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Eisfeld C, van Breukelen BM, Medema G, van der Wolf JM, Velstra J, Schijven JF. QMRA of Ralstonia solanacearum in potato cultivation: Risks associated with irrigation water recycled through managed aquifer recharge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:166181. [PMID: 37572894 DOI: 10.1016/j.scitotenv.2023.166181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/05/2023] [Accepted: 08/07/2023] [Indexed: 08/14/2023]
Abstract
Agricultural aquifer storage recovery and transfer (ASTR) stores excess fresh water for later reuse in irrigation. Moreover, water quality improves because chemical pollutants and pathogens will be removed by degradation and attachment to the aquifer material. The source water may contain the bacterial plant pathogen Ralstonia solanacearum which causes plant infections and high yield losses. We used quantitative microbial risk assessment (QMRA) to investigate the removal of R. solanacearum during ASTR to predict infection risks of potato plants after irrigation with the recovered water. Laboratory experiments analyzed the ASTR treatment by investigating the bacterial die-off in the water phase and the removal by attachment to the aquifer sediment. Die-off in the water phase depends on the residence time and ranged between 1.3 and 2.7 log10 after 10 or 60 days water storage, respectively. A subpopulation of the bacteria persisted for a prolonged time at low concentrations which may pose a risk if the water is recovered too early. However, the natural aquifer sand filtration proofed to be highly effective in removing R. solanacearum by attachment which depends on the distance between injection and abstraction well. The high removal by attachment alone (18 log10 after 1 m) would reduce bacterial concentrations to negligible numbers. Upscaling to longer soil passages is discussed in the paper. Infection risks of potato plants were calculated using a dose-response model and ASTR treatment resulted in negligible infection risks of a single plant, but also when simulating the irrigation of a 5 ha potato field. This is the first QMRA that analyzed an agricultural ASTR and the fate of a plant pathogen focusing on plant health. QMRA is a useful (water) management tool to evaluate the treatment steps of water reclamation technologies with the aim to provide safe irrigation water and reduce risks disseminating plant diseases.
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Affiliation(s)
- Carina Eisfeld
- Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Stevinweg 1, 2628 CN Delft, the Netherlands.
| | - Boris M van Breukelen
- Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Stevinweg 1, 2628 CN Delft, the Netherlands
| | - Gertjan Medema
- Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Stevinweg 1, 2628 CN Delft, the Netherlands; KWR Water Research Institute, Water Quality & Health, Groningenhaven 7, 3433 PE, Nieuwegein, the Netherlands
| | - Jan M van der Wolf
- Wageningen Plant Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands
| | - Jouke Velstra
- Acacia Water B.V., Van Hogendorpplein 4, 2805 BM Gouda, the Netherlands
| | - Jack F Schijven
- National Institute of Public Health and the Environment, Department of Statistics, Informatics and Modelling, 3720 BA Bilthoven, the Netherlands; Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Heidelberglaan 2, 3584 CS Utrecht, the Netherlands
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Trikannad SA, van Halem D, Foppen JW, van der Hoek JP. The contribution of deeper layers in slow sand filters to pathogens removal. WATER RESEARCH 2023; 237:119994. [PMID: 37116371 DOI: 10.1016/j.watres.2023.119994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/09/2023]
Abstract
Slow Sand Filtration is popular in drinking water treatment for the removal of a wide range of contaminants (e.g., particles, organic matter, and microorganisms). The Schmutzdecke in slow sand filters (SSFs) is known to be essential for pathogen removal, however, this layer is also responsible for increased head loss. Since the role of deeper layers in bacteria and virus removal is poorly understood, this research investigated the removal of E.coli WR1 and PhiX 174 at different depths of a full-scale SSF. Filter material from top (0-5 cm), middle (5-20 cm) and deep (20-35 cm) layers of an established filter was used in an innovative experimental set-up to differentiate physical-chemical and biological removal processes. In the analysis, we distinguished between removal by biological activity, biofilm and just sand. In addition, we modelled processes by a one-side kinetic model. The different layers contributed substantially to overall log removal of E.coli WR1 (1.4-1.7 log10) and PhiX 174 (0.4-0.6 log10). For E.coli WR1, biological activity caused major removal, followed by removal within biofilm and sand, whereas, removal of PhiX 174 mainly occurred within sand, followed by biofilm and biological activity. Narrow pore radii in the top layer obtained by micro-computed tomography scanner suggested enhanced retention of bacteria due to constrained transport. The retention rates of E.coli WR1 and PhiX 174 in top layer were four and five times higher than deeper layers, respectively (kret 1.09 min-1 vs 0.26 min-1 for E.coli WR1 and kret 0.32 min-1 vs of 0.06 min-1 for PhiX 174). While this higher rate was restricted to the Schmutzdecke alone (top 5 cm), the deeper layers extend to around 1 m in full-scale filters. Therefore, the contribution of deeper layers of established SSFs to the overall log removal of bacteria and viruses is much more substantial than the Schmutzdecke.
