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Yang Y, Zhang X, Fu L, Li C, Zhang S. The number of test organisms might influence the toxicity evaluation of hydrophobic micropollutants. CHEMOSPHERE 2024; 355:141814. [PMID: 38554862 DOI: 10.1016/j.chemosphere.2024.141814] [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: 01/06/2024] [Revised: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
Evaluating the toxicity of micropollutants forms the basis for understanding their potential risks to the ecosystem and/or human health. To accurately evaluate the toxicity of micropollutants in toxicity tests, many factors have been carefully considered, while the impact of the number of test organisms on toxicity results has rarely been taken into account. In this study, the role of the organism number on the developmental toxicity of five micropollutants was investigated using embryos of the marine polychaete Platynereis dumerilii. The toxicity of hydrophobic micropollutants was found to decrease significantly with increasing the number of embryos used in the test. A quantitative model was developed to better describe how the number of embryos affected developmental toxicity. The model showed a satisfactory fit to the raw data in all scenarios tested. The intrinsic half-maximal effective concentration EC50,int was then determined using the model. For a given compound, the EC50,int was a stable parameter that did not depend on the number of test embryos and thus provided an indication of the intrinsic toxicity of the compounds tested. Compared with the EC50 values determined with the commonly used embryo number (around 120), the EC50,int values of all tested hydrophobic micropollutants were lower. The more hydrophobic the compounds tested, the more pronounced the reduction in toxicity. This suggested that hydrophobic micropollutants could be more toxic than reported in the literature. Some suggestions were also made to eliminate the effect of the number of organisms used in the toxicity evaluation.
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Affiliation(s)
- Yun Yang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China.
| | - Longshan Fu
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Can Li
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Siwei Zhang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
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2
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Zhang M, Lü X, Yuan C, He W, Qiu C, Lan B, He J, Zhang L, Li Y. Impact of non-aged and UV-aged microplastics on the formation of halogenated disinfection byproducts during chlorination of drinking water and its mechanism. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123394. [PMID: 38266699 DOI: 10.1016/j.envpol.2024.123394] [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: 08/15/2023] [Revised: 11/05/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Microplastics (MPs) are ubiquitously present in source water and undergo ultraviolet (UV) aging in aquatic environments before entering drinking water treatment plants. The presence of MPs in drinking water can impact the formation of halogenated disinfection byproducts (DBPs) during chlorine disinfection, yet the exact effect of MPs on DBP formation remain unclear. In this study, we conducted an investigation into the influence of non-aged and UV-aged MPs on halogenated DBP formation in drinking water and unveiled the underlying mechanisms. In comparison to source water samples devoid of MPs, the total organic halogen concentration was reduced by 19%-43% and 4%-13% in the drinking water samples containing non-aged and aged MPs, respectively. The differing effects on halogenated DBP formation can be attributed to the alternation in physical and chemical characteristics of MPs following UV aging. Aged MPs exhibited larger surface area with signs of wear and tear, heightened hydrophilicity, surface oxidation, increased oxygen-containing functional groups and dechlorination during the UV aging process. Both non-aged and aged MPs possess the capability to adsorb natural organic matter, leading to a reduction in the concentration of DBP precursors in the source water. However, the release of organic compounds from aged MPs outweighed the adsorption of organics. Furthermore, as a result of the surface activation of MPs through the UV aging process, the aged MPs themselves can also serve as DBP precursors. Consequently, the presence of halogenated DBP precursors in source water increased, contributing to a higher level of DBP formation compared to source water containing non-aged MPs. Overall, this study illuminates the intricate relationship among MPs, UV aging, and DBP formation in drinking water. It highlights the potential risks posed by aged MPs in influencing DBP formation and offers valuable insights for optimizing water treatment processes.
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Affiliation(s)
- Meihui Zhang
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Xianghong Lü
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Cheng Yuan
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Weiting He
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Chuyin Qiu
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Bingyan Lan
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Junfeng He
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Liguo Zhang
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Yu Li
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China.
