1
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Jathan Y, Pagilla KR, Marchand EA. Understanding the influence of dissolved organic nitrogen characteristics on enhanced coagulation performance for water reuse. CHEMOSPHERE 2023; 337:139384. [PMID: 37414300 DOI: 10.1016/j.chemosphere.2023.139384] [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: 05/12/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/08/2023]
Abstract
With the recent focus on using advanced water treatment processes for water reuse, interest is growing for utilizing enhanced coagulation to remove dissolved chemical species. Up to 85% of the nitrogen in wastewater effluent is made up of dissolved organic nitrogen (DON), but there is a knowledge gap regarding its removal during coagulation, which can be influenced by DON characteristics. To address this issue, tertiary-treated wastewater samples were analyzed before and after coagulation with polyaluminum chloride and ferric chloride. Samples were size-fractionated into four molecular weight fractions (0.45 μm, 0.1 μm, 10 kDa, and 3 kDa) using vacuum filtration and ultrafiltration. Each fraction was further evaluated by coagulating it separately to assess DON removal during enhanced coagulation. The size fractionated samples were also separated into hydrophilic and hydrophobic fractions using C18 solid phase extraction disks. Fluorescence excitation-emission matrices were used to investigate the characteristics of dissolved organic matter contributing to DON during the coagulation process. The results showed that DON compounds of size <3 kDa constituted a majority of the total DON. Coagulation removed more than 80% DON from size fractions 0.45 μm-0.1 μm and 0.1 μm-10 kDa, but less than 20% was removed from 10 kDa to 3 kDa and <3 kDa fractions. Coagulation on pre-filtered samples removed 19% and 25% of the <3 kDa DON fraction using polyaluminum chloride and ferric chloride, respectively. In all molecular weight fractions, hydrophilic DON compounds were found to be dominant (>90%), and enhanced coagulation was not effective in removing hydrophilic DON compounds. LMW fractions respond poorly to enhanced coagulation due to their hydrophilic nature. Enhanced coagulation effectively removes humic acid-like substances, but poorly removes proteinaceous compounds such as tyrosine and tryptophan. This study's findings provide insights into DON behavior during coagulation and factors affecting its removal, potentially improving wastewater treatment strategies.
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Affiliation(s)
- Yasha Jathan
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Reno, NV, 89557, USA
| | - Krishna R Pagilla
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Reno, NV, 89557, USA
| | - Eric A Marchand
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Reno, NV, 89557, USA.
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2
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Pan R, Huang Y, Ao J, Wu Y, Bu L, Zhou S, Deng L, Shi Z. A molecular-level mechanism analysis of PFS coagulation behaviors: Differences in natural organic matter and algal organic matter. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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3
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Chen M, Shen S, Zhang F, Zhang C, Xiong J. Biodegradable Dissolved Organic Carbon (BDOC) Removal from Micro-Polluted Water Source Using Ultrafiltration: Comparison with Conventional Processes, Operation Conditions and Membrane Fouling Control. Polymers (Basel) 2022; 14:polym14214689. [PMID: 36365681 PMCID: PMC9658970 DOI: 10.3390/polym14214689] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/18/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
The biodegradable dissolved organic carbon (BDOC) in micro-polluted water sources affects the drinking water quality and safety in the urban water supply. The conventional technology of “coagulation-sedimentation-filtration” in a water plant located in the lower reaches of the Yangtze River removed dissolved organic carbon (DOC) with a molecular weight (MW) > 30 kDa effectively, but the BDOC elimination only ranged 27.4−58.1%, due to their predominant smaller MW (<1 kDa), leading to a high residual BDOC of 0.22−0.33 mg/L. To ensure the biological stability of drinking water, i.e., the inability to support microbial growth (BDOC < 0.2 mg/L), a pilot-scale ultrafiltration process (UF, made of aromatic polyamide with MW cut-off of 1 kDa) was operated to remove BDOC as an advanced treatment after sand-filtration. Results showed the membrane flux decreased with the increase in the influent BDOC concentration and decrease in operating pressure. With an operating pressure of 0.25 MPa, the BDOC removal by UF reached 80.7%, leading to a biologically stable BDOC concentration of 0.08 mg/L. The fouling of the membrane was mainly caused by organic pollution. The H2O2−HCl immersion washing method effectively cleaned the membrane surface fouling, with a recovery of membrane flux of 98%.
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Affiliation(s)
- Ming Chen
- School of Civil Engineering, Southeast University, Nanjing 210096, China
- Correspondence: (M.C.); (J.X.)
| | - Shuhuai Shen
- School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Fan Zhang
- Huzhou Ecological Environment Bureau, Changxing Branch, Huzhou 313100, China
| | - Cong Zhang
- School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Jianglei Xiong
- China Electronics System Engineering No.2 Construction Co., Ltd., Wuxi 214115, China
- Correspondence: (M.C.); (J.X.)
