Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Sci Total Environ. 2017 Dec 15;603-604:140-147. doi: 10.1016/j.scitotenv.2017.06.097. Epub 2017 Jun 15.
Wastewater treatment plant (WWTP) secondary effluent is a main source for polycyclic aromatic hydrocarbons (PAHs) and their derivatives (SPAHs) to wastewater receiving rivers in Beijing. The treatment technologies are being upgraded in the WWTPs as the tertiary treatment. To assess the improvement of the removal efficiencies of PAHs and SPAHs after the treatment upgrading, we investigated 16 PAHs and 4 types of SPAHs in the secondary and tertiary treatment process in 5 major WWTPs. Most of the parent PAHs, methyl PAHs, oxygenated PAHs and chlorinated PAHs were detected in the influent, secondary and tertiary effluent. The concentrations of ΣSPAHs (61ng/L-529ng/L) were similar to ΣPAHs (89ng/L-474ng/L), indicating that SPAHs should not be ignored when studying the PAH contamination. ΣPAHs and ΣSPAHs were largely removed by the secondary treatment (45%-82%) and less by the tertiary treatment (0%-24%). The removal efficiencies were lower in the secondary and tertiary treatment in WWTPs than in the lab-scale experiment conducted previously, probably a result of the association of PAHs and SPAHs with dissolved organic matters (DOMs) in wastewater. DOMs might be a limiting factor for the removal of PAHs and SPAHs in WWTPs. The estimated yearly loadings of the total PAHs and SPAHs decreased only 21% in the tertiary effluent compared with the secondary effluent in WWTP1 and 9% in WWTP3. Therefore, the upgrading of WWTPs did not efficiently improve the removal of PAHs and SPAHs. DOMs should be further considered for improving the removal of PAHs, SPAHs and similar contaminants in WWTPs.
污水处理厂（WWTP）二级出水是北京受纳河流中多环芳烃（PAHs）及其衍生物（SPAHs）的主要来源。随着三级处理的升级，污水处理厂正在升级处理技术。为了评估处理升级后 PAHs 和 SPAHs 去除效率的提高，我们在 5 个主要的 WWTP 中调查了二级和三级处理过程中的 16 种 PAHs 和 4 种 SPAHs。在进水、二级和三级出水中均检测到母体 PAHs、甲基 PAHs、含氧 PAHs 和氯化 PAHs。ΣSPAHs（61ng/L-529ng/L）的浓度与ΣPAHs（89ng/L-474ng/L）相似，表明在研究 PAH 污染时不应忽视 SPAHs。二级处理（45%-82%）大量去除了ΣPAHs 和ΣSPAHs，而三级处理（0%-24%）去除较少。与之前进行的实验室规模实验相比，WWTP 中的二级和三级处理去除效率较低，这可能是由于 PAHs 和 SPAHs 与废水中的溶解有机物（DOMs）有关。DOMs 可能是 WWTP 中去除 PAHs 和 SPAHs 的限制因素。与二级出水相比，在 WWTP1 中，三级出水中总 PAHs 和 SPAHs 的年负荷仅减少了 21%，在 WWTP3 中减少了 9%。因此，WWTP 的升级并没有有效地提高 PAHs 和 SPAHs 的去除率。应进一步考虑 DOMs 以提高 WWTP 中 PAHs、SPAHs 和类似污染物的去除率。
