Impacts of backwashing on micropollutant removal and associated microbial assembly processes in sand filters  

作　　者：Donglin Wang Jie Zhou Hui Lin Junwen Chen Jing Qi Yaohui Bai Jiuhui Qu 

机构地区：[1]Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Center for Water and Ecology,State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of Environmental Science & Engineering》2023年第3期87-92,共6页环境科学与工程前沿（英文）

基　　金：the National Key R&D Program of China(No.2018YFE0204101);the National Natural Science Foundation of China(No.51778603);the Alliance of International Science Organizations(ANSO-CR-KP-2020-05).

摘　　要：Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filters.Here,we used a series of manganese and quartz sand filters under empty bed contact times(EBCTs)of 2 h and 4 h to explore variations in micropollutant degradation and temporal dynamics of the microbial community after backwashing.The results showed that the removal efficiencies of caffeine,sulfamethoxazole,sulfadiazine,trimethoprim,atrazine,and active biomass recovered within 2 d after backwashing in both types of sand filters at 2-h EBCT,but the recovery of sulfadiazine and trimethoprim was not observed at 4-h EBCT.Moreover,the removal efficiency of atenolol increased after backwashing in the manganese sand filters,whereas maintained almost complete removal efficiency in the quartz sand filters at both EBCTs.Pearson correlation analysis indicated that microbial community composition gradually recovered to the pre-backwashing level(R increased from 0.53 to 0.97)at 2-h EBCT,but shifted at 4-h EBCT(R<0.25)after backwashing.Furthermore,the compositions of the recovered,depleted,and improved groups of microbes were distinguished by applying hierarchical clustering to the differentially abundant amplicon sequence variants.The cumulative relative abundance of recovered microbes at 2-h EBCT was 82.76%±0.43%and 46.82%±4.34%in the manganese and quartz sand filters,respectively.In contrast,at 4-h EBCT,the recovered microbes dropped to 15.55%–25.69%in both types of sand filters.

关 键 词：Sand filter BACKWASHING RECOVERY MICROPOLLUTANTS Community composition 

分 类 号：X513[环境科学与工程—环境工程]