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Li W, Han J, Zhang X, Chen G, Yang Y. Contributions of Pharmaceuticals to DBP Formation and Developmental Toxicity in Chlorination of NOM-containing Source Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18775-18787. [PMID: 37505917 DOI: 10.1021/acs.est.3c00742] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Pharmaceuticals have been considered a priority group of emerging micropollutants in source waters in recent years, while their role in the formation and toxicity of disinfection byproducts (DBPs) during chlorine disinfection remains largely unclear. In this study, the contributions of natural organic matter (NOM) and pharmaceuticals (a mixture of ten representative pharmaceuticals) to the overall DBP formation and toxicity during drinking water chlorination were investigated. By innovatively "normalizing" chlorine exposure and constructing a kinetic model, we were able to differentiate and evaluate the contributions of NOM and pharmaceuticals to the total organic halogen (TOX) formation for source waters that contained different levels of pharmaceuticals. It was found that at a chlorine contact time of 1.0 h, NOM (2 mg/L as C) and pharmaceuticals (total 0.0062-0.31 mg/L as C) contributed 79.8-99.5% and 0.5-20.2%, respectively, of TOX. The toxicity test results showed that the chlorination remarkably increased the toxicity of the pharmaceutical mixture by converting the parent compounds into more toxic pharmaceutical-derived DBPs, and these DBPs might contribute significantly to the overall developmental toxicity of chlorinated waters. This study highlights the non-negligible role of pharmaceuticals in the formation and toxicity of overall DBPs in chlorinated drinking water.
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Affiliation(s)
- Wanxin Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR 00000, China
| | - Jiarui Han
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR 00000, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR 00000, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch), and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong SAR 00000, China
| | - Yun Yang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR 00000, China
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Zhou N, Liu H, Yang X, Watson P, Yang F. Disinfection byproducts of iopamidol, iohexol, diatrizoate and their distinct acute toxicity on Scenedesmus sp., Daphnia magna and Danio rerio. CHEMOSPHERE 2023; 333:138885. [PMID: 37209847 DOI: 10.1016/j.chemosphere.2023.138885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/24/2023] [Accepted: 05/06/2023] [Indexed: 05/22/2023]
Abstract
The COVID-19 pandemic resulted in increasing the usage of iodinated contrast media (ICM), and thus an increase in the prevalence of ICM-contaminated wastewater. While ICM is generally safe, this has the potential to be problematic because as medical wastewater is treated and disinfected, various ICM-derived disinfection byproducts (DBPs) may be generated and released into the environment. However, little information was available about whether ICM-derived DBPs are toxic to aquatic organisms. In this study, the degradation of three typical ICM (iopamidol, iohexol, diatrizoate) at initial concentration of 10 μM and 100 μM in chlorination and peracetic acid without or with NH4+ was investigated, and the potential acute toxicity of treated disinfected water containing potential ICM-derived DBPs on Daphnia magna, Scenedesmus sp. and Danio rerio was tested. The degradation results suggested that only iopamidol was significantly degraded (level of degradation >98%) by chlorination, and the degradation rate of iohexol and diatrizoate were significantly increased in chlorination with NH4+. All three ICM were not degraded in peracetic acid. The toxicity analysis results indicate that only the disinfected water of iopamidol and iohexol by chlorination with NH4+ were toxic to at least one aquatic organism. These results highlighted that the potential ecological risk of ICM-contained medical wastewater by chlorination with NH4+ should not be neglected, and peracetic acid may be an environment-friendly alternative for the disinfection of wastewater containing ICM.
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Affiliation(s)
- Nan Zhou
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Huihui Liu
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Xianhai Yang
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Peter Watson
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, 06268, CT, United States
| | - Feifei Yang
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs, 06268, CT, United States
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5
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Peng Y, Yang X, Huang H, Su Q, Ren B, Zhang Z, Shi X. Fluorescence and molecular weight dependence of disinfection by-products formation from extracellular organic matter after ultrasound irradiation. CHEMOSPHERE 2023; 323:138279. [PMID: 36863625 DOI: 10.1016/j.chemosphere.2023.138279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Algal blooms have a negative impact on the safety of drinking water. Ultrasonic radiation technology is an "environment-friendly" technology that is widely used in algae removal. However, this technology leads to the release of intracellular organic matter (IOM), which is an important precursor of disinfection by-products (DBPs). This study investigated the relationship between the release of IOM in Microcystis aeruginosa and the generation of DBPs after ultrasonic radiation as well as analyzed the generation mechanism of DBPs. Results showed that the content of extracellular organic matter (EOM) in M. aeruginosa increased in the order of 740 kHz >1120 kHz >20 kHz after 2 min of ultrasonic radiation. Organic matter with a molecular weight (MW) greater than 30 kDa increased the most, including protein-like, phycocyanin (PC) and chlorophyll a, followed by small-molecule organic matter less than 3 kDa, mainly humic-like substances and protein-like. DBPs with an organic MW range of less than 30 kDa were dominated by trichloroacetic acid (TCAA), while those with an MW greater than 30 kDa had the highest trichloromethane (TCM) content. Ultrasonic irradiation changed the organic structure of EOM, affected the amount and type of DBPs, and tended to generate TCM.
