Article
Engineering, Environmental
Irina Shulga, Parmila Devi, Ajay. K. Dalai
Summary: The study found that the concentration and speciation of chloramines depend strongly on solution pH and chlorine to ammonia molar ratios. Among the chloramines, NCl3 showed the fastest depletion with a quantum yield of 2.16 mol E-1. Kinetics study showed that the rate of photodecay and quantum yield of NCl3 was 8-times and 13-times higher than NHCl2 and NH2Cl, respectively.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Wei Hu, Yunho Lee, Sebastien Allard
Summary: This study demonstrates that Cu(II) can significantly enhance the decomposition rate of bromamines, with an increase in pH leading to a decrease in self-decomposition rate of bromamines. Additionally, increasing Cu(II) concentration promotes the production of N2O.
Article
Environmental Sciences
Jian Ao, Lingjun Bu, Yuwei Wu, Yangtao Wu, Shiqing Zhou
Summary: The formation of brominated disinfection byproducts (Br-DBPs) in drinking water disinfection is a growing concern due to their significantly higher toxicity compared to chlorinated analogues and the widespread presence of bromide in source water. However, the mechanism and pathways of Br-DBPs formation are still not fully understood. This study demonstrated that brominated haloacetonitriles (Br-HANs) were more likely to form than brominated trihalomethanes when using glycine, alanine, and serine as model precursors. Organic bromamines were proposed to play a significant role in the formation of Br-HANs, similar to organic chloramines. The decay of organic bromamines was found to be faster than that of organic chloramines, confirming the hypothesis. The pH and disinfectant used were also found to influence the formation of Br-HANs.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Anette T. Mensah, Yingying Xiang, Florence Berne, Sylvie Soreau, Herve Gallard
Summary: Monobromamine (NH2Br) and dibromamine (NHBr2), derived from the reactions of hypobromous acid (HOBr) with ammonia, can react with phenolic structures of natural organic matter (NOM) to form disinfection byproducts, including bromoform (CHBr3). The reactivity of NH2Br depends on the reaction with phenolates, while the reactions of NHBr2 are negligible compared to self-decomposition. Kinetic modeling was developed to determine the formation and decomposition of bromamines, as well as the reactivity of HOBr and NH2Br with phenolic compounds. The study emphasizes the importance of considering the reactions between brom(am)ines and phenolic structures during disinfection processes in water treatment.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Junlang Qiu, Yi Zhang, Caley Craven, Zhongshan Liu, Yanpeng Gao, Xing-Fang Li
Summary: This study identifies a natural product called MTCCA in source water, which can produce multiple nitrosamines through chloramination. The widespread presence of MTCCA in source water and wastewater, along with its resistance to degradation and removal, suggests that natural N-heterocyclic compounds may be a new source of nitrosamine precursors.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
Yang Guo, Qian Yang, Jie Xu, Xueling Bai, Qihuan Han, Jie Nie, Luo Zhang, Hongtao Li, Haixiang Gao, WenFeng Zhou, Jing Li
Summary: The study utilized a novel analytical method to monitor the volatile byproducts of organic chloramines during chlorination and identified (CH3)2NCl and (C2H5)2NCl as important organic chloramines, which may promote the formation of other disinfection byproducts.
Article
Engineering, Environmental
Eric R. Noe, Jiaqi Li, William A. Arnold, Raymond M. Hozalski
Summary: This study investigates the effectiveness of preoxidation with ozone, free chlorine, or both on the removal of NDMA precursors in different types of water samples. The results show that ozone preoxidation effectively decreases NDMA concentrations in all water samples, and the combination of free chlorine and ozone is more effective at removing NDMA precursors in recarbonated water.
ENVIRONMENTAL ENGINEERING SCIENCE
(2023)
Article
Chemistry, Analytical
Zizhang Ren, Yue Qiu, Mengxue Huan, Yong Dong Liu, Rugang Zhong
Summary: Chlorinated amino acids and peptides are model modified protein structures relevant to pathogen inactivation and disinfection byproducts (DBPs) with potential health risks. Identifying all chlorinated amino acids and peptides is a huge challenge due to the large variety and multiple reaction sites. Quantum chemical computation can uncover the chlorination sites and products.