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4
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Li S, Liu M, Meng F, Hu X, Yu W. Removal of F - and organic matter from coking wastewater by coupling dosing FeCl 3 and AlCl 3. J Environ Sci (China) 2021; 110:2-11. [PMID: 34593190 DOI: 10.1016/j.jes.2021.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/10/2021] [Indexed: 06/13/2023]
Abstract
Coagulation and precipitation is a widely applied method to remove F- from wastewater. In this work, the effect of coagulation on the removal of F- and organic matter from coking wastewater was studied using AlCl3 and FeCl3 as compound coagulants. The removal rates of F- and organic matter under different coagulant doses and pH conditions were investigated. The results show that the highest removal rates of F- by AlCl3 and FeCl3 are 94.4% and 25.4%, respectively; when the dosage is 10 mmol/L, the TOC removal rates of FeCl3 and AlCl3 reach 20.4% and 34.7%, respectively. Therefore, the removal rate of F- by AlCl3 is higher than that of FeCl3, but the removal rate of organic matter by FeCl3 is relatively higher. The addition of Ca2+ can promote the removal of F-, but the removal rate of organic matter decreases. In addition, by investigating the effects of different pH and Fe-Al ratio on the removal rate, the removal effect of adding FeCl3 and AlCl3 at the same time was discussed. The results show that the most suitable working condition for the removal of organic matter and F- is that the pH is 6.5 and the molar ratio of Al/Fe is 8:2. Overall, the removal mechanism of F- and organic matter in coking wastewater by FeCl3 and AlCl3 was explored in this study. The experimental results can provide reference for the advanced treatment of coking wastewater.
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Affiliation(s)
- Shuo Li
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China
| | - Mengjie Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China
| | - Fuming Meng
- Jinan Municipal Engineering Design & Research Institute (Group) Co. LTD, China
| | - Xia Hu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100086, China.
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5
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Dong H, Zhang H, Wang Y, Qiang Z, Yang M. Disinfection by-product (DBP) research in China: Are we on the track? J Environ Sci (China) 2021; 110:99-110. [PMID: 34593199 DOI: 10.1016/j.jes.2021.03.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 06/13/2023]
Abstract
Disinfection by-products (DBPs) formed during water disinfection has drawn significant public concern due to its toxicity. Since the first discovery of the trihalomethanes in 1974, continued effort has been devoted on DBPs worldwide to investigate the formation mechanism, levels, toxicity and control measures in drinking water. This review summarizes the main achievements on DBP research in China, which included: (1) the investigation of known DBP occurrence in drinking water of China; (2) the enhanced removal of DBP precursor by water treatment process; (3) the disinfection optimization to minimize DBP formation; and (4) the identification of unknown DBPs in drinking water. Although the research of DBPs in China cover the whole formation process of DBPs, there is still a challenge in effectively controlling the drinking water quality risk induced by DBPs, an integrated research framework including chemistry, toxicology, engineering, and epidemiology is especially crucial.
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Affiliation(s)
- Huiyu Dong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Haifeng Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yan Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhimin Qiang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Min Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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6
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Sriboonnak S, Induvesa P, Wattanachira S, Rakruam P, Siyasukh A, Pumas C, Wongrueng A, Khan E. Trihalomethanes in Water Supply System and Water Distribution Networks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18179066. [PMID: 34501655 PMCID: PMC8430772 DOI: 10.3390/ijerph18179066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/16/2022]
Abstract
The formation of trihalomethanes (THMs) in natural and treated water from water supply systems is an urgent research area due to the carcinogenic risk they pose. Seasonal effects and pH have captured interest as potential factors affecting THM formation in the water supply and distribution systems. We investigated THM occurrence in the water supply chain, including raw and treated water from water treatment plants (coagulation, sedimentation, sand filtration, ClO2-disinfection processes, and distribution pipelines) in the Chiang Mai municipality, particularly the educational institute area. The effects of two seasons, rainy (September–November 2019) and dry (December 2019–February 2020), acted as surrogates for the water quality profile and THM occurrence. The results showed that humic acid was the main aromatic and organic compound in all the water samples. In the raw water sample, we found a correlation between surrogate organic compounds, including SUVA and dissolved organic carbon (DOC) (R2 = 0.9878). Four species of THMs were detected, including chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Chloroform was the dominant species among the THMs. The highest concentration of total THMs was 189.52 μg/L. The concentration of THMs tended to increase after chlorination when chlorine dioxide and organic compounds reacted in water. The effect of pH on the formation of TTHMs was also indicated during the study. TTHM concentrations trended lower with a pH ≤ 7 than with a pH ≥ 8 during the sampling periods. Finally, in terms of health concerns, the concentration of TTHMs was considered safe for consumption because it was below the standard (<1.0) of WHO’s Guideline Values (GVs).
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Affiliation(s)
- Sornsiri Sriboonnak
- Ph.D.’s Degree Program in Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand;
- Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Phacharapol Induvesa
- Bodhivijjalaya College, Srinakharinwirot University, Nakhon Nayok 26120, Thailand;
| | - Suraphong Wattanachira
- Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand; (S.W.); (P.R.)
| | - Pharkphum Rakruam
- Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand; (S.W.); (P.R.)
| | - Adisak Siyasukh
- Department of Industrial Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Chayakorn Pumas
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
- Research Center in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Aunnop Wongrueng
- Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand; (S.W.); (P.R.)
