人工湿地对抗生素复合污染的净化效果及微生物群落响应

为研究人工湿地对氟喹诺酮类(FQs)、磺胺类(SFs)、四环素类(TCs)抗生素的净化性能及微生物群落的响应,以运行多年的单层及多层(3层、6层)基质结构的水平潜流入工湿地为对象,分别采用固相萃取-高效液相色谱法和高通量测序来检测抗生素含量和微生物菌落结构,分析对比分层结构湿地系统中3类8种抗生素的去除规律、对常规污染...

Purification effect of constructed wetland on antibiotic compound pollution and the microbial community response

To understand the purification performance and microbial community structure response of constructed wetlands to antibiotics additions of fluoroquinolones(FQs),sulfonamides(SFs)and tetracyclines(TCs),we measured the antibiotic contents and microbial community structure in horizontal subsurface flow constructed wetlands with single-layer matrix structure and multi-layer matrix structure(3 and 6 layers)which have been in operation for many years,with solid phase extraction-high performance liquid chromatography and high-throughput sequencing,respectively.We analyzed the removal results of eight antibiotics belonging to three types in wetland systems,the effects on the removal of conventional pollutants,and changes of microbial community structure.The results showed that the constructed wetlands had good removal effects on FQs,sulfathiazole,sulfamethazine and oxytetracycline(>95%),but with relatively poor effects on sulfadiazine and tetracycline(61.9%-66.8%)under the same conditions.The purification effect of multi-layer wetland systems on antibiotics was 3.2%higher than that of singlelayer wetland system.The addition of antibiotics increased the removal efficiency of COD and NH4₊^-N by 18.5%and 16.5%,respectively,but decreased that of TP by 28.6%.After the addition of FQs,SFs,and TCs,mean Shannon index in the three wetland systems decreased from5.80 to 4.66,while mean Simpson index increased from 0.017 to 0.063.Before and after the addition of antibiotics,the main dominant phyla(Proteobacteria and Bacteroidetes)remained unchanged,while the primary and secondary positions of the other dominant phyla(Chloroflexi,Firmicutes,Verrucomicrobia,and Acidobacteria)changed.There were obvious changes in the structure of dominant genera.The abundance of denitrifying bacteria Acinetobacter,Aquabacterium and Pseudomonas were significantly increased,replacing the phosphorus-removing bacteria Dechloromonas and Flavobacterium as the main dominant genera.