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2022)
Article
Environmental Sciences
Haoyuan Zhang, Peng Gao, Yongze Liu, Ziwen Du, Li Feng, Liqiu Zhang
Summary: This study systematically investigated the effects of different types of nitrogen sources on the formation of nitrogenous disinfection by-products (N-DBPs). It was found that organic nitrogen sources and inorganic nitrogen sources have different effects on the formation of N-DBPs. Chloramine was identified as the major nitrogen contributor to the formation of N-DBPs in the presence of multiple nitrogen sources. Moreover, environmental factors such as reaction time, pH, and bromide were found to influence the formation of N-DBPs.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Karim-Alexandre Essaied, Lucy Victoria Brown, Urs von Gunten
Summary: The composition of oxidant-reactive dissolved organic nitrogen (DON) is still not well characterized, but may form a variety of disinfection by-products containing nitrogen-oxygen bonds. Through oxidation and batch experiments, it was found that some amino acids have a high tendency to form nitrate (NO3), while other compounds have lower capabilities to form nitrate and chloramines.
Review
Engineering, Environmental
Renjie Pan, Tian-Yang Zhang, Huan He, Zheng-Xiong Zheng, Zheng-Yu Dong, Heng-Xuan Zhao, Meng-Yuan Xu, Zhen-Ning Luo, Chen-Yan Hu, Yu-Lin Tang, Mohamed Gamal El-Din, Bin Xu
Summary: This review provides a comprehensive overview of the occurrences, characteristics, analysis methods, and control strategies of mixed chlorine/chloramines in drinking water distribution systems. It highlights the challenges posed by mixed chlorine/chloramine species, such as accelerated pipeline corrosions, increased risks of disinfection by-products, off-flavors in drinking water, and bio-instability issues. The review recommends three promising strategies for alleviating the problems caused by mixed chlorine/chloramines and discusses future research directions.
Article
Biotechnology & Applied Microbiology
Hitoshi Kodamatani, Taketo Tanisue, Takahiro Fujioka, Ryo Kanzaki, Takashi Tomiyasu
Summary: This study evaluated the influence of alkyl chain lengths of N-nitrosamine precursors on the formation of N-nitrosamines. The results showed that amines with methyl groups have higher potential for producing corresponding N-nitrosamines than those with ethyl groups. These findings could be useful for enhancing source control of water and wastewater containing high concentrations of specific N-nitrosamine precursors.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Environmental Sciences
Jiaxing Zhao, Shaoyang Hu, Lizhong Zhu, Wei Wang
Summary: This study investigated the formation of chlorinated halobenzoquinones from three free aromatic amino acids during chlorination, and explained the formation pathways based on detected intermediates and influencing factors. The results showed that four chlorinated halobenzoquinones were formed, with 2,6-dichloro-1,4-benzoquinone being the dominant species. The yields of chlorinated halobenzoquinones were affected by free chlorine dosage, pH, and temperature. Ten intermediates were successfully detected and the formation pathways were validated using theoretical calculation.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Emily A. Curling, Michael J. McKie, Laura Meteer, Blair Saunders, Susan A. Andrews, Robert C. Andrews
Summary: Chloramines, as a secondary disinfectant, can reduce disinfection by-product formation and improve residual stability compared to free chlorine. However, maintaining an acceptable residual in distribution systems may be challenging due to potential high maintenance costs. This study aimed to identify the primary sources of chloramine demand in a distribution system receiving surface and groundwater. Decay in the bulk water was quantified using a bottle point method, and bench-scale pipe section reactors were used to evaluate decay associated with different pipe materials.
