Operation Mechanism and Efficiency of Bioretention System Constructed with 4 Prepared Media Soil under a Longer Time-Span
In order to explore the operation mechanism and efficiency of bioretention system under a longer timespa,four bioretention systems built with different prepared media soil were designed.The results showed that the four systems still had good removal rate on total nitrogen(TN)and nitrate nitrogen(NO3--N)during a 22-month operating period.When the soil-sand ratio was 7∶3,the depth of the filler layer was 400 mm,7.5%nutrient soil was added,the highest removal rates of ammonia nitrogen,TN,NO3--N,chemical oxygen demand(CODCr)and TP(total phosphorus)appeared,reaching 88.83%,88.89%,93.16%,93.10%and 94.69%,respectively.Different construction methods had an effect on the content of extracellular polymeric substances(EPS)and electron transfer activity(ETSA).The increase of EPS could accelerate the electron transfer rate,thereby improving the denitrification efficiency.Correlation analysis showed that the infiltration rate of the bioretention system was significantly negatively correlated with the removal of TN and NO3--N(p＜0.05),while the protein(PN)and NO3--N were significantly positively correlated with the TN removal rate(p＜0.05).The results provided a technical reference for improving the running efficiency and more scientific construction of bioretention systems.
国家科技期刊平台
NSTL
万方数据
