1
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Xu L, Song S, Graham NJD, Yu W. Simultaneous removal of NOM and sulfate in a bioelectrochemical integrated biofilter treating reclaimed water. WATER RESEARCH 2024; 252:121193. [PMID: 38290239 DOI: 10.1016/j.watres.2024.121193] [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: 12/04/2023] [Accepted: 01/23/2024] [Indexed: 02/01/2024]
Abstract
Biofiltration is an environmentally 'green' technology that is compatible with the recently proposed sustainable development goals, and which has an increasingly important future in the field of water treatment. Here, we explored the impacts of bioelectrochemical integration on a bench-scale slow rate biofiltration system regarding its performance in reclaimed water treatment. Results showed that the short-term (<3 months) integration improved the removal of natural organic matter (NOM) (approximately 8.8%). After long-term (5 months and thereafter) integration, the cathodic charge transfer resistance was found to have a significant reduction from 2662 to 1350 Ω. Meanwhile, bioelectrochemical autotrophic sulfate (SO42-) reduction (over 27.6% reduction) through the syntrophic metabolism between hydrogen oxidation strains (genus Hydrogenophaga) and sulfate-reducing microbes (genera Dethiobacter, Desulfovibrio, and Desulfomicrobium) at the cathodic region was observed. More significantly, the microbial-derived chromophoric humic substances were found to act as electron shuttles at the cathodic region, which might facilitate the process of bioelectrochemical SO42- reduction. Overall, this study provided valuable insights into the potential application of bioelectrochemical-integrated biofilter for simultaneous reduction of NOM and SO42- treating reclaimed water.
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Affiliation(s)
- Lei Xu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Shian Song
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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2
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Huang F, Tang J, Xu L, Campos LC. Deciphering the synergistic effects of photolysis and biofiltration to actuate elimination of estrogens in natural water matrix. WATER RESEARCH 2024; 249:120976. [PMID: 38064783 DOI: 10.1016/j.watres.2023.120976] [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: 05/25/2023] [Revised: 11/18/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
The presence of estrogens in water environments has raised concerns for human health and ecosystems balance. These substances possess potent estrogenic properties, causing severe disruptions in endocrine systems and leading to reproductive and developmental problems. Unfortunately, conventional treatment methods struggle to effectively remove estrogens and mitigate their effects, necessitating technological innovation. This study investigates the effectiveness of a novel sequential photolysis-granular activated carbon (GAC) sandwich biofiltration (GSBF) system in removing estrogens (E1, E2, E3, and EE2) and improving general water quality parameters. The results indicate that combining photolysis pre-treatment with GSBF consistently achieved satisfactory performance in terms of turbidity, dissolved organic carbon (DOC), UV254, and microbial reduction, with over 77.5 %, 80.2 %, 89.7 %, and 92 % reduction, respectively. Furthermore, this approach effectively controlled the growth of microbial biomass under UV irradiation, preventing excessive head loss. To assess estrogen removal, liquid chromatography-tandem mass spectrometry (LC-MS) measured their concentrations, while bioassays determined estrogenicity. The findings demonstrate that GSBF systems, with and without photolysis installation, achieved over 96.2 % removal for estrogens when the spike concentration of each targeted compound was 10 µg L-1, successfully reducing estrogenicity (EA/EA0) to levels below 0.05. Additionally, the study evaluated the impact of different thicknesses of GAC layer filling (8 cm, 16 cm, and 24 cm) and found no significant difference (p>0.05) in estrogen and estrogenicity removal among them.
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Affiliation(s)
- Fan Huang
- Centre for Urban Sustainability and Resilience, Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom; State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Junwang Tang
- Department of Chemical Engineering, University College London, WC1E 6BT, United Kingdom; Industrial Catalysis Center, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Like Xu
- Centre for Urban Sustainability and Resilience, Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Luiza C Campos
- Centre for Urban Sustainability and Resilience, Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom.
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3
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Huang X, Geng M, Wang K, He Y, Li G, Feng C, Shi B. Suppression of performance of activated carbon filter due to residual aluminum accumulation. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130637. [PMID: 37056009 DOI: 10.1016/j.jhazmat.2022.130637] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/13/2022] [Accepted: 12/18/2022] [Indexed: 06/19/2023]
Abstract
Extending the lifetime of granular activated carbon (GAC) filters with no significant loss in their effectiveness is a considerable challenge for drinking water supply utilities. However, the effects of residual Al from coagulants on GAC performance are rarely considered. Herein, in-service GAC samples obtained from full-scale water treatment plants were investigated to evaluate the amount of accumulated Al. Although the Al concentration in water was two to three times lower than the Ca concentration, Al exhibited considerable accumulation (second to Ca accumulation) in in-service GAC samples (0.68-8.63 mg g-1). Surface characterization results indicated that Al accumulation could have been caused by the co-precipitation of Al with Ca and Si to form Ca4Al2Si3O10·H2O and Ca4Al6O12SO4, self-precipitation or complexion with -OH/-COOH on the GAC or biofilm surfaces. Correlation analysis of the accumulated Al and GAC properties implied that Al accumulation considerably reduced the surface area of GAC by ∼30%. Lab simulation experiments indicated that the removal of dissolved organic matter was reduced by 6-10% when additional Al was loaded. In addition, results showed that the residual Al (up to 200 μg L-1) considerably affected the extracellular polymeric substance component and microorganism community structure. In summary, strict control of residual Al is beneficial for maintaining the efficacies of GAC and biologically activated carbon.
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Affiliation(s)
- Xin Huang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Mengze Geng
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Kaiyun Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yitian He
- 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
| | - Chenghong Feng
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, 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.
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4
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Feng J, Li X, Yang Y, Fan X, Zhou Z, Ren J, Tan X, Li H. Insight into biofouling mechanism in biofiltration-facilitated gravity-driven membrane (GDM) system: Beneficial effects of pre-deposited adsorbents. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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5
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Lu Z, Jing Z, Huang J, Ke Y, Li C, Zhao Z, Ao X, Sun W. Can we shape microbial communities to enhance biological activated carbon filter performance? WATER RESEARCH 2022; 212:118104. [PMID: 35114529 DOI: 10.1016/j.watres.2022.118104] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/16/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
A new focus on biofiltration has emerged that aims to shape microbial communities to improve treatment efficacy. It is therefore necessary to understand the linkages between microbial community structure and biofilter function. However, the assembly and interaction of microbial communities in biological activated carbon (BAC) filters are unknown. In this study, we selected one coal-based granular activated carbon (GAC), GAC-13, with simultaneously developed micropore and micro-level macropore volume used for a bench-scale BAC column experiment, and compared it with other coal-based GACs and wood-based GAC in terms of the dissolved organic carbon (DOC) removal and microbial community characteristics. The results showed that there was no difference between the DOC removal efficiency of BAC-13 and the other two coal-based BAC filters with high iodine value in the period dominated by adsorption, while the DOC removal efficiency of BAC-13 (64.7±0.6%) was significantly higher than that of other BAC filters (36.3±0.8-54.1±0.4%) with a difference of 0.3-0.7 mg/L in DOC during the steady state. The bacterial communities were strongly assembled by deterministic rather than stochastic factors, where the surface polarity of GAC had a greater effect on the microbial communities than its physical properties. The corresponding co-occurrence network revealed that microbes in the BAC filter may be more cooperative than competitive. The keystone bacterium Hyphomicrobium, which had a relatively low abundance, contributed 0.3-1% more to the most abundant functions and produced 5-21 proteins/(g·GAC) more than the dominant bacterium Sphingobium. The metaproteomic-based approach could provide more accurate information regarding the contributions of different species to metabolic functions. The pore size distribution of GAC was found to be an important factor in determining BAC filter performance; the most important pore sizes were micropores and micro-level macropores (0.2-10 μm and >100 μm in diameter), and the latter impacted the abundance of keystone species. Overall, our findings provide new insights into shaping microbial communities by optimizing pore size structure to improve BAC performance, especially the abundance of keystone species.
