沈阳某冶炼厂污染土壤中砷的稳定化研究

Arsenic Stabilization of Contaminated Soil of a Smeltery in Shenyang

稳定化是一种相对经济有效的治理重金属污染土壤的方法。文章以沈阳某冶炼厂厂区旧址的重金属复合污染土壤为研究对象,通过向土壤中添加不同药剂,研究了不同碱性化学物质对土壤砷稳定化的效果。结果表明,碳酸钠和硫化钠的加入对土壤pH的贡献均较大,但使砷的浸出毒性增强,对土壤中砷的稳定起负作用;碳酸钙和多硫化钙对土壤中砷的稳定化效果也不明显;氧化钙的效果最好,使得该重污染土壤中砷的浸出毒性降低到危险废弃物毒性浸出标准(GB5085.3-1996)以内。

Stabilization represents a comparatively cost-effective treatment alternative for metal-contaminated soil. Taking a smeltery in Shenyang, Liaoning Province as research object, several alkali chemicals were added to increase the soil pH and reduce leaching toxicity of arsenic in soil impacted by heavy metals. Results indicated that inclusion of sulfured matrium and sodium carbonate chemicals increased soil pH without reducing arsenic leaching toxicity, and inclusion of calcium carbonate and multi-sulfured calcium had no clear effect on stabilization of soil arsenic. The best effect was calcium oxide, which reduced arsenic leaching toxicity under Dangerous Waste Toxicity Leaching Standard （GB5085.3-1996）.