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.
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.
Environ Res. 2021 Jul;198:111291. doi: 10.1016/j.envres.2021.111291. Epub 2021 May 10.
Substituted diphenylamine antioxidants (SDPAs) are additives used in various commodities and are commonly found in environmental samples. However, limited information was available on their fate and removal in wastewater treatment plants (WWTPs). This paper reports the results on the occurrence and removal efficiency of ten selected SDPAs in six WWTPs equipped with different treatment processes in Northeast China. Quite similar distributions of different SDPA congeners were shown in the studied WWTPs, with ditertoctyl-diphenylamine (C8/C8-DPA), tertbutyl-tertoctyl-diphenylamine (C4/C8-DPA), and tertoctyl-diphenylamine (C8-DPA) being always dominant in the influent, effluent, and sludge (total > 80%). A cyclic activated sludge system combined with a V-shape filter achieved the highest removal efficiencies of SDPAs among various treatment processes. Styrenated-diphenylamine1 (S-DPA1) (96 ± 10%), C8-DPA (95 ± 5.5%), and distyrenated-diphenylamine1 (DS-DPA1) (94 ± 9.3%) showed high and stable removal efficiencies, whereas C4/C8-DPA (85 ± 31%) and C8/C8-DPA (84 ± 62%) showed considerably varied removal efficiencies. Per-day discharges of SDPAs to the receiving environment through effluent and sludge were estimated as 828 ± 350 and 5578 ± 5196 mg, respectively. A median of 85% of the initial mass loadings of SDPAs was found in the sludge samples, suggesting that the observed removal of SDPAs in the WWTPs was caused by their sorption to the sludge, rather than biodegradation/transformation. This work provides an overall description of the occurrence, fate, and mass balance of SDPAs in WWTPs in Northeast China and highlights a new emission route to the environment via WWTPs.
取代二苯胺抗氧化剂（SDPAs）是各种商品中使用的添加剂，通常存在于环境样品中。然而，关于它们在废水处理厂（WWTP）中的命运和去除情况的信息有限。本文报告了在中国东北地区六个配备不同处理工艺的 WWTP 中十种选定的 SDPAs 的出现和去除效率。在所研究的 WWTP 中，不同 SDPA 同系物的分布非常相似，在进水、出水和污泥中（总量>80%）始终以二特辛基二苯胺（C8/C8-DPA）、叔丁基特辛基二苯胺（C4/C8-DPA）和特辛基二苯胺（C8-DPA）为主。一个循环活性污泥系统与 V 形过滤器相结合，在各种处理工艺中实现了 SDPAs 的最高去除效率。苯乙烯化二苯胺 1（S-DPA1）（96±10%）、C8-DPA（95±5.5%）和二苯乙烯化二苯胺 1（DS-DPA1）（94±9.3%）表现出高而稳定的去除效率，而 C4/C8-DPA（85±31%）和 C8/C8-DPA（84±62%）则表现出相当大的变化的去除效率。通过出水和污泥排放到受纳环境中的 SDPAs 日排放量估计分别为 828±350 和 5578±5196mg。在污泥样品中发现，SDPAs 的初始质量负荷的中位数为 85%，这表明 WWTP 中观察到的 SDPAs 去除是由于它们被污泥吸附，而不是生物降解/转化。这项工作全面描述了 SDPAs 在东北中国 WWTP 中的出现、命运和质量平衡，并强调了通过 WWTP 向环境排放的新途径。