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Affiliation(s)
- Zedong Lu
- School of Environment, Tsinghua University, Beijing 100084, China; Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou 215163, China
| | - Zibo Jing
- School of Environment, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jing Huang
- Beijing Drainage Group Co. Ltd. (BDG), Beijing 100022, China
| | - Yanchu Ke
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Chen Li
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhinan Zhao
- School of Environment, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xiuwei Ao
- 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.
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Pilot-Scale Biological Activated Carbon Filtration–Ultrafiltration System for Removing Pharmaceutical and Personal Care Products from River Water. WATER 2022. [DOI: 10.3390/w14030367] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biological activated carbon (BAC) biofilter coupling ultrafiltration (UF) is a promising process for the treatment of river water contaminated by pharmaceutical and personal care products (PPCPs). However, the pilot-scale study should be conducted to reveal the long-term removal performance and the respective contributions of BAC and UF. In this study, a BAC-UF system with treatment capacity of 0.16 m3 h−1 was operated for 130 days. The water quality was analyzed in terms of CODMn, UV254, NH4+-N, and PPCPs. The results showed that both BAC and UF were related to the removal of organic matter (CODMn and UV254), achieving the removals of 56.00% and 55.25%, respectively. Similarly, BAC and UF were both relevant to the removal effects of ammonia nitrogen, nitrite, and nitrate. Moreover, the BAC-UF process was featured with a high efficiency in the removal of PPCPs, and the average removal of total PPCPs reached 47.84%, especially anhydroerythromycin, sulfachloropyridazine, sulfadiazine, trimethoprim, and caffeine. Besides, it was found that the BAC unit played a key role in PPCPs removal and the UF unit also degraded them by the biomass on UF membranes. Therefore, this study proved the removal performance of BAC-UF for treating popular pollutants from river water, and the BAC-UF process in this work can be considered as a feasible method of producing clean drinking water.
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Yu Y, Huang X, Chen R, Pan L, Shi B. Control of disinfection byproducts in drinking water treatment plants: Insight into activated carbon filter. CHEMOSPHERE 2021; 280:130958. [PMID: 34162113 DOI: 10.1016/j.chemosphere.2021.130958] [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: 02/08/2021] [Revised: 04/27/2021] [Accepted: 05/16/2021] [Indexed: 06/13/2023]
Abstract
The removal efficiencies of disinfection byproducts formation potentials (DBPFPs) and generated DBPs under pre-chlorination condition (pre-generated DBPs) during different drinking water treatment trains in eight full-scale drinking water treatment plants (WTPs) were investigated through field and laboratory studies. Haloacetic acids (HAAs) and haloacetonitriles (HANs) were identified to be two representative DBPs based on cytotoxicity and genotoxicity assessments. The performances of advanced treatment train for HAAs and HANs were better than that of conventional treatment train. However, the efficacy of ozone - biological activated carbon (O3-BAC) was affected by its service time and position in the water treatment process. In addition, the consumption of free chlorine by activated carbon in old granular activated carbon (GAC) filter was higher than that in new one under pre-chlorination condition, resulting in the increase of HAAs and HANs in the GAC filter effluent. This demonstrated that the organic matter adsorbed on older activated carbon generated more HAAs and HANs during pre-chlorination, which inhibited the adsorption of pre-generated DBPs. The ability of GAC/O3-BAC to remove HAAs and HANs was consistent with that of protein-like and low molecular weight organic substances, which could predict the performance of GAC and O3-BAC in treating DBPs.
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Affiliation(s)
- Ying 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
| | - Xin Huang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Ruya Chen
- 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
| | - 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
| | - 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.
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8
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Qin W, Hammes F. Substrate Pre-loading Influences Initial Colonization of GAC Biofilter Biofilms. Front Microbiol 2021; 11:596156. [PMID: 33510720 PMCID: PMC7835318 DOI: 10.3389/fmicb.2020.596156] [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: 08/19/2020] [Accepted: 12/11/2020] [Indexed: 12/05/2022] Open
Abstract
Microbial community composition and stability affect pollutant removal for biological/granular activated carbon (BAC/GAC) processes. Here, we pre-loaded the organic carbon substrates sucrose, lactose, and Lysogeny Broth (LB) medium onto new GAC prior to use and then tested whether this substrate pre-loading promoted development of biofilms with high coverage that remained stable for prolonged operational periods. Temporal dynamics of the biomass and microbial community on the GAC were monitored via flow cytometry (FCM) and sequencing, respectively, in both batch and continuous-flow experiments. In comparison with the non-loaded GAC (control), the initial biofilm biomass on substrate-loaded GAC was 3–114 times higher, but the initial richness was considerably lower (only accounting for 13–28% of the control). The initial community compositions were significantly different between batch and continuous-flow column experiments, even when loaded with the same substrates. In the continuous-flow column experiments, both biomass and microbial community composition became remarkably similar to the control filters after 64 days of operation. From these findings, we conclude that substrate-loaded GAC could enhance initial colonization, affecting both biomass and microbial community composition. However, the biomass and composition did not remain stable during long-term operation due to continuous dispersal and competition from influent bacteria.
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Affiliation(s)
- Wen Qin
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, China.,Department of Environmental Microbiology, Eawag-Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Frederik Hammes
- Department of Environmental Microbiology, Eawag-Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
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Xing X, Li T, Bi Z, Qi P, Li Z, Wang H, Lyu L, Gao Y, Hu C. Enhancing inhibition of disinfection byproducts formation and opportunistic pathogens growth during drinking water distribution by Fe 2O 3/Coconut shell activated carbon. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115838. [PMID: 33099195 DOI: 10.1016/j.envpol.2020.115838] [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: 06/20/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 06/11/2023]
Abstract
The effects of biological activated carbon treatment using Fe2O3 modified coconut shell-based activated carbon (Fe/CAC) were investigated on the occurrence of opportunistic pathogens (OPs) and formation of disinfection by-products (DBPs) in simulated drinking water distribution systems (DWDSs) with unmodified CAC as a reference. In the effluent of annular reactor (AR) with Fe/CAC, the OPs growth and DBPs formation were inhibited greatly. Based on the differential pulse voltammetry and dehydrogenase activity tests, it was verified that extracellular electron transfer was enhanced in the attached biofilms of Fe/CAC, hence improving the microbial metabolic activity and biological removal of organic matter especially DBPs precursors. Meanwhile, the extracellular polymeric substances (EPS) on the surface of Fe/CAC exhibited stronger viscosity, higher flocculating efficiency and better mechanical stability, avoiding bacteria or small-scale biofilms falling off into the water. Consequently, the microbial biomass and EPS substances amount decreased markedly in the effluent of Fe/CAC filter. More importantly, Fe/CAC did significantly enhance the shaping role on microbial community of downstream DWDSs, continuously excluding OPs advantage and inhibiting EPS production. The weakening of EPS in DWDSs resulted in decrease of microbial chlorine-resistance ability and EPS-derived DBPs precursors supply. Therefore, the deterioration of water quality in DWDSs was inhibited greatly, sustainably maintaining the safety of tap water. Our findings indicated that optimizing biological activated carbon treatment by interface modification is a promising method for improving water quality in DWDSs.
