摘要

       污水处理厂作为一种社会生态耦合体，通过对周围社区污水的浓缩、处理和随后的环境排放，常常被认为是抗生素耐药菌（ARB）和抗生素耐药基因（ARGs）的研究热点。虽然研究已经确定了ARB/ARGs在处理过的液体污水中的释放，但对通过废水生物气溶胶排放的潜在分散性知之甚少。本研究的目的是为了更好地确定污水处理厂生物气溶胶对ARB/ARGs潜在环境分布的贡献。在城市污水处理厂的曝气池中，生物气溶胶在逆风和顺风的情况下被立即收集，并从曝气池中获得液态污泥样品。从生物气溶胶和液体样本中，qPCR分析鉴定出44种ARGs，它们对多种抗生素产生耐药性。通过比较样品中的ARG剖面，发现下风生物气溶胶剖面与液态污泥样品中的剖面相似68%。群落16srRNSA基因测序也表明，下风生物气溶胶的分类特征与液态污泥相似，而逆风生物气溶胶的分类特征有明显差异。初步的ARG扩散模型估计，污泥中ARG的排放速率约为10620个基因/小时，表明生物气溶胶有可能被风速带离污水处理厂的源头数公里。这项研究的总体结果表明，污水处理厂过程中产生的生物气溶胶有助于细菌和ARG的排放和扩散，从而可能导致人类暴露和沉积到周围环境中。

       Wastewater treatment plants act as socio-ecological couplers through the concentration, treatment, and subsequent environmental release of sewage collected from surrounding communities and are often considered hotspots for antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). While studies have identified the release of ARB/ARGs in treated liquid sewage, little is known about potential dispersal through wastewater bioaerosol emissions. The aim of this study was to better define the contribution of WWTP bioaerosols to potential environmental distribution of ARB/ARGs. Bioaerosols were collected immediately upwind and downwind from the aeration tanks of a municipal wastewater treatment plant and liquid sludge samples were obtained from the aeration tanks. From the bioaerosol and liquid samples, qPCR assays identified 44 ARGs that confer resistance to a wide range of antibiotics. Comparison of the ARG profiles across samples showed that the downwind bioaerosol profile was 68% similar to the profile found in liquid sludge samples. Community 16S rRNA gene sequencing also showed that downwind bioaerosols had similar taxonomic profiles as those generated from liquid sludge while the upwind profiles showed a distinct difference. Preliminary ARG dispersion modeling estimated an ARG emission rate of ~10,620 genes per hour from the liquid sludge and indicated that the bioaerosols have the potential to be carried kilometers away from the WWTP source based on wind speed. The overall results from this study suggest that bioaerosols generated during WWTP processes can aid in the emission and dispersal of bacteria and ARGs, resulting in a possible route of human exposure and deposition into surrounding environments.

        https://www.sciencedirect.com/science/article/pii/S0048969719325148?via%3Dihub