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Affiliation(s)
- Shreya Ajith Trikannad
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands.
| | - Doris van Halem
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands
| | - Jan Willem Foppen
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands
| | - Jan Peter van der Hoek
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands; Waternet, Korte Ouderkerkerdijk 7, 1096 AC, Amsterdam, the Netherlands
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Halla FF, Massawa SM, Joseph EK, Acharya K, Sabai SM, Mgana SM, Werner D. Attenuation of bacterial hazard indicators in the subsurface of an informal settlement and their application in quantitative microbial risk assessment. ENVIRONMENT INTERNATIONAL 2022; 167:107429. [PMID: 35914337 DOI: 10.1016/j.envint.2022.107429] [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: 01/07/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Pit latrines provide essential onsite sanitation services to over a billion people, but there are concerns about their role in infectious disease transmission, and impacts on groundwater resources. We conducted fieldwork in an informal settlement in Dar es Salaam, where cholera is endemic. We combined plate counting with portable MinION sequencing and quantitative polymerase chain reaction (qPCR) methods for characterization of bacteria in pit latrine sludge, leachate, shallow and deep groundwater resources. Pit latrine sludge was characterized by log10 marker gene concentrations per 100 mL of 11.2 ± 0.2, 9.9 ± 0.9, 6.0 ± 0.3, and 4.4 ± 0.8, for total bacteria (16S rRNA), E. coli (rodA), human-host-associated Bacteroides (HF183), and Vibrio cholerae (ompW), respectively. The ompW gene observations suggested 5 % asymptomatic Vibrio cholerae carriers amongst pit latrine users. Pit leachate percolation through one-meter-thick sand beds attenuated bacterial hazard indicators by 1 to 4 log10 units. But first-order removal rates derived from these data substantially overestimated the longer-range hazard attenuation in the sand aquifers. Cooccurrence of human sewage marker gene HF183 in all shallow groundwater samples testing positive for ompW genes demonstrated the human origin of Vibrio cholerae hazards in the subsurface. All borehole water samples tested negative for ompW and HF183 genes, but 16S rRNA gene sequencing data suggested ingress of faecal pollution into boreholes at the peak of the "long rainy season". Quantitative microbial risk assessment (QMRA) predicted a gastrointestinal disease burden of 0.05 DALY per person per year for the community, well above WHO targets of 10-4-10-6 DALY for disease related to drinking water.
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Affiliation(s)
- Franella Francos Halla
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Said Maneno Massawa
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Elihaika Kengalo Joseph
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Kishor Acharya
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Shadrack Mwita Sabai
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Shaaban Mrisho Mgana
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania.
| | - David Werner
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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Li J, Liu J, Yu H, Zhao W, Xia X, You S, Zhang J, Tong H, Wei L. Sources, fates and treatment strategies of typical viruses in urban sewage collection/treatment systems: A review. DESALINATION 2022; 534:115798. [PMID: 35498908 PMCID: PMC9033450 DOI: 10.1016/j.desal.2022.115798] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
The ongoing coronavirus pandemic (COVID-19) throughout the world has severely threatened the global economy and public health. Due to receiving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a wide variety of sources (e.g., households, hospitals, slaughterhouses), urban sewage treatment systems are regarded as an important path for the transmission of waterborne viruses. This review presents a quantitative profile of the concentration distribution of typical viruses within wastewater collection systems and evaluates the influence of different characteristics of sewer systems on virus species and concentration. Then, the efficiencies and mechanisms of virus removal in the units of wastewater treatment plants (WWTPs) are summarized and compared, among which the inactivation efficiencies of typical viruses by typical disinfection approaches under varied operational conditions are elucidated. Subsequently, the occurrence and removal of viruses in treated effluent reuse and desalination, as well as that in sewage sludge treatment, are discussed. Potential dissemination of viruses is emphasized by occurrence via aerosolization from toilets, the collection system and WWTP aeration, which might have a vital role in the transmission and spread of viruses. Finally, the frequency and concentration of viruses in reclaimed water, the probability of infection are also reviewed for discussing the potential health risks.
