摘要

       为了减轻与在农业中使用处理过的废水相关的对人类健康的潜在影响，需要在废水回用过程中仔细监测抗生素抗性基因 (ARG)，并应通过开发高效处理技术。本研究的目的是评估用于农业回用城市废水的新型技术处理解决方案的 ARGs 减少效率。提议的解决方案包括先进的生物处理（序批式生物过滤颗粒反应器，SBBGR），在实验室和中试规模上进行分析，然后是砂过滤和两个不同的消毒最终阶段：紫外线（UV）辐射和过乙酸（PAA）处理.通过聚合酶链反应 (PCR)，分析了 9 个 ARG（ampC、mecA、ermB、sul1、sul2、tetA、tetO、tetW、vanA）的存在，并通过定量 PCR (qPCR) 确定了它们的去除。将获得的结果与总细菌（16S rDNA 基因）和粪便污染指标（大肠杆菌 uidA 基因）的减少进行比较。在原废水中仅检测到四个分析的基因（ermB、sul1、sul2、tetA），它们的丰度估计为 3.4 ± 0.7 x104 - 9.6 ± 0.5 x109 和 1.0 ± 0.3 x103 至 3.0 ± 0.1 x107 基因拷贝/mL分别在未经处理的废水和处理过的废水中。结果表明，SBBGR 技术有望减少 ARG，实现稳定的去除性能，范围为 1.0 ± 0.4 至 2.8 ± 0.7 log 单位，与传统活性污泥处理所报道的相当或更高。取而代之的是，没有获得归一化为总细菌含量 (16S rDNA) 的 ARG 量的减少，这表明这些基因与总细菌一起被移除，而不是被专门消除。通过砂过滤获得了增强的 ARG 去除，而在我们的研究中测试的 UV 和 PAA 消毒处理都没有实现减少。

       In order to mitigate the potential effects on the human health which are associated to the use of treated wastewater in agriculture, antibiotic resistance genes (ARGs) are required to be carefully monitored in wastewater reuse processes and their spread should be prevented by the development of efficient treatment technologies. Objective of this study was the assessment of ARGs reduction efficiencies of a novel technological treatment solution for agricultural reuse of municipal wastewaters. The proposed solution comprises an advanced biological treatment (Sequencing Batch Biofilter Granular Reactor, SBBGR), analysed both al laboratory and pilot scale, followed by sand filtration and two different disinfection final stages: ultraviolet light (UV) radiation and peracetic acid (PAA) treatments. By Polymerase Chain Reaction (PCR), the presence of 9 ARGs (ampC, mecA, ermB, sul1, sul2, tetA, tetO, tetW, vanA) were analysed and by quantitative PCR (qPCR) their removal was determined. The obtained results were compared to the reduction of total bacteria (16S rDNA gene) and of a faecal contamination indicator (Escherichia coli uidA gene). Only four of the analysed genes (ermB, sul1, sul2, tetA) were detected in raw wastewater and their abundance was estimated to be 3.4 ± 0.7 x104 - 9.6 ± 0.5 x109 and 1.0 ± 0.3 x103 to 3.0 ± 0.1 x107 gene copies/mL in raw and treated wastewaters, respectively. The results show that SBBGR technology is promising for the reduction of ARGs, achieving stable removal performance ranging from 1.0 ± 0.4 to 2.8 ± 0.7 log units, which is comparable to or higher than that reported for conventional activated sludge treatments. No reduction of the ARGs amount normalized to the total bacteria content (16S rDNA), was instead obtained, indicating that these genes are removed together with total bacteria and not specifically eliminated. Enhanced ARGs removal was obtained by sand filtration, while no reduction was achieved by both UV and PAA disinfection treatments tested in our study.

https://www.sciencedirect.com/science/article/abs/pii/S0048969716315005