- Research Center in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Research Program in Control of Hazardous Contaminants in Raw Water Resources for Water Scarcity Resilience, Center of Excellence on Hazardous Substance Management, Bangkok 10330, Thailand
- Correspondence: ; Tel.: +66-53-94-4101-3
| | - Eakalak Khan
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154, USA;
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7
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Natural Organic Matter Removal from Raw Surface Water: Benchmarking Performance of Chemical Coagulants through Excitation-Emission Fluorescence Matrix Spectroscopy Analysis. WATER 2021. [DOI: 10.3390/w13020146] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Chemical disinfection of surface waters has been proven effective in minimizing the risk of contamination by water-borne pathogens. However, surface waters contain natural organic matter (NOM) which, upon chemical disinfection, is readily converted into hazardous disinfection-by-products. Hence, NOM removal from these waters is critical. Chemical coagulation is a readily implementable technology to minimize these undesired side-effects by NOM removal. Herein, capabilities of ferric chloride (FeCl3) and polyaluminum chloride (PACl) as pre-treatment for NOM abatement from natural raw surface water have been benchmarked. Excitation-emission fluorescence matrix (EEM) spectroscopy characterization of NOM fractions demonstrated high removal efficiency. A two-level full factorial design was employed to analyze the effects of coagulant dosage and initial pH on the removal of turbidity, humic acid-like substances and fulvic acid-like substances from the raw water. Higher removal of ~77% NOM was attained with PACl than with FeCl3 (~72%). Optimization through response surface methodology showed that the initial pH—coagulant dosage interaction was significant in removing NOM and turbidity for both PACl and FeCl3. These results identify the opportunity for coagulation technologies to prevent and minimize disinfection-by-products formation through NOM removal.
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8
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Wang X, Xu H, Wang D. Mechanism of fluoride removal by AlCl 3 and Al 13: The role of aluminum speciation. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:122987. [PMID: 32512458 DOI: 10.1016/j.jhazmat.2020.122987] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/10/2020] [Accepted: 05/16/2020] [Indexed: 06/11/2023]
Abstract
Coagulation is an important defluorination process. However, because of the poor sedimentation properties, conventional coagulants often result in limited defluorination performance and excessive residual aluminum. In this study, AlCl3 and the highly-positively-charged molecule [AlO4Al12(OH)24(H2O)12]7+ (Al13) was utilized to treat fluoride-containing water. By comparison, the role of aluminum speciation in fluoride removal was elucidated. Under initial pH of 6.0, 7.0 and 8.0, the highest defluorination efficiencies of high-fluoride water ([F-]0 = 8.0 mg/L) were 78.2%, 71.6% and 83.2% at Al13 dosage of 20 mg/L, 40 mg/L and 50 mg/L. Combined with detailed investigations of the chemical compositions of flocs, along with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) analysis of residual aluminum, the defluorination mechanisms of both coagulants were discussed. In acidic conditions, both coagulants hydrolyzed and formed various Al clusters, among which transient Al (Alts) was the intermediate of the other clusters. The coprecipitation of high-polymerized Al and F- contributed most of the defluorination rate. While under neutral and alkaline conditions, hydrogen bonding and ion exchange together with coprecipitation were the main roles for Al13. The effects of AlCl3 were merely physical actions, and were affected by the decreased pH. This work provides new insights into the coagulation and defluorination process.
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Affiliation(s)
- Xi Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18, Shuangqing Road, Beijing, 100085, China; University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Xu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18, Shuangqing Road, Beijing, 100085, China; University of the Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dongsheng Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18, Shuangqing Road, Beijing, 100085, China; University of the Chinese Academy of Sciences, Beijing, 100049, China.
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9
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Zhou Y, Xie Y, Wang M, Zou F, Zhang C, Guan Z, Yan M. In-situ characterization of dissolved organic matter removal by coagulation using differential UV-Visible absorbance spectroscopy. CHEMOSPHERE 2020; 242:125062. [PMID: 31704527 DOI: 10.1016/j.chemosphere.2019.125062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
Removing dissolved organic matter (DOM) is of great concern due to its adverse effects on water supplies. Great effort has been given to studying DOM removal by coagulation, while the mechanism of DOM removal and the changes in its properties during coagulation have not been clearly illustrated due to the limitations of detection methods under practical environmental conditions. In this paper, the changes in DOM during coagulation were quantified using differential UV-Visible absorbance spectroscopy, and the differential spectra of DOM in the wavelength range of 200-600 nm could be deconvoluted into six Gaussian bands with maxima at approximately 200, 240, 276, 316, 385, and 457 nm after coagulation, respectively. The intensity of these maxima decreased with the type and dosage of coagulants. These observations should reflect the difference in the removability of DOM by coagulation, and this perspective was further confirmed by examining the deprotonation-protonation properties of DOM before and after coagulation. The affinity sites of DOM in coagulated waters, quantified by spectra parameter DlnA400 (differential log-transformed spectra at wavelength 400 nm) in combination with the revised NICA model, increased as the coagulant dosage, which indicates that coagulation is inclined to remove the DOM fraction with fewer functional groups. Polyaluminum chloride (PAC) and Al-aggregate (Al13) were more efficient than Alum for removing DOM due to their high efficiency for removing DOM fractions with fewer functional groups. The residual dissolved Al concentration depended on the total amount of reactive binding sites in DOM, and there was a strong linear correlation between residual dissolved Al and the total amount of reactive binding sites in DOM for Alum, while a weaker correlation was presented for PAC and Al13. This indicates that Ala was the dominant species to bind with the affinity sites in DOM to form residual dissolved Al.
