梯度过滤工艺对地表雨水径流净化规律

Purification law of surface rainwater runoff by gradient filtration process

通过采样分析确定了某高教区雨水径流中SS,COD,TN,NH_(3)-N,TP的时间质量浓度均值(EMC_(s)),综合比选了不同种类过滤介质的透水、抗堵塞性能和截污性能,探究了梯度过滤工艺应用于雨水径流处理时对于过滤系统抗堵塞能力和截污能力的改善情况.结果表明:该高教区雨水径流污染严重;各种类过滤介质的过滤速度和过滤压力之间呈线性关系,过滤介质单位面积质量越大或过滤精度越高,其透水、抗堵塞性能越差,截污能力越强;以单位面积质量为300 g/m^(2)的土工布作为过滤介质时,出水满足国标《城市污水再生利用景观环境用水水质》(GB/T 18921—2019)要求;梯度过滤工艺相较于单级梯度过滤工艺能有效改善梯度过滤系统的抗堵塞性能和截污性能,以150目规格尼龙网作为第一级梯度过滤介质、以300 g/m^(2)土工布作为第二级过滤介质时,梯度过滤系统抗堵塞性能、污染物截污性能最佳.

Based on the time mass concentrations(EMC_(s))values of SS,COD,TN,NH_(3)-N,and TP in rainwater runoff of a higher education district,the permeability,blockage resistance,and pollution interception performance of different filtration media were comprehensively compared and analyzed.The permeability,anti-blockage performance,and pollutant interception performance of different types of filter media were comprehensively compared.The improvement of anti-blockage and pollution interception capacity of filtration system when gradient filtration process was applied to rainwater runoff treatment was explored.The results show that rainwater runoff pollution in this higher education area is severe.There is a linear relationship between the filtration speed and filtration pressure of various types of filtration media.The larger the mass per unit area or the higher the filtration accuracy,the worse the permeability and anti-blocking performance,and the stronger the intercepting capacity.When using geotextile with a unit area mass of 300 g/m^(2) geotextile is used as a filter medium,the effluent meets the requirements of″Urban Sewage Recycling Landscape Environmental Water Quality″(GB/T 18921—2019).Compared with the single-stage gradient filtration process,the gradient filtration process can effectively improve the anti-blocking performance and pollution interception performance of the gradient filtration system.When the 150-mesh nylon mesh is used as the first-stage gradient filtration medium and 300 g/m^(2) geotextile is used as the second-stage filtration medium,the anti-blocking performance and pollutant interception performance of the gradient filtration system are the best.