摘要

       废水中残留的固体物质是一个重要的抗生素耐药基因库。虽然处理技术可以降低残余废水固体中的ARG水平，但这些技术在随后的土地利用过程中对土壤中ARG的影响尚不清楚。在这项研究中，我们研究了多种处理技术（空气干燥、好氧消化、中温厌氧消化、高温厌氧消化、巴氏杀菌和碱性稳定）在废水固体改良土壤微观结构中对ARGs和1级整合子命运的影响。应用定量聚合酶链反应对6个ARGs[erm（B）、qnrA、sul1、tet（A）、tet（W）和tet（X）]、1类整合素（intI1）的整合酶基因和16srrna基因进行了定量。在所有微观结构中，ARGs和intI1的数量都减少了，但高温厌氧消化、碱性稳定化和巴氏杀菌导致ARGs和intI1最广泛的腐烂，通常达到与未使用废水固体的对照微观结构相似的水平。相比之下，使用其他处理技术降低ARGs和intI1的速率大体相似，通常变化不到2倍。这些结果表明，废水固形物处理技术可以降低ARGs和intI1在土壤中的持久性。

         Residual wastewater solids are a significant reservoir of antibiotic resistance genes (ARGs). While treatment technologies can reduce ARG levels in residual wastewater solids, the effects of these technologies on ARGs in soil during subsequent land-application are unknown. In this study we investigated the use of numerous treatment technologies (air drying, aerobic digestion, mesophilic anaerobic digestion, thermophilic anaerobic digestion, pasteurization, and alkaline stabilization) on the fate of ARGs and class 1 integrons in wastewater solids-amended soil microcosms. Six ARGs [erm(B), qnrA, sul1, tet(A), tet(W), and tet(X)], the integrase gene of class 1 integrons (intI1), and 16S rRNA genes were quantified using quantitative polymerase chain reaction. The quantities of ARGs and intI1 decreased in all microcosms, but thermophilic anaerobic digestion, alkaline stabilization, and pasteurization led to the most extensive decay of ARGs and intI1, often to levels similar to that of the control microcosms to which no wastewater solids had been applied. In contrast, the rates by which ARGs and intI1 declined using the other treatment technologies were generally similar, typically varying by less than 2 fold. These results demonstrate that wastewater solids treatment technologies can be used to decrease the persistence of ARGs and intI1 during their subsequent application to soil.

       https://pubs.acs.org/doi/10.1021/acs.est.7b04760