强化渗蓄土壤改良实验研究

针对我国部分城市土壤渗透性能差、不利于径流雨水渗蓄减排等情况,分别以秸秆和沸石制成CSZ改良剂(conditioner of comstalk and zeolite),以泥炭和石英砂制成CTS改良剂(conditioner of turf and quartz sand),研究了上述两种改良剂对黏重土壤渗透性能改良和径流雨水水质净化效果的影响.结果表明:CSZ改良后的土壤稳定渗透速率为2×10-5～8×10-5m/s,渗透性能提高1 130～5 030倍,对COD的去除率为6%～25%,TP为30%～56%,NH3-N为27%～49%,TN为18%～33%;CTS改良后土壤稳定渗透速率为2×10-6～2×10-5m/s,渗透性能提高90～1 160倍;对COD去除率为88%～94%,TP为91%～99%,NH3-N为91%～93%,TN为6%～54%.因此,CSZ改良剂较适合以水量控制为主要目标的土壤改良,CTS改良剂较适合以水质控制为主要目标的土壤改良.上述研究结果可为我国土质黏重地区城市雨水径流的促渗减排、资源化、内涝控制以及绿地的规划设计提供科学依据.

Study of Soil Improvement to Enhance Stormwater Runoff Infiltration

Because of soil＇s poor penetrability in some cities of China,rainfall runoff is difficult to infiltrate and have retention.Two soil conditioners were manufactured： CSZ,which constituted by comstalk and zeolite;and CTS,which constituted by turf and sand.Through small-scale study,the soil conditioners＇ permeability amendment effect and runoff purification effect on heavy clay soil were detected.The results showed that： the soil reformed by CSZ,the stable infiltration rate range is from 2×10-5 m/s~8×10-5 m/s,the permeability is increased by about 1 130~5 030 times than the original soil,pollutant removal rate of the soil which ameliorated by CSZ for COD,TP,NH3-N,TN are 6%~25%,30%~56%,27%~49%,and 18%~33% respectively;the soil reformed by CTS,the stable infiltration rate range from 2×10-6 m/s~2×10-5 m/s,the permeability increased by about 90~1 160 times than the original soil,removal rate of COD,TP,NH3-N,TN are 88%~94%,91%~99%,91%~93% and 6%~54%.Therefore,CSZ is suitable for the soil improvement which takes water quantity control as the goal,and CTS is suitable for the soil improvement which takes water quality control as goal.The results can provide scientific support for the urban stormwater runoff＇s infiltration promoting and drainage reducing,rainwater utilization,waterlogging controll and green space＇s planning and designing in the heavy clay soil regions.