生物滞留池对雨水径流控制效果研究

Study on Control Effect of Bioretention Cells on Stormwater Runoff

基于浙江省杭州市某地区雨水径流水质条件,设计构建了不同填料配比和过滤填料层厚度的生物滞留池,研究分析了不同填料类型、降雨强度和污染物负荷对雨水径流控制效果的影响,探究了生物滞留池中填料优化配比以及适宜的过滤填料层厚度。结果表明,在中小降雨强度下,当沸石和蛭石的比例从10%增加到20%,过滤填料层厚度为800 mm时,生物滞留池峰值削减率可达到50%以上;径流污染物去除效果显著提高,TP和NH_(3)-N的总量削减率提高至70%以上,COD和TN的总量削减率提高至40%以上。高通量测序分析表明,生物滞留池不同种类填料中门水平的优势菌群主要有10种,其相对丰度总和占群落的93.46%~98.48%;变形菌门和硝化螺旋菌门中含有大量硝化细菌,厚壁菌门和绿弯菌门中含有大量反硝化细菌,它们对雨水径流中TN的去除起到了重要作用。

Based on the quality conditions of rainwater runoff in a certain area of Hangzhou,Zhejiang Province,the bioretention cells with different proportions and thickness of filler were designed to analyze the effect of filler type,rainfall intensity and pollutant concentration on rainwater runoff control effect and explore optimal proportions and suitable filler thickness.The results show that the peak reduction rate of bioretention cells was more than 50% under medium or small rainfall intensity when the proportions of zeolite and vermiculite increased from 10% to 20% and the filler thickness is 800 mm.The remove rate of the pollutants can be significantly improved.The remove ratio of total phosphorus(TP)and ammonia nitrogen(NH_(3)-N)were more than 70%,total reduction rate of chemical oxygen demand(COD)and total nitrogen(TN)was more than 40%.By high-throughput sequencing analysis,there are 10 predominant phyla in different kinds of filler in the bioretention cells with relative abundance accounts for 93.46%~98.48% of the community.Proteobacteria and Nitrospirae include many nitrification bacteria,while Firmicutes and Chloroflexi include plenty of denitrification bacteria,which play an important role in TN removal in rainwater runoff pollution.