hui Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Shan Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Yuekai Liu
- Qingdao Municiple Engineering Design & Research Institute, Qingdao 266000, PR China
| | - Min Yang
- China Northwest Architecture Design and Research Institute Co. Ltd, Xi'an 710018, PR China
| | - Xue Zhou
- Shenzhen Water Resources Planning and Design Institute Co., Ltd, Shenzhen 518000, PR China
| | - Ghulam Abbas
- Department of Chemical Engineering and Technology, University of Gujrat, Gujrat 50700, Pakistan
| | - Long Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Jinsuo Lu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
| |
Collapse
|
5
|
Søborg DA, Højris B, Brinkmann K, Pedersen MR, Skovhus TL. Characterizing the development of biofilm in polyethylene pipes in the non-chlorinated Danish drinking-water distribution system. BIOFOULING 2024; 40:262-279. [PMID: 38695072 DOI: 10.1080/08927014.2024.2343839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 04/11/2024] [Indexed: 06/11/2024]
Abstract
In newly commissioned drinking-water polyethylene (PE) pipes, biofilm develops on the inner pipe surface. The microbial community composition from colonization to the establishment of mature biofilms is less known, including the effect on the distributed water quality. Biofilm development was followed through 1.5 years in PE-pipe side streams at two locations of a full-scale, non-chlorinated drinking-water distribution system (leaving a waterworks versus 5-6 km from a waterworks) along with inlet and outlet water quality. Mature biofilms were established after ∼8-9 months, dominated by Proteobacteria, Actinobacteria and Saccharibacteria (61-93% relative abundance), with a higher diversity (OTUs/Shannon Index/16S rRNA gene amplicon sequencing) in pipes in the far end of the distribution system. Comamonadaceae, and specifically Aquabacterium (>30% of reads), dominated young (∼1.5-month-old) biofilms. Young biofilms were linked to increased microbiological counts in drinking water (HPC/ATP/qPCR), while the establishment of mature biofilms led to a drop in HPC and benefited the water quality, highlighting the importance of optimizing commissioning procedures for rapidly achieving mature and stable biofilms.
Collapse
Affiliation(s)
- Ditte A Søborg
- Research Centre for Built Environment, Climate, Water Technology and Digitalization, VIA University College, Horsens, Denmark
| | - Bo Højris
- Water Application and Technology, GRUNDFOS Holding A/S, Bjerringbro, Denmark
| | | | | | - Torben L Skovhus
- Research Centre for Built Environment, Climate, Water Technology and Digitalization, VIA University College, Horsens, Denmark
| |
Collapse
|
6
|
Ren A, Yao M, Fang J, Dai Z, Li X, van der Meer W, Medema G, Rose JB, Liu G. Bacterial communities of planktonic bacteria and mature biofilm in service lines and premise plumbing of a Megacity: Composition, Diversity, and influencing factors. ENVIRONMENT INTERNATIONAL 2024; 185:108538. [PMID: 38422875 DOI: 10.1016/j.envint.2024.108538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/14/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
Although simulated studies have provided valuable knowledge regarding the communities of planktonic bacteria and biofilms, the lack of systematic field studies have hampered the understanding of microbiology in real-world service lines and premise plumbing. In this study, the bacterial communities of water and biofilm were explored, with a special focus on the lifetime development of biofilm communities and their key influencing factors. The 16S rRNA gene sequencing results showed that both the planktonic bacteria and biofilm were dominated by Proteobacteria. Among the 15,084 observed amplicon sequence variants (ASVs), the 33 core ASVs covered 72.8 %, while the 12 shared core ASVs accounted for 62.2 % of the total sequences. Remarkably, it was found that the species richness and diversity of biofilm communities correlated with pipe age. The relative abundance of ASV2 (f_Sphingomonadaceae) was lower for pipe ages 40-50 years (7.9 %) than for pipe ages 10-20 years (59.3 %), while the relative abundance of ASV10 (f_Hyphomonadaceae) was higher for pipe ages 40-50 years (19.5 %) than its presence at pipe ages 20-30 years (1.9 %). The community of the premise plumbing biofilm had significantly higher species richness and diversity than that of the service line, while the steel-plastics composite pipe interior lined with polyethylene (S-PE) harbored significantly more diverse biofilm than the galvanized steel pipes (S-Zn). Interestingly, S-PE was enriched with ASV27 (g_Mycobacterium), while S-Zn pipes were enriched with ASV13 (g_Pseudomonas). Moreover, the network analysis showed that five rare ASVs, not core ASVs, were keystone members in biofilm communities, indicating the importance of rare members in the function and stability of biofilm communities. This manuscript provides novel insights into real-world service lines and premise plumbing microbiology, regarding lifetime dynamics (pipe age 10-50 years), and the influences of pipe types (premise plumbing vs. service line) and pipe materials (S-Zn vs. S-PE).
Collapse
Affiliation(s)
- Anran Ren
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; University of Chinese Academy of Sciences, Beijing, China
| | - Mingchen Yao
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; University of Chinese Academy of Sciences, Beijing, China
| | - Jiaxing Fang
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Science and Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Zihan Dai
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Xiaoming Li
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Walter van der Meer
- Science and Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands; Oasen Drinkwater, PO Box 122, 2800 AC, Gouda, The Netherlands
| | - Gertjan Medema
- Oasen Drinkwater, PO Box 122, 2800 AC, Gouda, The Netherlands; KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands; Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48823, USA
| | - Joan B Rose
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48823, USA
| | - Gang Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; University of Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
7
|
Kalu CM, Mudau KL, Masindi V, Ijoma GN, Tekere M. Occurrences and implications of pathogenic and antibiotic-resistant bacteria in different stages of drinking water treatment plants and distribution systems. Heliyon 2024; 10:e26380. [PMID: 38434035 PMCID: PMC10906316 DOI: 10.1016/j.heliyon.2024.e26380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 12/05/2023] [Accepted: 02/12/2024] [Indexed: 03/05/2024] Open
Abstract
Different stages of drinking water treatment plants (DWTPs) play specific roles in diverse contaminants' removal present in natural water sources. Although the stages are recorded to promote adequate treatment of water, the occurrence of pathogenic bacteria (PB) and antibiotic-resistant bacteria (ARB) in the treated water and the changes in their diversity and abundance as it passed down to the end users through the drinking water distribution systems (DWDSs), is a great concern, especially to human health. This could imply that the different stages and the distribution system provide a good microenvironment for their growth. Hence, it becomes pertinent to constantly monitor and document the diversity of PB and ARB present at each stage of the treatment and distribution system. This review aimed at documenting the occurrence of PB and ARB at different stages of treatment and distribution systems as well as the implication of their occurrence globally. An exhaustive literature search from Web of Science, Science-Direct database, Google Scholar, Academic Research Databases like the National Center for Biotechnology Information, Scopus, and SpringerLink was done. The obtained information showed that the different treatment stages and distribution systems influence the PB and ARB that proliferate. To minimize the human health risks associated with the occurrence of these PB, the present review, suggests the development of advanced technologies that can promote quick monitoring of PB/ARB at each treatment stage and distribution system as well as reduction of the cost of environomics analysis to promote better microbial analysis.
Collapse
Affiliation(s)
- Chimdi M. Kalu
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Khuthadzo L. Mudau
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Vhahangwele Masindi
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
- Magalies Water, Scientific Services, Research & Development Division, Brits, South Africa
| | - Grace N. Ijoma
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Memory Tekere
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| |
Collapse
|
8
|
Ke Y, Sun W, Chen Z, Zhu Y, Chen X, Yan S, Li Y, Xie S. Effects of disinfectant type and dosage on biofilm's activity, viability, microbiome and antibiotic resistome in bench-scale drinking water distribution systems. WATER RESEARCH 2024; 249:120958. [PMID: 38064782 DOI: 10.1016/j.watres.2023.120958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 01/03/2024]
Abstract
Drinking water distribution systems (DWDSs) are important for supplying high-quality water to consumers and disinfectant is widely used to control microbial regrowth in DWDSs. However, the disinfectant's influences on microbial community and antibiotic resistome in DWDS biofilms and the underlying mechanisms driving their dynamics remain elusive. The study investigated the effects of chlorine and chloramine disinfection on the microbiome and antibiotic resistome of biofilms in bench-scale DWDSs using metagenomics assembly. Additionally, the biofilm activity and viability were monitored based on adenosine triphosphate (ATP) and flow cytometer (FCM) staining. The results showed that both chlorine and chloramine disinfectants decreased biofilm ATP, although chloramine at a lower dosage (1 mg/L) could increase it. Chloramine caused a greater decrease in living cells than chlorine. Furthermore, the disinfectants significantly lowered the microbial community diversity and altered microbial community structure. Certain bacterial taxa were enriched, such as Mycobacterium, Sphingomonas, Sphingopyxis, Azospira, and Dechloromonas. Pseudomonas aeruginosa exhibited high resistance towards disinfectants. The disinfectants also decreased the complexity of microbial community networks. Some functional taxa (e.g., Nitrospira, Nitrobacter, Nitrosomonas) were identified as keystones in chloramine-treated DWDS microbial ecological networks. Stochasticity drove biofilm microbial community assembly, and disinfectants increased the contributions of stochastic processes. Chlorine had greater promotion effects on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and ARG hosts than chloramine. The disinfectants also selected pathogens, such as Acinetobacter baumannii and Klebsiella pneumonia, and these pathogens also harbored ARGs and MGEs. Overall, this study provides new insights into the effects of disinfectants on biofilm microbiome and antibiotic resistome, highlighting the importance of monitoring and managing disinfection practices in DWDSs.
Collapse
Affiliation(s)
- Yanchu Ke
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenjun Sun
- School of Environment, Tsinghua University, Beijing 100084, China; Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou 215163, China.
| | - Zhongyun Chen
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Ying Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiuli Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shuang Yan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yangyang Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shuguang Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| |
Collapse
|
9
|
Zhang T, Liao P, Fang L, Zhang D. Effect of booster disinfection on the prevalence of microbial antibiotic resistance and bacterial community in a simulated drinking water distribution system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:122902. [PMID: 37949160 DOI: 10.1016/j.envpol.2023.122902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023]
Abstract
Booster disinfection was often applied to control the microorganism's growth in long-distance water supply systems. The effect of booster disinfection on the changing patterns of antibiotic resistance and bacterial community was investigated by a simulated water distribution system (SWDS). The results showed that the antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) were initially removed after dosing disinfectants (chlorine and chloramine), but then increased with the increasing water age. However, the relative abundance of ARGs significantly increased after booster disinfection both in buck water and biofilm, then decreased along the pipeline. The pipe materials and disinfectant type also affected the antibiotic resistance. Chlorine was more efficient in controlling microbes and ARGs than chloramine. Compared with UPVC and PE pipes, SS pipes had the lowest total bacteria, ARB concentration, and ARB percentage, mainly due to higher disinfectant residuals and a smoother surface. The significant correlation (rs = 0.77, p < 0.001) of the 16S rRNA genes was observed between buck water and biofilm, while the correlations of targeted ARGs were found to be weak. Bray-Curtis similarity index indicated that booster disinfection significantly changed the biofilm bacterial community and the disinfectant type also had a marked impact on the bacterial community. At the genus level, the relative abundance of Pseudomonas, Sphingomonas, and Methylobacterium significantly increased after booster disinfection. Mycobacterium increased after chloramination while decreased after chlorination, indicating Mycobacterium might resist chloramine. Pseudomonas, Methylobacterium, and Phreatobacter were found to correlate well with the relative abundance of ARGs. These results highlighted antibiotic resistance shift and bacterial community alteration after booster disinfection, which may be helpful in controlling potential microbial risk in drinking water.