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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
| | - Yaping Xie
- Department of Environmental Engineering, Chang'An University, Xi'an, 710064, Shanxi, China
| | - Min Wang
- Technology Institute of Beijing Waterworks Group Co., Ltd., Beijing, 100085, China
| | - Fang Zou
- Technology Institute of Beijing Waterworks Group Co., Ltd., Beijing, 100085, China
| | - Chenyang Zhang
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871, China
| | - Zengfu Guan
- 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.
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10
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Efficient treatment of oil sands produced water: Process integration using ion exchange regeneration wastewater as a chemical coagulant. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.03.070] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Racar M, Dolar D, Farkaš M, Milčić N, Špehar A, Košutić K. Rendering plant wastewater reclamation by coagulation, sand filtration, and ultrafiltration. CHEMOSPHERE 2019; 227:207-215. [PMID: 30986603 DOI: 10.1016/j.chemosphere.2019.04.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/28/2019] [Accepted: 04/06/2019] [Indexed: 06/09/2023]
Abstract
The rendering plant secondary effluent (SE) was reclaimed with coagulation, sand filtration and ultrafiltration for reuse in the plant and for potential reuse in irrigation. The best coagulant was selected and the pH and coagulant dosage were optimized with response surface methodology (RSM) to achieve low turbidity, conductivity, and content of carbon at a higher pH. Residual flocs from the coagulation were separated with sand filtration, and afterward, the effluent was treated with six ultrafiltration membranes. The pretreatment (coagulation and sand filtration) drastically reduced fouling (50-95%). The main water parameters (turbidity, conductivity, pH, content of carbon, chemical oxygen demand, and content of cations and anions) were determined in each treatment step. The physico-chemical parameters and microbiological analysis of the resulting permeate showed that it could be reused in the rendering plant for washing purposes, and it satisfies the main regulations and guidelines for wastewater reuse, i.e. US EPA and FAO.
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Affiliation(s)
- M Racar
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia.
| | - D Dolar
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia.
| | - M Farkaš
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia
| | - N Milčić
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia
| | - A Špehar
- Agroproteinka, Strojarska cesta 11, HR-10361 Sesvetski Kraljevec, Croatia
| | - K Košutić
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia
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12
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Optimizing Chemically Enhanced Primary Treatment Processes for Simultaneous Carbon Redirection and Phosphorus Removal. WATER 2019. [DOI: 10.3390/w11030547] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There has been increased interest towards maximizing wastewater energy recovery by enhancing the carbon captured through the primary treatment process such as chemically enhanced primary treatment (CEPT). This research was conducted to optimize the CEPT performance in terms of redirection of carbon and nutrients in both bench- and full-scale operations. In order to improve the CEPT process, the performance of ferric chloride and seven types of polymers were evaluated through jar testing. The optimal coagulant (15 mg/L ferric chloride) and flocculant (0.5 mg/L poly aluminum chloride (PACl)) combination achieved total COD, soluble COD, total suspended solids (TSS), and total phosphorus (TP) removal efficiencies of 76, 58, 89, and 84, respectively, in a full-scale primary clarifier operation. In doing so the organic matter and phosphorus were concentrated in CEPT sludge, making them available for recovery. Furthermore, the relationship between influent characteristics and removal rates under varying operating conditions was investigated. It was found that soluble COD removal appeared to be season-dependent, and TSS removals were independent of influent TSS concentrations in all scenarios. The removal of tCOD, sCOD, and TP had a positive relationship with their corresponding concentrations when the polymer Alcomer® 120L was used, whereas no correlation between removal and concentration was observed with PACl.
