摘要

    基于硫酸盐自由基（自由基dotSO4-的）的调节方法，例如零价铁（ZVI，即Fe0）或亚铁离子（Fe2 +）活化的过氧二硫酸盐（S2O82-），最近已经开发出来以改善污泥的脱水性，但目前尚不清楚它们如何影响污水污泥中的细胞内和细胞外抗生素抗性基因（ARG）。在这项研究中，发现在酸性初始污泥pH下使用ZVI / S2O82-或Fe2 + / S2O82-系统进行的调理处理可去除污水污泥中的细胞内ARGs和intI1和细胞外intI1，但会导致污泥的积累。条件污泥中aadA-01，aadA-02，aadA1，aadA2-03和strB的细胞外ARG。在用ZVI / S2O82-或Fe2 + / S2O82-处理污泥的过程中，ARGs和intI1的细菌宿主被严重溶解，从而将细胞内ARGs和intI1释放到细胞外环境，从而去除了污泥中的细胞内ARGs和intI1，同时释放了ARGs和intI1主要由产生的自由基dotSO4-降解，以减弱大多数细胞外ARG和intI1。但是，自由基dotSO4-对aadA-01，aadA-02，aadA1，aadA2-03和strB的细胞外ARG的降解能力相对较低，导致它们在条件污泥中积累。因此，可以使用基于自由基dotSO4的调理方法来减少污泥中的ARGs，但是污泥脱水滤液的后续处理需要引起更多关注。

    Sulfate radical (radical dotSO4−)-based conditioning methods, such as zero-valent iron (ZVI, i.e., Fe0) or ferrous iron (Fe2+) activated peroxydisulfate (S2O82-), have recently developed to improve sludge dewaterability, but it remains unclear how they impact the intracellular and extracellular antibiotic resistance genes (ARGs) in sewage sludge. In this study, it was found that conditioning treatments that used ZVI/S2O82- or Fe2+/S2O82- system, at an acidic initial sludge pH, removed the intracellular ARGs and intI1 and the extracellular intI1 from sewage sludge, but led to the accumulation of extracellular ARGs of aadA-01, aadA-02, aadA1, aadA2-03, and strB in conditioned sludge. During sludge conditioning with ZVI/S2O82- or Fe2+/S2O82-, bacterial hosts of ARGs and intI1 were seriously lysed to release the intracellular ARGs and intI1 to the extracellular environment, thus removing intracellular ARGs and intI1 in sludge, while the released ARGs and intI1 were primarily degraded by the produced radical dotSO4− to attenuate most extracellular ARGs and intI1. However, the relatively lower degradation ability of radical dotSO4− for extracellular ARGs of aadA-01, aadA-02, aadA1, aadA2-03, and strB led to their accumulation in conditioned sludge. Therefore, radical dotSO4−-based conditioning methods can be employed to reduce ARGs in sludge, but the subsequent treatment of sludge dewatering filtrate requires more attention.

    https://www.sciencedirect.com/science/article/abs/pii/S0304389419319363