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Affiliation(s)
- Yazhou Peng
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Xiongwei Yang
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Hongqi Huang
- Changsha Economic and Technical Development Zone Water Purification Engineering Co.,Ltd, Changsha, 410100, China
| | - Qitao Su
- Changsha Economic and Technical Development Zone Water Purification Engineering Co.,Ltd, Changsha, 410100, China
| | - Bozhi Ren
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
| | - Zhi Zhang
- Laboratory of Three Gorges Reservoir Region, Chongqing University, Chongqing, 400045, China
| | - Xueping Shi
- Shanghai Urban Construction Design and Research Institute, Shanghai, 200125, China
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6
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Bai Y, Shi C, Zhou Y, Zhou Y, Zhang H, Chang R, Hu X, Hu J, Yang C, Peng K, Xiang P, Zhang Z. Enhanced inactivation of Escherichia coli by ultrasound combined with peracetic acid during water disinfection. CHEMOSPHERE 2023; 322:138095. [PMID: 36758811 DOI: 10.1016/j.chemosphere.2023.138095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Peracetic acid (PAA) is a desirable disinfectant for municipal wastewater because of its potent disinfection performance and limited toxic by-products. This study explored the efficiency and mechanism of Escherichia coli inactivation by PAA combined with ultrasound simultaneously (ultrasound + PAA) or (ultrasound → PAA) sequentially. The result showed that 60 kHz ultrasound combined with PAA sequentially (60 kHz → PAA) had excellent inactivation performance on E. coli, up to 4.69-log10. The result also showed that the increase of pH and humic acid concentration in solution significantly reduced the inactivation efficiency of 60 kHz → PAA treatment. We also observed that the increase of temperature was beneficial to the disinfection, while anions (Cl-; HCO3-) had little effect. With 60 kHz → PAA, the PAA and the synergism between PAA and ultrasound played major contribution to the inactivation, which we assumed might be due to both the diffusion of PAA into the cells and the damage to the cytomembrane by ultrasound, as evidenced through the laser confocal microscopy (LSCM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The inactivation mechanism involved the destruction of cell membrane and loss of intracellular material. Empirically, 60 kHz → PAA was found to be effective for the inactivation of E. coli in actual wastewater, and the regrowth potential of E. coli treated by 60 kHz → PAA was significantly lower than that treated only by PAA.
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Affiliation(s)
- Yun Bai
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Chunhai Shi
- Northwest China Municipal Engineering Design and Research Institute, Lanzhou, 730000, China
| | - Yuanhang Zhou
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Yingying Zhou
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Haocheng Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Ruiting Chang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Xueli Hu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Jiawei Hu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Chuanyao Yang
- Analysis and Testing Center, Chongqing University, Chongqing, 400045, China
| | - Kedi Peng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Ping Xiang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
| | - Zhi Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
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Zhao S, Yang X, Liu H, Xi Y, Li J. Potential Disrupting Effects of Wastewater-Derived Disinfection Byproducts on Chinese Rare Minnow ( Gobiocypris rarus) Transthyretin: An In Vitro and In Silico Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3228-3237. [PMID: 36780642 DOI: 10.1021/acs.est.2c06192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The available information about whether wastewater-derived disinfection byproducts (DBPs) could elicit potential endocrine-related detrimental effects on aquatic organisms was scarce. Herein, the potential disrupting effects and underlying binding mechanism of 14 wastewater-derived aliphatic and aromatic DBPs and 12 other substances on Chinese rare minnow (Gobiocypris rarus) transthyretin (CrmTTR) were tested and revealed by in vitro and in silico methods. The amino acid sequences of CrmTTR were determined, and the recombinant CrmTTR with a molecular mass of 66.3 kDa was expressed and purified. In vitro assay results indicated that eight selected aromatic DBPs exhibited detectable CrmTTR disrupting ability. Meanwhile, six aliphatic DBPs were not CrmTTR binders. Molecular modeling results implied that hydrophobic hydrogen bonds and/or ionic pair interactions were non-negligible. Four binary classification models with high classification performance were constructed. A significant positive linear relationship was observed for the binding affinity data from CrmTTR and human TTR (n = 18, r = 0.922, p < 0.0001). However, the binding affinity for 13 out of 18 tested compounds with CrmTTR was higher than that with human TTR. All the results highlighted that some wastewater-derived DBPs may be potential disruptors on the aquatic organism endocrine system, and interspecies variation should not be neglected in future determination of the potential endocrine disrupting effects of wastewater-derived DBPs.
