硫酸污染土壤原位搅拌中和修复案例分析

Case Study on In-situ Mixing and Neutralization Remediation of Sulphuric Acid Contaminated Soil

文章主要研究了某硫酸污染土壤原位搅拌中和处置工程。通过地球物理探测和精细化调查确定了填埋场内的防渗膜埋深和土壤分区污染程度。按污染空间分布划分为pH 3~4、4~5、5~6共3个浓度区,针对3个浓度区分别采用质量比为4%、2%、1%的氢氧化钙药剂,将土壤pH调节成6~9。考察了搅拌桩原位中和过程中土壤孔隙率、含水量、药剂添加量、地层土压力对修复效果的影响,确定氢氧化钙浆液的浓度配比和注浆压力。修复结果表明借助于科学的氢氧化钙添加量和工程机械混合措施能快速有效地修复酸化地块土壤。

The paper investigates an in-situ mixing and neutralization treatment project of soil contaminated by sulfuric acid.The depth of impermeable membranes and the contamination of soil in landfill were determined by geophysical exploration and fine investigation.According to the spatial distribution of the pollution,it was divided into three concentration regions:pH 3~4,pH 4~5,pH 5~6.Soil pH was adjusted to 6~9 by the addition of 4%,2%and 1%calcium hydroxide for regions of pH 3~4,pH 4~5 and pH 5~6,respectively.At the end,according to the soil porosity,agent addition and underground soil pressure,the concentration of calcium hydroxide suspension and injection pressure during the in-situ neutralization were determined.The results indicate that the acid contaminated soil can be quickly and efficiently neutralized by scientific addition of calcium hydroxide and stir of engineering machine.