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13
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Kumari M, Gupta SK. Removal of aromatic and hydrophobic fractions of natural organic matter (NOM) using surfactant modified magnetic nanoadsorbents (MNPs). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:25565-25579. [PMID: 29959738 DOI: 10.1007/s11356-018-2611-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
The present study investigated the potential of surfactant modified magnetic nanoadsorbents (MNPs) for the removal of aromatic and hydrophobic fractions of natural organic matter (NOM), leading to the formation of trihalomethanes (THMs) in chlorinated drinking water. Co-precipitation method was used for the synthesis of MNPs. However, MNPs have a tendency to form an agglomeration. Therefore, polyethylene glycol (PEG) was used as a surface modifier to reduce the agglomeration. The PEG-coated MNPs were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), BET surface area, X-ray diffraction (XRD), Fourier transform spectrometer (FTIR), and zeta (ζ) potential. FESEM observation indicates that PEG-coated MNPs were spherical in shape and 25 nm in size. Zeta potential values (- 58.35 to - 74.9 mV) indicated excellent stability of PEG-MNPs. FTIR spectra indicated the presence of a -CH2 group, responsible for the chemical interaction between aromatic and humic content. Batch experiments were conducted by studying the effect of pH, contact time, and adsorbent dosage on NOM removal. Excellent removal of DOC (94.49%) and UV254 (89.32%) was observed at the optimum dose of adsorbent (0.75 g/L) and at pH 7.0. Adsorption kinetics followed pseudo-second-order reaction (R2, 0.973) and occurs by multilayer chemisorption which is due to the chemical interaction between aromatic and humic compounds of NOM with MNPs. Thus, MNPs showed great potential as a novel adsorbent for the removal of aromatic and hydrophobic compounds of NOM and can significantly be used to curtail the problem of THMs in drinking water supplies.
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Affiliation(s)
- Minashree Kumari
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
| | - Sunil Kumar Gupta
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India
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14
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Sillanpää M, Ncibi MC, Matilainen A, Vepsäläinen M. Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review. CHEMOSPHERE 2018; 190:54-71. [PMID: 28985537 DOI: 10.1016/j.chemosphere.2017.09.113] [Citation(s) in RCA: 252] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/19/2017] [Accepted: 09/24/2017] [Indexed: 06/07/2023]
Abstract
Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs). Nonetheless, with the increased fluctuation of NOM in water (concentration and composition), the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH), developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes.
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Affiliation(s)
- Mika Sillanpää
- Laboratory of Green Chemistry, School of Engineering Science, Lappeenranta University of Technology, Sammonkatu 12, 50130, Mikkeli, Finland; Department of Civil and Environmental Engineering, Florida International University, Miami FL, 33174, USA
| | - Mohamed Chaker Ncibi
- Laboratory of Green Chemistry, School of Engineering Science, Lappeenranta University of Technology, Sammonkatu 12, 50130, Mikkeli, Finland.
| | - Anu Matilainen
- Finnish Safety and Chemicals Agency, Kalevantie 2, 33100 Tampere, Finland
| | - Mikko Vepsäläinen
- CSIRO Mineral Resources Flagship, Box 312, Clayton South, VIC, 3169, Australia
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Su Z, Liu T, Yu W, Li X, Graham NJD. Coagulation of surface water: Observations on the significance of biopolymers. WATER RESEARCH 2017; 126:144-152. [PMID: 28941400 DOI: 10.1016/j.watres.2017.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/06/2017] [Accepted: 09/10/2017] [Indexed: 06/07/2023]
Abstract
Although the treatment of natural surface waters by coagulation has been investigated extensively, the detailed interaction between natural organic matter and alum is still not adequately understood or predictable, owing to the complexity of different components of the organic matrix and the conditions during coagulation. In this paper, we present the results of a novel approach to the study of the topic, which involved the progressive separation of organic components according to size, followed by coagulation of the filtrate solution, in order to expose the influence of particular organic fractions. Using two natural water sources, representative of lake and river waters, solutions of different organic content were obtained by progressively filtering the source waters using membranes of decreasing pore size; viz. microfiltration (MF), ultrafiltration (UF), and two grades of nanofiltration (NF). While MF had little impact on the range of organics present, UF was able to separate biopolymers (MW > 100 kDa), and NF had a substantially impact on the separation of medium-high MW (1-10 kDa) substances. The results of the coagulation tests showed that the size of flocs was substantially greater when biopolymers were present, suggesting their beneficial role in bridging precipitated Al(OH)3 nanoparticles. For the smaller organic fractions (<10 kDa), the results showed a trend of increasing floc size with decreasing organic MW and concentration, but the trend was minor and may be explained by charge effects. Very similar results were found with both water sources, which support the main finding that biopolymers have an important influence on floc formation.
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Affiliation(s)
- Zhaoyang Su
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100024, China.
| | - Ting Liu
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
| | - Wenzheng Yu
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
| | - Xing Li
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100024, China.
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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Su Z, Li X, Yang Y. Regrowth ability and coagulation behavior by second dose: Breakage during the initial flocculation phase. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.05.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Racar M, Dolar D, Špehar A, Kraš A, Košutić K. Optimization of coagulation with ferric chloride as a pretreatment for fouling reduction during nanofiltration of rendering plant secondary effluent. CHEMOSPHERE 2017; 181:485-491. [PMID: 28460295 DOI: 10.1016/j.chemosphere.2017.04.108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/19/2017] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
The treatment and reuse of rendering plant wastewater with membrane processes is a poorly investigated area that could result in substantial water savings. Membrane fouling is still the main obstacle when treating secondary effluents (SEs) with high content of effluent organic matter (EfOM). Thus, the optimization of coagulation with ferric(III) chloride (FeCl3) as a pretreatment for nanofiltration was performed to reduce membrane fouling and achieve higher permeate quality. Coagulation was modeled (total carbon, inorganic carbon, dissolved organic carbon (DOC), turbidity, conductivity, and resulting pH) and optimized with response surface methodology (RSM) to remove DOC and turbidity with a pH close to neutral. The effluent after coagulation at optimal conditions (5.58 pH and 26.38 mg L-1 of Fe3+) and sand filtration (SF) was subjected to nanofiltration (NF270, NF, and NF90 membranes). The fouling was compared to evaluate the efficiency of each pretreatment. Coagulation with FeCl3 reduced the flux decline of nanofiltration membranes 4.2 to 19.3 times while SF barely reduced the fouling. Coagulation increased the flux recovery and chemical cleanliness after the membrane washing. In addition to fouling reduction, higher permeate quality was achieved.
