摘要

       混凝已被公认为一种具有成本效益且环境友好的去除污染物的方法。在我们最近的工作中，两种具有剂量梯度的聚氯化铝 (PAC) 和聚氯化铝铁 (PAFC) 混凝剂和一种阴离子聚丙烯酰胺 (PAM) 混凝助剂被用于研究它们去除颗粒相关 (PA) 和游离颗粒的潜力。 -通过高通量 qPCR (HT-qPCR) 方法检测到的活 (FL) ARG 和 MGE。结果表明，PAFC 用量为 50.0mg/L 时，PA- 和 FL-ARGs 的去除效率最高（4.67- 和 3.18-logs）。过多的 PAFC 剂量会妨碍去除尺寸分级的 ARG。作为PAC助剂，阴离子PAM（1.0mg/L）对PA-ARG去除的促进作用有限，而在PAC用量为50.0mg/L时，FL-ARG去除率提高了0.34log。拟合曲线表明PAC、PAFC和PAC与PAM联合去除总ARGs和MGEs的最佳化学剂量分别为40.5、64.7和50.0mg/L。此外，我们发现与 PA-ARGs 相比，去除 FL-ARGs 需要更多的凝结剂。通过絮凝对大小分级 ARG 的去除效率可能受混凝剂类型、剂量、助凝剂、Zeta 电位和微生物生活方式（PA 或 FL）的影响。

      Coagulation has been accepted as a cost-effective and environmental-friendly method to remove pollutants. In our recent work, two coagulants of polyaluminum chloride (PAC) and polyaluminum ferric chloride (PAFC) with dosage gradients, and one coagulant aid of anionic polyacrylamide (PAM) were used to investigate their potential to remove particle-associated (PA) and free-living (FL) ARGs and MGEs detected by high throughput qPCR (HT-qPCR) method. The results indicated that the maximum removal efficiencies of PA- and FL-ARGs (4.67- and 3.18-logs) were obtained at the PAFC dosage of 50.0 mg/L. Excessive PAFC dosage can hamper the removal of size-fractionated ARGs. As PAC aid, anionic PAM (1.0 mg/L) had limited effects to promote the removal of PA-ARG, while FL-ARG removal was enhanced by 0.34 log at the PAC dosage of 50.0 mg/L. The fitted curves suggested that the optimal chemical dosages of PAC, PAFC and PAC coupled with PAM in the removal of total ARGs and MGEs were 40.5, 64.7 and 50.0 mg/L, respectively. In addition, we found that much more coagulants were needed to remove FL-ARGs compared to that of PA-ARGs. The removal efficiencies of size-fractionated ARGs by flocculation can be affected by coagulant type, dosage, coagulant aid, Zeta potential and microorganism lifestyle (PA or FL).

https://www.sciencedirect.com/science/article/abs/pii/S0304389420322858