Collapse
Affiliation(s)
- Tuqiao Zhang
- College of Civil Engineering and Architecture Zhejiang University, Hangzhou, 310058, China; Future Water Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314000, China; Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province, Hangzhou, 310058, China.
| | - Pubin Liao
- College of Civil Engineering and Architecture Zhejiang University, Hangzhou, 310058, China; Future Water Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314000, China; Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province, Hangzhou, 310058, China.
| | - Lei Fang
- College of Civil Engineering and Architecture Zhejiang University, Hangzhou, 310058, China; Future Water Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing, 314000, China; Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province, Hangzhou, 310058, China.
| | - Dongyang Zhang
- College of Civil Engineering and Architecture Zhejiang University, Hangzhou, 310058, China; Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province, Hangzhou, 310058, China.
| |
Collapse
|
10
|
Abkar L, Moghaddam HS, Fowler SJ. Microbial ecology of drinking water from source to tap. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168077. [PMID: 37914126 DOI: 10.1016/j.scitotenv.2023.168077] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 11/03/2023]
Abstract
As drinking water travels from its source, through various treatment processes, hundreds to thousands of kilometres of distribution network pipes, to the taps in private homes and public buildings, it is exposed to numerous environmental changes, as well as other microbes living in both water and on surfaces. This review aims to identify the key locations and factors that are associated with changes in the drinking water microbiome throughout conventional urban drinking water systems from the source to the tap water. Over the past 15 years, improvements in cultivation-independent methods have enabled studies that allow us to answer such questions. As a result, we are beginning to move towards predicting the impacts of disturbances and interventions resulting ultimately in management of drinking water systems and microbial communities rather than mere observation. Many challenges still exist to achieve effective management, particularly within the premise plumbing environment, which exhibits diverse and inconsistent conditions that may lead to alterations in the microbiota, potentially presenting public health risks. Finally, we recommend the establishment of global collaborative projects on the drinking water microbiome that will enhance our current knowledge and lead to tools for operators and researchers alike to improve global access to high-quality drinking water.
Collapse
Affiliation(s)
- Leili Abkar
- Civil Engineering Department, University of British Columbia, Canada.
| | | | - S Jane Fowler
- Department of Biological Sciences, Simon Fraser University, Canada.
| |
Collapse
|
11
|
Ke Y, Sun W, Liu S, Zhu Y, Yan S, Chen X, Xie S. Seasonal variations of biofilm C, N and S cycling genes in a pilot-scale chlorinated drinking water distribution system. WATER RESEARCH 2023; 247:120759. [PMID: 37897999 DOI: 10.1016/j.watres.2023.120759] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 10/30/2023]
Abstract
Biofilms in drinking water distribution systems (DWDS) host diverse microorganisms. However, the functional attributes of DWDS biofilms and their associations with seasonality remain unclear. This study aims to characterize variations in the microbial metabolic traits of DWDS biofilms collected during different seasons, using a pilot-scale DWDS in dark under plug-flow conditions during one-year operation period. Network analysis was used to predict the functional gene hosts. The overall functional attributes determined by shotgun metagenomics exhibited significant differences among seasons. Genes associated with aromatic metabolism, fatty acid biosynthesis and degradation, and capsular extracellular polymeric substance (EPS) were significantly upregulated in summer owing to the higher temperatures and chlorine in the influent of the DWDS. Moreover, the pathways associated with nitrogen, sulfur, glycolysis, and tricarboxylic acid (TCA) cycling, as well as carbon fixation were reconstructed and displayed according to the sampling season. Nitrogen reduction pathways [dissimilatory nitrate reduction to ammonium (DNRA) 73 %, assimilatory nitrate reduction to ammonium (ANRA) 21 %] were identified in DWDS biofilms, but nitrogen oxidation pathways were not. Sulfur cycling were involved in diverse pathways and genes. Glycolysis and TCA cycling offered electron donors and energy sources for nitrogen and sulfur reduction in biofilms. Carbon fixation was observed in DWDS biofilms, with the predominant pathway for fixing carbon dioxide being the reductive citrate cycle (38 %). Constructed functional gene networks composed of carbon, nitrogen, and sulfur cycling-related genes demonstrated synergistic effects (Positive proportion: 63.52-71.09 %). In addition, from spring to autumn, the network complexity decreased and network modularity increased. The assembly mechanism of carbon, nitrogen and sulfur cycling-related genes was driven by stochastic processes for all samples. These results highlight the diverse functional genes in DWDS biofilms, their synergetic interrelationships, and the seasonality effect on functional attributes.
Collapse
Affiliation(s)
- Yanchu Ke
- School of Environment, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Wenjun Sun
- School of Environment, Tsinghua University, Beijing 100084, China; Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou 215163, China.
| | - Shuming Liu
- School of Environment, Tsinghua University, Beijing 100084, China; Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou 215163, China
| | - Ying Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shuang Yan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiuli Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shuguang Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| |
Collapse
|
12
|
Niu J, Chen D, Shang C, Xiao L, Wang Y, Zeng W, Zheng X, Chen Z, Du X, Chen X. Niche Differentiation of Biofilm Microorganisms in a Full-scale Municipal Drinking Water Distribution System in China and Their Implication for Biofilm Control. MICROBIAL ECOLOGY 2023; 86:2770-2780. [PMID: 37542538 DOI: 10.1007/s00248-023-02274-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/21/2023] [Indexed: 08/07/2023]
Abstract
Biofilms on the inner surface of a drinking water distribution system (DWDS) affect water quality and stability. Understanding the niche differentiation of biofilm microbial communities is necessary for the efficient control of DWDS biofilms. However, biofilm studies are difficult to conduct in the actual DWDS because of inaccessibility to the pipes buried underground. Taking the opportunity of infrastructure construction and relevant pipeline replacement in China, biofilms in a DWDS (a water main and its branch pipes) were collected in situ, followed by analysis on the abundances and community structures of bacterial and archaeal using quantitative PCR and high-throughput sequencing, respectively. Results showed that archaea were detected only in the biofilms of the water main, with a range of 9.4×103~1.1×105 copies/cm2. By contrast, bacteria were detected in the biofilms of branch pipes and the distal part of the water main, with a range of 8.8×103~9.6×106 copies/cm2. Among the biofilm samples, the archaeal community in the central part of the water main showed the highest richness and diversity. Nitrosopumilus was found to be predominant (86.22%) in the biofilms of the proximal part of the water main. However, Methanobrevibacter (87.15%) predominated in the distal part of the water main. The bacterial community of the water main and branch pipes was primarily composed of Firmicutes and Proteobacteria at the phylum level, respectively. Regardless of archaea or bacteria, only few operational taxonomic units (OTUs) (<0.5% of total OTUs) were shared by all the biofilms, indicating the niche differentiation of biofilm microorganisms. Moreover, the high Mn content in the biofilms of the distal sampling location (D3) in the water main was linked to the predominance of Bacillus. Functional gene prediction revealed that the proportion of infectious disease-related genes was 0.44-0.67% in the tested biofilms. Furthermore, functional genes related to the resistance of the bacterial community to disinfections and antibiotics were detected in all the samples, that is, glutathione metabolism-relating genes (0.14-0.65%) and beta-lactam resistance gene (0.01-0.05%). The results of this study indicate the ubiquity of archaea and bacteria in the biofilms of water main and branch pipes, respectively, and pipe diameters could be a major influencing factor on bacterial community structure. In the water main, the key finding was the predominant existence of archaea, particularly Nitrosopumilus and methanogen. Hence, their routine monitoring and probable influences on water quality in pipelines with large diameter should be given more attention. Besides, since Mn-related Bacillus and suspected pathogenic Enterococcus were detected in the biofilm, supplementation of disinfectant may be a feasible strategy for inhibiting their growth and ensuring water quality. In addition, the monitoring on their abundance variation could help to determine the frequency and methods of pipeline maintenance.
Collapse
Affiliation(s)
- Jia Niu
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Daogan Chen
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Chenghao Shang
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Liang Xiao
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou, 350108, People's Republic of China
| | - Yue Wang
- Fuzhou Water Supply Company, Fuzhou, Fujian, 350001, People's Republic of China
| | - Wuqiang Zeng
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Xianliang Zheng
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Ziyi Chen
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Xupu Du
- Center of Safe and Energy-saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian, 350118, People's Republic of China
| | - Xiaochen Chen
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou, 350108, People's Republic of China.
| |
Collapse
|
13
|
Hu D, Li X, Zeng J, Xiao X, Zhao W, Zhang J, Yu X. Hidden risks: Simulated leakage of domestic sewage to secondary water supply systems poses serious microbiological risks. WATER RESEARCH 2023; 244:120529. [PMID: 37666151 DOI: 10.1016/j.watres.2023.120529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/22/2023] [Accepted: 08/25/2023] [Indexed: 09/06/2023]
Abstract
There are continuous reports about the pollution of the secondary water supply systems (SWSSs), among which domestic sewage leakage is the most serious. In this study, a pilot experiment lasting 70 days was conducted to explore the changes in physicochemical water quality and the microbial profiles in SWSSs polluted by different doses of domestic sewage through qPCR and high-throughput sequencing methods. The results showed that when domestic sewage entered the simulated water storage tank, a large amount of organic matter brought by domestic sewage quickly consumed chlorine disinfectants. High pollution levels (pollution index ≥ 1/1000) were accompanied by significant increases in turbidity and ammonia nitrogen concentration (p < 0.05) and by abnormal changes in sensory properties. Although different microbial community structures were found only at high pollution levels, qPCR results showed that the abundance of the bacterial 16S rRNA gene and some pathogenic gene markers in the polluted tank increased with the pollution level, and the specific gene marker of pathogens could be detected even at imperceptible pollution levels. In particular, the high detection frequency and abundance of Escherichia coli and Enterococcus faecails in polluted tank water samples demonstrated that they can be used for early warning. Moreover, it seems that the microorganisms that came with the domestic sewage lost their cultivability soon after entering SWSSs but could recover their activities during stagnation. In addition, the biofilm biomass in the polluted tank with high pollution levels increased faster at the initial stage, while after a longer contact time, it tended to remain at the same level as the control tank. This study emphasized the high microbial risk introduced by sewage water leakage even at imperceptible levels and could provide scientific suggestions for early warning and prevention of pollution to SWSSs.
Collapse
Affiliation(s)
- Dong Hu
- School of Public Health, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China
| | - Xiang Li
- School of Public Health, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China
| | - Jie Zeng
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto 615-8540, Japan
| | - Xinyan Xiao
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Wenya Zhao
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Jiakang Zhang
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Xin Yu
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
14
|
Cavallaro A, Rhoads WJ, Sylvestre É, Marti T, Walser JC, Hammes F. Legionella relative abundance in shower hose biofilms is associated with specific microbiome members. FEMS MICROBES 2023; 4:xtad016. [PMID: 37705999 PMCID: PMC10496943 DOI: 10.1093/femsmc/xtad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/13/2023] [Accepted: 08/14/2023] [Indexed: 09/15/2023] Open
Abstract
Legionella are natural inhabitants of building plumbing biofilms, where interactions with other microorganisms influence their survival, proliferation, and death. Here, we investigated the associations of Legionella with bacterial and eukaryotic microbiomes in biofilm samples extracted from 85 shower hoses of a multiunit residential building. Legionella spp. relative abundance in the biofilms ranged between 0-7.8%, of which only 0-0.46% was L. pneumophila. Our data suggest that some microbiome members were associated with high (e.g. Chthonomonas, Vrihiamoeba) or low (e.g. Aquabacterium, Vannella) Legionella relative abundance. The correlations of the different Legionella variants (30 Zero-Radius OTUs detected) showed distinct patterns, suggesting separate ecological niches occupied by different Legionella species. This study provides insights into the ecology of Legionella with respect to: (i) the colonization of a high number of real shower hoses biofilm samples; (ii) the ecological meaning of associations between Legionella and co-occurring bacterial/eukaryotic organisms; (iii) critical points and future directions of microbial-interaction-based-ecological-investigations.
Collapse
Affiliation(s)
- Alessio Cavallaro
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zürich, Switzerland
| | - William J Rhoads
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Émile Sylvestre
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Thierry Marti
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zürich, Switzerland
| | - Jean-Claude Walser
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zürich, Switzerland
- Department of Environmental Systems Science, Genetic Diversity Centre (GDC), ETH Zurich, 8092 Zürich, Switzerland
| | - Frederik Hammes
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| |
Collapse
|
15
|
Ke Y, Sun W, Chen X, Zhu Y, Guo X, Yan W, Xie S. Seasonality Determines the Variations of Biofilm Microbiome and Antibiotic Resistome in a Pilot-Scale Chlorinated Drinking Water Distribution System Deciphered by Metagenome Assembly. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:11430-11441. [PMID: 37478472 DOI: 10.1021/acs.est.3c01980] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Understanding the biofilm microbiome and antibiotic resistome evolution in drinking water distribution systems (DWDSs) is crucial to ensure the safety of drinking water. We explored the 10 month evolution of the microbial community, antibiotic resistance genes (ARGs), mobile gene elements (MGEs) co-existing with ARGs and pathogenic ARG hosts, and the ARG driving factors in DWDS biofilms using metagenomics assembly. Sampling season was critical in determining the microbial community and antibiotic resistome shift. Pseudomonas was the primary biofilm colonizer, and biofilms diversified more as the formation time increased. Most genera tended to cooperate to adapt to an oligotrophic environment with disinfectant stress. Biofilm microbial community and antibiotic resistome assembly were mainly determined by stochastic processes and changed with season. Metagenome assembly provided the occurrence and fates of MGEs co-existing with ARGs and ARG hosts in DWDS biofilms. The abundance of ARG- and MGE-carrying pathogen Stenotrophomonas maltophilia was high in summer. It primarily harbored the aph(3)-IIb, multidrug transporter, smeD, and metallo-beta-lactamase ARGs, which were transferred via recombination. The microbial community was the most crucial factor driving the antibiotic resistance shift. We provide novel insights about the evolution of pathogens and ARGs and their correlations in DWDS biofilms to ensure the safety of drinking water.
