International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; International Joint Research Center for Arctic Environment and Ecosystem (IJRC-AEE), Polar Academy, Harbin Institute of Technology, Harbin 150090, China; Environment and Climate Change Canada, Science and Technology Branch, 867 Lakeshore Road Burlington, ON, L7S1A1, Canada.
International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; International Joint Research Center for Arctic Environment and Ecosystem (IJRC-AEE), Polar Academy, Harbin Institute of Technology, Harbin 150090, China.
Water Res. 2021 Feb 1;189:116602. doi: 10.1016/j.watres.2020.116602. Epub 2020 Nov 3.
Diphenylamine antioxidants (DPAs) are widely used industrial chemicals. Wastewater effluents and biosolids are important pathways for DPAs to enter the environment. Information on the fate of DPAs in wastewater treatment plants (WWTPs) and their environmental releases is limited. In this study, we characterized the occurrence, removal efficiencies, distribution, mass balance, and environmental releases of 17 DPAs in ten Canadian WWTPs and four landfill sites from 2013 to 2015. These WWTPs are different in sizes, and treatment technologies. Median concentrations of ΣDPAs were 78 ng/L in influent, 6.9 ng/L in effluent, 326 ng/L in leachate, and 445 ng/g in biosolids (dry weight), respectively. Diphenylamine (DPA) and ditertoctyl-diphenylamine (DTO-DPA) were the predominant congeners of DPAs in all the matrices. Residues of DPAs were not completely removed during wastewater treatment processes: most DPAs were detected in at least one sample of WWTP effluent with the highest concentration of 117 ng/L (DPA). Overall, high removal efficiencies (median > 90%) of most of the DPAs were observed in the secondary and advanced treatment, as well as in the facultative and aerated lagoons. In contrast, primary treatment exhibited a lower removal efficiency of the DPAs. Mass balance analysis shows that sorption to biosolids is the major removal pathway of DPAs in WWTPs. The results also highlight that environmental releases of DPAs via biosolid applications (70 mg/d/1000 people) can be over several times higher than that via wastewater effluent (2.5-36 mg/d/1000 people).
二苯胺类抗氧化剂（DPAs）是广泛应用的工业化学品。废水和生物固体是 DPAs 进入环境的重要途径。有关 DPAs 在废水处理厂（WWTP）中的命运及其环境释放的信息有限。在这项研究中，我们从 2013 年到 2015 年，在加拿大的 10 个 WWTP 和 4 个垃圾填埋场中，对 17 种 DPAs 的出现、去除效率、分布、质量平衡和环境释放进行了特征描述。这些 WWTP 在规模和处理技术上有所不同。ΣDPAs 的中值浓度分别为进水 78ng/L、出水 6.9ng/L、渗滤液 326ng/L 和生物固体（干重）445ng/g。在所有基质中，二苯胺（DPA）和二特丁基二苯胺（DTO-DPA）都是 DPAs 的主要同系物。DPAs 在废水处理过程中没有被完全去除：大多数 DPAs 在至少一个 WWTP 出水样本中被检出，最高浓度为 117ng/L（DPA）。总体而言，在二级和高级处理以及兼性和充气塘中，大多数 DPAs 的去除效率较高（中位数>90%）。相比之下，初级处理对 DPAs 的去除效率较低。质量平衡分析表明，吸附到生物固体是 WWTP 中 DPAs 的主要去除途径。研究结果还表明，通过生物固体应用（70mg/d/1000 人）释放的 DPAs 的环境释放量可能是通过废水排放（2.5-36mg/d/1000 人）的数倍以上。
