Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Jimo District, Qingdao, Shandong 266237, China.
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Jimo District, Qingdao, Shandong 266237, China; College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
Water Res. 2022 Sep 1;223:119023. doi: 10.1016/j.watres.2022.119023. Epub 2022 Aug 28.
In this study, a novel wastewater treatment process combining sequencing batch reactor, constructed wetland and microalgal membrane photobioreactor (BCM process) was proposed, and its performance on removal, transformation and toxicity reduction of polycyclic aromatic hydrocarbons (PAHs) was intensively explored. Satisfactory PAHs removal (90.58%-97.50%) was achieved and molecular weight had significant impact on the removal pathways of different PAHs. Adsorption dominated the removal of high molecular weight PAHs, while the contribution ratio of microbial degradation increased with the decrease of molecular weight of PAHs. More importantly, it was reported for the first time that substituted PAHs (SPAHs) produced by microbial degradation of PAHs would lead to increased toxicity during the BCM process. High PAHs (75.37%-88.52%) and SPAHs removal (99.56%-100.00%) were achieved in the microalgae unit due to its abundant cytochrome P450 enzyme, which decreased the bacterial toxicity by 90.93% and genotoxicity by 93.08%, indicating that microalgae played significance important role in ensuring water security. In addition, the high quantitative relationship (R = 0.98) between PAHs, SPAHs and toxicity exhibited by regression model analysis proved that more attention should be paid to the ecotoxicity of derivatives of refractory organic matters in wastewater treatment plants.
在这项研究中，提出了一种将序批式反应器、人工湿地和微藻膜光生物反应器相结合的新型废水处理工艺（BCM 工艺），并深入探讨了其对多环芳烃（PAHs）的去除、转化和毒性降低的性能。该工艺实现了令人满意的 PAHs 去除率（90.58%-97.50%），且分子量对不同 PAHs 的去除途径有显著影响。吸附主导了高分子量 PAHs 的去除，而微生物降解的贡献比例随着 PAHs 分子量的降低而增加。更重要的是，据报道，BCM 工艺中，由 PAHs 微生物降解产生的取代多环芳烃（SPAHs）会导致毒性增加。由于微藻中含有丰富的细胞色素 P450 酶，因此在微藻单元中实现了高 PAHs（75.37%-88.52%）和 SPAHs（99.56%-100.00%）的去除，这降低了细菌毒性 90.93%和遗传毒性 93.08%，表明微藻在确保水质安全方面发挥了重要作用。此外，回归模型分析表明，PAHs、SPAHs 和毒性之间存在高度定量关系（R=0.98），这证明了在污水处理厂中应更加关注难处理有机物质的衍生物的生态毒性。
