脱硫石膏改良碱化土壤对土壤重金属环境的影响

脱硫石膏中的主要成分硫酸钙能与碱性土壤中的交换性Na+进行反应以改良碱性土壤。采集了10个燃煤火力发电厂的脱硫石膏样品进行测试分析,结果表明不同电厂脱硫石膏的硫酸钙含量和砷、汞、铅、铬、镉重金属元素含量存在差异,其硫酸钙含量在51.8~89%之间,重金属含量基本低于适用于耕地的国家土壤环境质量二级标准(GB15618-1995)。利用这些脱硫石膏改良碱化土壤并种植油葵,连续五年监测土壤中的重金属含量,结果表明利用脱硫石膏改良碱化土壤不影响重金属的含量,为今后脱硫石膏改良盐碱地的大面积示范推广提供了安全可靠的依据。

Environmental Impact on Alkali Soil Amelioration using FGD Gypsum

The calsium ions in FGD (flue gas desulfurization) gypsum could replace the natrium ions (Na+) in alkali soil to cause its amelioration. FGD gypsum samples from 10 coal-fired power plants were collected and analyzed. Its calcium sulfate contents and heavy metal contents were gotten. The results showed that the concentrations of calcium sulfate and As, Hg, Pb, Cr, and Cd were different among the samples. The content of calcium sulfate in FGD gypsum was about 51.8~89% and the concentrations of heavy metals were lower than the limits permitted by the National Environmental Quality Standard for Soil (GB15618-1995). Oil sunflower was planted on the alkali soil ameliorated by the FGD gypsum collected. The five-year continuous monitoring revealed that the concentrations of heavy metals in soil ameliorated by FGD gypsum were not affected, which provided reliable data and proof for large-scale utilization FGD gypsum to alkali soil amelioration.