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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
| | - Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Lai Lyu
- 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
| | - Yaowen Gao
- 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.
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10
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Hess A, Bettex C, Morgenroth E. Influence of intermittent flow on removal of organics in a biological activated carbon filter (BAC) used as post-treatment for greywater. WATER RESEARCH X 2020; 9:100078. [PMID: 33299980 PMCID: PMC7704463 DOI: 10.1016/j.wroa.2020.100078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/09/2020] [Accepted: 11/06/2020] [Indexed: 05/04/2023]
Abstract
Highly variable flow has to be expected in decentralized greywater treatment and can lead to intermittent operation of the treatment system. However, few studies have addressed the influence of variable flow on the treatment performance of a biological activated carbon filter (BAC). In this study, we investigated the influence of intermittent flow using small-scale BAC columns, which treat greywater as a second treatment step following a membrane bioreactor (MBR). Three operating strategies to respond to variable flow were evaluated. The activated carbon was characterized before and after the experiments in terms of biological activity and sorption capacity. The performance of the BAC filters was assessed based on total organic carbon (TOC) removal, TOC fractions and growth potential. No significant differences were observed between constant flow compared to on-off operation with intermittent flow over the range of tested influent concentrations. Peaks with high TOC during 24 h periods were attenuated by sorption and biological degradation. Adsorbed TOC was released after switching back to normal concentrations for influent concentrations more than 5 times higher than usually observed, the BAC functioned as a temporary sink. In line with these results, the high influent TOC values led to increased biological activity in the filter but did not influence the sorption capacity. The experiments showed that intermittent flow does not negatively impact the performance of a BAC and that there is no need for additional equalization tanks to buffer the variable flow, for example in household-scale greywater treatment.
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Affiliation(s)
- Angelika Hess
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland
- ETH Zürich, Institute of Environmental Engineering, 8093, Zürich, Switzerland
| | - Cécile Bettex
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland
| | - Eberhard Morgenroth
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland
- ETH Zürich, Institute of Environmental Engineering, 8093, Zürich, Switzerland
- Corresponding author. Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.
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11
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Rui M, Chen H, Ye Y, Deng H, Wang H. Effect of Flow Configuration on Nitrifiers in Biological Activated Carbon Filters for Potable Water Production. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14646-14655. [PMID: 33118354 DOI: 10.1021/acs.est.0c02479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Up-flow biological activated carbon (BAC) filters have been empirically employed in drinking water treatment plants (DWTPs) to address the challenges of its down-flow counterparts (e.g., high head loss and insufficient use of BAC beds), yet their performances and mechanisms toward ammonia removal are not fully evaluated. This study characterized the occurrence, distribution, and diversities of nitrifiers in up-flow and down-flow BAC filters by investigating 18 full-scale drinking water treatment trains in different geographic locations. Quantitative polymerase chain reaction analysis of gene markers of target microorganisms demonstrated higher numbers of total bacteria, ammonia-oxidizing bacteria (AOB), and Nitrospira in the up-flow filters relative to the down-flow filters (P < 0.05), implying enhanced biological activities and nitrification potential within up-flow filters. The dominance of ammonia-oxidizing archaea (AOA) over AOB (i.e., 1.3-4.0 log10 gene copies higher) in 17 BAC filters illustrated the critical role of AOA in drinking water nitrification. Stratification of biomass was mainly found in the down-flow filters rather than the up-flow filters, suggesting better mixing of filter media across up-flow filter beds. Analysis of similarity results revealed that the AOA and Nitrospira community compositions were mainly affected by water sources and locations (P < 0.05) but not flow configurations. These results provide insight into nitrification mechanisms in BAC filters with different flow configurations in real-world DWTPs.
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Affiliation(s)
- Min Rui
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., Shanghai 200092, China
| | - Haoshen Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., Shanghai 200092, China
| | - Yinyin Ye
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, New York 14260, United States
| | - Huiping Deng
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China
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12
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Yu X, Lin T, Xu H, Tao H, Chen W. Ultrafiltration of up-flow biological activated carbon effluent: Extracellular polymer biofouling mechanism and mitigation using pre-ozonation with H 2O 2 backwashing. WATER RESEARCH 2020; 186:116391. [PMID: 32947101 DOI: 10.1016/j.watres.2020.116391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
Biofouling is a key problem in membrane filtration, and extracellular polymer substances (EPS) play a key role in biofouling. Biofouling contributes to membrane fouling during ultrafiltration of up-flow biological activated carbon filter (UBACF) effluent. EPS are released when pollutants get attached with membrane surface and when pollutants are in solution phase from cell lysis and by cell secretions. In our study of EPS + humic acid (HA) prepared as the effluent pollutants for ultrafiltration, we found that EPS increased the interfacial forces between the pollutants and the membrane, resulting in membrane fouling. In the early stages of filtration, the main contribution of EPS to membrane fouling was to bond with organic colloids, which led to an increase in the pollutant particle size and zeta potential. This increased the short-range Lewis acid-base (AB) forces from -4.89 nN to -12.59 nN and accelerated the formation of a cake layer. In the late stage of filtration, the EPS increased both the AB and London-van der Waals (LW) forces, thus accelerating membrane fouling. In order to mitigate biofouling, we developed a method of pretreating the effluent with 0.4 mg/L ozone prior to ultrafiltration and backwashing with 8 mg/L H2O2 to sterilize bacteria attached to the membrane surface. This method not only changed the characteristics of the EPS, but also inactivated bacteria by disinfection with H2O2, thereby reducing the amount of EPS. The proposed method provided a long-term stable operation guarantee for ultrafiltration of UBACF effluent.
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Affiliation(s)
- Xiaofei Yu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Hang Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hui Tao
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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13
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Rolph CA, Jefferson B, Brookes A, Hassard F, Villa R. Achieving drinking water compliance levels for metaldehyde with an acclimated sand bioreactor. WATER RESEARCH 2020; 184:116084. [PMID: 32668301 DOI: 10.1016/j.watres.2020.116084] [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: 04/11/2019] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Metaldehyde removal was delivered to below the 0.1 μg L-1 regulatory concentration in a laboratory scale continuous upflow fluidised sand bioreactor that had undergone acclimation through selective enrichment for metaldehyde degradation. This is the first reported case of successful continuous flow biological treatment of metaldehyde from real drinking water sources treating environmentally realistic metaldehyde concentrations. The impact of the acclimation process was impermanent, with the duration of effective treatment directly related to the elevated concentration of metaldehyde used during the enrichment process. The efficacy of the approach was demonstrated in continuous flow columns at both laboratory and pilot scale enabling degradation rates of between 0.1 and 0.2 mg L-1 h-1. Future work needs to focus on optimisation of the sand bioreactor and the acclimation process to ensure viability and feasibility of the approach at full scale.
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Affiliation(s)
| | | | - Adam Brookes
- Anglian Water, Thorpewood House, Peterborough, UK
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Liu C, Sun Z, Chen W. Variation in the biological characteristics of BAC during ultrasonic regeneration. ULTRASONICS SONOCHEMISTRY 2020; 61:104689. [PMID: 31733452 DOI: 10.1016/j.ultsonch.2019.104689] [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: 12/04/2018] [Revised: 07/05/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
Ultrasonic treatment has been shown to have a favorable effect on the regeneration of spent biological activated carbon (BAC) from drinking water treatment plants. In this study, the use of ultrasound as a regeneration method had a significant effect on the recovery of spent BAC after 7.5 years of use; it effectively increased the iodine value from 300 mg/g to 600 mg/g and restored the specific surface area and pore volume of BAC. Ultrasound effectively changed the structure of the biofilm inside and on the surfaces of BAC particles, on the basis of confocal laser scanning microscopy (CLSM) images. The thickness of the surface biofilm attached to BAC reached an "active" level (about 100 μm) at the regeneration frequency of 40 kHz. The dehydrogenase activity significantly improved from 4.50 mg TF/g BAC to 9.13 mg TF/g BAC, and the content of adenosine-triphosphate (ATP) in regenerated BAC was maintained at a high level (2.501 × 10-6g ATP/g BAC), thus allowing the development of microbial growth. The production of soluble microbial products (SMPs) from regenerated BAC decreased during the reuse process. The removal efficiency of DOC, CODMn, NH4+ and NO3- control increased by approximately 78%, 71%, 50% and 20%, respectively.