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Affiliation(s)
- Jianju Li
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jing Liu
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
- School of Geosciences, China University of Petroleum, Qingdao 266580, China
| | - Hang Yu
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Weixin Zhao
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xinhui Xia
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shijie You
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jun Zhang
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hailong Tong
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
- Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Liangliang Wei
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
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Microbial ecology of biofiltration used for producing safe drinking water. Appl Microbiol Biotechnol 2022; 106:4813-4829. [PMID: 35771243 PMCID: PMC9329406 DOI: 10.1007/s00253-022-12013-x] [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: 04/01/2022] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022]
Abstract
Abstract
Biofiltration is a water purification technology playing a pivotal role in producing safe drinking water. This technology attracts many interests worldwide due to its advantages, such as no addition of chemicals, a low energy input, and a high removal efficiency of organic compounds, undesirable taste and odours, and pathogens. The current review describes the microbial ecology of three biofiltration processes that are routinely used in drinking water treatment plants, i.e. (i) rapid sand filtration (RSF), (ii) granular activated carbon filtration (GACF), and (iii) slow sand filtration (SSF). We summarised and compared the characteristics, removal performance, and corresponding (newly revealed) mechanisms of the three biofiltration processes. Specifically, the microbial ecology of the different biofilter processes and the role of microbial communities in removing nutrients, organic compounds, and pathogens were reviewed. Finally, we highlight the limitations and challenges in the study of biofiltration in drinking water production, and propose future perspectives for obtaining a comprehensive understanding of the microbial ecology of biofiltration, which is needed to promote and optimise its further application. Key points • Biofilters are composed of complex microbiomes, primarily shaped by water quality. • Conventional biofilters contribute to address safety challenges in drinking water. • Studies may underestimate the active/functional role of microbiomes in biofilters. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-12013-x.
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Biological Layer in Household Slow Sand Filters: Characterization and Evaluation of the Impact on Systems Efficiency. WATER 2022. [DOI: 10.3390/w14071078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Schmutzdecke, the biofilm formed on the top of the sand bed in household slow sand filters (HSSF) is a key factor for the filters’ high efficiency in removing particles and microorganisms from water. This paper aims to investigate the extracellular polymeric substances composition (carbohydrates and proteins), biomass, dissolved oxygen, and microbial community in two types of HSSFs and identify a correlation between them and their efficiency. A continuous- and an intermittent-HSSF (C-HSSF and I-HSSF) were studied to treat river water for 48 days. Their efficiencies for bacteria (E. coli and total coliforms), turbidity, and apparent color removals were analyzed. Results clearly showed an increase of carbohydrates (from 21.4/22.5 to 101.2/93.9 mg·g−1 for C-/I-HSSF) and proteins (from 34.9 to 217/307.8 mg g−1 for C-/I-HSSF), total solids (from 0.03/<0.03 to 0.11/0.19 g L−1 for C-/I-HSSF), dissolved oxygen depletion inside the filter (6.00 and 5.15 mg L−1 for C- and I-HSSF) and diversity of microorganisms over time, pointing out the schmutzdecke development. A clear improvement on the HSSFs’ efficiency was observed during operation, i.e., E. coli removal of 3.23 log and 2.98 log for total coliforms, turbidity from 60 to 95%, and apparent color from 50 to 90%.
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Song S, Rong L, Dong K, Liu X, Le Clech P, Shen Y. Particle-scale modelling of fluid velocity distribution near the particles surface in sand filtration. WATER RESEARCH 2020; 177:115758. [PMID: 32278990 DOI: 10.1016/j.watres.2020.115758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
Sand filtration is widely used in drinking water treatment processes, yet the hydraulic fundamentals at particle-scale are not well defined, especially the fluid velocity profile near the sand particles surface. In this study, a numerical model is developed by combining the Lattice Boltzmann (LBM) and the Discrete Element Method (DEM), used to describe the fluid flow over the sand particles surface and the micro-structure details of the sand packed bed respectively. The model is validated by comparing the simulation results with the experimental measurements using two systems, showing that the model can describe the fluid velocity distribution around the particles surface. Critical flow velocity is introduced as the balance between hydrodynamic and adhesive torques acting on sand particle surface. Furthermore, a new concept - effective filter surface (EFS), is defined as the area where the velocity near sand particles surface is less than the critical flow velocity, aiming for indirectly evaluating the performance of sand filtration. It is quantitatively demonstrated that increasing the sand particle size or feed flow velocity results in the decrease of both critical flow velocity and EFS under the given tested conditions. The LBM-DEM model provides a useful tool for understanding the fundamentals of liquid flow distribution and also estimating sand filtration performance under different operation conditions.