Collapse
Affiliation(s)
- Yanchu Ke
- School of Environment, Tsinghua University, Beijing 100084, China
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Wenjun Sun
- School of Environment, Tsinghua University, Beijing 100084, China
- Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou 215163, China
| | - Xiuli Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Ying Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xu Guo
- Fangshan District Water Bureau, Beijing 102445, China
| | - Weixin Yan
- Beijing BiSheng United Water Company, Beijing 102400, China
| | - Shuguang Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
16
|
Liu S, Li Q, Jiang R, Liu P, Zhang XX. Shift of human pathogen community composition and their potential human health risk after supply suspension in tap water. Sci Rep 2023; 13:12419. [PMID: 37528119 PMCID: PMC10393962 DOI: 10.1038/s41598-023-39225-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/21/2023] [Indexed: 08/03/2023] Open
Abstract
Water supply suspension-restoration can occur frequently due to the overhauling of civil infrastructure in developing countries and the shutdown of commercial buildings during the pandemic. For comprehensive insights into the effects of water supply suspension-restoration, this study characterized the variations of the pathogen community composition of the tap water and their infection risk under different water supply scenarios. Metagenomic sequencing revealed a significant change of the human pathogen profiles, among which the most dominant pathogen changed from Pseudomonas aeruginosa (4.91%) to Acinetobacter johnsonii (0.59%). Furthermore, absolute quantification of pathogens by propidium-monoazide-qPCR revealed that the abundance of the three typical pathogens (Pseudomonas aeruginosa, Mycobacterium avium and Salmonella sp.) showed an increase of 2.44 log to 3.60 log immediately after water supply suspension-restoration and did not return to the normal level even after 2-h supply restoration, except for Pseudomonas aeruginosa. Quantitative microbial risk assessment suggested the infection risks of the three pathogens arising from direct utilization of tap water under stable water supply, including dermal exposure and oral intake, were all above the threshold of 10-4, and evidently increased after water supply suspension-restoration. This study warns us against the risk induced by the pathogens in tap water, especially after water supply suspension-restoration.
Collapse
Affiliation(s)
- Shengnan Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Qisheng Li
- China Three Gorges Construction Engineering Corporation, Beijing, 100048, China
| | - Ruiming Jiang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China
| | - Peng Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China.
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Road, Nanjing, 210023, China.
| |
Collapse
|
17
|
Zou Q, Meng W, Wang C, Wang T, Liu X, Li D. Sodium dichloroisocyanurate: improving broiler health by reducing harmful microbial levels in the waterline. Front Vet Sci 2023; 10:1234949. [PMID: 37588972 PMCID: PMC10427219 DOI: 10.3389/fvets.2023.1234949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/21/2023] [Indexed: 08/18/2023] Open
Abstract
Sodium dichloroisocyanurate (NaDCC) is commonly used for treating drinking water, industrial water, and wastewater. This study aimed to investigate the potential effects of NaDCC-treated waterline drinking water on the growth of AA+ broilers by reducing microbial levels in the waterline. A total of 480 healthy 1-day-old AA+ broilers (46.77 ± 0.50 g) were selected for the experiment and randomly divided into four groups with six replicates of 20 birds each. The control group received regular drinking water, while the test groups received drinking water with NaDCC concentrations of 10, 30, and 50 mg/L. The test groups consumed the treated water on specific days throughout the 42-day experimental period. Results showed that NaDCC treatment significantly reduced the levels of E. coli, Salmonella, S. aureus and Moulds in the drinking water at the waterline (p < 0.05). Drinking water with NaDCC also led to reduced broiler fecal emissions of NH3 and H2S, as well as reduced counts of E. coli, Salmonella, S. aureus and Moulds (p < 0.05), particularly at 30 mg/L and 50 mg/L concentrations. Broilers consuming NaDCC at 50 mg/L exhibited a significant increase in ADG from days 1-42 (p < 0.05). The levels of E. coli, Salmonella, S. aureus and Moulds in the drinking water at the waterline were significantly and positively correlated with the bacterial count in the feces (p < 0.05, R > 0.6). Additionally, bacterial levels in drinking water and broiler feces were negatively correlated with broiler production performance indicators, including ADG, ADFI, F/G and AWC. In conclusion, NaDCC can indirectly enhance broiler performance by reducing the levels of harmful bacteria in the waterline without affecting normal drinking water. The addition of 30 mg/L or 50 mg/L of NaDCC to the waterline in poultry production can effectively control harmful microorganisms and improve poultry health. Based on the experiment's results, it is recommended to preferentially use 30 mg/L NaDCC in the waterline to reduce farming costs.
Collapse
Affiliation(s)
- Qiangqiang Zou
- College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, China
| | - Weishuang Meng
- College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, China
| | - Chunqiang Wang
- College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, China
| | - Tieliang Wang
- College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, China
- Liaoning Kaiwei Biotechnology Co., Ltd., Jinzhou, China
| | - Xiao Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Desheng Li
- College of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou, China
| |
Collapse
|
18
|
Fang J, Dai Z, Li X, van der Hoek JP, Savic D, Medema G, van der Meer W, Liu G. Service-lines as major contributor to water quality deterioration at customer ends. WATER RESEARCH 2023; 241:120143. [PMID: 37276656 DOI: 10.1016/j.watres.2023.120143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/16/2023] [Accepted: 05/28/2023] [Indexed: 06/07/2023]
Abstract
Biofilm detachment contributes to water quality deterioration. However, the contributions of biofilm detachment from different pipes have not been quantified or compared. Following the introduction of partial reverse osmosis (RO) in drinking water production, this study analyzed particles at customers' ends and tracked their origins to water distribution mains and service lines. For doing so, filter bags were installed in front of water meters to capture upstream detached particles, while biofilm from water main and service line were sampled by cutting pipe specimens. The results showed that elemental concentrations of the biofilm in mains were higher than those of service lines (54.3-268.5 vs. 27.1-44.4 μg/cm2), both dominated by Ca. Differently, filter bags were dominated by Fe/Mn (77.5-98.1%). After introducing RO, Ca significantly decreased in biofilms of mains but not service lines, but the released Fe/Mn rather than Ca arrived at customers' ends. The ATP concentrations of service lines were higher than mains, which decreased on mains but increased in service lines after introducing RO. For the core ASVs, 13/24 were shared by service lines (17), mains (21), and filter bags (17), which were assigned mainly to Nitrospira spp., Methylomagnum spp., Methylocytis spp., and IheB2-23 spp. According to source tracking results, service lines contributed more than mains to the particulate material collected by filter bags (57.6 ± 13.2% vs. 13.0 ± 11.6%). To the best of our knowledge, the present study provides the first evidence of service lines' direct and quantitative contributions to potential water quality deterioration at customers' ends. This highlights the need for the appropriate management of long-neglected service line pipes, e.g., regarding material selection, length optimization, and proper regulation.
Collapse
Affiliation(s)
- Jiaxing Fang
- Key Lab of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085, Beijing, PR China; Membrane Science and Technology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500, AE, Enschede, the Netherlands; Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600, GA, Delft, the Netherlands
| | - Zihan Dai
- Key Lab of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085, Beijing, PR China
| | - Xiaoming Li
- Key Lab of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085, Beijing, PR China
| | - Jan Peter van der Hoek
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600, GA, Delft, the Netherlands; Waternet, P.O. Box 94370, 1090, GJ Amsterdam, the Netherlands
| | - Dragan Savic
- KWR Water Research Institute, P.O. Box 1072, 3430, BB, Nieuwegein, the Netherlands; Centre for Water Systems, University of Exeter, Exeter EX4 4QF, United Kingdom; University of Belgrade, Faculty of Civil Engineering, Department for Hydraulic and environmental engineering, Bulevar kralja Aleksandra 73, Belgrade, Serbia
| | - Gertjan Medema
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600, GA, Delft, the Netherlands; KWR Water Research Institute, P.O. Box 1072, 3430, BB, Nieuwegein, the Netherlands; Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48823, USA
| | - Walter van der Meer
- Membrane Science and Technology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500, AE, Enschede, the Netherlands; Oasen Water Company, PO BOX 122, 2800, AC, Gouda, the Netherlands
| | - Gang Liu
- Key Lab of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085, Beijing, PR China; Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600, GA, Delft, the Netherlands.
| |
Collapse
|
19
|
Koppanen M, Kesti T, Rintala J, Palmroth M. Can online particle counters and electrochemical sensors distinguish normal periodic and aperiodic drinking water quality fluctuations from contamination? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162078. [PMID: 36764531 DOI: 10.1016/j.scitotenv.2023.162078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Early warning systems monitoring the quality of drinking water need to distinguish between normal quality fluctuations and those caused by contaminants. Thus, to decrease the number of false positive events, normal water quality fluctuations, whether periodic or aperiodic, need to be characterized. For this, we used a novel flow-imaging particle counter, a light-scattering particle counter, and electrochemical sensors to monitor the drinking water quality of a pressure zone in a building complex for 109 days. Data were analyzed to determine the feasibility of the sensors and particle counters to distinguish periodic and aperiodic fluctuations from real-life contaminants. The concentrations of particles smaller than 10 μm and N, Small, Large, and B particles showed sudden changes recurring daily, likely due to the flow rate changes in the building complex. Conversely, the concentrations of larger than 10 μm particles and C particles, in addition to the responses of electrochemical sensors, remained in their low typical values despite flow rate changes. The aperiodic events, likely resulting from an abnormally high flow rate in the water mains due to maintenance, were detected using particle counters and electrochemical sensors. This study provides insights into choosing water quality sensors by showing that machine learning-based particle classes, such as B, C, F, and particles larger than 10 μm are promising in distinguishing contamination from aperiodic and periodic fluctuations while the use of other particle classes and electrochemical sensors may require dynamic baseline to decrease false positive events in an early warning system.
Collapse
Affiliation(s)
- Markus Koppanen
- Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101, Tampere, Finland.
| | - Tero Kesti
- Uponor Corporation, Kaskimäenkatu 2, FI-33900 Tampere, Finland
| | - Jukka Rintala
- Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101, Tampere, Finland
| | - Marja Palmroth
- Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101, Tampere, Finland
| |
Collapse
|
20
|
Chen X, Xiao L, Niu J, Wang Y, Zhang X, Gong L, Yao F, Xu K. Early succession of biofilm bacterial communities in newly built drinking water pipelines via multi-area analysis. Appl Microbiol Biotechnol 2023; 107:3817-3828. [PMID: 37074383 DOI: 10.1007/s00253-023-12517-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 02/07/2023] [Accepted: 04/04/2023] [Indexed: 04/20/2023]
Abstract
Biofilms inhabiting pipeline walls are critical to drinking water quality and safety. With massive pipeline replacement underway, however, biofilm formation process in newly built pipes and its effects on water quality are unclear. Moreover, differences and connections between biofilms in newly built and old pipes are unknown. In this study, early succession (≤ 120 days) of biofilm bacterial communities (abundance and diversity) in upper, middle and bottom areas of a newly built cement-lined ductile iron pipeline were evaluated using improved Propella™ biofilm reactor and multi-area analysis. A comparison with old pipelines (grey cast iron, 10 years) was performed. In the newly built pipeline, the abundance of biofilm bacteria did not change significantly between 40 and 80 days, but increased significantly between 80 and 120 days. The biofilm bacterial abundance (per unit area) in the bottom area was always higher than that in the upper and middle areas. Based on alpha diversity index and PCoA results, biofilm bacterial community richness, diversity and composition did not change significantly during the 120-day operation. Besides, biofilm shedding from the walls of newly built pipeline significantly increased bacterial abundance in the outlet water. Opportunistic pathogen-containing genera, such as Burkholderia, Acinetobacter and Legionella, were identified in both water and biofilm samples from newly built pipelines. The comparison between new and old pipelines suggested a higher bacterial abundance per unit area at the middle and bottom areas in old pipelines. Moreover, the bacterial community composition of biofilms in old pipelines was similar to that of newly built pipelines. These results contribute to accurate prediction and management of biofilm microbial communities in drinking water pipelines, ensuring the biosafety of drinking water. KEY POINTS: • Biofilm bacterial communities in different areas of pipe wall were revealed. • The abundance of biofilm bacteria increased significantly between 80 and 120 days. • Biofilm bacterial community compositions of newly built and old pipes were similar.