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Affiliation(s)
- Cheng Liu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Zhehao Sun
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, China
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, China
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15
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Chen H, Lin T, Chen W, Xu H, Tao H. Different removal efficiency of disinfection-byproduct precursors between dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) by up-flow biological activated carbon (UBAC) process. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:25874-25882. [PMID: 31273652 DOI: 10.1007/s11356-019-05736-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
Up-flow biological activated carbon (UBAC) filter has been widely used in waterworks due to its less hydraulic loss, stronger biodegradation ability, and the prevention of excessive biomass growth relative to down-flow BAC treatment. In this study, the different removal efficiency (DRE) of disinfection byproduct precursors between dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) was evaluated when UBAC filter was used as advanced treatment process. Results showed that the UBAC filter with approximately 36 months of usage time had a poor performance in the removal of DCAcAm formation potential (FP) (i.e. 9.3-19.1%) compared to DCAN FP (i.e., 22.5-34.1%). After chlorination of UBAC effluent, the hydrolysis of DCAN to form DCAcAm only partly contributed to the DRE variations of both DCAN FP and DCAcAm FP. Using the high-throughput sequencing technology and the redundancy analysis (RDA), the second dominant genus Bacillus in UBAC filter, which may transform precursors of DCAN into inorganic matters, could be another reason that led to the DRE in DCAN and DCAcAm FP. The formation and leakage of soluble microbial products (SMPs) was identified by excitation-emission matrix (EEM) peak intensities as well as variation of biological index (BIX). The SMPs released into UBAC effluent, favoring the formation of DCAcAm, also contributed to the precursors of both DCAN and DCAcAm, causing a poor removal performance in DCAcAm FP by UBAC filter.
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Affiliation(s)
- Han Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China.
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Hang Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Hui Tao
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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Occurrence and Succession of Bacterial Community in O 3/BAC Process of Drinking Water Treatment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16173112. [PMID: 31461864 PMCID: PMC6747196 DOI: 10.3390/ijerph16173112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 11/21/2022]
Abstract
In the drinking water industry, a common advanced treatment process is comprised of treatment with ozone, followed by biological-activated carbon (O3/BAC). However, the bacterial community formation and succession procedures associated with activated carbon have rarely been reported. In this study, the dynamics of bacterial communities at three different depths were investigated using a pilot-scale O3/BAC filter. The average chemical oxygen demand (CODMn), turbidity removal and dissolved oxygen (DO) consumption rate of the filter were 26.43%, 16.57% and 16.4% during the operation period, respectively. Bacterial communities dominated by proteobacteria and Bacteroidetes attached on activated carbon were determined by polymerase chain reaction-density gradient gel electrophoresis (PCR-DGGE). Principal component analysis (PCA) revealed that the compositions and structures of bacterial communities in different layers clustered after fluctuation. A redundancy analysis (RDA) indicated that Ramlibacter henchirensis was positively correlated to chemical oxygen demand (CODMn) removal and nitrate-N removal, and Georgfuchsia toluolica also showed a positive correlation with CODMn removal. Aquabacterium parvum and Phaeobacterium nitratireducens were positively-correlated with turbidity removal. Pedobacter glucosidilyticus and Pseudomonas sp. were associated with high dissolved oxygen (DO) consumption. These results provide insight into the succession characteristics of the bacterial community of O3/BAC treatment and the interactions of the bacterial community with filter operation performance.
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Yang K, Yu J, Guo Q, Wang C, Xia P, Yang YJ, Yang M. Treatment performance comparison between regular O 3-BAC and O 3-BAC with rear sand filtration: verification in a full-scale study. ENVIRONMENTAL SCIENCES EUROPE 2019; 31:41. [PMID: 33747698 PMCID: PMC7970512 DOI: 10.1186/s12302-019-0229-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/01/2019] [Indexed: 06/11/2023]
Abstract
BACKGROUND To improve the microbial safety of drinking water, an arrangement of O3-BAC with rear sand filtration (O3-BAC-sand) has been proposed. In this study, efforts were devoted to evaluate the benefits and drawbacks of O3-BAC-sand in a full-scale water treatment plant. The performance of the two configurations was compared in terms of particles, turbidity, CODMn and typical odorants and pesticides. RESULTS The O3-BAC-sand yielded lower turbidity but higher CODMn (by approximately 7%) in the finished water than regular O3-BAC (sand-O3-BAC). Both systems removed odors in raw water; however, sand-O3-BAC was more effective on septic and musty odorants. The total pesticide removals by sand-O3-BAC and O3-BAC-sand were 78% and 72%, respectively; though the latter had shorter activated carbon durable years. CONCLUSION The re-location of the sand filter would sacrifice the BAC efficiency in removals of organic matter and micropollutants. This tradeoff is a result of the loss of the particulate organic matter removal by sand filters, because locating the sand filter behind BAC causes particle load increase on BAC; some measures of enhanced coagulation should be suggested to improve the turbidity and particle removal. The study will be helpful for improvement of the O3-BAC process in drinking water treatment.
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Affiliation(s)
- Kai Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China
- University of the Chinese Academy of Sciences, Beijing 100019, China
| | - Jianwei Yu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China
- University of the Chinese Academy of Sciences, Beijing 100019, China
| | - Qingyuan Guo
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China
- Yancheng Institute of Technology, Yancheng 224051, China
| | - Chunmiao Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China
- University of the Chinese Academy of Sciences, Beijing 100019, China
| | - Ping Xia
- Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai 200082, China
| | - Y. Jeffrey Yang
- US Environmental Protection Agency, Office of Research and Development, Cincinnati, OH 45286, USA
| | - Min Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Beijing 100085, China
- University of the Chinese Academy of Sciences, Beijing 100019, China
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18
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Im D, Nakada N, Fukuma Y, Tanaka H. Effects of the inclusion of biological activated carbon on membrane fouling in combined process of ozonation, coagulation and ceramic membrane filtration for water reclamation. CHEMOSPHERE 2019; 220:20-27. [PMID: 30579170 DOI: 10.1016/j.chemosphere.2018.12.071] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 11/09/2018] [Accepted: 12/09/2018] [Indexed: 06/09/2023]
Abstract
We investigated the effects of the inclusion of biological activated carbon (BAC) on membrane fouling in combined process of ozonation, coagulation and ceramic membrane filtration (O3 + PACl + CMF) for treating secondary effluent. Inclusion of BAC between ozonation and coagulation reduced membrane permeability. The normalized flux decreased to 90% of the initial value after 305 h of operation in O3 + PACl + CMF, while it decreased to 20% in combined process of ozonation, BAC, coagulation and ceramic membrane filtration. BAC not only decreased residual ozone that is helpful to mitigate ceramic membrane fouling, but also released microorganisms. In addition, BAC doubled the integrated fluorescence intensity of soluble microbial products (SMP), which cause irreversible fouling. The SMP produced and accumulated by microorganisms on the BAC bed likely flowed into the BAC effluent with the microorganisms. The proportion of SMP in the extracted foulant increased from 25% without BAC to 31% with BAC. Moreover, the inclusion of BAC nearly doubled the concentration of protein in the extracted foulant to 13 g/m2 and quadrupled that of carbohydrate to 6 g/m2. BAC was effective in improving the quality of ceramic membrane permeates and reducing health risk associated with formaldehyde and N-nitrosodimethylamine. However, the release of SMP from BAC accelerated membrane fouling in subsequent ceramic membrane filtration.