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Affiliation(s)
- Shuang Song
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Liangwan Rong
- School of Civil Engineering & Transportation, South China University of Technology, Guangzhou, Guangdong, 510640, China
| | - Kejun Dong
- Centre for Infrastructure Engineering, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Xuefei Liu
- UNSW Centre for Transformational Environmental Technologies, Yixing, Jiangsu, 214200, China
| | - Pierre Le Clech
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Yansong Shen
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.
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Abstract
Point-of-use biosand water filters are widely distributed in undeveloped or developing regions due to their water treatment success and low-cost design, but two gaps remain in the basic technology: (1) the filter body is oversized relative to its contaminant removal performance, and (2) the heavy design largely excludes difficult to reach locations in need of clean water solutions. Here, we model design modifications to the v.10 Centre for Affordable Water and Sanitation Technology biosand filter using a reduced filter height, increased biolayer area, and conserved reservoir volume. We compare the hydraulic characteristics (dynamic velocity and head pressure) and percent contaminant removal of bacteria Escherichia coli and virus MS2 of the modified designs to the traditional control design using a finite element approximation of Darcy’s law with discrete time steps and a slow-sand filtration model. We demonstrate that a reduced-height design has a greater impact on contaminant removal compared to the traditional design (largely due to the increased residence time from the decreased flow rate inside the filter). For example, our 70% reduced-height filter design removed 99.5% and 73.93% of E. coli and MS2, respectively, where the traditional filter design removed 62.81% and 27.6%, respectively. Reduced-height designs should be pursued as a viable solution to improve filter performance while allowing for alternative construction techniques with greater end-user accessibility compared to the traditional design.
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Soliman MYM, van Halem D, Medema G. Virus removal by ceramic pot filter disks: Effect of biofilm growth and surface cleaning. Int J Hyg Environ Health 2020; 224:113438. [PMID: 31978734 DOI: 10.1016/j.ijheh.2019.113438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/14/2019] [Accepted: 12/17/2019] [Indexed: 10/25/2022]
Abstract
Ceramic pot filters are household water treatment and safe storage (HWTS) systems designed to improve the microbial quality of drinking water. They yield high log reduction values (LRVs) for bacterial and protozoan pathogens but provide very little removal of viruses. This study investigated virus removal of ceramic filter discs (CFDs), using feed water with 3 different nutrient levels under extended continuous operation and limited cleaning frequency. The results show that filter use without cleaning resulted in biofilm growth and MS2 LRV values increased with increasing feed water nutrient content. Cleaning the filter surface by scrubbing led to a partial or total loss in improved LRVs, indicating the importance of this biological top layer to the removal of MS2. Overall, the removal capacity of a matured biofilm remained constant, regardless of its age. MS2 LRVs ranged between 0.9 ± 0.2 LRV for low nutrient (LN), 1.6 ± 0.2 LRV for medium nutrient (MN) and 2.4 ± 0.5 LRV for high nutrient (HN) biofilms. Interestingly, a change in feed conditions for the HN filters resulted in an unprecedented high LRV of >4 LRV, which supports further investigation of the mechanistic role of biofilms in virus removal.
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Affiliation(s)
- Mona Y M Soliman
- Delft University of Technology, Department of Water Management, Stevinweg 1, 2628 CN, Delft, the Netherlands.
| | - Doris van Halem
- Delft University of Technology, Department of Water Management, Stevinweg 1, 2628 CN, Delft, the Netherlands.
| | - Gertjan Medema
- Delft University of Technology, Department of Water Management, Stevinweg 1, 2628 CN, Delft, the Netherlands; KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB, Nieuwegein, the Netherlands.
