生物滞留系统介质土的理化性质比较研究

Comparison of Physical-chemical Properties of Soil Media in Bioretention System

为了解国内外生物滞留系统介质土理化性质的异同,梳理归纳了国内外技术规范、导则等对生物滞留系统介质土的相关说明,并以美国马里兰州生物滞留系统实际应用场地为例,检测分析了其介质土的粒径时空分布特点。研究表明,深圳市、厦门市和湖南省的规范中生物滞留系统介质土的渗透系数低于国外,而介质土层深度高于国外;国内建议介质土组分为高砂低有机质,而国外还在此基础上进一步对氮和磷的含量、阳离子交换容量等指标做了详细说明。马里兰州生物滞留系统介质土的主要组分是砂(62%~86%),且表层土的黏土和细砂含量(17%和31%)高于底层土(10%和26%),表层土的砾石和粗砂含量(14%和38%)低于底层土(21%和42%)。

In order to understand the similarities and differences of physical-chemical properties of soil media in bioretention system at home and abroad,the technical specifications and guidelines at home and abroad for soil media in bioretention system were summarized.Meanwhile,the particle size spatial and temporal distribution characteristics of the soil media were analyzed in bioretention system in Maryland,USA.It was found that the permeability coefficient of soil media in Shenzhen City,Xiamen City and Hunan Province was lower than that of foreign countries,while the depth of the media was higher compared with that of foreign countries.Soil media with high sand content and low organic matter proportion were recommended in China.However,the contents of nitrogen and phosphorus,cation exchange capacity and other indexes were further described in detail in foreign countries.Sand was the main component(62%-86%)of the soil media in the bioretention systems in Maryland.The clay content(17%)and fine sand content(31%)of the topsoil were higher than that in underlying soil(10%and 26%),but the gravel content(14%)and coarse sand content(38%)of the topsoil were lower than that of the underlying soil(21%and 42%).