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Affiliation(s)
- Dongbum Im
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, 520-0811, Japan
| | - Norihide Nakada
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, 520-0811, Japan.
| | - Yasuyuki Fukuma
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, 520-0811, Japan
| | - Hiroaki Tanaka
- Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, 520-0811, Japan
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Chen H, Lin T, Chen W, Tao H, Xu H. Removal of disinfection byproduct precursors and reduction in additive toxicity of chlorinated and chloraminated waters by ozonation and up-flow biological activated carbon process. CHEMOSPHERE 2019; 216:624-632. [PMID: 30391883 DOI: 10.1016/j.chemosphere.2018.10.052] [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: 08/07/2018] [Revised: 10/05/2018] [Accepted: 10/07/2018] [Indexed: 06/08/2023]
Abstract
The variations of disinfection byproduct (DBP) precursors and DBPs-associated toxic potencies were evaluated by ozonation, followed by a up-flow biological activated carbon (O3/UBAC) filter treating two reconstituted water samples, featuring either high bromide (105.3 μg/L) or dissolved organic nitrogen (0.73 mg N/L) concentration, respectively. Ozonation contributed to ∼20% decrease in dissolved organic carbon (DOC) concentration at a dosage of 0.7 mg of O3/mg of DOC, but no further reduction in DOC level was observed with an increased dose of 1.0 mg of O3/mg of DOC. When chlorine or preformed monochloramine was used as a disinfectant, UBAC process led to ∼40% reduction in the sum of detected DBP formation potential (FP) due to the removal of precursors at a feasible empty bed contact time of 15 min. The integrated effect of ozonation and UBAC biofiltration decreased the sum of DBP FP by ∼50% including halonitromethanes (THNMs), N-nitrosamines (NAs), and bromate, which increased in the effluent of ozonation. Chloramination produced less DBPs by weight as well as DBPs-associated additive toxic potencies than chlorination. The reduction in additive toxic potencies was generally lower than the removal efficiency of DBP FP after chlor(am)ination of treated waters by O3/UBAC, indicating that the removal of DBPs-associated additive toxic potencies should be focused to better understand on the residual risk to public health in controlling DBP precursors.
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Affiliation(s)
- Han Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hui Tao
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hang Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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20
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Liu L, Xing X, Hu C, Wang H. O 3-BAC-Cl 2: A multi-barrier process controlling the regrowth of opportunistic waterborne pathogens in drinking water distribution systems. J Environ Sci (China) 2019; 76:142-153. [PMID: 30528006 DOI: 10.1016/j.jes.2018.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 06/09/2023]
Abstract
Simulated drinking water distribution system (DWDS) treated with O3-BAC-Cl2 (ozone-biological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens (OPs). It was found that O3-BAC-Cl2 could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl2 and O3-Cl2 with the same residual chlorine levels. However, the effect of O3-BAC-Cl2 on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process. The quantification of target OPs in the BAC-filter column demonstrated that OPs decreased with the increase of depth, which was likely due to the organic nutrient gradient and microbial competition inside the BAC-filter. Increase in the ozone dose could further reduce the OPs at the bottom of the BAC-filter. Spearman correlation analysis demonstrated that some significant correlations existed between target microorganisms, suggesting potential microbial ecological relationships. Overall, our results demonstrated that the BAC-filter may act as a "battlefield" suppressing the OPs through microbial competition. O3-BAC-Cl2 could be an effective multi-barrier process to suppress the proliferation of OPs in the bulk water of DWDS. However, OPs protected by the biofilms of DWDS should receive further attention because OPs may be detached and released from the biofilms.
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Affiliation(s)
- Lizhong Liu
- 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
| | - Xueci Xing
- 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.
| | - Chun Hu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, 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
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Dong L, Liu W, Yu Y, Hou L, Gu P, Chen G. Preparation, characterization, and application of macroporous activated carbon (MAC) suitable for the BAC water treatment process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 647:1359-1367. [PMID: 30180343 DOI: 10.1016/j.scitotenv.2018.07.280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 05/24/2023]
Abstract
To address the sharp decrease in efficiency of the biological activated carbon (BAC) process at low temperatures, a new type of activated carbon (AC), macroporous activated carbon (MAC), was developed from bamboo waste scraps via a special compression, carbonation and activation process without the introduction of chemicals. MAC contains not only the micron-level macropores (Vmaco > 0.71 ml/g) sufficient for bacteria to access and multiply, but ensures the developed smaller pores (particularly micropores, Vmicro > 0.41 ml/g) and a higher hardness (>90%). In addition, the desired volume of macropores with an adiabatic function, which will provide livable space environment for bacteria, can be obtained by adjusting the compression ratio (1:5-1:10). Because of the maximum macropore volume (Vmaco = 0.805 ml/g) and the most abundant macropore distribution (particularly diameters>10,000 nm), MAC (1:6) was selected for the parallel experiment in the laboratory, taking three representative commercial ACs (PICABIOL® 2, raw coal AC-1 and briquetting AC-2) as controls, in which the filtration effluent of a water treatment plant was used as the influent and glucose was added to accelerate bacterial growth. The results showed that MAC (1:6) exhibited the highest DOC removal and biological activity at room/low temperatures (4 °C), indicating that the abundant macropores distribution with adiabatic function in MAC (1:6) is conducive to the growth and breeding of microorganisms. It is equivalent to artificially increasing the surface suitable for bacteria attachment. This is coupled with the higher adsorption capacity for pollutants supplied by the developed micropores in MAC, which provided the substrate for bacteria growth, thus forming a benign circle for water treatment by the BAC process. The results provide significant technical support for BAC's application, particularly at cold temperatures.
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Affiliation(s)
- Lihua Dong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; School of Environment, Tsinghua University, Beijing 100084, China.
| | - Wenjun Liu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yi Yu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Li'an Hou
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Xi'an High-tech Institute, Xi'an 710025, China
| | - Ping Gu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Guanyi Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
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Tak S, Vellanki BP. Natural organic matter as precursor to disinfection byproducts and its removal using conventional and advanced processes: state of the art review. JOURNAL OF WATER AND HEALTH 2018; 16:681-703. [PMID: 30285951 DOI: 10.2166/wh.2018.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Natural organic matter (NOM) is ubiquitous in the aquatic environment and if present can cause varied drinking water quality issues, the major one being disinfection byproduct (DBP) formation. Trihalomethanes (THMs) are major classes of DBP that are formed during chlorination of NOM. The best way to remove DBPs is to target the precursors (NOM) directly. The main aim of this review is to study conventional as well as advanced ways of treating NOM, with a broad focus on NOM removal using advanced oxidation processes (AOPs) and biofiltration. The first part of the paper focuses on THM formation and removal using conventional processes and the second part focuses on the studies carried out during the years 2000-2018, specifically on NOM removal using AOPs and AOP-biofiltration. Considering the proven carcinogenic nature of THMs and their diverse health effects, it becomes important for any drinking water treatment industry to ameliorate the current water treatment practices and focus on techniques like AOP or synergy of AOP-biofiltration which showed up to 50-60% NOM reduction. The use of AOP alone provides a cost barrier which can be compensated by the use of biofiltration along with AOP with low energy inputs, making it a techno-economically feasible option for NOM removal.