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van den Berg H, Friederichs L, Versteegh J, Smeets P, de Roda Husman A. How current risk assessment and risk management methods for drinking water in The Netherlands cover the WHO water safety plan approach. Int J Hyg Environ Health 2019; 222:1030-1037. [DOI: 10.1016/j.ijheh.2019.07.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/28/2019] [Accepted: 07/03/2019] [Indexed: 10/26/2022]
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Zhao Y, Wang X, Liu C, Wang S, Wang X, Hou H, Wang J, Li H. Purification of harvested rainwater using slow sand filters with low-cost materials: Bacterial community structure and purifying effect. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 674:344-354. [PMID: 31005836 DOI: 10.1016/j.scitotenv.2019.03.474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 03/30/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
Abstract
Slow sand filters (SSFs) have been shown to effectively improve water quality. The aim of the present study was to obtain low-cost materials (LCMs) as filter mediums (FMs) to efficiently purify harvested rainwater and to document the relationship between bacterial community structure and water purification. The red clay was mixed with crushed limestone and crushed brick, respectively. The mixtures or brick powder were used as the filter media for SSFs. Laboratory column tests were conducted in conjunction with the monitoring of representative water quality parameters (COD, NH4+, CFU and total coliforms) to estimate the performance of low-cost material slow sand filters (LCM-SSFs), including the time needed for biofilm maturation. The relationship between bacterial community structure and SSF performance was determined using a combination of 16S rRNA gene sequencing and an array of statistical techniques. The results demonstrated that LCM-SSFs perform well in purifying harvested rainwater, and are of superior economic benefit. LCMs had a stronger adsorptivity than quartz sand, which enhanced the purification of harvested rainwater before the biofilms matured, and shorten the time required for biofilm maturation. During the 90-day laboratory experiment, a mixture of crushed limestone and red clay exhibited the best performance. The abundance of Opitutae could be used as a potential indicator of NH4+ removal efficiency by SSFs. Schmutzdecke was characterized by abundant, diverse and evenly distributed bacterial communities that produced rich, stable and robust environmental functions, and that possessed an excellent purifying capacity. Environmental conditions associated with low ecological stress, such as neutral pH filter mediums and lucifugal experimental conditions, were conducive to the diversity and evenness of effluent bacterial communities and improved the performance of LCM-SSFs in purifying harvested rainwater.
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Affiliation(s)
- Yuewen Zhao
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Xiuyan Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China.
| | - Changli Liu
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Shuaiwei Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Xihua Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Hongbing Hou
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Jingjing Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
| | - Hongzhao Li
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China
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Synthesis and evaluation of the antibacterial effect of silica-coated modified magnetic poly-(amidoamine) G5 nanoparticles on E. coli and S. aureus. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.11.101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Zhan S, Yang Y, Shen Z, Shan J, Li Y, Yang S, Zhu D. Efficient removal of pathogenic bacteria and viruses by multifunctional amine-modified magnetic nanoparticles. JOURNAL OF HAZARDOUS MATERIALS 2014; 274:115-23. [PMID: 24769848 DOI: 10.1016/j.jhazmat.2014.03.067] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 03/26/2014] [Accepted: 03/31/2014] [Indexed: 05/10/2023]
Abstract
A novel amine-functionalized magnetic Fe3O4-SiO2-NH2 nanoparticle was prepared by layer-by-layer method and used for rapid removal of both pathogenic bacteria and viruses from water. The nanoparticles were characterized by TEM, EDS, XRD, XPS, FT-IR, BET surface analysis, magnetic property tests and zeta-potential measurements, respectively, which demonstrated its well-defined core-shell structures and strong magnetic responsivity. Pathogenic bacteria and viruses are often needed to be removed conveniently because of a lot of co-existing conditions. The amine-modified nanoparticles we prepared were attractive for capturing a wide range of pathogens including not only bacteriophage f2 and virus (Poliovirus-1), but also various bacteria such as S. aureus, E. coli O157:H7, P. aeruginosa, Salmonella, and B. subtilis. Using as-prepared amine-functionalized MNPs as absorbent, the nonspecific removal efficiency of E. coli O157:H7 or virus was more than 97.39%, while it is only 29.8% with Fe3O4-SiO2 particles. From joint removal test of bacteria and virus, there are over 95.03% harmful E. coli O157:H7 that can be removed from mixed solution with polyclonal anti-E. coli O157:H7 antibody modified nanoparticles. Moreover, the synergy effective mechanism has also been suggested.
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Affiliation(s)
- Sihui Zhan
- College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, United States.
| | - Yang Yang
- College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Zhiqiang Shen
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin 300050, PR China
| | - Junjun Shan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, United States
| | - Yi Li
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, United States; Department of Chemistry, Tianjin University, Tianjin 300072, PR China
| | - Shanshan Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, United States
| | - Dandan Zhu
- College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
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