Effect of Rainfall Interval and Packing Combinations on Purification Effectiveness of Bioretention Facilities
Rainfall interval and packings are the essential factors impacting on the pollutant purification effectiveness of bioretention facilities.In this study,the performance of bioretention facilities with three different packing combinations on pollutants was investigated under different rainfall intervals(2,7 days and 15 days)and different influent pollutant loading conditions.The results showed that:the rainfall interval had the greatest influence on the removal effect of NO3--N,the longer the rainfall interval was,the more unfavorable the NO3--N removal was,and there was even the phenomenon of a negative removal rate.The removal rate of CODCr decreased under long rainfall interval(15 days),and the removal effect of ammonia nitrogen and TP was slightly influenced by rainfall interval.Compared with the rest two packing combinations,manganese sand+maifanite+zeolite+soil hybrid packing could improve the drought resistance and pollutant load impact resistance of bioretention facilities,maintained superior CODCr removal rate(around 90％)and stable NO3--N removal capacity under high rainfall interval(15 days),and NO3--N removal rate was higher(more than 40％)under different pollutant loads.The study results can provide a reference for the reasonable design and application of biological detention facilities in Hangzhou.
万方数据
维普