Collapse
Affiliation(s)
- Xiaochen Chen
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, No.2 Wulongjiangbei Road, Fuzhou, 350108, China
| | - Liang Xiao
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, No.2 Wulongjiangbei Road, Fuzhou, 350108, China
| | - Jia Niu
- Center of Safe and Energy-Saving Engineering Technology for Urban Water Supply and Drainage System, School of Ecological Environment and Urban Construction, Fujian University of Technology, No.33 Xuefunan Road, Fuzhou, 350118, China.
| | - Yue Wang
- Fuzhou Water Supply Co, Ltd., No.104 Dongjie, Fuzhou, 350001, China
- Fuzhou Water Quality Monitoring Co., Ltd, No.104 Dongjie, Fuzhou, 350001, China
| | - Xiaomin Zhang
- Fuzhou Water Supply Co, Ltd., No.104 Dongjie, Fuzhou, 350001, China
- Fuzhou Water Quality Monitoring Co., Ltd, No.104 Dongjie, Fuzhou, 350001, China
| | - Longcong Gong
- Fuzhou Water Supply Co, Ltd., No.104 Dongjie, Fuzhou, 350001, China
| | - Fengbing Yao
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, No.2 Wulongjiangbei Road, Fuzhou, 350108, China
| | - Kaiqin Xu
- College of Civil Engineering, Fuzhou University, No.2 Wulongjiangbei Road, Fuzhou, 350108, China
- National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Japan
| |
Collapse
|
21
|
Hilal MG, Han B, Yu Q, Feng T, Su W, Li X, Li H. Insight into the dynamics of drinking water resistome in China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121185. [PMID: 36736566 DOI: 10.1016/j.envpol.2023.121185] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/12/2023] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Antibiotic resistance (AR) is a serious environmental hazard of the current age. Antibiotic resistance genes (ARGs) are the fundamental entities that spread AR in the environment. ARGs are likely to be transferred from the non-pathogenic to pathogenic microbes that might ultimately be responsible for the AR in humans and other organisms. Drinking water (DW) is the primary interaction route between ARGs and humans. Being the highest producer and consumer of antibiotics China poses a potential threat to developing superbugs and ARGs dissemination. Herein, we comprehensively seek to review the ARGs from dominant DW sources in China. Furthermore, the origin and influencing factors of the ARGs to the DW in China have been evaluated. Commonly used methods, both classical and modern, are being compiled. In addition, the risk posed and mitigation strategies of DW ARGs in China have been outlined. Overall, we believe this review would contribute to the assessment of ARGs in DW of China and their dissemination to humans and other animals and ultimately help the policymakers and scientists in the field to counteract this problem on an emergency basis.
Collapse
Affiliation(s)
- Mian Gul Hilal
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China; MOE, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, 730000, Gansu, PR China
| | - Binghua Han
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Qiaoling Yu
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Tianshu Feng
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Wanghong Su
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China
| | - Xiangkai Li
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, 730000, Gansu, PR China
| | - Huan Li
- Institute of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou, 730000, China.
| |
Collapse
|
22
|
Community Composition and Antibiotic Resistance of Tap Water Bacteria Retained on Filtration Membranes. DIVERSITY 2023. [DOI: 10.3390/d15030427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Community composition and antibiotic resistance of tap water bacteria are still not known well enough. This study fills the gaps in knowledge regarding this matter. To provide representativeness of collected samples, tap water bacteria were concentrated from huge amounts of water, using filtration membranes monthly during the continuous, semi-annual study, covering winter and spring seasons. Biomass was investigated both using a culture-based method (for total and antibiotic-resistant culturable bacteria counts) and metagenomic DNA sequencing (for taxonomic identification of bacteria). The results showed that bacteria resistant to ceftazidime were the most prevalent among the studied resistance phenotypes, whereas bacteria resistant to amoxicillin, ciprofloxacin, and tetracycline were scarce. On average, 20,059 and 26,200 CFU/mL per month was counted in the winter and spring season, respectively, whereas in terms of antibiotic-resistant bacteria, average counts were 14,270 and 9435 CFU/mL per month in the winter and spring season, respectively. In terms of bacterial community composition, Cyanobacteria, Proteobacteria and Actinobacteria were the most abundant phyla, reaching up to 77.71%, 74.40% and 21.85%, respectively, which is supported by previous studies conducted on the same water supply network and other drinking water distribution systems across the world. No season-dependent variations were observed for culturable antibiotic-resistant bacteria or bacterial community composition. The prevalence of culturable antibiotic-resistant bacteria was not correlated with any of the identified taxa.
Collapse
|
23
|
Jenks B, Pecci F, Stoianov I. Optimal design-for-control of self-cleaning water distribution networks using a convex multi-start algorithm. WATER RESEARCH 2023; 231:119602. [PMID: 36736109 DOI: 10.1016/j.watres.2023.119602] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
The provision of self-cleaning velocities has been shown to reduce the risk of discolouration in water distribution networks (WDNs). Despite these findings, control implementations continue to be focused primarily on pressure and leakage management. This paper considers the control of diurnal flow velocities to maximize the self-cleaning capacity (SCC) of WDNs. We formulate a new optimal design-for-control problem where locations and operational settings of pressure control and automatic flushing valves are jointly optimized. The problem formulation includes a nonconvex objective function, nonconvex hydraulic conservation law constraints, and binary variables for modelling valve placement, resulting in a nonconvex mixed integer nonlinear programming (MINLP) optimization problem. Considering the challenges with solving nonconvex MINLP problems, we propose a heuristic algorithm which combines convex relaxations (with domain reduction), a randomization technique, and a multi-start strategy to compute feasible solutions. We evaluate the proposed algorithm on case study networks with varying size and degrees of complexity, including a large-scale operational network in the UK. The convex multi-start algorithm is shown to be a more robust solution method compared to an off-the-shelf genetic algorithm, finding good-quality feasible solutions to all design-for-control numerical experiments. Moreover, we demonstrate the implemented multi-start strategy to be a fast and scalable method for computing feasible solutions to the nonlinear SCC control problem. The proposed method extends the control capabilities and benefits of dynamically adaptive networks to improve water quality in WDNs.
Collapse
Affiliation(s)
- Bradley Jenks
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BB, United Kingdom.
| | - Filippo Pecci
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BB, United Kingdom
| | - Ivan Stoianov
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BB, United Kingdom
| |
Collapse
|
24
|
Hu D, Zeng J, Chen J, Lin W, Xiao X, Feng M, Yu X. Microbiological quality of roof tank water in an urban village in southeastern China. J Environ Sci (China) 2023; 125:148-159. [PMID: 36375901 DOI: 10.1016/j.jes.2022.01.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/18/2022] [Accepted: 01/24/2022] [Indexed: 06/16/2023]
Abstract
Urban villages are unique residential neighborhoods in urban areas in China. Roof tanks are their main form of water supply, and water quality deterioration might occur in this system because of poor hygienic conditions and maintenance. In this study, water samples were seasonally collected from an urban village to investigate the influence of roof tanks as an additional water storage device on the variation in the microbial community structure and pathogenic gene markers. Water stagnation in the roof tank induced significant decreases in chlorine (p < 0.05), residual chlorine was as low as 0.02 mg/L in spring. Propidium monoazide (PMA)-qPCR revealed a one-magnitude higher level of total viable bacterial concentration in roof tank water samples (2.14 ± 1.81 × 105 gene copies/mL) than that in input water samples (3.57 ± 2.90 × 104 gene copies/mL, p < 0.05), especially in spring and summer. In addition, pathogenic fungi, Mycobacterium spp., and Legionella spp. were frequently detected in the roof tanks. Terminal users might be exposed to higher microbial risk induced by high abundance of Legionella gene marker. Spearman's rank correlation and redundancy analysis showed that residual chlorine was the driving force that promoted bacterial colonization and shaped the microbial community. It is worth noted that the sediment in the pipe will be agitated when the water supply is restored after the water outages, which can trigger an increase in turbidity and bacterial biomass. Overall, the findings provide practical suggestions for controlling microbiological health risks in roof tanks in urban villages.
Collapse
Affiliation(s)
- Dong Hu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Zeng
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Jing Chen
- Shitang Community Health Service Center, Xiamen 361026, China
| | - Wenfang Lin
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xinyan Xiao
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Mingbao Feng
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Xin Yu
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
| |
Collapse
|
25
|
Štiglić J, Ujević Bošnjak M, Héry M, Kurajica L, Kinsela AS, Casiot C, Capak K. Bacterial diversity across four drinking water distribution systems in Croatia: impacts of water management practices and disinfection by-products. FEMS Microbiol Ecol 2022; 99:fiac146. [PMID: 36473705 DOI: 10.1093/femsec/fiac146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024] Open
Abstract
Several factors may impact bacterial diversity in drinking water distribution systems (DWDSs) including the origin of the raw water, the water treatment technologies, and the disinfection practices applied. 16S rRNA metabarcoding was used for the in-depth characterization of bacterial communities in the four studied Croatian DWDSs (A, B, C, D) two of which had residual disinfectant (A, B) and two were without (C, D), while only B utilized the conventional water treatment technology. Significantly higher diversity and species richness were evidenced in non-disinfected DWDSs (p<0.05) compared to disinfected DWDSs. The phylum Proteobacteria was the most abundant in all the DWDSs, being proportionately higher in non-disinfected systems (p<0.05). The most abundant genera in DWDS-A Mycobacterium and Sphingomonas both positively correlated, whereas Lactobacillus negatively correlated with the concentration of disinfection by-products (DBPs) as a sum of haloacetic acids (HAAs). Conversely, the genus Ralstonia positively correlated with the individual DBP dichloroacetic acid. These results indicate that genera Sphingomonas, Mycobacterium, Lactobacillus and Ralstonia could have an effect on promoting the formation of DBPs, in a similar manner to how negatively correlated taxa may influence their degradation.
Collapse
Affiliation(s)
- J Štiglić
- Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia
| | - M Ujević Bošnjak
- Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia
| | - M Héry
- HydroSciences Montpellier, University of Montpellier, CNRS, IRD, Montpellier, France
| | - L Kurajica
- Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia
| | - A S Kinsela
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - C Casiot
- HydroSciences Montpellier, University of Montpellier, CNRS, IRD, Montpellier, France
| | - K Capak
- Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia
| |
Collapse
|
26
|
Entezari S, Al MA, Mostashari A, Ganjidoust H, Ayati B, Yang J. Microplastics in urban waters and its effects on microbial communities: a critical review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:88410-88431. [PMID: 36327084 DOI: 10.1007/s11356-022-23810-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Microplastic (MP) pollution is one of the emerging threats to the water and terrestrial environment, forcing a new environmental challenge due to the growing trend of plastic released into the environment. Synthetic and non-synthetic plastic components can be found in rivers, lakes/reservoirs, oceans, mountains, and even remote areas, such as the Arctic and Antarctic ice sheets. MPs' main challenge is identifying, measuring, and evaluating their impacts on environmental behaviors, such as carbon and nutrient cycles, water and wastewater microbiome, and the associated side effects. However, until now, no standardized methodical protocols have been proposed for comparing the results of studies in different environments, especially in urban water and wastewater. This review briefly discusses MPs' sources, fate, and transport in urban waters and explains methodological uncertainty. The effects of MPs on urban water microbiomes, including urban runoff, sewage wastewater, stagnant water in plumbing networks, etc., are also examined in depth. Furthermore, this study highlights the pathway of MPs and their transport vectors to different parts of ecosystems and human life, particularly through mediating microbial communities, antibiotic-resistant genes, and biogeochemical cycles. Overall, we have briefly highlighted the present research gaps, the lack of appropriate policy for evaluating microplastics and their interactions with urban water microbiomes, and possible future initiatives.
