深圳市地表沉积物粒径分布及污染特性研究

Particle Size Distribution and Organic Pollutants in Road-Deposited Sediment in Different Area of Shenzhen

该研究以深圳市龙岗区为对象,采集了商业区、居住小区、城中村、科教文卫区、交通用地、公园绿地等6种用地类型的地表沉积物,检测了地表沉积物粒径分布及总氮(TN)、氨氮(NH_(3)-N)、总磷(TP)的含量,分析了不同功能区地表沉积物中粒径分布的差异。在此基础上,分析了各功能区不同粒径沉积物中TN、NH_(3)-N与TP的分布特征。结果表明,各功能区地表沉积物累积强度差异较大,科教文卫区污染物累积量高于其他功能区,为203.47 g/m^(2),公园绿地累积量最小,为34.95 g/m^(2)。不同功能区地表沉积物TN、NH_(3)-N与TP负荷差异显著,城中村与住宅区的TN、NH_(3)-N负荷较大,而城中村、工业区和公园绿地TP负荷较大。不同功能区粒径>200μm的比例均值为40.5%,沉积物中大颗粒物质占主要部分。沉积物中TN与TP均表现出一定的富集特性,粒径<200μm的沉积物所携带TN、TP污染负荷比例最高分别可达90.1%、78.6%。因此,提高小颗粒物质的去除率是降低沉积物中氮、磷负荷的有效途径。

In this study,the road dust sediment in the different functional areas including commercial areas,residences,urban villages,education areas,traffic roads,and parkland were collected.The content of total nitrogen(TN),ammonia nitrogen(NH_(3)-N),and total phosphorus(TP)in the sediment was determined,and the particle size distribution of the sediment was measured.In addition,the relationship between the content of TN,NH_(3)-N,TP,and particle size distribution was further analyzed.The results indicated that the accumulations of road dust in the different functional areas were different,the education area showed the highest accumulation with the value of 203.47 g/m^(2),while the parkland showed the lowest accumulation with the value of 34.95 g/m^(2).The mean rate that the particle size larger than 200μm was 40.5%.The contents of TN,NH_(3)-N,and TP are significantly different in the various functional areas.The residential area and urban village showed higher TN and NH_(3)-N content,while the industrial land,parkland and urban village showed higher TP content.The nitrogen and phosphorus show an enrichment property,and the TN and TP carried by the sediment with a size lower than 200μm could reach 90.1%and 78.6%,respectively.Therefore,the removal of the finer particles should be considered during road sweeping.