剩余污泥热碱脱水过程中胞内外抗生素抗性基因丰度变化分析

Variation of intracellular and extracellular ARGs abundance in waste activated sludge during thermal-alkali dewatering

剩余污泥含有高丰度的抗生素抗性基因(ARGs)。随着剩余污泥的脱水,胞内ARGs(iARGs)可能会逐渐转化为胞外ARGs(eARGs)。为探究ARGs在剩余污泥脱水过程中的分布特征,分析了热碱预处理(TAP)对剩余污泥脱水前后iARGs和eARGs丰度的变化。结果表明,TAP能够有效提高污泥脱水率,并且借助响应曲面法(RSM)确定了最优工况,在pH=11、温度90℃条件下处理80 min后,其脱水率达到41.0%。随着脱水率提升,iARGs不断转化形成eARGs,TAP后污泥滤液中eARGs的绝对丰度常用对数提高了0.2~1.8。eARGs丰度的上升,增加了ARGs传播风险,给污泥脱水技术带来了巨大挑战。

Waste activated sludge(WAS)contains high abundance of antibiotic resistance genes(ARGs).With the WAS dewatering,intracellular ARGs(iARGs)may gradually transform into extracellular ARGs(eARGs).In order to explore the characteristics of ARGs abundance in WAS dewatering,the change of iARGs and eARGs abundance was analyzed in the WAS before and after thermal-alkali pretreatment(TAP).The results showed that TAP could effectively enhance the dewatering effeciency of WAS,and the optimal condition was determined by response surface methodology(RSM).The dewatering effeciency reached 41.0%after 80 min at pH=11 and 90℃.iARGs were transformed into eARGs during WAS dewatering.The common logarithm of absolute abundance of eARGs increased by 0.2-1.8 significantly after TAP,which increased the risk of ARGs spread and brought great challenges to WAS dewatering.