摘要

    在这项研究中，采用了混凝-溶解气浮（DAF）工艺作为增强的一级处理（EPT），以同时减少11种ARG（tetA，tetM，tetQ，tetX，sul1，sul2，qnrD，ermB，blaTEM，aac（ 6'）-lb-cr，floR），WWTP进水中的1类整合素整合酶基因（intI1）和常见污染物，然后与仅一次沉淀进行了比较。在混凝-DAF工艺中，达到超过总悬浮固体（TSS）90％的去除效率所需的PACl，FeCl3和Al2（SO4）3的最佳剂量分别为25 mg / L，75 mg / L和100 mg / L。用三种混凝剂联合混凝-DAF工艺处理的所有定量ARG的对数去除率均超过0.44-log，与仅初次沉降相比（0.03-log），ARG的去除效率更高。在三种混凝剂中，FeCl3对靶向ARGs的对数减少最高。另外，这三种凝结剂显示出相似的能力，可以非选择性地适度降低大多数ARG。大多数ARGs和intl1与处理后的废水中的理化参数去除效率表现出强烈的负相关性，这意味着在混合混凝过程中，胶体，固体，磷酸盐，铵和有机物的共同去除对降低ARGs起着至关重要的作用- DAF流程。特别是，在总磷（TP）和ARGs的减少之间观察到很强的相关性，这表明TP可以为该过程中ARGs的减少提供合适的代理。尽管处理由ARGs和高水平和多种类型的污染物组成的进水，但混凝-DAF工艺可改善ARGs和胶体物质的去除效果。因此，结果证明了混凝-DAF工艺可减少流入污水处理厂的ARGs的潜力。

    In this study, a combined coagulation-dissolved air flotation (DAF) process was employed as enhanced primary treatment (EPT) to simultaneously reduce eleven ARGs (tetA, tetM, tetQ, tetX, sul1, sul2, qnrD, ermB, blaTEM, aac(6′)-lb-cr, floR), class 1 integrons-integrase gene (intI1) and common pollutants in the influent of a WWTP and then compared to primary sedimentation alone. In the combined coagulation-DAF process, the optimum doses of PACl, FeCl3 and Al2(SO4)3 required to achieve a removal efficiency exceeding 90% of total suspended solids (TSS) were 25 mg/L, 75 mg/L and 100 mg/L, respectively. The log removal of all quantified ARGs treated by the combined coagulation-DAF process with the three coagulants exceeded 0.44-log, a higher removal efficiency of ARGs compared to primary sedimentation alone (0.03-log). Among the three coagulants, FeCl3 showed the highest log reduction for targeted ARGs. In addition, the three coagulants showed similar capabilities to non-selectively and modestly decrease most ARGs. Most ARGs and intl1 demonstrated strongly negative correlations with the removal efficiencies of physicochemical parameters in the treated wastewater, implying that co-removal of colloidal matter, solids, phosphate, ammonium and organic matter played a crucial role in reduction of ARGs during the combined coagulation-DAF process. Particularly, strong correlations were observed between the reduction of total phosphorus (TP) and ARGs, indicating that TP may provide a suitable proxy for reduction of ARGs in this process. Despite handling influent comprised of ARGs and pollutants of high levels and diverse types, the combined coagulation-DAF process led to improved removal of ARGs along with colloidal substances. Thus, the results demonstrate the potential of a combined coagulation-DAF process to reduce ARGs flowing into WWTPs.

    https://www.sciencedirect.com/science/article/abs/pii/S1383586620314209