Zheng Quan, Zhang Yinqiao, Wang Yujue, Yu Gang
School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
Chemosphere. 2023 Apr;319:138039. doi: 10.1016/j.chemosphere.2023.138039. Epub 2023 Feb 2.
The electro-peroxone (EP) process is an electricity-based oxidation process enabled by electrochemically generating hydrogen peroxide (HO) from cathodic oxygen (O) reduction during ozonation. In this study, the removal of antibiotic resistant bacteria (ARB) and plasmid-encoded antibiotic resistance genes (ARGs) during groundwater treatment by ozonation alone and the EP process was compared. Owing to the HO-promoted ozone (O) conversion to hydroxyl radicals (•OH), higher •OH exposures, but lower O exposures were obtained during the EP process than ozonation alone. This opposite change of O and •OH exposures decreases the efficiency of ARB inactivation and ARG degradation moderately during the EP process compared with ozonation alone. These results suggest that regarding ARB inactivation and ARG degradation, the reduction of O exposures may not be fully counterbalanced by the rise of •OH exposures when changing ozonation to the EP process. However, due to the rise of •OH exposure, plasmid DNA was more effectively cleaved to shorter fragments during the EP process than ozonation alone, which may decrease the risks of natural transformation of ARGs. These findings highlight that the influence of the EP process on ARB and ARG inactivation needs to be considered when implementing this process in water treatment.
电-过氧工艺（EP）是一种基于电的氧化工艺，通过在臭氧化过程中阴极氧（O）还原电化学产生活性氢（HO）来实现。在本研究中，比较了单独臭氧化和电-过氧工艺处理地下水过程中对抗生素抗性细菌（ARB）和质粒编码抗生素抗性基因（ARGs）的去除情况。由于HO促进臭氧（O）转化为羟基自由基（•OH），与单独臭氧化相比，电-过氧工艺过程中获得了更高的•OH暴露量，但O暴露量较低。与单独臭氧化相比，O和•OH暴露量的这种相反变化适度降低了电-过氧工艺过程中ARB失活和ARG降解的效率。这些结果表明，在从臭氧化转变为电-过氧工艺时，就ARB失活和ARG降解而言，O暴露量的减少可能无法完全被•OH暴露量的增加所抵消。然而，由于•OH暴露量的增加，与单独臭氧化相比，电-过氧工艺过程中质粒DNA更有效地被切割成更短的片段，这可能会降低ARG自然转化的风险。这些发现突出表明，在水处理中实施该工艺时，需要考虑电-过氧工艺对ARB和ARG失活的影响。