Collapse
Affiliation(s)
- Saber Entezari
- Environmental Engineering Division, Faculty of Civil & Env. Eng., TMU, Tehran, Iran
| | - Mamun Abdullah Al
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Amir Mostashari
- Environmental Engineering Division, Faculty of Civil & Env. Eng., TMU, Tehran, Iran
| | - Hossein Ganjidoust
- Environmental Engineering Division, Faculty of Civil & Env. Eng., TMU, Tehran, Iran.
| | - Bita Ayati
- Environmental Engineering Division, Faculty of Civil & Env. Eng., TMU, Tehran, Iran
| | - Jun Yang
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China
| |
Collapse
|
27
|
Zhao Y, Zhu S, Fan X, Zhang X, Ren H, Huang H. Precise portrayal of microscopic processes of wastewater biofilm formation: Taking SiO 2 as the model carrier. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 849:157776. [PMID: 35926593 DOI: 10.1016/j.scitotenv.2022.157776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Precise characterization of the microscopic processes of wastewater biofilm formation is essential for regulating biofilm behavior. Nevertheless, it remains a great challenge. This study investigated biofilm formation on SiO2 carriers under gradually increasing shear force combining the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory in a Couette-Taylor reactor, and precisely revealed the micro-interface interaction and species colonization during biofilm formation. The results indicated that bacterial reversible adhesion distance on SiO2 carrier surface was 3.06 ± 0.48 nm. Meanwhile, the secondary minimum of total XDLVO interaction energy could be used as a novel indicator to distinguish biofilm formation stages. The revealed biofilm formation stages were also confirmed by the electrochemical analysis. Additionally, the pioneer species that colonized at first were Comamonadaceae, Azospira, Flavobacterium and Azonexus, while keystone species such as Hydrogenophaga, AKYH767, Aquimonas and Ignavibacterium determined the stability of microbial community. In conclusion, this study provided a methodological example to study wastewater biofilm micro-interface behavior through the integration of an experimental platform as well as multiple monitoring and analysis methods, which opened up new perspectives for biofilm research and provided useful guidance for the regulation of biofilm-related treatment processes and new technology development.
Collapse
Affiliation(s)
- Ying Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Shanshan Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Xuan Fan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Xuxiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
| |
Collapse
|
28
|
Su Z, Liu T, Men Y, Li S, Graham N, Yu W. Understanding point-of-use tap water quality: From instrument measurement to intelligent analysis using sample filtration. WATER RESEARCH 2022; 225:119205. [PMID: 36215843 DOI: 10.1016/j.watres.2022.119205] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/19/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
In most cases, point-of-use tap water quality is not routinely monitored due to widely-dispersed sampling sites and the costly tests. Although previous studies have revealed the variation of drinking water quality during distribution in municipal networks, the influence of aging pipes in buildings on quality is still unknown and this makes it difficult for water utilities to conduct regular maintenance. Herein, we have undertaken a survey of tap water samples across 8 districts in Beijing (China) to evaluate the potential effects of pipe age on point-of-use water quality, including turbidity, organic matter characteristics, and bacterial community. By grouping the collected samples according to the pipe age and source water respectively, the results suggested that bacterial diversity is significantly influenced by the pipe age. However, bacterial community structure is clearly influenced by the source water. Similarly, aging pipes in buildings are also responsible for the deterioration of the final water quality, and their effects have been closely linked to selected water quality parameters by evaluating the relevant factors. Moreover, the interrelationships between physico-chemical parameters and bacteria abundance were identified. For example, pH, Ca2+, Mg2+, Na+ and K+ showed a positive relationship with Bacillus abundance. In addition, an intelligent analysis method for understanding pipe age, organic matter concentration, and hardness (i.e., Ca2+ and Mg2+ concentration), based on image analysis of filtered membranes has been developed. The accuracy of prediction was encouraging, but can be improved with the collection of more data from tap water samples. We expect that this method can be exploited by the public to monitor their tap water and provide a feasible and cost-effective approach for water suppliers to locate aging/deteriorating pipes which need to be replaced or maintained.
Collapse
Affiliation(s)
- Zhaoyang Su
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ting Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yujie Men
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Shuo Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Wenzheng Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| |
Collapse
|
29
|
Learbuch KLG, Smidt H, van der Wielen PWJJ. Water and biofilm in drinking water distribution systems in the Netherlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 831:154940. [PMID: 35367266 DOI: 10.1016/j.scitotenv.2022.154940] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/26/2022] [Accepted: 03/27/2022] [Indexed: 06/14/2023]
Abstract
To keep the high quality of drinking water in the future for non-chlorinated drinking water systems, knowledge about the variables that most strongly affect this quality is necessary in order to know where to focus on and possibly even change aspects of drinking water production and distribution. Therefore, the aim of this study was to investigate which variables (source of drinking water, growth potential and pipe material type) have the biggest influence on bacterial community composition and biomass concentration of drinking water and biofilm in distribution systems. Ten different distribution systems were sampled for water and biofilm, obtained from four different pipe materials, throughout the Netherlands. The distribution systems are supplied either with drinking water produced from groundwater or surface water, and differ in drinking water quality parameters such as the growth potential. We found a significant relationship for growth potential and ATP concentration in water, but for the ATP in the biofilm none of the parameters showed a significant effect. Furthermore, the source of the drinking water and the pipe material did not significantly affect the ATP concentration in water and biofilm. The bacterial composition of in both water and biofilm was significantly different between distribution systems delivering water with low and high growth potential and between drinking water produced from groundwater or surface water. In contrast, the different pipe materials did not significantly affect composition of biofilm-associated communities. We conclude from these results that the growth potential of the treated water best explains the variation in biomass and bacterial composition in water and biofilm of non-chlorinated drinking water distribution systems followed by the drinking water source, whereas pipe materials seem to be of lesser importance.
Collapse
Affiliation(s)
- K L G Learbuch
- KWR Water Research Institute, Groningenhaven 7, 3433PE Nieuwegein, the Netherlands
| | - H Smidt
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708WE Wageningen, the Netherlands
| | - P W J J van der Wielen
- KWR Water Research Institute, Groningenhaven 7, 3433PE Nieuwegein, the Netherlands; Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708WE Wageningen, the Netherlands.
| |
Collapse
|
30
|
Chen L, Li X, van der Meer W, Medema G, Liu G. Capturing and tracing the spatiotemporal variations of planktonic and particle-associated bacteria in an unchlorinated drinking water distribution system. WATER RESEARCH 2022; 219:118589. [PMID: 35597222 DOI: 10.1016/j.watres.2022.118589] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
The aperiodic changes in the quantity and community of planktonic and particle-associated bacteria have hampered the understanding and management of microbiological water quality in drinking water distribution systems. In this study, online sampling was combined with the microbial fingerprint-based SourceTracker2 to capture and trace the spatiotemporal variations in planktonic and particle-associated bacteria in an unchlorinated distribution system. The results showed that spatially, the particle load significantly increased, while in contrast, the quantity of particle-associated bacteria decreased sharply from the treatment plant to the distribution network. Similar to the trend of particle-associated bacterial diversity, the number of observed OTUs first slightly decreased from the treatment plant to the transportation network and then sharply increased from the transportation network to the distribution network. The SourceTracker2 results revealed that the contribution of particle-associated bacteria from the treatment plant decreased along the distribution distance. The spatial results indicate the dominant role of sedimentation of particles from the treatment plant, while the observed increases in particles and the associated bacteria mainly originated from the distribution network, which were confirmed directly by the increased contributions of loose deposits and biofilm. Temporally, the daily peaks of particle-associated bacterial quantity, observed OTU number, and contributions of loose deposits and biofilms were captured during water demand peaks (e.g., 18-21 h). The temporal results reveal clear linkages between the distribution system harboring bacteria (e.g., within loose deposits and biofilms) and the planktonic and particle-associated bacteria flowing through the distribution system, which are dynamically connected and interact. This study highlights that the spatiotemporal variations in planktonic and particle-associated bacteria are valuable and unneglectable for the widely on-going sampling campaigns required by water quality regulations and/or drinking water microbiological studies.
Collapse
Affiliation(s)
- Lihua Chen
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P.R China; Department of Water Management, Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, Delft 2600 GA, the Netherlands
| | - Xuan Li
- Department of Water Management, Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, Delft 2600 GA, the Netherlands
| | - Walter van der Meer
- Membrane Science and Technology, University of Twente, Drienerlolaan 5, Enschede 7522 NB, the Netherlands; Oasen Drinkwater, Nieuwe Gouwe O.Z. 3, Gouda 2801 SB, the Netherlands
| | - Gertjan Medema
- Department of Water Management, Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, Delft 2600 GA, the Netherlands; KWR Water Research Institute, P.O. Box 1072, Nieuwegein 3430 BB, the Netherlands; Michigan State University, 1405 S Harrison Rd, East-Lansing, MI 48823, United States
| | - Gang Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P.R China; Department of Water Management, Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, Delft 2600 GA, the Netherlands.
| |
Collapse
|
31
|
Li J, Ren A, van der Mark E, Liu G. Direct evidence of microbiological water quality changes on bacterial quantity and community caused by plumbing system. J Environ Sci (China) 2022; 116:175-183. [PMID: 35219416 DOI: 10.1016/j.jes.2021.04.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/22/2021] [Accepted: 04/25/2021] [Indexed: 06/14/2023]
Abstract
Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compared the water quality in the water main and at customer tap by preparing a sampling tap on the water main. The biomass was quantified by adenosine triphosphate (ATP) and the microbial community was profiled by 454 pyrosequencing. The results showed that in distribution pipes, biofilm contributed >94% of the total biomass, while loose deposits showed little contribution (< 2%) because of the low amount of loose deposits. The distribution of biological stable water had minor effects on the microbiocidal water quality regarding both quantity (ATP 1 ng/L vs. 1.7 ng/L) and community of the bacteria. Whereas the plumbing system has significant contribution to the increase of active biomass (1.7 ng/L vs. 2.9 ng/L) and the changes of bacterial community. The relative abundance of Sphingomonas spp. at tap (22%) was higher than that at water main (2%), while the relative abundance of Pseudomonas spp. in tap water (15%) was lower than that in the water from street water main (29%). Though only one location was prepared and studied, the present study showed that the protocol of making sampling tap on water main offered directly evidences about the impacts of plumbing system on tap water quality, which makes it possible to distinguish and study the processes in distribution system and plumbing system separately.
Collapse
Affiliation(s)
- Jun Li
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anran Ren
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ed van der Mark
- Dunea Water Company, Plaza of the United Nations 11-15, Zoetermeer 2700 AT, the Netherlands
| | - Gang Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sanitary engineering, Department of Water management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft 2600 GA, the Netherlands.
| |
Collapse
|
32
|
Song L, Li H, Li T, Xu J, Chen H. Sequential Speciation Analysis of Heavy Metals in Drinking Water Pipe Scales by Mass Spectrometry. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2131-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
33
|
Li G, Su Y, Wu B, Han G, Yu J, Yang M, Shi B. Initial Formation and Accumulation of Manganese Deposits in Drinking Water Pipes: Investigating the Role of Microbial-Mediated Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5497-5507. [PMID: 35420026 DOI: 10.1021/acs.est.1c08293] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Microbial Mn(II) oxidation occurs in areas with insufficient disinfectants in drinking water distribution systems. However, the overall processes of microbial-mediated Mn deposit formation are unclear. This research investigated the initial Mn(II) oxidation, deposit accumulation, and biofilm development in pipe loops fed with nondisinfected finished water for 300 days. The results show that it took 20 days for microbial Mn(II) oxidation and deposition to be initiated visibly in new pipes continuously receiving 100 μg/L Mn(II). Once started, the deposit accumulation accelerated. A pseudo-first-order kinetic model could simulate the disappearance of Mn(II) in well-mixed pipe loop water. The observed rate constant reached 2.81 h-1 [corresponding to a Mn(II) half-life of 0.25 h] after 136 days of operation. Without oxygen, Mn(II) in the water also decreased rapidly to 1.0 μg/L through adsorption to deposits, indicating that after the initial microbial formation of MnOx, subsequent MnOx accumulation was attributable to a combination of microbial and physicochemical processes. Compared to the no-Mn condition, Mn(II) input resulted in 1 order of magnitude increase in biofilm formation. This study sheds light on the increasingly rapid processes of Mn accumulation on the inner surfaces of water pipes resulting from the biological activity of Mn(II)-oxidizing biofilms and the build-up of MnOx with strong adsorption capacity.
