Study on treatment effect of vertical subsurface constructed wetland with two different substrates on sewage treatment plant effluent
To improve the treatment efficiency of sewage treatment plant effluent by constructed wetland,two kinds of vertical subsurface constructed wetlands using pyrite and gravel were set for treating wastewater from a sewage treatment plant in Wuhan.The removal effect of pollutants under different hydraulic loading conditions and microbial community structure were studied.Results showed that the two kinds of constructed wetlands had better removal effects on COD,TN,NO3-and TP under low hydraulic load(0.4～0.7 m3/(m2·d))condition,and ammonia nitrogen could be better removed under high hydraulic load(1.0～1.3 m3/(m2·d))condition.The removal effect of pyrite constructed wetland on COD,TN,NO3-and TP was better than that of gravel.The analysis result of microorganism at genus level showed that the main denitrifying bacteria in pyrite constructed wetland were Thiobacillus(relative abundance 16.68％)and Sulfurifustis(relative abundance 4.62％),Thiobacillus could improve phosphorus removal effect.The main denitrifying bacteria in gravel constructed wetland was Steroidobacter(relative abundance 4.56％).The abundance and diversity of bacteria for denitrification and phosphorus removal in constructed wetland increased after pyrite was used as the substrate,which was conducive to the denitrification and phosphorus removal of effluent.However,there existed high SO2 in the effluent of pyrite constructed wetland and it could be alleviated when filling pyrite at the bottom of the constructed wetland in engineering application.
万方数据
维普