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Affiliation(s)
- Songshan Zhao
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science & Technology, Nanjing 210094, China
| | - Xianhai Yang
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Huihui Liu
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yue Xi
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jing Li
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science & Technology, Nanjing 210094, China
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Cheng X, Xia Y, Ji Q, Ji Q, Li H, Guo J, Li S, Yang S, Zhang L, He H. Occurrence and risk of iodinated X-ray contrast media in source and tap water from Jiangsu province, China. JOURNAL OF HAZARDOUS MATERIALS 2023; 444:130399. [PMID: 36403453 DOI: 10.1016/j.jhazmat.2022.130399] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/31/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Microcontaminants in the water environment have received increasing attention due to their adverse effects on human health and wildlife. However, iodinated X-ray contrast media (ICM), a type of microcontaminants, have not yet been systematically documented in source and tap water. This study investigated ICM in water samples via a sampling activity from 25 drinking water sources and their corresponding 30 household taps in south-central Jiangsu Province, China. The total concentrations of ICM ranged from 14.2 to 138.5 ng/L in source water and 3.7 to 101.3 ng/L in tap water, respectively. The calculated average water treatment efficiency to remove ICM is 38.3% with large variation under different processes (ranging from 7.3% to 75.7%), which implied that ICM could not be effectively removed using current treatment technologies. By integrating other ICM into the predominant compound iohexol with relative potency factors, the health risks of total ICM through water consumption were assessed using the Monte Carlo simulation. The results concluded that the risk of ingesting ICM through tap water was not a major health concern for adults, teens, or children in the study area. Nevertheless, due to the lack of long-term toxicity data relevant for humans for ICM, this risk may be underestimated, which requires further research.
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Affiliation(s)
- Xinying Cheng
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Yubao Xia
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Qiuyi Ji
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Qingsong Ji
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Huiming Li
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Jiehong Guo
- Masonic Cancer Center, University of Minnesota at Twin Cities, Minneapolis, Minnesota 55455, USA; Department of Civil, Environmental, and Geospatial Engineering, Michigan Technological University, Michigan 49931, USA
| | - Shiyin Li
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Shaogui Yang
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Limin Zhang
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China; Green Economy Development Institute, Nanjing University of Finance and Economics, Nanjing, Jiangsu 210023, P.R. China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China; College of Ecological and Resource Engineering, Fujian Provincial Key laboratory of Eco-Industrial Green Technology, Wuyi University, Wuyishan, Fujian 354300, P.R. China.
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9
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Abusallout I, Hua G. Solar photocatalytic degradation of total organic halogen in water using TiO 2 catalyst. CHEMOSPHERE 2022; 308:136206. [PMID: 36049634 DOI: 10.1016/j.chemosphere.2022.136206] [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: 07/21/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Disinfection byproducts (DBPs) in treated wastewater effluents pose environmental and health risks during water reuse. Solar-TiO2 photocatalysis is a promising technology for degrading organic pollutants in treated effluents. In this study, total organic halogen (TOX) was used as an analytical tool to determine the efficiency of solar-TiO2 photocatalytic process for the dehalogenation of DBPs in water. Natural solar photocatalytic experiments using TiO2 particles were conducted to evaluate dehalogenation kinetics of different TOX groups formed by fulvic acid including total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI). The results showed that the mixed phase TiO2 (Aeroxide P25) was much more effective at TOX removal than the anatase (Hombikat UV-100) and rutile (TiOxide) TiO2 particles. The TOX photocatalytic degradation rates of different halogen substituents ranked as TOI > TOCl (NH2Cl) > TOBr > TOCl (Cl2). The TOX removal followed first-order kinetics with half-lives of 42.8, 11.0, 5.0 and 2.7 min for TOCl (Cl2), TOBr, TOCl (NH2Cl), and TOI, respectively, at the 100 mg L-1 TiO2 dose. The TOX dehalogenation was enhanced at pH 9 compared to pH 5, and the addition of hydrogen peroxide had limited improvement in the TOX removal. Hydrophobic and molecular weight (MW) > 1 kDa fractions of TOCl (Cl2) were more susceptible to the solar photocatalytic process than the hydrophilic and MW < 1 kDa fractions. The solar-TiO2 photocatalytic process also effectively removed TOX in chlorinated and chloraminated wastewater samples. The results of this study suggest that the solar-TiO2 photocatalysis is an effective treatment technology for TOX removal in water reuse.
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Affiliation(s)
- Ibrahim Abusallout
- CDM Smith, 14432 SE Eastgate Way Suite 100, Bellevue, WA, 98007, USA; Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA.
| | - Guanghui Hua
- Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA
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