摘要
南方部分城镇污水浓度偏低,而循环式活性污泥法(CASS)能较好地处理低浓度污水,处理性能与微生物群落特征密切相关,但鲜有研究涉及其沿程微生物群落结构变化。本研究选取广东省某CASS城镇污水厂作为典型案例,分析其沿程污染物去除特征和微生物变化,从微生物学角度探讨污染物的去除机理。结果表明:低进水浓度CASS生化池沿程耗氧有机物(以COD计)、TN、NO_(3)^(-)-N、TP主要在污泥选择区被吸附降解,进水1 h COD和TP值降至最低,NH_(4)^(+)-N主要在主反应区被氧化降解,生化池可去除污水中56.42%的耗氧有机物(以COD计)、41.71%的TN、77.78%的NH_(4)^(+)-N、99.59%的TP。生化池主要优势菌门有变形菌门、拟杆菌门、绿弯菌门和浮霉菌门,变形菌门是影响微生物多样性变化的关键菌门。属水平上,进水1 h选择区Zoogloea、Aeromonas和Thauera丰度较高,主反应区Nitrospira丰度较高;进水结束选择区Nitrospira丰度较高,主反应区Terrimonas和Lactobacillus丰度较高;沉淀1 h选择区Thauera丰度提高,主反应区Nitrosomonas丰度较高,主要发生氨氧化;闲置结束选择区脱氮菌类型多丰度高,主反应区Sulfuritalea、Haliangium、Zoogloea丰度较高。沿程功能性微生物丰度变化与污染物浓度变化相对应。NO_(3)^(-)-N对微生物群落结构的塑造影响最显著(解释度为38.92%)。氮代谢途径表明沿程主反应区均发生全程硝化反硝化,选择区均发生短程硝化和全程反硝化,除进水1 h外,其余阶段选择区的反硝化功能基因丰度均比主反应区高。
The concentration of sewage in some cities in southern China is low,while it can be treated by cyclic activated sludge system(CASS),and the treatment performance is closely related to the microbial community characteristics,but few studies had addressed the changes in microbial community structure along the process.In this study,a CASS urban wastewater plant in Guangdong Province was selected as a typical case to analyse the pollutant removal characteristics and microbial changes along the process,and to explore the pollutant removal mechanism from a microbiological perspective.The results showed that oxygen-consuming organic matter(COD),TN,NO_(3)^(-)-N and TP were mainly adsorbed and degraded in the sludge selection zone along the CASS biochemical tank with low influent concentration,and COD and TP values in the influent decreased to minimum at 1 hour,while NH_(4)^(+)-N was mainly oxidized and degraded in the main reaction zone.Biochemical tank could remove 56.42% of oxygen-consuming organic matter(COD),41.71% of TN,77.78% of NH_(4)^(+)-N,and99.59% of TP from the sewage.The main dominant bacterial phyla in the biochemical tank were Amoebacteria,Bacteroidetes,Green Campylobacter and Phyllobacterium,of which Amoebacteria was the key phylum influencing the microbial diversity.At the genus level,high abundance of Zoogloea,Aeromonas and Thauera occurred in the selection zone,and high abundance of Nitrospira occurred in the main reaction zone after 1 hour feeding.At the end of feeding,high abundance of Nitrospira occurred in the selection zone,high abundance of Terrimonas and Lactobacillus occurred in the main reaction zone.After 1 hour of sedimentation,the abundance of Thauera increased in the selection zone and high abundance of Nitrosomonas occurred in the main reaction zone,where ammonia oxidation mainly occurred.At the end of idle,high abundance and types of denitrifying bacteria occurred in selection zone,and high abundance of Sulfuritalea,Haliangium and Zoogloea occured in the main reaction zone.Changes in the abundance of functional microorganisms along the process corresponded to changes in pollutant concentrations.NO_(3)^(-)-N had the most significant effect on shaping the structure of the microbial community(38.92% explained).The nitrogen metabolic pathway showed that nitrification and denitrification occurred along the main reaction zone,short-course nitrification and full denitrification occurred in the selection zone,and the abundance of denitrification functional genes was higher in the selection zone than in the main reaction zone at all stages except for 1 hour feeding.
作者
梁子阳
彭嘉敏
张泳纯
仲海涛
余光伟
LIANG Ziyang;PENG Jiamin;ZHANG Yongchun;ZHONG Haitao;YU Guangwei(College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,China;Guangdong Provincial Key Laboratory of Agricultural&Rural Pollution Abatement and Environmental Safety,Guangzhou 510642,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第10期3219-3230,共12页
Chinese Journal of Environmental Engineering
基金
广东省科技计划项目(2021B1212040008)。
关键词
低进水浓度
CASS工艺
脱氮除磷
微生物群落
low influent concentrations
CASS process
nitrogen and phosphorus removal
microbial communities
