F/M对活性污泥微生物生态网络的影响  

Impacts of F/M Ratio on Microbial Networks in Activated Sludge

作　　者：张冰 孙晨翔 文湘华 ZHANG Bing;SUN Chen-xiang;WEN Xiang-hua(College of Life and Environmental Sciences,Minzu University of China,Beijing 100081,China;State Key Joint Laboratory of Environmental Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China)

机构地区：[1]中央民族大学生命与环境科学学院,北京100081 [2]清华大学环境学院环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《环境科学》2022年第3期1529-1534,共6页Environmental Science

基　　金：国家自然科学基金项目(52070109)。

摘　　要：为深入理解有机负荷率(F/M)对活性污泥(AS)微生物群落的影响,以F/M(以BOD/MLVSS计,下同)设计建议范围0.2~0.5 kg·(kg·d)^(-1)为依据,将采集的AS样品分为3组,运用基于随机矩阵理论(RMT)的网络分析方法,解析了不同F/M条件下的AS微生物生态网络拓扑性质及结构特征.结果表明,较低的F/M能够显著降低AS微生物群落的多样性和均匀度,但较高的F/M未对群落多样性和均匀度产生显著影响,表明多样性指标对高F/M不敏感.不同F/M条件下微生物生态网络均具有无标度、小世界和模块化的特征,但F/M较高或较低均会降低网络的规模及复杂度.当F/M在0.2~0.5 kg·(kg·d)^(-1)范围内,生态网络具有最多的总节点数、最大的平均聚集系数以及最小的平均路径距离;此时的网络规模最大,网络复杂度最高,AS群落的结构和功能也因此最为稳定.不同F/M条件下AS微生物间的正负相互作用关系也存在差异:其中F/M较低时,网络中节点的正连接比例为71.1%;当F/M在0.2~0.5 kg·(kg·d)^(-1)时,微生物间的正相关关系最多,为76.8%;当F/M超过0.5 kg·(kg·d)^(-1)时,正相关关系降至60.0%.此外,F/M在0.2~0.5 kg·(kg·d)^(-1)时网络识别出了24个关键物种,而F/M低于0.2 kg·(kg·d)^(-1)和高于0.5 kg·(kg·d)^(-1)时,网络仅识别出4个和7个关键物种.上述性质均表明F/M在0.2~0.5 kg·(kg·d)^(-1)范围内,AS微生物可能会更高效地进行物质传输和利用,同时抵御环境扰动的能力也更强,群落稳定性更高.The performance of wastewater treatment plants(WWTPs)mainly relies on the microbial community in activated sludge(AS).The food to microorganisms(F/M)ratio is an important operational parameter,the recommended value of which is between 0.2 and 0.5 kg·(kg·d)^(-1).The F/M directly influences microbial growth and metabolism,but how the F/M ratio affects AS microbial networks and the related mechanisms remain unclear.In this study,63 AS samples with different F/M ratios were analyzed by utilizing a random-matrix-theory based network pipeline.Firstly,all 63 samples were divided into three groups based on their F/M ratios(lower F/M group,normal F/M group,and higher F/M group).The results indicated that the lower F/M decreased microbial diversity and evenness significantly,but the higher F/M had no significant effects on the diversity of the microbial community.All three constructed networks were scale-free,small world,and modular,but network size and complexity were decreased in the lower and higher F/M groups.The network of the normal F/M ratio group was detected with the most nodes,the highest average clustering coefficient,and the shortest geodesic distance.The proportion of positive links was 76.8%when the F/M was within the normal range.On the contrary,71.1%and 60.0%of positive links were identified when the F/M was below 0.2 and above 0.5 kg·(kg·d)^(-1).Moreover,24 keystones were detected in the normal F/M network,whereas only 4 and 7 keystones were detected in the lower and higher F/M networks.Overall,our results provided clear evidence that the AS microbial community could be more stable and resilient to environmental disturbance when the F/M ratio was between 0.2 and 0.5 kg·(kg·d)^(-1).

关 键 词：活性污泥(AS) 微生物群落 有机负荷率(F/M) 生态网络 关键物种 

分 类 号：X172[环境科学与工程—环境科学]