Collapse
Affiliation(s)
- Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuliang Su
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, Guangdong 519000, China
| | - Bin Wu
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, Guangdong 519000, China
| | - Guohang Han
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, Guangdong 519000, China
| | - Jianwei Yu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
34
|
Qi P, Li T, Hu C, Li Z, Bi Z, Chen Y, Zhou H, Su Z, Li X, Xing X, Chen C. Effects of cast iron pipe corrosion on nitrogenous disinfection by-products formation in drinking water distribution systems via interaction among iron particles, biofilms, and chlorine. CHEMOSPHERE 2022; 292:133364. [PMID: 34933025 DOI: 10.1016/j.chemosphere.2021.133364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/28/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
The effects of cast iron pipe corrosion on nitrogenous disinfection by-products formation (N-DBPs) in drinking water distribution systems (DWDSs) were investigated. The results verified that in the effluent of corroded DWDSs simulated by annular reactors with corroded cast iron coupons, typical N-DBPs, including haloacetamides, halonitromethanes, and haloacetonitriles, increased significantly compared with the influent of DWDSs. In addition, more dissolved organic carbon, adenosine triphosphate, and iron particles were simultaneously detected in the bulk water of corroded DWDSs, thereby indicating that abundant iron particles acted as a "protective umbrella" for microorganisms. Under the condition of corroded DWDSs, the extracellular polymeric substances gradually exhibited distinct characteristics, including a higher content and lower flocculation efficiency, thereby resulting in a large supply of N-DBPs precursors. Corroded cast iron pipes, equivalent to a unique microbial interface, induced completely distinct microbial community structures and metabolic functions in DWDSs, thereby enhancing the formation of N-DBPs. This is the first study to successfully reveal the interactions among iron particles, biofilms, and chlorine in DWDSs, which may help to fully understand the biofilm transformation and microbial community succession in DWDSs.
Collapse
Affiliation(s)
- Peng Qi
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Tong Li
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Chun Hu
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Zesong Li
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Zhihao Bi
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Youyi Chen
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Huishan Zhou
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Ziliang Su
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Xinjun Li
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Xueci Xing
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China.
| | - Chaoxiang Chen
- Nanzhou Waterworks of Guangzhou Water Supply Co. Ltd., Guangzhou, 510000, China
| |
Collapse
|
35
|
Rahmatika I, Kurisu F, Furumai H, Kasuga I. Dynamics of the Microbial Community and Opportunistic Pathogens after Water Stagnation in the Premise Plumbing of a Building. Microbes Environ 2022; 37. [PMID: 35321996 PMCID: PMC8958293 DOI: 10.1264/jsme2.me21065] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In premise plumbing, microbial water quality may deteriorate under certain conditions, such as stagnation. Stagnation results in a loss of disinfectant residual, which may lead to the regrowth of microorganisms, including opportunistic pathogens. In the present study, microbial regrowth was investigated at eight faucets in a building over four seasons in one year. Water samples were obtained before and after 24 h of stagnation. In the first 100 mL after stagnation, total cell counts measured by flow cytometry increased 14- to 220-fold with a simultaneous decrease in free chlorine from 0.17–0.36 mg L–1 to <0.02 mg L–1. After stagnation, total cell counts were not significantly different among seasons; however, the composition of the microbial community varied seasonally. The relative abundance of Pseudomonas spp. was dominant in winter, whereas Sphingomonas spp. were dominant in most faucets after stagnation in other seasons. Opportunistic pathogens, such as Legionella pneumophila, Mycobacterium avium, Pseudomonas aeruginosa, and Acanthamoeba spp., were below the quantification limit for real-time quantitative PCR in all samples. However, sequences related to other opportunistic pathogens, including L. feeleii, L. maceachernii, L. micdadei, M. paragordonae, M. gordonae, and M. haemophilum, were detected. These results indicate that health risks may increase after stagnation due to the regrowth of opportunistic pathogens.
Collapse
Affiliation(s)
- Iftita Rahmatika
- Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo
| | - Futoshi Kurisu
- Research Center for Water Environment Technology, Graduate School of Engineering, The University of Tokyo
| | - Hiroaki Furumai
- Research Center for Water Environment Technology, Graduate School of Engineering, The University of Tokyo
| | - Ikuro Kasuga
- Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo
| |
Collapse
|
36
|
Chen J, Li W, Tan Q, Sheng D, Li Y, Chen S, Zhou W. Effect of disinfectant exposure and starvation treatment on the detachment of simulated drinking water biofilms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150896. [PMID: 34653459 DOI: 10.1016/j.scitotenv.2021.150896] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Biofilms were one of the main habitats of microbes in the drinking water distribution system. The variation of environmental conditions can lead to the detachment of biofilms and the deterioration of water quality. In this study, the effects of disinfectant exposure and starvation treatment on the detachment of biofilms were investigated. The results showed that detaching rate increased with the concentration of chloramine in the inlet water and 1.0 mg/L of chloramine led to the largest detached biomass. The starvation treatment resulted in less biofilm biomass but the detaching rates of treated biofilms were higher than those without starvation. The 16S rRNA sequencing results showed that detached and stubborn biofilms had a significant difference in microbial diversity and richness. The microbial community composition of the two types of biofilm showed the difference in the abundance of Nitrospira, Bryobacter, Hyphomicrobium, and Pedomicrobium. Chloramine exposure did not have a significant impact on the microbial community while the starvation treatment led to a higher abundance of chemolithotrophs bacteria. Metagenomic results indicated that detached biofilms had higher abundances of ARGs and starvation treatment could enrich the ARGs. The results of this research could provide the knowledge of biofilm sloughing and help understand the health risk of antibiotic resistance in drinking water.
Collapse
Affiliation(s)
- Jiping Chen
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Weiying Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
| | - Qiaowen Tan
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Dongfang Sheng
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yue Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Sheng Chen
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Zhou
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| |
Collapse
|
37
|
Pan L, Li G, Li J, Gao J, Liu Q, Shi B. Heavy metal enrichment in drinking water pipe scales and speciation change with water parameters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150549. [PMID: 34600211 DOI: 10.1016/j.scitotenv.2021.150549] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
Pipe scales that form in drinking water distribution systems (DWDS) can accumulate pollutants that may be re-released into bulk water, posing a significant threat to water safety. This study aims to evaluate the pollutant enrichment capacity of the pipe scale and identify speciation changes in heavy metals under variations in water quality. When the water quality conditions changed, the forms of inorganic metal elements in drinking water pipe scales also changed and the proportion of unstable forms increased, thereby increasing the risk of secondary pollution. Morphological analysis showed that the pipe scale samples had porous structures and large specific surface areas (the maximum was 52.94 m2/g, which is higher than that of many natural adsorbents), which could promote the accumulation of contaminants. XRD profiles also showed that the pipe scale samples were rich in substances with heavy metal adsorption capacities, such as Fe3O4. As the pH changed from 6 to 10, no significant difference in the release of heavy metals was found. The maximum release of Cu, Cr, As, Pb, and Cd at pH 8 was 0.56, 0.51, 1.82, 0.84, and 0.72 μg/g, respectively. Although the amounts were small, the speciation distribution of the heavy metals changed significantly. In addition, the proportion of unstable fractions increased, which increased the release risk of the pipe scale. The presence of humic acid accelerated the dissolution of organic matter and metals in the pipe scale, which further proved that the pipe scales were unstable and susceptible to water quality conditions. The pipe scales could not maintain stability when the water quality changed, and the DWDS should be regularly monitored and cleaned when necessary.
Collapse
Affiliation(s)
- Linlin Pan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jinglin Li
- China IPPR International Engineering Co., Ltd, Beijing 100083, China
| | - Jiali Gao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Quanli Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
38
|
Schurer R, Hijnen WAM, van der Wal A. The significance of the biomass subfraction of high-MW organic carbon for the microbial growth and maintenance potential of disinfectant-free drinking water produced from surface water. WATER RESEARCH 2022; 209:117898. [PMID: 34896810 DOI: 10.1016/j.watres.2021.117898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/15/2021] [Accepted: 11/23/2021] [Indexed: 06/14/2023]
Abstract
Drinking water must be sufficiently biostable to avoid excessive microbial and invertebrate growth in disinfectant-free distribution systems. The production of biologically stable drinking water is challenging for conventional surface water treatment plants using reservoirs as feed water due to the presence of slowly biodegradable particulate and high-molecular weight biopolymeric organic carbon (high-MW OC) which increases the Microbial Growth Potential (MGP) in the feed water and produced drinking water. The study presented here provides new insights in the relationship between high-MW OC and MGP for a full-scale surface water treatment plant. Controlled-conditions addition series experiments showed that MGP increases linearly with the high-MW OC concentration with a seasonally variable ratio. Laboratory filtration indicated that MGP is mainly attributable to the high-MW OC subfraction of > 0.12 µm particle size coinciding with microbial biomass. Intensive field monitoring revealed clear seasonal patterns in the plant's feed water and treated water levels of high-MW OC, biomass and MGP. These parameters reach maximum levels in the periods of high water temperature with the notable exception of the treated water's high-MW OC concentration which exhibits an opposite seasonal pattern (reflecting seasonally variable removal in the treatment). Moreover, the field monitoring showed that MGP correlates well with the concentrations of biodegradable biopolymeric OC and with microbial biomass measured as ATP (adenosine triphosphate) and cell counts, but not with the total high-MW OC concentration in the treated water. Theoretical estimations showed that the OC quantities present in and consumed by the microbial biomass are in the same order of magnitude as slowly biodegradable biopolymers. From these results it is concluded that specifically the microbial biomass-associated and biodegradable biopolymeric OC subfraction of the totally present high-MW OC is important for MGP. Finally, the MGP-assay results and theoretical calculations showed for the high-MW OC matrix that the microbial biomass' OC consumption for maintenance is significant vis-á-vis that for growth, and that stable and high levels of biomass are sustained in the treated water which may adversely affect biological stability in the distribution network.
Collapse
Affiliation(s)
- R Schurer
- Evides Water Company, PO Box 4472, 3006 AL Rotterdam, the Netherlands; Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands; IHE Delft Institute for Water Education, Environmental Engineering and Water Technology Department, Westvest 7, 2611 AX Delft, the Netherlands.
| | - W A M Hijnen
- Evides Water Company, PO Box 4472, 3006 AL Rotterdam, the Netherlands; KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB, Nieuwegein, the Netherlands
| | - A van der Wal
- Evides Water Company, PO Box 4472, 3006 AL Rotterdam, the Netherlands; Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands
| |
Collapse
|
39
|
Wang H, Yu P, Schwarz C, Zhang B, Huo L, Shi B, Alvarez PJJ. Phthalate Esters Released from Plastics Promote Biofilm Formation and Chlorine Resistance. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1081-1090. [PMID: 34991317 DOI: 10.1021/acs.est.1c04857] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Phthalate esters (PAEs) are commonly released from plastic pipes in some water distribution systems. Here, we show that exposure to a low concentration (1-10 μg/L) of three PAEs (dimethyl phthalate (DMP), di-n-hexyl phthalate (DnHP), and di-(2-ethylhexyl) phthalate (DEHP)) promotes Pseudomonas biofilm formation and resistance to free chlorine. At PAE concentrations ranging from 1 to 5 μg/L, genes coding for quorum sensing, extracellular polymeric substances excretion, and oxidative stress resistance were upregulated by 2.7- to 16.8-fold, 2.1- to 18.9-fold, and 1.6- to 9.9-fold, respectively. Accordingly, more biofilm matrix was produced and the polysaccharide and eDNA contents increased by 30.3-82.3 and 10.3-39.3%, respectively, relative to the unexposed controls. Confocal laser scanning microscopy showed that PAE exposure stimulated biofilm densification (volumetric fraction increased from 27.1 to 38.0-50.6%), which would hinder disinfectant diffusion. Biofilm densification was verified by atomic force microscopy, which measured an increase of elastic modulus by 2.0- to 3.2-fold. PAE exposure also stimulated the antioxidative system, with cell-normalized superoxide dismutase, catalase, and glutathione activities increasing by 1.8- to 3.0-fold, 1.0- to 2.0-fold, and 1.2- to 1.6-fold, respectively. This likely protected cells against oxidative damage by chlorine. Overall, we demonstrate that biofilm exposure to environmentally relevant levels of PAEs can upregulate molecular processes and physiologic changes that promote biofilm densification and antioxidative system expression, which enhance biofilm resistance to disinfectants.
