Antibiotic resistance genes (ARGs) have been defined as new environmental pollutants, which have been frequently detected in secondary effluent from wastewater treatment plants and have become a potential threat to human health and ecological security. In this study, the combined process of slow filtration and low-pressure nanofiltration (NF) was used to thoroughly remove ARGs and dissolved organic carbon (DOC) from secondary effluent. In addition, the removal efficiency of ARGs was discussed and the influence of the combined process on the membrane fouling mechanism was analyzed. The results showed that the combined biofilm slow filtration–NF process can effectively reduce ARGs and DOC in the secondary effluent. The removal amount of the four ARGs (tet A, tet W, sul I, and sul II) was in the range of 4.83- to 5.67-log and the removal rate of DOC was 82.5%. Four ARGs present in the water had a significant positive correlation with the total number of microorganisms, integron intI 1, and DOC concentration, validating that the removal of the above indicators could help reduce different types of ARGs. Compared with the direct NF and slow filtration–NF, the rate of decline of the membrane specific flux of biofilm slow filtration–NF was the lowest, with a minimal membrane fouling index. The membrane fouling characteristic curve also showed that the combined biofilm slow filtration–NF process exhibited mild membrane fouling. Overall, the combined slow filtration–NF process is considered to be a better process for removing ARGs.

中文翻译：

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纳滤解决二级出水中抗生素抗性基因造成的膜污染问题

抗生素抗性基因(Antibiotic resistance genes, ARGs)被定义为新型环境污染物，在污水处理厂二级出水中频繁检出，已成为对人类健康和生态安全的潜在威胁。在本研究中，采用慢速过滤和低压纳滤 (NF) 的组合工艺彻底去除二级出水中的 ARGs 和溶解有机碳 (DOC)。此外，讨论了ARGs的去除效率，分析了组合工艺对膜污染机理的影响。结果表明，生物膜慢滤-纳滤联合工艺可有效降低二级出水中的ARGs和DOC。四种 ARGs ( tet A , tet W , sul I, 和sul II ) 在 4.83-5.67-log 范围内，DOC 去除率为 82.5%。水中存在的四种ARGs与微生物总数、整合子intI 1和DOC浓度呈显着正相关，证实去除上述指标有助于减少不同类型的ARGs。与直接纳滤和慢滤-纳滤相比，生物膜慢滤-纳滤的膜比通量下降率最低，膜污染指数最小。膜污染特征曲线也表明生物膜慢速过滤-纳滤组合工艺表现出轻微的膜污染。总体而言，组合的慢速过滤-NF 工艺被认为是去除 ARGs 的更好工艺。