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Affiliation(s)
- Marko Racar
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000, Zagreb, Croatia.
| | - Davor Dolar
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000, Zagreb, Croatia
| | - Ana Špehar
- Agroproteinka, Strojarska cesta 11, HR-10361, Sesvetski Kraljevec, Croatia
| | - Ana Kraš
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000, Zagreb, Croatia
| | - Krešimir Košutić
- University of Zagreb, Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000, Zagreb, Croatia
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Gar Alalm M, Nasr M, Ookawara S. Assessment of a novel spiral hydraulic flocculation/sedimentation system by CFD simulation, fuzzy inference system, and response surface methodology. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2016.06.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Watson MA, Tubić A, Agbaba J, Nikić J, Maletić S, Molnar Jazić J, Dalmacija B. Response surface methodology investigation into the interactions between arsenic and humic acid in water during the coagulation process. JOURNAL OF HAZARDOUS MATERIALS 2016; 312:150-158. [PMID: 27031919 DOI: 10.1016/j.jhazmat.2016.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 06/05/2023]
Abstract
Interactions between arsenic and natural organic matter (NOM) are key limiting factors during the optimisation of drinking water treatment when significant amounts of both must be removed. This work uses Response Surface Methodology (RSM) to investigate how they interact during their simultaneous removal by iron chloride coagulation, using humic acid (HA) as a model NOM substance. Using a three factor Box-Behnken experimental design, As and HA removals were modelled, as well as a combined removal response. ANOVA results showed the significance of the coagulant dose for all three responses. At high initial arsenic concentrations (200μg/l), As removal was significantly hindered by the presence of HA. In contrast, the HA removal response was found to be largely independent of the initial As concentration, with the optimum coagulant dose increasing at increasing HA concentrations. The combined response was similar to the HA removal response, and the interactions evident are most interesting in terms of optimising treatment processes during the preparation of drinking water, highlighting the importance of utilizing RSM for such investigations. The combined response model was successfully validated with two different groundwaters used for drinking water supply in the Republic of Serbia, showing excellent agreement under similar experimental conditions.
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Affiliation(s)
- Malcolm Alexander Watson
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
| | - Aleksandra Tubić
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
| | - Jasmina Agbaba
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
| | - Jasmina Nikić
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
| | - Snežana Maletić
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
| | - Jelena Molnar Jazić
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
| | - Božo Dalmacija
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia
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Han Q, Yan H, Zhang F, Xue N, Wang Y, Chu Y, Gao B. Trihalomethanes (THMs) precursor fractions removal by coagulation and adsorption for bio-treated municipal wastewater: Molecular weight, hydrophobicity/hydrophily and fluorescence. JOURNAL OF HAZARDOUS MATERIALS 2015; 297:119-126. [PMID: 25956642 DOI: 10.1016/j.jhazmat.2015.04.070] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 06/04/2023]
Abstract
Due to concerns over health risk of disinfection byproducts (DBPs), removal of trihalomethanes (THMs) precursor from bio-treated wastewater by coagulation and adsorption was investigated in this study. Ultrafiltration (UF) membranes and nonionic resins were applied to fractionate THMs precursor into various molecular weight (MW) fractions and hydrophobic/hydrophilic fractions. Characteristics of coagulated water and adsorbed water were evaluated by the three-dimensional excitation and emission matrix (3DEEM) fluorescence spectroscopy. Results showed that coagulation and adsorption were suitable for removing different hydrophobic/hydrophilic and fluorescent fractions. Coagulation decreased THMs concentration in hydrophobic acids (HoA) fraction from 59 μg/L to 39 μg/L, while the lowest THMs concentration (9 μg/L) in hydrophilic substances (HiS) fraction was obtained in adsorbed water. However, both coagulation and adsorption were ineffective for removing fractions with MW<5 kDa. Although coagulation and adsorption processes could reduce THMs formation, some specific THMs formation potential (STHMFP) in residual dissolved organic matter (DOM) fractions increased in this study. Hydrophobic acid and hydrophilic fractions increased after coagulation treatment, and low MW and hydrophobic fractions increased after adsorption treatment. In addition, active carbon adsorbed more organic matter than coagulant, but brominated disinfection byproducts (Br-DBPs) in adsorbed water turned to the major THMs species after chlorination.