Collapse
Affiliation(s)
- Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Pingfeng Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
- Department of Civil and Environmental Engineering, Rice University, Houston 77005, United States
| | - Cory Schwarz
- Department of Civil and Environmental Engineering, Rice University, Houston 77005, United States
| | - Bo Zhang
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Lixin Huo
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston 77005, United States
| |
Collapse
|
40
|
Lee D, Calendo G, Kopec K, Henry R, Coutts S, McCarthy D, Murphy HM. The Impact of Pipe Material on the Diversity of Microbial Communities in Drinking Water Distribution Systems. Front Microbiol 2021; 12:779016. [PMID: 34992587 PMCID: PMC8724538 DOI: 10.3389/fmicb.2021.779016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/01/2021] [Indexed: 01/04/2023] Open
Abstract
As many cities around the world face the prospect of replacing aging drinking water distribution systems (DWDS), water utilities must make careful decisions on new pipe material (e.g., cement-lined or PVC) for these systems. These decisions are informed by cost, physical integrity, and impact on microbiological and physicochemical water quality. Indeed, pipe material can impact the development of biofilm in DWDS that can harbor pathogens and impact drinking water quality. Annular reactors (ARs) with cast iron and cement coupons fed with chloraminated water from a municipal DWDS were used to investigate the impact of pipe material on biofilm development and composition over 16 months. The ARs were plumbed as closely as possible to the water main in the basement of an academic building to simulate distribution system conditions. Biofilm communities on coupons were characterized using 16S rRNA sequencing. In the cast iron reactors, β-proteobacteria, Actinobacteria, and α-proteobacteria were similarly relatively abundant (24.1, 22.5, and 22.4%, respectively) while in the cement reactors, α-proteobacteria and Actinobacteria were more relatively abundant (36.3 and 35.2%, respectively) compared to β-proteobacteria (12.8%). Mean alpha diversity (estimated with Shannon H and Faith's Phylogenetic Difference indices) was greater in cast iron reactors (Shannon: 5.00 ± 0.41; Faith's PD: 15.40 ± 2.88) than in cement reactors (Shannon: 4.16 ± 0.78; Faith's PD: 13.00 ± 2.01). PCoA of Bray-Curtis dissimilarities indicated that communities in cast iron ARs, cement ARs, bulk distribution system water, and distribution system pipe biofilm were distinct. The mean relative abundance of Mycobacterium spp. was greater in the cement reactors (34.8 ± 18.6%) than in the cast iron reactors (21.7 ± 11.9%). In contrast, the mean relative abundance of Legionella spp. trended higher in biofilm from cast iron reactors (0.5 ± 0.7%) than biofilm in cement reactors (0.01 ± 0.01%). These results suggest that pipe material is associated with differences in the diversity, bacterial composition, and opportunistic pathogen prevalence in biofilm of DWDS.
Collapse
Affiliation(s)
- Debbie Lee
- Water, Health and Applied Microbiology Laboratory (WHAM Lab), Department of Epidemiology and Biostatistics, College of Public Health, Temple University, Philadelphia, PA, United States
| | - Gennaro Calendo
- Water, Health and Applied Microbiology Laboratory (WHAM Lab), Department of Epidemiology and Biostatistics, College of Public Health, Temple University, Philadelphia, PA, United States
| | - Kristin Kopec
- Water, Health and Applied Microbiology Laboratory (WHAM Lab), Department of Epidemiology and Biostatistics, College of Public Health, Temple University, Philadelphia, PA, United States
| | - Rebekah Henry
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Clayton, VIC, Australia
| | - Scott Coutts
- Micromon, Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - David McCarthy
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University, Clayton, VIC, Australia
| | - Heather M. Murphy
- Water, Health and Applied Microbiology Laboratory (WHAM Lab), Department of Epidemiology and Biostatistics, College of Public Health, Temple University, Philadelphia, PA, United States
- Water, Health and Applied Microbiology Laboratory (WHAM Lab), Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
41
|
Zhou W, Li W, Chen J, Zhou Y, Wei Z, Gong L. Microbial diversity in full-scale water supply systems through sequencing technology: a review. RSC Adv 2021; 11:25484-25496. [PMID: 35478887 PMCID: PMC9037190 DOI: 10.1039/d1ra03680g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/10/2021] [Indexed: 01/07/2023] Open
Abstract
The prevalence of microorganisms in full-scale water supply systems raises concerns about their pathogenicity and threats to public health. Clean tap water is essential for public health safety. The conditions of the water treatment process from the source water to tap water, including source water quality, water treatment processes, the drinking water distribution system (DWDS), and building water supply systems (BWSSs) in buildings, greatly influence the bacterial community in tap water. Given the importance of drinking water biosafety, the study of microbial diversity from source water to tap water is essential. With the development of molecular biology methods and bioinformatics in recent years, sequencing technology has been applied to study bacterial communities in full-scale water supply systems. In this paper, changes in the bacterial community and the influence of each treatment stage on microbial diversity in full-scale water supply systems are classified and analyzed. Microbial traceability analysis and control are discussed, and suggestions for future drinking water biosafety research and its prospects are proposed.
Collapse
Affiliation(s)
- Wei Zhou
- College of Environmental Science and Engineering, Tongji University Shanghai 200092 China .,State Key Laboratory of Pollution Control and Resource Reuse, Tongji University Shanghai 200092 China
| | - Weiying Li
- College of Environmental Science and Engineering, Tongji University Shanghai 200092 China .,State Key Laboratory of Pollution Control and Resource Reuse, Tongji University Shanghai 200092 China
| | - Jiping Chen
- College of Environmental Science and Engineering, Tongji University Shanghai 200092 China
| | - Yu Zhou
- College of Environmental Science and Engineering, Tongji University Shanghai 200092 China
| | - Zhongqing Wei
- Fuzhou Water Affairs Investment Development Co., Ltd. Fuzhou 350000 Fujian China
| | | |
Collapse
|
42
|
Fan X, Zhu SS, Zhang XX, Ren HQ, Huang H. Revisiting the Microscopic Processes of Biofilm Formation on Organic Carriers: A Study under Variational Shear Stresses. ACS APPLIED BIO MATERIALS 2021; 4:5529-5541. [DOI: 10.1021/acsabm.1c00344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuan Fan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Shan-Shan Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hong-Qiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| |
Collapse
|
43
|
Xing X, Li T, Bi Z, Qi P, Li Z, Chen Y, Zhou H, Wang H, Xu G, Chen C, Ma K, Hu C. Destruction of microbial stability in drinking water distribution systems by trace phosphorus polluted water source. CHEMOSPHERE 2021; 275:130032. [PMID: 33652278 DOI: 10.1016/j.chemosphere.2021.130032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/11/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
The effects of trace phosphate concentrations (0, 0.3 and 0.6 mg/L) in water source were investigated on microbial stability of the drinking water distribution systems (DWDSs). Obviously, the results verified that in the effluent of DWDSs simulated by annular reactors (ARs), the total microbial biomass and the absolute concentration of opportunistic pathogens such as Legionella pneumophila, Mycobacterium avium, and Hartmanella vermiformis increased significantly with phosphate concentration increasing. Based on X-ray powder diffractometer and zeta potentials measurement, trace phosphate did change physicochemical properties of corrosion products, hence promoting microbes escape from corrosion products to bulk water to a certain extent. Stimulated by chlorine disinfectant and phosphate, the extracellular polymeric substances (EPS) from the suspended biofilms of AR-0.6 gradually exhibited superior characteristics including higher content, flocculating efficiency, hydrophobicity and tightness degree, contributing to formation of large-scale suspended biofilms with strong chlorine-resistance ability. However, the disinfection by-products concentration in DWDSs barely changed due to the balance of EPS precursors contribution and biodegradation effect, covering up the microbiological water quality risk. Therefore, more attention should be paid to the trace phosphorus polluted water source though its concentration was much lower than wastewater. This is the first study successfully revealing the influence mechanism of trace phosphate on microbial stability in DWDSs, which may help to fully understand the biofilms transformation and microbial community succession in DWDSs.
Collapse
Affiliation(s)
- Xueci Xing
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Tong Li
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Zhihao Bi
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Peng Qi
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Zesong Li
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Youyi Chen
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Huishan Zhou
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Gang Xu
- Nanzhou Waterworks of Guangzhou Water Supply Co. Ltd., Guangzhou, 510000, China
| | - Chaoxiang Chen
- Nanzhou Waterworks of Guangzhou Water Supply Co. Ltd., Guangzhou, 510000, China
| | - Kunyu Ma
- Nanzhou Waterworks of Guangzhou Water Supply Co. Ltd., Guangzhou, 510000, China
| | - Chun Hu
- Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| |
Collapse
|
44
|
Siedlecka A, Wolf-Baca M, Piekarska K. Microbial communities of biofilms developed in a chlorinated drinking water distribution system: A field study of antibiotic resistance and biodiversity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145113. [PMID: 33610999 DOI: 10.1016/j.scitotenv.2021.145113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/21/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Antibiotic resistance and biodiversity were investigated in microbial communities attached to inner surfaces of water supply fittings in a chlorinated drinking water distribution system (DWDS) supplied by two independent water treatment plants (WTPs) drawing the same source water. The investigation of the effect of the season, the applied water treatment technology, and type, material, and age of water supply fittings on both antibiotic resistance and biodiversity in biofilms involved collection of tubercles during summer and winter seasons throughout the DWDS. A total of 16 samples were collected (8 per season) from areas supplied by two independent WTPs. Culturable aerobic antibiotic resistant bacteria (ARB) proved more prevalent in summer. Various antibiotic resistance genes (ARGs) were detected, confirming the role of biofilms as ARGs reservoirs, but the abundances of quantified genes (sulI, ermB, qacEΔ1, intI1) were low (a range of <LOQ to 2313 gene copies/mg dry mass of tubercles) throughout the DWDS. In terms of microbial community composition, Proteobacteria were dominant in each sample (51.51-97.13%), and the most abundant genus was Desulfovibrio (0.01-66.69%) belonging to sulphate-reducing bacteria. Biodiversity of microbial communities was shaped by many coexisting factors, including season, water supply fitting material, and sampling site location. Spatial distribution analysis revealed that although only samples collected at the same sampling sites were similar to each other in terms of antibiotic resistance, some samples collected in the close proximity were similar in terms of biodiversity. This suggests that antibiotic resistance spreads only locally over small distances in drinking water biofilms. Although actual drinking water biofilms have been previously investigated in terms of microbial biodiversity, this is the first study that characterised both antibiotic resistance and biodiversity of microbial communities attached to inner surfaces of a real DWDS functioning for decades.
Collapse
Affiliation(s)
- Agata Siedlecka
- Department of Environmental Protection Engineering, Faculty of Environmental Engineering, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Mirela Wolf-Baca
- Department of Environmental Protection Engineering, Faculty of Environmental Engineering, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Katarzyna Piekarska
- Department of Environmental Protection Engineering, Faculty of Environmental Engineering, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
| |
Collapse
|
45
|
Preparation and bacteriostatic research of porous polyvinyl alcohol / biochar / nanosilver polymer gel for drinking water treatment. Sci Rep 2021; 11:12205. [PMID: 34108587 PMCID: PMC8190314 DOI: 10.1038/s41598-021-91833-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/27/2021] [Indexed: 11/29/2022] Open
Abstract
Microbial contamination in drinking water has become an important threat to human health. There is thus an urgent need to develop antibacterial materials to treat drinking water. Here, porous silver-loaded biochar (C–Ag) was prepared using corn straw as the substrate and silver as the antibacterial agent. C–Ag was then uniformly distributed in polyvinyl alcohol gel beads of eluted calcium carbonate to prepare p-PVA/C–Ag antibacterial composite. The polymer composites were tested by FT-IR, XRD, SEM and TG-DSC. The results showed that C–Ag was more evenly distributed in the PVA gel spheres. Antibacterial experiments showed that p-PVA/C–Ag greatly inhibited Escherichia coli. Practical application tests revealed that p-PVA/C–Ag showed high and sustained bactericidal inhibition and reusability. Generally, p-PVA/C–Ag composite shows high potential to be applied to drinking water treatment.
