摘要
      抗生素抗性基因（ARGs）被认为是新出现的环境污染物，应由废水处理厂进行控制，以防止其排放到环境中。然而，常规治疗技术通常无法成功减少ARGs，并且低估了无细胞ARGs的释放。在本研究中，与氯化铁（Fe（III））和聚氯化铝（PACl）预处理工艺相比，高铁酸钾（Fe（VI））预处理与超滤（UF）工艺相结合，可去除实际二级出水中的细胞相关和无细胞ARG。研究发现，Fe（VI）氧化能有效地去除总ARGs，尤其是无细胞ARGs。然而，由于二级出水中Fe（VI）形成的带负电颗粒的沉降性较差，与Fe（III）和PACl预处理相比，细胞相关ARGs的去除较少。Fe（VI）和UF的组合去除了最多的ARGs（3.26-5.01 log），这是因为Fe（Ⅵ）有效地去除了无细胞的ARGs.（>2.15 log），并共同拦截了细胞相关ARGs和UF中形成的Fe（VI）颗粒。高通量测序显示，Fe（VI）降低了潜在ARGs宿主的生存能力和相对丰度。Fe（VI）-UF对腐殖类荧光有机物的去除效果最好，对出水的植物毒性最小。此外，Fe（VI）预处理显著减轻了膜污染，这是因为（1）Fe（Ⅵ）去除了会堵塞膜孔的蛋白质类和多糖类物质等大分子；（2）Fe（VI）提高了污染物的亲水性，减少了污染物与膜之间的疏水吸附。总之，Fe（VI）-UF是一种很有前途的技术，可以有效去除ARGs（尤其是无细胞ARGs），缓解废水回收中UF膜的污染。
Abstract
Antibiotic resistance genes (ARGs) are considered as emerging environmental contaminants, which should be controlled by wastewater treatment plants to prevent their discharge into the environment. However, conventional treatment techniques generally fail to successfully reduce ARGs, and the release of cell-free ARGs was underestimated. In this study, potassium ferrate (Fe(VI)) pretreatment combined with ultrafiltration (UF) process was developed to remove both cell-associated and cell-free ARGs in real secondary effluent, compared to ferric chloride (Fe(III)) and poly-aluminum chloride (PACl) pretreatment processes. It was found that total ARGs especially cell-free ARGs were effectively removed by Fe(VI) oxidation. However, due to the poor settleability of the negatively charged particles formed by Fe(VI) in the secondary effluent, the removal of cell-associated ARGs was less compared to Fe(III) and PACl pretreatments. The combination of Fe(VI) and UF removed the most ARGs (3.26 - 5.01 logs) due to the efficient removal of cell-free ARGs by Fe(VI) (> 2.15 logs) and co-interception of both cell-associated ARGs and Fe(VI) formed particles of the UF. High-throughput sequencing revealed that Fe(VI) decreased the viability and relative abundances of the potential ARGs hosts. Fe(VI)-UF exhibited the best performance on humic-like fluorescent organic matters removal, as well as the least phytotoxicity in the effluent. Moreover, membrane fouling was remarkably alleviated by Fe(VI) pretreatment because (1) Fe(VI) removed macromolecules such as protein-like and polysaccharide-like substances which would block the membrane pores, (2) Fe(VI) improved the hydrophilicity of foulants and reduced the hydrophobic adsorption between foulants and membrane. In short, Fe(VI)-UF is a promising technology to efficiently remove ARGs (especially cell-free ARGs) and alleviate UF membrane fouling in wastewater reclamation.

https://www.sciencedirect.com/science/article/abs/pii/S0043135422003360