人工湿地去除抗生素抗性基因的研究进展

Research Progress on Removing Antibiotic Resistance Genes in Constructed Wetlands

抗生素抗性基因(ARGs)在环境中的污染现状和危害逐渐受到重视.常规的水处理工艺在减少抗生素耐药菌(ARB)方面表现出非常好的效果.然而,即使在消毒过程中ARB完全失活,产生游离的ARGs也可能通过转化或转导等手段整合到其他微生物体内,使ARGs在环境中传播和扩散.因此,需要有特定的工艺处理废水中的ARGs.人工湿地是目前有效且经济环保的废水处理工艺,并且已有大量研究表明在去除抗生素和ARGs方面有显著效果.通过综述目前国内外人工湿地水处理系统对ARGs的去除效率的研究进展,结果表明,潜流人工湿地相较于表面流人工湿地对ARGs的去除效率更高.人工湿地对ARGs的去除效率因人工湿地强化类型、植物、温度和pH等因素而异,在去除环境中ARGs的应用有广阔的前景,同时也面临挑战.

Recently,the issue of environmental pollution and emerging antibiotic resistance genes(ARGs)has gradually gained attention.Antibiotic resistant bacteria(ARB)can be effectively reduced via the conventional water treatment processes.Although the ARB are completely inactivated during the disinfection process,the free ARGs can be incorporated into other microorganisms through transformation or transduction,allowing the ARGs to spread and propagate.Therefore,ARGs in wastewater must be handled by a specific process.It has been demonstrated in several studies that treatment using constructed wetland is an effective,economical,and environmentally friendly method of removing antibiotics and resistance genes from wastewater.Here,the research progress on the removal effect of constructed wetland water treatment systems on ARGs at home and abroad was reviewed.The results revealed that the removal efficiency of ARGs in subsurface flow constructed wetland was higher than that in surface flow-constructed wetlands.The composite-constructed wetland had significantly improved removal efficiency of ARGs compared to that in the ordinarily constructed wetland;however,the parameter setting of the composite process still requires further research.Several studies have reported that the removal efficiency of ARGs using constructed wetlands varies depending on the type of constructed wetland enhancement,plant,temperature,pH,and other factors.The results of the current study revealed that cross-mixing was the best way to combine plants,whereas the selection of plant species has not yet shown a clear dominant species.Temperature and pH affected the removal of ARGs by altering the microbial community in constructed wetlands.Although longer hydraulic residence time could increase the removal efficiency of ARGs,it also increased the enrichment risk of ARGs.The selection of constructed wetland substrate type should focus on fillers with a high specific surface area;the flow direction of the up-flow type was generally more efficient than the down-flow type in removing ARGs.In conclusion,the various factors(such as,the constructed wetland type,substrate type,hydraulic retention time,ambient temperature,and plant species)need to be integrated into the design of the constructed wetland system parameters to achieve the most effective treatment effect.The application of constructed wetlands in removing ARGs from the environment has broad prospects but also faces challenges.