title: Removal and transformation of polycyclic aromatic hydrocarbons during electrocoagulation treatment of an industrial wastewater.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are an important class of water pollutants because of their known ecological and human toxicity. Electrocoagulation (EC) is a promising technology for mitigating industrial wastewater pollution, but the removal and transformation of PAHs during EC treatment has not yet been understood. Therefore, a paper-making wastewater effluent (PMWW) was employed in this study to investigate the relationship between PAHs' removal and transformation during EC treatment. The results show that 86% of PAHs were effectively removed not only by the electro-oxidation reactions, but also by adsorption onto Fe hydroxide flocs. The removal and transformation of PAHs were related to the number of rings in their structures. Some PAHs composed of two aromatic rings (e.g., naphthaline and dimethylnaphthalene) were produced from humic acid-like and fulvic acid-like organics in PMWW, while PAHs with three to four rings were degraded, thus being removed efficiently. Therefore, PAH transformation during EC treatment exerted double-sided effects on the removal of PAHs; the net effect appeared to be positive. Overall, this study revealed the existence and importance of PAH transformation during EC treatment and provided useful guidance for pulp and paper mills to improve the design and operation of wastewater treatment facilities.
authors: School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing, 100875, China; Environmental Protection Research Institute of Light Industry, Beijing Academy of Science and Technology, No.1 Gao Li Zhang Road, Beijing, 100095, China.
authors: Chenhao
authors: C
authors: Gong
authors: School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing, 100875, China.
authors: Gang
authors: G
authors: Shen
authors: School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing, 100875, China. Electronic address: huanghaiou@bnu.edu.cn.
authors: Haiou
authors: H
authors: Huang
authors: Environmental Protection Research Institute of Light Industry, Beijing Academy of Science and Technology, No.1 Gao Li Zhang Road, Beijing, 100095, China.
authors: Peiran
authors: P
authors: He
authors: Environmental Protection Research Institute of Light Industry, Beijing Academy of Science and Technology, No.1 Gao Li Zhang Road, Beijing, 100095, China. Electronic address: cn.zhang@163.com.
authors: Zhongguo
authors: Z
authors: Zhang
authors: Shandong Century Sunshine Paper Group Co., Ltd., Changle Economic Development Zone, Weifang, 266400, China.
authors: Baoqing
authors: B
authors: Ma
mesh_terms: D000327:Adsorption; D055664:Electrochemical Techniques / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D011084:Polycyclic Aromatic Hydrocarbons; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Electrochemical degradation; Electrocoagulation; Excitation-emission matrix; Polycyclic aromatic hydrocarbons; Transformation