摘要
      施用粪肥后，抗生素和重金属在土壤中共存，对环境和人类健康都有很高的风险，因此迫切需要有效的修复方法。本研究探讨了电动修复（EKR）对共污染水稻土中抗生素耐药性和砷（As）的协同作用。与不施用猪粪相比，施用猪粪（EKR-PD）的土壤EKR处理表现出更好的修复效率。详细地说，由于EKR-PD的电流密度相对较高，修复7天后，有效As的含量和抗生素抗性细菌（ARB）的丰度分别下降了25.2%−41.4%和9.5%−21.1%。电场的作用导致了33.9%的抗生素降解。具有核糖体保护和酶失活类型的抗生素抗性基因（ARGs）更容易去除，EKR-PD的去除率为37.8%-41.6%。Brevundimonas是修复过程中差异最大的物种。芽孢杆菌和梭状芽孢杆菌是电场中ARGs的潜在宿主菌。膜传输可能是微生物应对电场和共污染环境压力的有效策略。这项研究支持EKR在粪肥施用下重金属共同污染和抗生素耐药性中的潜在作用。
Abstract
The co-existence of antibiotics and heavy metals in soil with manure application poses high risk to both environment and human health, and thus effective remediation methods are in urgent need. This study investigated the synergistic effects of electrokinetic remediation (EKR) on antibiotic resistance and arsenic (As) in co-contaminated paddy soils. EKR treatments in soil amended with pig manure (EKR-PD) showed better remediation efficiency compared with that without pig manure. In detail, the content of available As and the abundance of antibiotic-resistant bacteria (ARB) decreased by 25.2 %−41.4 % and 9.5 %−21.1 % after 7-d remediation, respectively, due to a relatively higher current density for EKR-PD. The role of the electric field contributed to 33.9 % of antibiotic degradation. Antibiotic resistance genes (ARGs) with ribosomal-protection and enzymatic-deactivation types were easier to remove, with the removal ratio of 37.8 %−41.6 % in EKR-PD. Brevundimonas was the most significantly different species during remediation. Bacillus and Clostridium_ sensu_stricto_1 were potential host bacteria of ARGs in the electric field. Membrane transport might be an effective strategy for microorganisms to respond to the stress of both electric field and co-contaminated environments. This study supports the potential role of EKR in the co-contamination of heavy metals and antibiotic resistance under manure application.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422016910