典型纳米污染物和重金属复合胁迫抑制污水生物脱氮的机制解析  

Mechanism Analysis of typical Nano Pollutants and Heavy Metals Combined Stress Inhibiting Biological Nitrogen Removal from Wastewater

作　　者：王秋利 蒙小俊 WANG Qiuli;MENG Xiaojun(School of Tourism,Resources and Environment,Ankang University,Ankang 725000,China)

机构地区：[1]安康学院旅游与资源环境学院,陕西安康725000

出　　处：《水处理技术》2023年第8期104-109,共6页Technology of Water Treatment

基　　金：陕西省科技厅青年基金项目(2021JQ-835);陕西省教育厅专项(2013JK0891,21JK0464);陕西省院士专家工作站。

摘　　要：为明确金属纳米颗粒与重金属复合胁迫对活性污泥生物脱氮的影响,通过改变进水纳米Ag和Cu的浓度,探究了两者复合胁迫对生物脱氮的影响并揭示相关机制。结果表明,纳米Ag和Cu复合胁迫影影响生物脱氮性能,且与纳米Ag和Cu的暴露浓度有关。2.0 mg/L纳米Ag复合15.0 mg/L Cu组内COD和TN去除率下降至61.5%~68.9%和61.6%~62.3%,低于纳米Ag或Cu单独影响。此外,复合胁迫降低了污泥沉降性和有机质的含量并促进了胞外聚合物(EPS)的合成,EPS最大值高达125.6~128.5 mg/g,其中蛋白质和多糖的含量均显著增加。微生物群落结构受到纳米Ag和Cu污染而发生改变,并降低了Proteobacteria、Bacteroidetes和Nitrospirae的相对丰度。脱氮功能基因分析证实纳米Ag和Cu复合污染降低了生物脱氮相关机制。研究结果为金属纳米颗粒与重金属复合污染下生物脱氮技术提供了一定的数据支撑和理论依据。In order to clarify the effect of metal nanoparticles and heavy metals combined stress on biological nitrogen removal of activated sludge,the influence of the combined stress of metal nanoparticles and heavy metals on biological nitrogen removal was explored by changing the concentration of nano Ag and Cu in influent water,and the relevant mechanism was revealed.The results showed that the combined stress of nano Ag and Cu affected the biological denitrification performance and was related to the exposure concentration of nano Ag and Cu.The removal efficiency of COD and TN in the 2.0 mg/L nano Ag compound 15.0 mg/LCu group decreased to 61.5%~68.9%and 61.6%~62.3%,lower than that affected by nano Ag or Cu alone.In addition,combined stress reduced sludge sedimentation and organic matter content,and promoted the synthesis of extracellular polymer(EPS).The maximum value of EPS reached 125.6~128.5 mg/g,in which the content of protein and polysaccharide increased significantly.The microbial community structure is changed by nano Ag and Cu pollution,and the relative abundance of Proteobateria,Bacteroidetes and Nitrospirae is reduced.Gene analysis of denitrification function confirmed that the combined pollution of nano Ag and Cu reduced the relevant mechanism of biological denitrification.The research results provide some data support and theoretical basis for biological nitrogen removal technology under the combined pollution of metal nanoparticles and heavy metals.

关 键 词：复合污染 生物脱氮 污泥特征 胞外聚合物 微生物群落特征 

分 类 号：X703.1[环境科学与工程—环境工程]