生物转盘耦合垂直流人工湿地对生活污水的净化效果及其微生物群落结构特征

Purification Effect of Bio-rotary Coupled Vertical Flow Constructed Wetland on Domestic Wastewater and Characteristics of Microbial Community Structure.

为提高垂直流人工湿地对农村生活污水的净化效率,构建生物转盘耦合垂直流人工湿地系统。以实际生活污水为对象,研究耦合系统对生活污水的净化效果,并采用高通量测序分析其微生物群落结构特征,揭示微生物群落结构与污染物处理效率之间的关系。结果表明:系统对化学需氧量(COD)、氨氮(NH_(4)^(+)-N)和总磷(TP)的去除率分别为64.97%、86.84%和79.18%,出水平均质量浓度分别为71.70、3.21和0.67 mg·L^(-1);新型湿地系统适于处理COD、ρ(NH_(4)^(+)-N)和ρ(TP)分别为<250、30~50和<2 mg·L^(-1)的生活污水,且24 h为系统最佳运行时间;2个系统中不同填料区微生物种类无较大差别,相对丰度差别较大,共有的优势菌门、优势菌纲和优势菌目分别有5、8和10类,系统中除氮微生物主要为氢噬胞菌属(Hydrogenophaga)、假单胞菌属(Pseudomonas)等,除磷功能微生物主要有假单胞菌属、脱氯单胞菌(Dechloromonas)、不动杆菌属(Acinetobacter)、红球菌属(Rhodococcus)等;细菌群落影响污染物的去除,NH_(4)^(+)-N、TP和COD去除率与变形菌门和蓝细菌门呈显著正相关,TP浓度与绿弯菌门、COD与绿菌门呈显著正相关(P<0.05);各污染物主要在火山石区、沸石区被去除。研究结果明确了生物转盘耦合垂直流人工湿地微生物群落结构特征及其与污染物去除之间的关系,可为进一步提高人工湿地的处理效率提供科学参考。

The present study is aimed at improving the efficiency of vertical flow artificial wetlands in the purification of rural domestic wastewater,constructing a bio-rotary-coupled vertical flow constructed wetland system,and revealing the relationship between the structure of the microbial community and the pollutant treatment efficacy.Actual domestic wastewater is used as the research object in order to study the purification effects of bio-rotary-coupled vertical flow wetland construction and the microbial community structure,as analyzed by high-throughput sequencing.The results show that the removal rates of chemical oxygen demand(COD),ammonium-ion nitrogen content(NH_(4)^(+)-N),and total phosphorus(TP)were 64.97%,86.84%and 79.18%,respectively,with the average concentrations of 71.70,3.21,and 0.67 mg·L^(–1),respectively,in the effluent.These results demonstrate that the proposed wetland system is suitable for treating domestic wastewater with COD,NH_(4)^(+)-N and TP concentrations of<250,30-50 and<2 mg·L^(-1),respectively,and 24 h is the optimal operating time of the system;There were no significant differences in microorganism species in each filling area(volcanic stone and zeolite)of the bio-rotary-coupled vertical flow system and the conventional treatment system,while the relative abundances varied greatly.Each system contains 5,8,and 10 categories of dominant phylum,class,and order,respectively,with little differences in species.In particular,the nitrogen removing microorganisms in the new system are mainly Hydrogenophaga and Pseudomonas,while the phosphorus-removing microorganisms are mainly Pseudomonas,Dechloromonas,Acinetobacter,and Rhodococcus.Notably,the NH_(4)^(+)-N,TP,and COD removal are positively correlated with the presence of Proteobacteria and Cyanobacteria,while the TP concentration is positively correlated with Chloroflexi,and the COD is positively correlated with Chlorobi(P<0.05),and each pollutant is mainly removed in the volcanic stone and zeolite areas.The present results clarify the structural characteristics of the microbial community in the bio-rotary coupled vertical flow constructed wetland and its relationship with pollutant removal,thus providing a scientific reference for further improving the treatment efficiency of the artificial wetland.