Environmental Chemistry
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2012
·Vol. 9
·期 6
·558-563
·
IF 2.57
Lei Wu,Xuefeng Hu,Lei Wu,Xuefeng Hu
Environmental context Aromatic amines are widely used chemicals, which show enhanced toxicity and longer environmental persistence when halogenated. We investigated the chlorination of aniline in seawater and in natural aqueous solutions containing Fe3+ and Cl–, under simulated sunlight irradiation. The results increase our understanding of the transformation pathway of typical nitrogen-containing aromatic contaminants in the environment. Photochlorination of aniline was observed in aqueous solutions containing dissolved FeIII and chloride ions under simulated solar light irradiation. Effects of O2, Cl–, Fe3+ and pH on the formation of chloroanilines (CAs) were investigated. para-chloroaniline (4CA) was identified as the main chlorinated product. The formation of 4CA is enhanced with increased concentrations of Cl– or Fe3+, and decreased pH, whereas oxygen plays a negligible role in the process. The results indicate that, Cl• is formed mainly by the photodissociation of FeCl2+–FeCl2+ complexes, and reacts with Cl– to produce Cl2•–. Aniline is then oxidised by Cl2•– into an anilino radical cation, which further reacts with Cl2•– to generate CAs. The photochlorination of aniline in natural seawater was also observed. Other phototransformation products of aniline were detected and a transformation pathway was proposed. This work provides evidence for the photochemical chlorination path of aniline-based aromatic amines in aqueous solutions.
研究领域:
环境科学
·
化学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Mina Yang,Haijing Zhang,Fei Chang,Xuefeng Hu
Chlorinated organic compounds are ubiquitously detected in saline waters. The photochlorination of organic compounds is one possible source, and chlorine radicals originating from other photosensitive substances have been reported to be responsible for organic compounds chlorination in previous reports. In this study, benzo[ a ]pyrene (BaP) chlorination in 10% acetonitrile/NaCl aqueous solution was initiated by self-sensitization of BaP, while chlorine radicals were not involved in the reaction. After 45 min of photoreaction in four seawater samples, chlorinated product (6-ClBaP) accounted for 10–17% of the fraction of transformed BaP, which was higher than that previously reported. The influences of Cl − , pH, humic acid , electron donors, and particulate matter on the formation of chlorobenzo[ a ]pyrene were systematically investigated. A self-sensitized photochlorination reaction mechanism was proposed as follow: photoexited BaP was activated to singlet state and then transformed to triplet state through inter-system crossing. Then the excited triplet state and oxygen formed [ 3 BaP*- 3 O 2 ] or [BaP- 1 O 2 ] complex, which further reacted with Cl − to produce 6-ClBaP.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Peng Liu,Xiaowei Wu,Suyi Pan,Jiamin Dai,Zixuan Zhang,Xuetao Guo
Wastewater treatment plants (WWTPs) are the important source of microplastics (MPs) in the environment, and disinfection processes bear high potential to degrade MPs. This study investigated the physicochemical degradation, dissolved organic products and interaction with co-existed pollutants (heavy metal and pharmaceutical) on polyethylene (PE), polypropylene (PP) and polystyrene (PS) MPs during simulated disinfection processes. Compared to photo or chlorination, photochlorination significantly resulted in the physicochemical degradation, including morphology alteration, fragmentation, and chemical oxidation on PP and PS MPs, but showed relatively low effect on PE, indicating the different resistance among polymers to disinfected treatment. Photochlorination also caused the formation of chain-scission organic compounds and even chlorinated products from MPs (e.g. C 11 H 19 O 4 Cl for PP and monochlorophenol, dichlorophenol, chloroacetophenone and chlorobenzoic acid for PS), which may form disinfection byproducts to induce healthy risk. The adsorption potentials of MPs for Cr(VI) or amlodipine were enhanced by photochlorination since the cracking and formed oxygen functional groups enhanced the pore filling and surface precipitation of Cr(VI), and the electrostatic attraction and hydrogen bonding with amlodipine. The findings indicated the physicochemical degradation of MPs and the combined pollution with co-existed pollutants, highlighting the health risks of MP-derived organic products during the disinfection treatments (even in normal dosage) in WWTPs.
研究领域:
环境科学
·
毒理学
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Tingting Du,Song Shao,Liwen Qian,Ru Meng,Tong Li,Lijun Wu,Yao Li
With the increasingly severe plastic pollution, the environmental behavior and effects of nanoplastics (NPs) have attracted much attention. The transformation of NPs in natural and engineered environments (e.g., photooxidation, disinfection) can significantly alter the physicochemical properties and thus affect the fate and toxicity of NPs. However, how solar irradiation with free chlorine, an inevitable process once NPs enter the environment from wastewater treatment plants, affects the physicochemical properties of NPs is still unclear. In this study, the behavior and mechanism of polystyrene (PS) NPs transformation in the solar/chlorine process were evaluated. The results demonstrated that solar irradiation significantly enhanced the physicochemical transformation of PS NPs during chlorination, including chain scission, surface oxidation, and organic release. In addition, two-dimensional correlation spectroscopy analysis using Fourier transform infrared spectroscopy and reactive species quenching experiments showed that chain scission and surface oxidation of PS NPs were primarily caused by direct oxidation of hydroxyl radicals and ozone, while reactive chlorine species played an indirect role. Moreover, photochlorination-induced changes in the properties of PS NPs enhanced the colloidal stability in synthetic wastewater solution and toxicity to Caenorhabditis elegans . These findings reveal an important transformation behavior of nanoplastics in the environment and emphasize the importance of accounting for photochlorination to accurately assess the ecological risk of nanoplastics.
研究领域:
环境科学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）