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Affiliation(s)
- Qi Han
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China
| | - Han Yan
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China
| | - Feng Zhang
- Shandong Tobacco Co., Ltd., Jinan 250100, PR China
| | - Nan Xue
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China
| | - Yan Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China.
| | - Yongbao Chu
- School of Environmental and Safety Engineering, Qingdao University of Science & Technology, Qingdao 266042, PR China
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, PR China
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Sutherland S, Parsons S, Daneshkhah A, Jarvis P, Judd S. THM precursor rejection by UF membranes treating Scottish surface waters. Sep Purif Technol 2015. [DOI: 10.1016/j.seppur.2015.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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22
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Sadrnourmohamadi M, Gorczyca B. Removal of dissolved organic carbon (DOC) from high DOC and hardness water by chemical coagulation – relative importance of monomeric, polymeric and colloidal aluminum species. SEP SCI TECHNOL 2015. [DOI: 10.1080/01496395.2015.1014494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Klymenko NA, Samsoni-Todorov EA, Savchina LA. Raising the efficiency of coagulation treatment of the Dnieper River water. J WATER CHEM TECHNO+ 2014. [DOI: 10.3103/s1063455x14050051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Gough R, Holliman PJ, Willis N, Freeman C. Dissolved organic carbon and trihalomethane precursor removal at a UK upland water treatment works. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 468-469:228-239. [PMID: 24035843 DOI: 10.1016/j.scitotenv.2013.08.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 08/02/2013] [Accepted: 08/17/2013] [Indexed: 06/02/2023]
Abstract
The removal of dissolved organic carbon (DOC) during potable water treatment is important for maintaining aesthetic water quality standards, minimising concentrations of micro-pollutants, controlling bacterial regrowth within distribution systems and, crucially, because it contains a sub-component that can act as trihalomethane (THM) precursors. In this study, the concentration and characteristics of raw water DOC and THM formation potential (THMFP) entering an upland potable water treatment works were analysed over twelve months. Correlations between raw water DOC characteristics, standardised THMFP (STHMFP) and % DOC removal were also investigated. DOC and THM precursor removal during a series of treatment stages was examined over this period, as well as potential selectivity in the removal of DOC fractions, to assess the importance of different treatment stages for DOC removal and THM amelioration. Though THMFP removal remained high and fairly stable throughout the study period (83-89%), the data suggest that this was mostly the result of high DOC removal rates rather than the selective removal of THM precursors. Whilst this chemical agnosticism makes DOC removal more robust, it may make the overall process more vulnerable to exceeding permissible THM concentrations under changing climatic conditions. The kinetics of the reaction between DOC and chlorine appeared to vary seasonally, indicating temporal changes in the proportions of fast- and slow-reacting precursors with implications for THM concentrations at the point of delivery to the consumer. The initial treatment stages, comprising coagulation-flocculation and dissolved air floatation (DAF) were by far the most important in terms of bulk DOC removal and the preferential removal of THM precursors, though, surprisingly, DOC quality was also modified following chlorination and secondary rapid gravity filtration (RGF). Though net THM concentration decreased following initial treatment stages, a doubling in the proportion of brominated THMs (BrTHMs), which are reported to be more carcinogenic, was also observed.
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Affiliation(s)
- Rachel Gough
- School of Biological Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK.
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25
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Aslam Z, Chow CW, Murshed F, van Leeuwen JA, Drikas M, Wang D. Variation in character and treatability of organics in river water: An assessment by HPAC and alum coagulation. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2013.09.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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26
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Zhao Y, Xiao F, Wang D, Yan M, Bi Z. Disinfection byproduct precursor removal by enhanced coagulation and their distribution in chemical fractions. J Environ Sci (China) 2013; 25:2207-2213. [PMID: 24552048 DOI: 10.1016/s1001-0742(12)60286-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Raw water from the Songhua River was treated by four types of coagulants, ferric chloride (FeCI3), aluminum sulfate (AI2(SO4)3), polyaluminum chloride (PACI) and composite polyaluminum (HPAC), in order to remove dissolved organic matter (DOM). Considering the disinfection byproduct (DBP) precursor treatability, DOM was divided into five chemical fractions based on resin adsorption. Trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) were measured for each fraction. The results showed that hydrophobic acids (HoA), hydrophilic matter (HiM) and hydrophobic neutral (HoN) were the dominant fractions. Although both HoN and HoA were the main THM precursors, the contribution for THMFP changed after coagulation. Additionally, HoA and HiM were the main HAA precursors, while the contribution of HoN to HAAFP significantly increased after coagulation. HoM was more easily removed than HiM, no matter which coagulant was used, especially under enhanced coagulation conditions. DOC removal was highest for enhanced coagulation using FeCI3 while DBPFP was lowest using PACI. This could indicate that not all DOC fractions contained the precursors of DBPs. Reduction of THMFP and HAAFP by PACI under enhanced coagulation could reach 51% and 59% respectively.