Collapse
|
46
|
Gabrielli M, Turolla A, Antonelli M. Bacterial dynamics in drinking water distribution systems and flow cytometry monitoring scheme optimization. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 286:112151. [PMID: 33609931 DOI: 10.1016/j.jenvman.2021.112151] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Water biostability is desired within drinking water distribution systems (DWDSs) to limit microbiologically-related operational, aesthetic and, eventually, health-related issues. However, variations in microbiological quality can take place both spatially along DWDS pipelines and temporally at single locations due to biofilm detachment, water quality seasonality and other processes. In this study, long- and short-term trends of bacterial concentration and community structure were investigated in a secondary branch of an unchlorinated DWDS for several months using high-frequency flow cytometry (FCM) and traditional laboratory monitoring campaigns. Long-term trends of bacterial concentrations and community structures were likely caused by changes in the water physical-chemical quality (i.e. pH and conductivity). Short-term daily pattern, instead, resulted in significant variations between the bacterial concentrations and community structures at different hours, likely due to biofilm detachment and loose deposits resuspension related to changes in the local water flow. These patterns, however, showed broad variations and did not persist during the entire monitoring campaign presumably due to the stochasticity of local instantaneous demand and seasonal changes in water consumption. During periods without sensible long-term trends, the sampling hours explain a comparable or larger fraction of the bacterial community diversity compared to dates. The variations observed with FCM were poorly or not detected by traditional laboratory analyses, as the correlation between the two were rather weak, highlighting the limited information provided by traditional approaches. On the other hand, FCM data correlated with water pH and conductivity, underlining the relation between physical-chemical and microbiological water quality. Such results suggest that the advanced control of the physical-chemical water quality could minimize the microbiological water quality variations. Moreover, monitoring campaign planning should take into account the sampling time to reduce the noise caused by daily fluctuations and/or assess the overall quality variations. Finally, as monitoring costs are one of the barriers which prevent a more widespread use of FCM, a monitoring scheme optimization strategy was developed. Such strategy employs the data from an initial high-frequency sampling period to select the sampling hours which maximize the observed variations of bacterial concentration and community composition.
Collapse
Affiliation(s)
- Marco Gabrielli
- Politecnico di Milano, Department of Civil and Environmental Engineering (DICA), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Andrea Turolla
- Politecnico di Milano, Department of Civil and Environmental Engineering (DICA), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Manuela Antonelli
- Politecnico di Milano, Department of Civil and Environmental Engineering (DICA), Piazza Leonardo da Vinci 32, Milano, 20133, Italy.
| |
Collapse
|
47
|
Yu Y, Chen X, Wang Y, Mao J, Ding Z, Lu Y, Wang X, Lian X, Shi Y. Producing and storing self-sustaining drinking water from rainwater for emergency response on isolated island. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144513. [PMID: 33453540 DOI: 10.1016/j.scitotenv.2020.144513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Drinking water on isolated islands includes treated rainwater, water shipped from the mainland, and desalinated seawater. However, marine transportation and desalination plants are vulnerable to emergencies, such as extreme weather, making self-sustaining stand-by water for emergency response essential. Rainwater is ideal for producing the stand-by water, and rainwater harvesting is sustainable and clean, and prolonged biostability can be ensured by managing biological and chemical parameters. The present study applied a stand-by drinking water purification system (primarily including nanofiltration and low-dose chlorination) to explore the feasibility of producing and storing cleaner drinking water from rainwater and the following conclusions were drawn. First, treatment of rainwaters ensures biosafety for seven days, which is longer than that for untreated rainwater; the proportion of opportunistic pathogens decreased from 23.40-7.77% after nanofiltration, and it was proposed that the microbial community converges after advanced water treatment. Second, chemical qualities were improved. Local resource coral sand prevents pH in rainwater from decreasing below 6.5, and treated rainwater had lower disinfection by-product potential and higher disinfection efficiency, allowing periodical rainwater recycling. Third, harvesting rainwater was extremely cost-effective, with an operation cost of 1.5-2.5 RMB/m3. From biosafety, chemical safety, and economic cost perspectives, self-sustaining water from rainwater can contributes to the development of sustainable and cost-effective water supply systems on isolated islands. Mixing treated rainwater and desalinated seawater reasonably guarantees sufficiency and safety.
Collapse
Affiliation(s)
- Yingjun Yu
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Xiao Chen
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Yi Wang
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China.
| | - Jinfeng Mao
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China.
| | - Zhibin Ding
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Yaofeng Lu
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Xiuchun Wang
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Xiaoying Lian
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| | - Yue Shi
- College of Defense Engineering, Peoples' Liberation Army Engineering University, Nanjing 210007, China
| |
Collapse
|
48
|
Goraj W, Pytlak A, Kowalska B, Kowalski D, Grządziel J, Szafranek-Nakonieczna A, Gałązka A, Stępniewska Z, Stępniewski W. Influence of pipe material on biofilm microbial communities found in drinking water supply system. ENVIRONMENTAL RESEARCH 2021; 196:110433. [PMID: 33166536 DOI: 10.1016/j.envres.2020.110433] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/17/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
The biofilms and water samples from a model installation built of PVC-U, PE-HD and cast iron pipes were investigated using standard heterotrophic plate count and 16S rRNA Next Generation Sequencing. The results of the high throughput identification imply that the construction material strongly influences the microbiome composition. PVC-U and PE-HD pipes were dominated with Proteobacteria (54-60%) while the cast pipe was overgrown by Nitrospirae (64%). It was deduced that the plastic pipes create a more convenient environment for the potentially pathogenic taxa than the cast iron. The 7-year old biofilms were described as complex habitats with sharp oxidation-reduction gradients, where co-existence of methanogenic and methanotrophic microbiota takes place. Furthermore, it was found that the drinking water distribution systems (DWDS) are a useful tool for studying the ecology of rare bacterial phyla. New ecophysiological aspects were described for Aquihabitans, Thermogutta and Vampirovibrio. The discrepancy between identity of HPC-derived bacteria and NGS-revealed composition of biofilm and water microbiomes point to the need of introducing new diagnostical protocols to enable proper assessment of the drinking water safety, especially in DWDSs operating without disinfection.
Collapse
Affiliation(s)
- Weronika Goraj
- Department of Biology and Biotechnology of Microorganisms, Institute of Biological Sciences, The John Paul II Catholic University of Lublin, Konstantynów Street 1 I, 20-708, Lublin, Poland
| | - Anna Pytlak
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland.
| | - Beata Kowalska
- Faculty of Environmental Protection Engineering, Lublin University of Technology, ul. Nadbystrzycka 40B, 20-618, Lublin, Poland
| | - Dariusz Kowalski
- Faculty of Environmental Protection Engineering, Lublin University of Technology, ul. Nadbystrzycka 40B, 20-618, Lublin, Poland
| | - Jarosław Grządziel
- Department of Agricultural Microbiology, Institute of Soil Science and Plant Cultivation-State Research Institute (IUNG-PIB), Czartoryskich Street 8, 24-100, Puławy, Poland
| | - Anna Szafranek-Nakonieczna
- Department of Biology and Biotechnology of Microorganisms, Institute of Biological Sciences, The John Paul II Catholic University of Lublin, Konstantynów Street 1 I, 20-708, Lublin, Poland
| | - Anna Gałązka
- Department of Agricultural Microbiology, Institute of Soil Science and Plant Cultivation-State Research Institute (IUNG-PIB), Czartoryskich Street 8, 24-100, Puławy, Poland
| | - Zofia Stępniewska
- Department of Biochemistry and Environmental Chemistry, The John Paul II Catholic University of Lublin, Konstantynów Street 1 I, 20-708, Lublin, Poland
| | - Witold Stępniewski
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland
| |
Collapse
|
49
|
Zhang C, Qin K, Struewing I, Buse H, Santo Domingo J, Lytle D, Lu J. The Bacterial Community Diversity of Bathroom Hot Tap Water Was Significantly Lower Than That of Cold Tap and Shower Water. Front Microbiol 2021; 12:625324. [PMID: 33967975 PMCID: PMC8102780 DOI: 10.3389/fmicb.2021.625324] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/12/2021] [Indexed: 12/17/2022] Open
Abstract
Microbial drinking water quality in premise plumbing systems (PPSs) strongly affects public health. Bacterial community structure is the essential aspect of microbial water quality. Studies have elucidated the microbial community structure in cold tap water, while the microbial community structures in hot tap and shower water are poorly understood. We sampled cold tap, hot tap, and shower water from a simulated PPS monthly for 16 consecutive months and assessed the bacterial community structures in those samples via high-throughput sequencing of bacterial 16S rRNA genes. The total relative abundance of the top five most abundant phyla (Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, and Firmicutes) was greater than 90% among the 24 identified phyla. The most abundant families were Burkholderiaceae, Sphingomonadaceae, unclassified Alphaproteobacteria, unclassified Corynebacteriales, and Mycobacteriaceae. A multiple linear regression suggests that the bacterial community diversity increased with water temperature and the age of the simulated PPS, decreased with total chlorine residual concentration, and had a limited seasonal variation. The bacterial community in hot tap water had significantly lower Shannon and Inverse Simpson diversity indices (p < 0.05) and thus a much lower diversity than those in cold tap and shower water. The paradoxical results (i.e., diversity increased with water temperature, but hot tap water bacterial community was less diverse) were presumably because (1) other environmental factors made hot tap water bacterial community less diverse, (2) the diversity of bacterial communities in all types of water samples increased with water temperature, and (3) the first draw samples of hot tap water could have a comparable or even lower temperature than shower water samples and the second draw samples of cold tap water. In both a three-dimensional Non-metric multidimensional scaling ordination plot and a phylogenetic dendrogram, the samples of cold tap and shower water cluster and are separate from hot tap water samples (p < 0.05). In summary, the bacterial community in hot tap water in the simulated PPS had a distinct structure from and a much lower diversity than those in cold tap and shower water.
Collapse
Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH, United States
| | - Ke Qin
- Oak Ridge Institute for Science and Education Participation Program, Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| | - Ian Struewing
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| | - Helen Buse
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| | - Jorge Santo Domingo
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| | - Darren Lytle
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
| |
Collapse
|
50
|
Ahmad JI, Dignum M, Liu G, Medema G, van der Hoek JP. Changes in biofilm composition and microbial water quality in drinking water distribution systems by temperature increase induced through thermal energy recovery. ENVIRONMENTAL RESEARCH 2021; 194:110648. [PMID: 33358877 DOI: 10.1016/j.envres.2020.110648] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Drinking water distribution systems (DWDSs) have been thoroughly studied, but the concept of thermal energy recovery from DWDSs is very new and has been conceptualized in the past few years. Cold recovery results in a temperature increase of the drinking water. Its effects on drinking water quality and biofilm development are unclear. Hence, we studied both bulk water and biofilm phases for 232 days in two parallel pilot scale distribution systems with two temperature settings after cold recovery, 25 °C and 30 °C, and compared these with a reference pilot system without cold recovery. In all three pilot distributions systems (DSs) our results showed an initial increase in biomass (ATP) in the biofilm phase, along with occurrence of primary colonizers (Betaproteobacteriales) and subsequently a decrease in biomass and an increasing relative abundance of other microbial groups (amoeba resisting groups; Xanthobacteraceae, Legionellales), including those responsible for EPS formation in biofilms (Sphingomonadaceae). The timeline for biofilm microbial development was different for the three pilot DSs: the higher the temperature, the faster the development took place. With respect to the water phase within the three pilot DSs, major microbial contributions came from the feed water (17-100%) and unkown sources (2-80%). Random contributions of biofilm (0-70%) were seen between day 7-77. During this time period six-fold higher ATP concentration (7-11 ng/l) and two-fold higher numbers of high nucleic acid cells (5.20-5.80 × 104 cells/ml) were also observed in the effluent water from all three pilot DSs, compared to the feed water. At the end of the experimental period the microbial composition of effluent water from three pilot DSs revealed no differences, except the presence of a biofilm related microbial group (Sphingomonadaceae), within all three DSs compared to the feed water. In the biofilm phase higher temperatures initiated the growth of primary colonizing bacteria but this did not lead to differences in microbial diversity and composition at the end of the experimental period. Hence, we propose that the microbiological water quality of DWDSs with cold recovery should be monitored more frequently during the first 2-3 months of operation.
Collapse
Affiliation(s)
- Jawairia Imtiaz Ahmad
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600GA, Delft, the Netherlands; Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Science and Technology, H-12 Sector, Islamabad, Pakistan.
| | - Marco Dignum
- Waternet, Korte Ouderkerkerdijk 7, 1096 AC, Amsterdam, the Netherlands
| | - Gang Liu
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600GA, Delft, the Netherlands; Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Gertjan Medema
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600GA, Delft, the Netherlands; KWR Water Research Institute, P.O. Box 1072, 3430 BB, Nieuwegein, the Netherlands; Michigan State University, 1405 S Harrison Rd, East-Lansing, 48823, USA
| | - Jan Peter van der Hoek
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, P.O. Box 5048, 2600GA, Delft, the Netherlands; Waternet, Korte Ouderkerkerdijk 7, 1096 AC, Amsterdam, the Netherlands
| |
Collapse
|