深圳市土壤表层汞污染等级结构与空间特征分析

在深圳市采集并分析了200个表层土壤样品中的汞浓度,并利用克里格插值与单因子污染指数评价等方法研究了该区土壤表层汞污染数量结构与空间分异特征.结果表明,深圳市土壤汞平均值为70.52ng/g,中值为58.82ng/g.37%的样点土壤汞浓度超过土壤背景值,5%的样点处于中度以上汞污染水平.样点的土壤汞浓度随着的高程和坡度的增加呈现出均值降低,偏差减小的变化趋势.汞污染严重的区域为南山蛇口工业区、宝安西部工业区、龙岗大工业区与东部工业区和罗湖商业区等,人类活动与城市土壤汞浓度密切相关,污染的主要来源为工业区化石燃料燃烧、含汞废物排放、商业区长期的人类活动以及生活垃圾的处理等.

Spatial distribution of mercury contents in surface soil in Shenzhen City

Two hundred surface soil samples were collected from Shenzhen for determination of mercury contents. Kriging interpolation method and single pollution index of soil were used to study soil Hg spatial distribution. The average concentration of topsoil Hg was 70.52 ng/g (median, 58.82 ng/g). Approximate 37% of all samples exceeded the background Hg value in Shenzhen; over 5% of them were in moderate pollution. Overall, Hg content in topsoil of Shenzhen ranged from 45 ng/g to 75 ng/g. The Hg concentration decreased with the uprising of altitude and slope. The mercury pollution were serious in Shekou of Nanshan, West of Baoan, East of Longgang and commercial area in Luohu, which were mainly caused by fuel combustion in industry, Hg-containing waste emission and garbage disposal from longtime commercial activities.