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Affiliation(s)
- Surbhi Tak
- Environmental Engineering Laboratory, Department of Civil Engineering, Indian Institute of Technology, Roorkee, Uttrakhand 247667, India E-mail:
| | - Bhanu Prakash Vellanki
- Environmental Engineering Laboratory, Department of Civil Engineering, Indian Institute of Technology, Roorkee, Uttrakhand 247667, India E-mail:
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Zheng J, Lin T, Chen W, Tao H, Tan Y, Ma B. Removal of precursors of typical nitrogenous disinfection byproducts in ozonation integrated with biological activated carbon (O 3/BAC). CHEMOSPHERE 2018; 209:68-77. [PMID: 29913401 DOI: 10.1016/j.chemosphere.2018.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/26/2018] [Accepted: 06/03/2018] [Indexed: 06/08/2023]
Abstract
The O3/BAC process has been widely used in drinking water treatment to improve the removal of dissolved organic matters (DOMs), including the precursors of nitrogenous disinfection byproducts (N-DBPs). In this study, the removal of N-DBP precursors by biological activated carbon (BAC) filters with different usage time of granular activated carbon (GAC) was investigated. Results showed that the BAC filter with 6 years of usage time of GAC (old BAC filter) had a poor performance in the removal of precursors of N-DBPs such as dichloroacetonitrile (DCAN; an average of only 4.7%), dichloroacetamide (DCAcAm), and trichloronitromethane (TCNM) when compared with the BAC filter with 1 year of usage time of GAC (new BAC filter). Particularly, the organic fraction >10 kDa and the percentage of autochthonous substances were increased in the effluent of the old BAC filter. The red shift of the fluorescence peaks was evident in the excitation-emission matrix spectrum of the effluent from the old BAC filter. The abiotic adsorption of precursors by the old BAC filter was less. In addition, less amino acids and polysaccharides were removed, but more amino sugars and proteins were produced because of microbial metabolism. The metabolism strength of the attached biofilm decreased with increased operation time of the BAC filter. The relative abundance of Sphingomonas significantly decreased in the biofilm of the old BAC filter. The diversity of microbial community in the old BAC filter was higher, but the equitability was lower than those of the new BAC filter. The less removal of N-DBP precursors by the old BAC filter was attributed to the changes in abiotic adsorption capacity and microbial metabolism properties, in which soluble microbial products played an important role.
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Affiliation(s)
- Jian Zheng
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hui Tao
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Yiwen Tan
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Baiwen Ma
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
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Xing X, Wang H, Hu C, Liu L. Effects of phosphate-enhanced ozone/biofiltration on formation of disinfection byproducts and occurrence of opportunistic pathogens in drinking water distribution systems. WATER RESEARCH 2018; 139:168-176. [PMID: 29635153 DOI: 10.1016/j.watres.2018.03.073] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 03/12/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
The effects of ozone-biologically activated carbon (O3-BAC) treatment with various phosphate doses (0, 0.3 or 0.6 mg/L) were investigated on the formation of disinfection by-products (DBPs) and occurrence of opportunistic pathogens (OPs) in drinking water distribution systems (DWDSs) simulated by annular reactors (ARs). It was found that the lowest DBPs and the highest inactivation of OPs such as Mycobacterium spp., Mycobacterium avium, Aeromonas spp., Pseudomonas aeruginosa and Hartmanella vermiformis, occurred in the effluent of the AR with 0.6 mg/L phosphate addition. Based on the results of different characterization techniques, for the AR with 0.6 mg/L phosphate-enhanced O3-BAC treatment, dissolved organic carbon in the influent exhibited the lowest concentration and most stable fraction due to the improved biodegradation effect. Moreover, the total amount of suspended extracellular polymeric substances (EPS) in the bulk water of the AR decreased greatly, resulting in the lowest chlorine consumption and DBPs formation in the AR. In Fourier transform infrared spectra of the suspended EPS, the amide II band (1600-1500 cm-1) disappeared and the protein/polysaccharide ratio decreased remarkably, indicating the destruction of protein and a decrease in hydrophobicity. Moreover, β-sheets and α-helices in the protein secondary structures were degraded while the random coils increased sharply as phosphate addition increased to 0.6 mg/L, inhibiting microbial aggregation and hence weakening the chlorine-resistance capability. Thus, most of the OPs in suspended biofilms were more easily inactivated by residual chlorine, resulting in the lowest OPs occurrence in the effluent of the AR. Our findings indicated that enhancing the efficiency of the BAC filter by adding phosphate is a promising method for improving water quality in DWDSs.
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Affiliation(s)
- Xueci Xing
- 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
| | - Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chun Hu
- Key Laboratory forWater Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, GuangzhouUniversity, Guangzhou 510006, China.
| | - Lizhong Liu
- 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
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Xing X, Wang H, Hu C, Liu L. Characterization of bacterial community and iron corrosion in drinking water distribution systems with O 3-biological activated carbon treatment. J Environ Sci (China) 2018; 69:192-204. [PMID: 29941255 DOI: 10.1016/j.jes.2017.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 06/08/2023]
Abstract
Bacterial community structure and iron corrosion were investigated for simulated drinking water distribution systems (DWDSs) composed of annular reactors incorporating three different treatments: ozone, biologically activated carbon and chlorination (O3-BAC-Cl2); ozone and chlorination (O3-Cl2); or chlorination alone (Cl2). The lowest corrosion rate and iron release, along with more Fe3O4 formation, occurred in DWDSs with O3-BAC-Cl2 compared to those without a BAC filter. It was verified that O3-BAC influenced the bacterial community greatly to promote the relative advantage of nitrate-reducing bacteria (NRB) in DWDSs. Moreover, the advantaged NRB induced active Fe(III) reduction coupled to Fe(II) oxidation, enhancing Fe3O4 formation and inhibiting corrosion. In addition, O3-BAC pretreatment could reduce high-molecular-weight fractions of dissolved organic carbon effectively to promote iron particle aggregation and inhibit further iron release. Our findings indicated that the O3-BAC treatment, besides removing organic pollutants in water, was also a good approach for controlling cast iron corrosion and iron release in DWDSs.
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Affiliation(s)
- Xueci Xing
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Haibo Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Chun Hu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lizhong Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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26
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Sun Z, Liu C, Cao Z, Chen W. Study on regeneration effect and mechanism of high-frequency ultrasound on biological activated carbon. ULTRASONICS SONOCHEMISTRY 2018; 44:86-96. [PMID: 29680631 DOI: 10.1016/j.ultsonch.2018.01.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/13/2018] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
High frequency ultrasonic radiation technology was developed as a novel and efficient means of regenerating spent biological activated carbon (BAC) used in drinking water treatment plants (DWTPs). The results of this study indicated that high frequency ultrasonic treatment could recover the spent BAC, to some extent, with the following optimal conditions: a frequency of 400 kHz, sonication power of 60 W, water temperature of 30 °C, and sonication time of 6 min. Under the above conditions, the iodine value increased from 300 mg/g to 409 mg/g, the volume of total pores and micropores increased from 0.2600 cm3/g and 0.1779 cm3/g to 0.3560 cm3/g and 0.2662 cm3/g, respectively; the specific surface area of micropores and the mean pore diameter expanded from 361.15 m2/g and 2.0975 nm to 449.92 m2/g and 2.1268 nm, respectively. The biological activity increased from 0.0297 mgO2/gC·h to 0.0521 mgO2/gC·h, while the biomass decreased from 203 nmolP/gC to 180 nmolP/gC. The results of high throughput 16S rRNA gene amplicon sequencing showed that microorganisms such as Clostridia and Nitrospira were markedly decreased due to high frequency ultrasound. The method used in this study caused the inhibition of certain carbon-attached microbials resulting in a negative effect on the removal rate of ammonia-N during the initial stage of the long-term reuse operation. The removal of UV254 and atrazine were restored from 8.1% and 55% to 21% and 76%, respectively.
