改良玻璃轻石对雨水径流高效脱氮研究

Research on High-efficient Nitrogen Removal of Pollutants in Rainwater Runoff by Modified Glass Pumice

为了改良玻璃轻石对雨水径流高效脱氮的影响,以沸石、蛭石、陶粒、普通玻璃轻石、改良玻璃轻石为渗滤柱填料,分析人工配制雨水流经渗滤柱在不同运行时间(5,10,20,30,40 h)及不同出水口对径流雨水TN和NH+4-N的去除效果。结果表明:改良玻璃轻石∶沸石∶蛭石∶陶粒=4∶2∶2∶2(体积比)分层填装的渗滤柱对TN的去除率达到了92.71%,改良玻璃轻石∶沸石∶蛭石∶陶粒=4∶2∶2∶2(体积比)混合填装的渗滤柱对NH+4-N的去除率达到了92.81%,出水浓度达到《地表水环境质量标准》(GB 3838—2002)III类标准。在基础填料中添加改良玻璃轻石有效改善了填料渗滤性,使渗滤柱对雨水中的NH+4-N、TN均具有较好的去除效果,且在运行10 h时基质层深65 cm处过滤吸附作用最好。

This study investigated the efficient nitrogen removal of pollutants in rainwater runoff by modified glass pumicer.Zeolite,vermiculite,ceramsite,ordinary glass pumice,and modified glass pumice were used as filtration materials,this study developed a system composed of artificial rainwater and infiltration column to simulate the purification effect of bioretention pool on rainwater runoff at different operation time(5,10,20,30,40 h)and different outlets,to study the pollutant removal effect of TN and NH+4-N in rainwater runoff of modified glass pumice.The results showed that the TN removal rate of the modified glass pumice∶zeolite∶vermiculite∶ceramsite=4∶2∶2∶2(volume ratio)layered filling filtration column reached 92.71%,while the NH+4-N removal rate of the modified glass pumice∶zeolite∶vermiculite∶ceramsite=4∶2∶2∶2(volume ratio)mixed filling filtration column reached 92.81%,and the TN and NH+4-N content all met the Class III standard of Environmental Quality Standard for Surface Water(GB 3838—2002).The addition of modified glass pumice to the basic filtration materials has a good filtration adsorption effect on the four pollutants and effectively improves the permeability of filtration materials.In a comprehensive view,the best removal effect is achieved at the depth of 65 cm of the substrate layer,when running for 10 h.