JOURNAL OF WATER PROCESS ENGINEERING
(2022)
Article
Engineering, Environmental
Di Zhang, Tom Bond, Mingli Li, Shengkun Dong, Yang Pan, Erdeng Du, Rong Xiao, Wenhai Chu
Summary: This study conducted formation potential tests on real water samples from drinking water treatment plants to identify the main precursors and formation pathways of Chlorophenylacetonitriles (CPANs). The results showed that amino acids, particularly tyrosine and tryptophan, are important CPAN precursors. Fluorescence spectroscopy and high-resolution mass spectrometry provided evidence for this hypothesis.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Review
Environmental Sciences
Zuo Tong How, Mohamed Gamal El-Din
Summary: Cannabinoids, organic compounds found in cannabis, are contaminants of concern due to limited information on their environmental impacts. THC and CBD, the main constituents, are expected to increase in water systems post legalization. Studies on their occurrence and toxicity in various water systems are necessary for accurate assessment of their impact.
ENVIRONMENTAL POLLUTION
(2021)
Article
Engineering, Environmental
Abdallatif Satti Abdalrhman, Chengjin Wang, Zuo Tong How, Mohamed Gamal El-Din
Summary: The study found that the ideal condition for degrading CHA using the UV/Chlorine process is to continuously add chlorine at a constant rate to reduce chlorine consumption and minimize the radical scavenging effect, resulting in a higher removal rate.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Environmental Sciences
Aaron Boyd, Connor B. Stewart, Danielle A. Philibert, Zuo Tong How, Mohamed Gamal El-Din, Keith B. Tierney, Tamzin A. Blewett
Summary: The study simulated the effects of UV filters on Daphnia in freshwater ecosystems, finding that immobilization mainly occurred in octocrylene at environmentally realistic concentrations, while avobenzone and oxybenzone caused behavioral and physiological disruptions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Mirna Alameddine, Zuo Tong How, Mohamed Gamal El-Din
Summary: The study found that PAC-catalyzed ozonation is more effective for removing organics and O-3-resistant MPs, while both single ozonation and PAC-catalyzed ozonation can significantly reduce E. coli and the acute, genetic toxicity, and estrogenic activity of wastewater.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Junying Song, Zuo Tong How, Zhanbin Huang, Mohamed Gamal El-Din
Summary: A sludge-based biochar/iron oxide (B-FeOx) catalyst with a 3D flower-like structure was prepared and successfully employed for the removal of two model NA compounds, showing high degradation efficiency and rate. The enhanced degradation efficiency of the catalyst was attributed to the increased surface area, pore volume, and abundant reactive sites induced by the flower-like structure.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Zhijun Luo, Lingjun Meng, Zuo Tong How, Pamela Chelme-Ayala, Lingling Yang, Chelsea Benally, Mohamed Gamal El-Din
Summary: The environmentally-friendly treatment method based on photochemical reactions of ferricarboxylate complexes effectively degrades classical naphthenic acids (NAs) in oil sands process water (OSPW) under visible light irradiation, with degradation ratios depending on the initial pH of the OSPW. Ferric citrate has excellent visible light absorption ability and can produce both Fe2+ and H2O2 in situ, acting as a Fenton reagent to non-selectively degrade NAs.
CHEMICAL ENGINEERING JOURNAL
(2022)
Review
Energy & Fuels
Jia Li, Zuo Tong How, Hongbo Zeng, Mohamed Gamal El-Din
Summary: This study systematically reviews the properties of silica and dissolved organics in SAGD produced water, as well as various techniques for their removal. The advantages, limitations, and effectiveness of each technology are discussed, along with remaining challenges and future research perspectives.
Article
Environmental Sciences
Ming Zheng, Suwen Tang, Yangyang Bao, Kevin D. Daniels, Zuo Tong How, Mohamed Gamal El-Din, Jie Wang, Liang Tang
Summary: A fully automated SPE coupled with UHPLC-MS/MS method was developed for analysis of antibiotics with optimized sample preparation and instrument parameters. This method can meet the needs of trace antibiotic residues detection in waters with high sensitivity and precision.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Dustin M. E. Lillico, Nora A. S. Hussain, Yemaya Y. Choo-Yin, Rui Qin, Zuo Tong How, Mohamed Gamal El-Din, James L. Stafford
Summary: In this study, it is demonstrated that oil sands process-affected waters (OSPW) contain factors that activate immune cells' antimicrobial and proinflammatory responses. The bioactivity of two different OSPW samples and their isolated fractions was investigated using the murine macrophage RAW 264.7 cell line. The results show that the after water capping (AWC) sample has significant inflammatory bioactivity, while the before water capping (BWC) sample has reduced bioactivity primarily associated with its inorganic fraction (IF).