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Affiliation(s)
- Zhehao Sun
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China
| | - Cheng Liu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Zhen Cao
- College of Environment, Hohai University, Nanjing 210098, PR China
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China
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Ao L, Liu W, Zhang M, Wang X. Analysis of effect of particles on cake layer compressibility during ultrafiltration of upflow biological activated carbon effluent. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 619-620:232-238. [PMID: 29149747 DOI: 10.1016/j.scitotenv.2017.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/26/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
Three different hollow-fibre ultrafiltration (UF) membranes were applied to treat upflow biological activated carbon (UBAC) effluent to determine the characteristics of membrane biofouling by microorganisms and particles. At the beginning of filtration, the cake layer formed on the membrane was loose and highly compressible, and the trans-membrane pressure (TMP) rapidly increased. When compressed to a certain extent, cake layer with low compressibility was formed by the accumulated particles and resulted in slower TMP increment. Thus, the decreased compressibility of the cake layer formed on the UF membrane during filtration of UBAC effluent led to the rapid increase in TMP at the beginning and slow increment in subsequently. The results were confirmed by filtering Escherichia coli, Staphylococcus aureus and kaolinite mixed suspensions with flat-sheet UF membrane. Our findings provide a new insight into membrane biofouling control and may facilitate better membrane application in drinking water treatment.
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Affiliation(s)
- Lu Ao
- Department of National Defence Architecture Planning & Environmental Engineering, Logistic Engineering University, Chongqing 401331, China
| | - Wenjun Liu
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Minglu Zhang
- School of Food and Chemical Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Xiaomao Wang
- School of Environment, Tsinghua University, Beijing 100084, China
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Wang S, Lin T, Chen W, Chen H. Optimization of the precursor removal of dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product, in an up-flow BAC filter. CHEMOSPHERE 2017; 189:309-318. [PMID: 28942257 DOI: 10.1016/j.chemosphere.2017.09.065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/11/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
The process parameters of the up-flow biological activated carbon filter (UBACF) were optimized in a pilot-scale trial for controlling the precursor of dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product. The experiments were performed using a central composite design (CCD) with the response surface methodology (RSM). The results showed that the removal efficiencies of formation potentials (FP) of DCAN increased from 28.9% to 64.4% with the optimized ozone dose, expansion rate of BAC and backwashing cycle, being scheduled to 1.52 mg/L, 27% and 9.5 d, respectively. Excitation and emission matrix (EEM) spectra indicated that the fluorescence peaks of aromatic protein (AP) and soluble microbial products-like (SMPs)-like region were weakened significantly in the effluent of improved process (IP) with optimization, which were main precursors of DCAN. The bacterial community before and after the optimization of UBACF was determined using the high-throughput sequencing technology. The class and genus of microorganism demonstrated that the IP had a more diverse microbial community and more even distribution of species in BAC filter. It was favor of the growth of Alphaproteobacteria, Bacilli and Betaproteobacteria attached to the BAC particles, which could biodegrade effectively the precursors of DCAN.
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Affiliation(s)
- Shuai Wang
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Wei Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Han Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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29
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Liu C, Olivares CI, Pinto AJ, Lauderdale CV, Brown J, Selbes M, Karanfil T. The control of disinfection byproducts and their precursors in biologically active filtration processes. WATER RESEARCH 2017; 124:630-653. [PMID: 28822343 DOI: 10.1016/j.watres.2017.07.080] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 06/07/2023]
Abstract
While disinfection provides hygienically safe drinking water, the disinfectants react with inorganic or organic precursors, leading to the formation of harmful disinfection byproducts (DBPs). Biological filtration is a process in which an otherwise conventional granular filter is designed to remove not only fine particulates but also dissolved organic matters (e.g., DBP precursors) through microbially mediated degradation. Recently, applications of biofiltration in drinking water treatment have increased significantly. This review summarizes the effectiveness of biofiltration in removing DBPs and their precursors and identifies potential factors in biofilters that may control the removal or contribute to formation of DBP and their precursors during drinking water treatment. Biofiltration can remove a fraction of the precursors of halogenated DBPs (trihalomethanes, haloacetic acids, haloketones, haloaldehydes, haloacetonitriles, haloacetamides, and halonitromethanes), while also demonstrating capability in removing bromate and halogenated DBPs, except for trihalomethanes. However, the effectiveness of biofiltration mediated removal of nitrosamine and its precursors appears to be variable. An increase in nitrosamine precursors after biofiltration was ascribed to the biomass sloughing off from media or direct nitrosamine formation in the biofilter under certain denitrifying conditions. Operating parameters, such as pre-ozonation, media type, empty bed contact time, backwashing, temperature, and nutrient addition may be optimized to control the regulated DBPs in the biofilter effluent while minimizing the formation of unregulated emerging DBPs. While summarizing the state of knowledge of biofiltration mediated control of DBPs, this review also identifies several knowledge gaps to highlight future research topics of interest.
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Affiliation(s)
- Chao Liu
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625, USA
| | - Christopher I Olivares
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625, USA
| | - Ameet J Pinto
- Department of Civil & Environmental Engineering, Northeastern University, 269 SN, 360 Huntington Avenue, Boston, MA 02115, USA
| | | | - Jess Brown
- Carollo Engineers, Inc., 3150 Bristol Street, Suite 500, Costa Mesa, CA 92929, USA
| | - Meric Selbes
- Hazen and Sawyer, Environmental Engineers and Scientists, Fairfax, VA 22030, USA
| | - Tanju Karanfil
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625, USA.
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30
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Zhou Y, Yan M, Liu R, Wang D, Qu J. Investigating the effect of hardness cations on coagulation: The aspect of neutralisation through Al(III)-dissolved organic matter (DOM) binding. WATER RESEARCH 2017; 115:22-28. [PMID: 28259076 DOI: 10.1016/j.watres.2017.02.041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/15/2017] [Accepted: 02/18/2017] [Indexed: 06/06/2023]
Abstract
Hardness cations are ubiquitous and abundant in source water, while the effect of hardness on the performance of coagulation for dissolved organic matter (DOM) removal in water treatment remains unclear due to the limitation of methods that can characterise the subtle interactions between DOM, coagulant and hardness cations. This work quantified the competition between coagulant Al3+ and hardness cations to bind onto DOM using absorbance spectroscopy acquired at different Al3+ concentrations in the absence and presence of Ca2+ or Mg2+. The results indicate that, in the presence of either Mg2+ or Ca2+, an increasing depression of the binding of Al3+-DOM could be observed in the differential spectra of DOM with the increasing of Mg2+ or Ca2+ at a level of 10, 100 and 1000 μM, with the observation being more significant at higher pH from 6.5 to 8.5. The results of zeta potentials of DOM indicate that the competition of hardness cations results in the negative DOM being less efficiently neutralised by Al3+. This study demonstrates that the removal of DOM by coagulation would significantly deteriorate with the presence of hardness cations, which would compete with coagulant Al3+ to neutralise the unsaturated sites in DOM.
