ClO_(2)消毒工艺对污水处理厂出水超级耐药基因的影响

Effects of Chlorine Dioxide Disinfection on the Profile of the Super Antibiotic Resistance Genes in a Wastewater Treatment Plant

为了研究二氧化氯(chlorine dioxide,ClO_(2))消毒工艺对污水处理厂出水中超级耐药基因(super antibiotic resistance genes,SARGs)的去除效果,对污水处理厂出水消毒前后的水样进行了全年采集,并采用微孔滤膜正压过滤法及核酸吸附柱-洗脱法分别富集水中细菌和胞外核酸后,利用荧光定量PCR技术对其中的9种SARGs进行定量检测.结果表明,无论是胞内还是胞外核酸,均有NDM-1、MCR-1和MEC-A被检测出;同时,ClO_(2)消毒后上述3种SARGs的胞内相对总浓度明显上升(P<0.05),且ClO_(2)消毒对胞内SARGs相对浓度的影响与季节有关,其中春季、夏季和秋季均发生上升,且春季升高最为明显,达2倍,而冬季出水在消毒前后均未测出胞内SARGs;胞外SARGs则在ClO_(2)消毒前后没有明显浓度变化.因此,ClO_(2)消毒不能有效去除污水处理厂出水中胞内和胞外SARGs污染.

In order to study the effects of chlorine dioxide(ClO_(2))disinfection on the super antibiotic resistance genes(SARGs),the final effluents before and after chlorine dioxide were sampled throughout one year in a wastewater treatment plant(WWTP).The bacteria and extracellular nucleic acid were collected using microporous membrane filtration and nucleic acid adsorption particles,respectively.A total of 9 SARGs was detected through a quantitative real-time polymerase chain reaction(qPCR).The results revealed that both intracellular and extracellular NDM-1,MCR-1,and MEC-A could be positively detected in the samples.Overall,ClO_(2)disinfection enhanced the relative abundance of the iSARGs(P<0.05),exhibiting a seasonal pattern,and increasing in the spring,summer,and autumn.In spring,it improved the most,up to twice the abundance.No SARGs were detected positive in the winter,either intracellularly or extracellularly.There was no significant variation in the concentrations of eSARGs before and after ClO_(2)disinfection.Therefore,ClO_(2)disinfection cannot effectively remove iSARGs and eSARGs in the final effluent from the WWTP.