Investigation of the Performance and Microbial Community of Bioretention Systems Under Three Different Filter Media Combinations
In response to the low and unstable removal efficiency of N,P,and COD in traditional bioretention system,a study was conducted on the purification of initial rainwater using improved filter media bioretention system.90％traditional filter material and 5％biochar were set as the main body,and 5％wood chips,5％vermiculite,and 5％zeolite were added respectively to form improved filter materials,in the order of device A,B,and C.The variation patterns of simulated initial rainwater in improved filter materials with outflow time,rainfall load,and concentration were explored,and the differences in pollutant removal rate and microbial community structure evolution in the filter layer under drought alternation with improved media were analyzed.The results showed that device B had the best infiltration effect and had the best removal effect on NH4+-N and TP.Devices A and C have high removal rates for N,P,and COD,but their infiltration effect is poor and overflow is prone to occur.Their comprehensive treatment effect is worse than that of device B.In the alternate drying-rewetting time of 0,1,3,5,8,and 11 days,drought time of 8 and 11 days is beneficial for the removal of TN and NO3--N,but has an inhibitory effect on the degradation of NH4+-N and COD.In the alternate drying-rewetting time experiment,the three devices showed similar distribution patterns at the phylum level,with Proteobacteria,Actinobacteria,Patescibactera,Bacte-roidota,and Chloroflexiota reaching over 81.23％.There were significant differences in classification at the genus and species levels(P＜0.05),and there were dominant genera and species with higher abundance in devices B and C.In devices A,B,and C,there are nitrifying and denitrifying bacteria genera such as Pseudomonas_E and Thermomonas;Thauera_A,Hydrogenoph-aga,and Thermomonas;Thauera_A,Rubellimicrobium,and Hydrogenophaga,respectively.However,in device B,Thau-era_A and Hydrogenophaga have the highest abundance and better denitrification efficiency.
initial rainwaterbioretention systemimproved filter materialsalternate drying-rewettingmicrobial community
万方数据
维普