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Affiliation(s)
- Yuxuan Zhou
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China
| | - Mingquan Yan
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
| | - Ruiping Liu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, CAS, POB 2871, Beijing 100085, China
| | - Dongsheng Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, CAS, POB 2871, Beijing 100085, China
| | - Jiuhui Qu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, CAS, POB 2871, Beijing 100085, China
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31
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Liu C, Sun Y, Wang D, Sun Z, Chen M, Zhou Z, Chen W. Performance and mechanism of low-frequency ultrasound to regenerate the biological activated carbon. ULTRASONICS SONOCHEMISTRY 2017; 34:142-153. [PMID: 27773230 DOI: 10.1016/j.ultsonch.2016.05.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/18/2016] [Accepted: 05/20/2016] [Indexed: 06/06/2023]
Abstract
Biological activated carbon (BAC) filter has been widely used as an effective water treatment but regenerations of BAC are costly. Ultrasound has been successfully applied for regeneration of activated carbon but has been less frequently applied to the regenerate the BAC. In this study, bench-scale and pilot-scale experiments were conducted to evaluate the regeneration performance and mechanism of BAC with low-frequency ultrasound. Adsorption indices, microbiological parameters, pore structure and removal efficiencies were further investigated. The results showed that low-frequency ultrasound could regenerate the BAC effectively. The regeneration effects were significantly affected by the frequency, sonication intensity, sonication time, and water temperature, but not the usage time of the BAC. The optimized conditions were identified as 40kHz of frequency, 115×10-3W/cm3 of sonication intensity, 25-30°C of water temperature and 5min of sonication time. The iodine value and methylene blue value increased from 480mg/g and 100mg/g to 680mg/g and 133mg/g respectively, the biomass decreased from 310nmolP/gC to 245nmolP/gC, while the biological activity increased from 0.03mg O2/hgC to 0.0355mg O2/hgC under the optimized condition. After three months of continuous operation, removal efficiencies of regenerated BAC were still high for the removal of organic contaminants, atrazine, and 2-MIB. Analysis of pore structure, BET surface area, and scanning electron microscopy indicated that ultrasound mainly acted on surface and macro-pores of BAC through the high-speed microjets and high-pressure microstreams resulted from the collapse of cavitation bubbles.
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Affiliation(s)
- Cheng Liu
- Key Laboratory of Integrated Regulation and Resource Development Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yakun Sun
- College of Environment, Hohai University, Nanjing 210098, China
| | - Dongying Wang
- College of Environment, Hohai University, Nanjing 210098, China
| | - Zhehao Sun
- College of Environment, Hohai University, Nanjing 210098, China
| | - Ming Chen
- Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Zhi Zhou
- Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Wei Chen
- Key Laboratory of Integrated Regulation and Resource Development Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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32
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Korotta-Gamage SM, Sathasivan A. A review: Potential and challenges of biologically activated carbon to remove natural organic matter in drinking water purification process. CHEMOSPHERE 2017; 167:120-138. [PMID: 27716585 DOI: 10.1016/j.chemosphere.2016.09.097] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 09/12/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
The use of biologically activated carbon (BAC) in drinking water purification is reviewed. In the past BAC is seen mostly as a polishing treatment. However, BAC has the potential to provide solution to recent challenges faced by water utilities arising from change in natural organic matter (NOM) composition in drinking water sources - increased NOM concentration with a larger fraction of hydrophilic compounds and ever increasing trace level organic pollutants. Hydrophilic NOM is not removed by traditional coagulation process and causes bacterial regrowth and increases disinfection by-products (DBPs) formation during disinfection. BAC can offer many advantages by removing hydrophilic fraction and many toxic and endocrine compounds which are not otherwise removed. BAC can also aid the other downstream processes if used as a pre-treatment. Major drawback of BAC was longer empty bed contact time (EBCT) required for an effective NOM removal. This critical review analyses the strategies that have been adopted to enhance the biological activity of the carbon by operational means and summarises the surface modification methods. To maximize the benefit of the BAC, a rethink of current treatment plant configuration is proposed. If the process can be expedited and adopted appropriately, BAC can solve many of the current problems.
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Affiliation(s)
| | - Arumugam Sathasivan
- School of Computing, Engineering and Mathematics, Western Sydney University, NSW 2747, Australia.
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33
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Evaluation of backwash strategies on biologically active carbon filters by using chloroacetic acids as indicator chemicals. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Comparison of Three Solid Phase Materials for the Extraction of Carboxylic Acids from River Water Followed by 2D GC × GC-TOFMS Determination. Int J Anal Chem 2016; 2016:6396938. [PMID: 27274730 PMCID: PMC4870361 DOI: 10.1155/2016/6396938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/29/2015] [Accepted: 01/13/2016] [Indexed: 11/17/2022] Open
Abstract
The extraction and determination of aliphatic and aromatic carboxylic acids as well as their influence on the aromaticity and molecularity relationship of natural organic matter (NOM) in water are reported in this study. Three solid phase extraction (SPE) sorbents were used and their extraction efficiencies evaluated after chromatographic determinations (using gas chromatography with a time of flight mass spectrometer (GC × GC-TOFMS) and liquid chromatography with organic carbon detector (LC-OCD)). More than 42 carboxylic acids were identified in raw water from the Vaal River, which feeds the Lethabo Power Generation Station, South Africa, with cooling water. The aromatic carboxylic acid efficiency (28%) was achieved by using Strata™ X SPE while the highest aliphatic carboxylic acid efficiency (92.08%) was achieved by silica SPE. The hydrophobic nature of NOM in water depends on the nature of organic compounds in water, whether aromatic or aliphatic. The LC-OCD was used to assess the hydrophobicity levels of NOM as a function of these carboxylic acids in cooling water. The LC-OCD results showed that the aromatic nature of NOM in SPE filtered water followed the order Silica>Strata X>C-18. From the results, the hydrophobicity degree of the samples depended on the type and number of carboxylic acids that were removed by the SPE cartridges.
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35
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Ao L, Liu W, Zhao L, Wang X. Membrane fouling in ultrafiltration of natural water after pretreatment to different extents. J Environ Sci (China) 2016; 43:234-243. [PMID: 27155429 DOI: 10.1016/j.jes.2015.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
The combined fouling during ultrafiltration (UF) of surface water pretreated to different extents was investigated to disclose the roles of polysaccharides, proteins, and inorganic particles in UF membrane fouling. Both reversible and irreversible fouling decreased with enhanced pretreatment (biologically active carbon (BAC) treatment and sand filtration). The sand filter effluent fouled the membrane very slowly. The UF membrane removed turbidity to less than 0.1 nephelometric turbidity unit (NTU), reduced polysaccharides by 25.4%-29.9%, but rejected few proteins. Both polysaccharides and inorganic particles were detected on the fouled membranes, but inorganic particles could be effectively removed by backwashing. The increase of turbidity in the sand filter effluent to 3.05 NTU did not significantly increase the fouling rate, but an increase in the turbidity in the BAC effluent to 6.11 NTU increased the fouling rate by more than 100%. The results demonstrated that the polysaccharide, not the protein, constituents of biopolymers were responsible for membrane fouling. Membrane fouling was closely associated with a small fraction of polysaccharides in the feed water. Inorganic particles exacerbated membrane fouling only when the concentration of fouling-inducing polysaccharides in the feed water was relatively high. The combined fouling was largely reversible, and polysaccharides were the predominant substances responsible for irreversible fouling.
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Affiliation(s)
- Lu Ao
- School of Environment, Tsinghua University, Beijing 100084, China; Department of National Defence Architecture Planning & Environmental Engineering, Logistic Engineering University, Chongqing 401311, China.
| | - Wenjun Liu
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Lin Zhao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaomao Wang
- School of Environment, Tsinghua University, Beijing 100084, China
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