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Affiliation(s)
- Yanmei Zhao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Feng Xiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Dongsheng Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Mingquan Yan
- Department of Environmental Engineering, Peking University, Beijing 100871, China
| | - Zhe Bi
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Tubić A, Agbaba J, Dalmacija B, Molnar J, Maletić S, Watson M, Perović SU. Insight into changes during coagulation in NOM reactivity for trihalomethanes and haloacetic acids formation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2013; 118:153-160. [PMID: 23428464 DOI: 10.1016/j.jenvman.2012.11.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/08/2012] [Accepted: 11/29/2012] [Indexed: 06/01/2023]
Abstract
Natural organic matter (NOM) in raw water can contribute in many ways to the poor quality of drinking water, including the formation of disinfection byproducts such as trihalomethanes (THM) and haloacetic acids (HAA) during disinfection. This paper investigates the role of individual NOM fractions on changes in THM and HAA formation during coagulation with iron chloride (FeCl3) and a combination of polyaluminium chloride and iron chloride (FeCl3/PACl). The dissolved organic carbon (DOC) in the raw water and after coagulation was fractionated into four fractions, based on their hydrophobicity. Fractionation showed that most of the DOC (68%) in the raw water comes from the fulvic acid fraction, yielding 41% of the total THM precursors and 21% of the total HAA precursors. Both coagulants remove the humic acid fraction, but result in different changes to the reactivity of the remaining NOM fractions towards THM and HAA formation, indicating that coagulation occurs by different pathways, depending upon the type of coagulant used. In particular, significant changes in the reactivities of the hydrophilic acidic and non-acidic fractions were observed.
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Affiliation(s)
- Aleksandra Tubić
- University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Trg Dositeja Obradovica 3, 21000 Novi Sad, Serbia.
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Zhou Z, Yang Y, Li X, Gao W, Liang H, Li G. Coagulation efficiency and flocs characteristics of recycling sludge during treatment of low temperature and micro-polluted water. J Environ Sci (China) 2012; 24:1014-20. [PMID: 23505868 DOI: 10.1016/s1001-0742(11)60866-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Drinking water treatment sludge, characterized as accumulated suspended solids and organic and inorganic matter, is produced in large quantities during the coagulation process. The proper disposal, regeneration or reuse of sludge is, therefore, a significant environmental issue. Reused sludge at low temperatures is an alternative method to enhance traditional coagulation efficiency. In the present study, the recycling mass of mixed sludge and properties of raw water (such as pH and turbidity) were systematically investigated to optimize coagulation efficiency. We determined that the appropriate dosage of mixed sludge was 60 mL/L, effective initial turbidity ranges were below 45.0 NTU, and optimal pH for DOMs and turbidity removal was 6.5-7.0 and 8.0, respectively. Furthermore, by comparing the flocs characteristics with and without recycling sludge, we found that floc structures with sludge were more irregular with average size growth to 64.7 microm from 48.1 microm. Recycling sludge was a feasible and successful method for enhancing pollutants removal, and the more irregular flocs structure after recycling might be caused by breakage of reused flocs and incorporation of powdered activated carbon into larger flocs structure. Applied during the coagulation process, recycling sludge could be significant for the treatment of low temperature and micro-polluted source water.
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Affiliation(s)
- Zhiwei Zhou
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China.
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29
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Chan CC, Choudhury NR, Majewski P. Fabrication and characterisation of self-assembled monolayers of N-[3-(trimethoxysilyl)propyl]diethylenetriamine on silica particles. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2010.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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30
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Matilainen A, Vepsäläinen M, Sillanpää M. Natural organic matter removal by coagulation during drinking water treatment: a review. Adv Colloid Interface Sci 2010; 159:189-97. [PMID: 20633865 DOI: 10.1016/j.cis.2010.06.007] [Citation(s) in RCA: 497] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 06/17/2010] [Accepted: 06/21/2010] [Indexed: 11/16/2022]
Abstract
Natural organic matter (NOM) is found in all surface, ground and soil waters. An increase in the amount of NOM has been observed over the past 10-20 years in raw water supplies in several areas, which has a significant effect on drinking water treatment. The presence of NOM causes many problems in drinking water and drinking water treatment processes, including (i) negative effect on water quality by causing colour, taste and odor problems, (ii) increased coagulant and disinfectant doses (which in turn results in increased sludge volumes and production of harmful disinfection by-products), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. NOM can be removed from drinking water by several treatment options, of which the most common and economically feasible processes are considered to be coagulation and flocculation followed by sedimentation/flotation and sand filtration. Most of the NOM can be removed by coagulation, although, the hydrophobic fraction and high molar mass compounds of NOM are removed more efficiently than hydrophilic fraction and the low molar mass compounds. Thus, enhanced and/or optimized coagulation, as well as new process alternatives for the better removal of NOM by coagulation process has been suggested. In the present work, an overview of the recent research dealing with coagulation and flocculation in the removal of NOM from drinking water is presented.
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Affiliation(s)
- Anu Matilainen
- Laboratory of Applied Environmental Chemistry, Department of Environmental Sciences, University of Eastern Finland, Patteristonkatu 1, FI-50100 Mikkeli, Finland
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