JOURNAL OF ENVIRONMENTAL SCIENCES
(2023)
Article
Environmental Sciences
Jia Li, Zuo Tong How, Mohamed Gamal El-Din
Summary: This investigation studied the degradation of anionic polyacrylamide (A-PAM) under different temperature and microorganism conditions and its effects on water chemistry and toxicity in oil sands tailings. The results showed that A-PAM removal efficiency was highest at 41.0% in tailings water with augmented microorganisms at 20 degrees C. Both temperature and microorganisms significantly influenced the degradation of A-PAM and residual acrylamide monomer. The study also indicated that biodegradation could be the main pathway for A-PAM degradation in oil sands tailings.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Aaron Boyd, Jessica Choi, Grace Ren, Zuo Tong How, Mohamed Gamal El-Din, Keith B. Tierney, Tamzin A. Blewett
Summary: Organic ultraviolet filters (UVFs) are commonly found in aquatic environments and have been found to pose a threat to invertebrate species. However, long-term studies on their effects are limited. This study examined the effects of exposure to UVFs on Daphnia magna and found that while avobenzone and octocrylene had minor and transient effects on reproduction and wet mass, oxybenzone resulted in significant negative impacts on mortality and reproduction, although normal function was largely regained by the next generation.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Engineering, Environmental
Lingjun Meng, Zuo Tong How, Pamela Chelme-Ayala, Chelsea Benally, Mohamed Gamal El-Din
Summary: A novel photocatalyst, Bi2WO6/NiO/Ag, with a unique hierarchical flower-like Z-scheme heterojunction, exhibited excellent stability and photocatalytic activity over a wide light spectrum. It was successfully synthesized and used for the remediation of real oil sands process water (OSPW), achieving complete removal of aromatics, classical naphthenic acids (NAs), and heteroatomic NAs after 6 hours of photocatalytic treatment. The study demonstrated that the Z-scheme electron transfer mechanism among Ag, NiO, and Bi2WO6 played a significant role in enhancing the photocatalytic efficiency, supported by in-situ irradiated XPS analysis. This research is of great importance in designing engineered passive treatment approaches for OSPW remediation using solar light-driven catalyst.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Panduo Shan, Jiayi Lin, Yanbo Zhai, Shuai Dong, Zuo Tong How, Rui Qin
Summary: The chemical transformation of DHHB, a UV filter found in sunscreens and personal care products, in outdoor swimming pools was investigated. Free chlorine was the dominant factor contributing to the degradation of DHHB, while sunlight and reactive species had a smaller impact. The presence of certain substances inhibited or promoted DHHB degradation. The study highlights the significant health risks posed by DHHB and its chlorinated transformation by-products.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Zhi Fang, Pamela Chelme-Ayala, Soliu O. Ganiyu, Xiaoyuan Zhang, Bin Xu, Chunmao Chen, Mohamed Gamal El-Din
Summary: This study explores the degradation of naphthenic acids (NAs) in oil sands process water (OSPW) using peroxymonosulfate (PMS) activated by ozone. The results show that the ozone/PMS system accelerates the degradation of NA model compounds, with a high removal rate observed. The synergetic effect of ozone and PMS is responsible for the enhanced degradation.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Environmental Sciences
Qiuyun Lu, Qiwei Xu, Jia Meng, Zuo Tong How, Pamela Chelme-Ayala, Xihua Wang, Mohamed Gamal El-Din, Xuehua Zhang
Summary: This study demonstrates that the photodegradation efficiency of micro-pollutants in water can be improved by using polymeric microlenses (MLs). The photodegradation efficiency is approximately linearly correlated with the sum of the intensity from all focal points of the MLs. ML arrays can enhance the photodegradation efficiency compared to heterogeneous MLs on an unpatterned substrate. MLs can be used to enhance water treatment and achieve faster photodegradation of micropollutants.