根据贵州某燃煤电厂所处的地形及气象条件,采集燃煤电厂周边环境中的玉米及表层土壤样,用ASF-930型双道原子荧光光度计测量了样品中Hg元素的含量,并应用地统计学方法分析了电厂周边表层土壤中Hg含量的空间分布特性。结果表明:电厂周边玉米样中Hg含量在0.011~0.119mg/kg,平均值为0.081mg/kg;土壤样Hg含量为0.092~0.320mg/kg,平均值为0.178mg/kg,高于贵州(0.102mg/kg)、全国(0.042mg/kg)和世界(0.030mg/kg)土壤中的平均值,低于《土壤环境质量标准》(GB15618-1995)中的二级标准值(pH值在6.5~7.5,Hg≤0.5mg/kg);周边土壤环境中Hg含量的空间分布表现出大致的条带状分布格局,未表现出明显的汞污染特征。通过对电厂脱硫石膏、飞灰、原煤、石灰石的汞含量分析发现,ESP+WFGD烟气净化系统对燃煤烟气中的汞具有一定的脱除作用。
According to the local terrain and meteorological conditions,maize and surface soil samples were collected in the surrounding environment of a coal-fired power plant.The concentration of Hg element in the samples were determined by ASF-930 double-channel atomic fluorescence spectrophotometer,and the spatial distribution characteristics of Hg content in the topsoil around the power plant were analyzed by geostatistics method.The results showed that the concentration of Hg varied from 0.011 mg/kg to 0.119 mg/kg in the collected maize samples,and the average concentration of Hg was 0.081 mg/kg.The content of Hg in soil samples ranged from 0.092 mg/kg to 0.320 mg/kg,with the average content of 0.178 mg/kg,which was higher than that in Guizhou(0.102 mg/kg),the country(0.042 mg/kg)and the world(0.030 mg/kg),but lower than the secondary standard value(pH 6.5-7.5,Hg≤0.5 mg/kg) of "soil environmental quality standards"(GB15618-1995).The spatial distribution of Hg content in the surrounding environment showed an approximate striped pattern,and there was no obvious mercury pollution.Through the mercury analysis of fly ash,gypsum,coal and limestone in the power plant,it was found that the ESP+WFGD flue gas purification system had a role in removal of mercury from the coal-fired flue gas.