工业废渣固化稳定铬污染土的工程安全特性

以某工业场地的铬污染土为研究对象,选用工业废渣(CGB)为固化剂,对铬污染土进行安全修复。通过含水率试验、pH试验、强度试验、浸出试验研究了工业废渣固化稳定后铬污染土的环境安全特性,并以相同掺量的普通硅酸盐水泥(OPC)做参照。结果表明：CGB固化稳定后的铬污染土具有较好的环境安全特性,而OPC固化稳定后的铬污染土仍具有较高的环境风险。虽然OPC固化稳定后的铬污染土的含水率、pH和抗压强度略优于CGB固化稳定后的铬污染土,但OPC固化稳定后的铬污染土浸出浓度仍高于我国危险废弃物鉴别标准(GB/T5085.3-2007)的限值,而当掺量为20%的CGM固化稳定后的铬污染土即可满足我国危险废弃物鉴别标准(GB/T5085.3-2007)。形态提取结果表明：CGM固化稳定后的铬污染土化学稳定性高于OPC固化稳定后的铬污染土,CGB主要将Cr从弱酸态转为可氧化态,而OPC主要将Cr从弱酸态转为可还原态。

The Environmental Security Characteristics of Chromium Contaminated Soils Stabilized/solidified by Industrial Waste Slag

In order to study the environmental security characteristics of chromium contaminated soils stabilized/solidified by industrial waste slag (CGB) and ordinary portland cement (OPC). The water content, pH, unconfined compressive strength, leaching test and sequential extractions test were used in this paper. Results show that the environmental security characteristics of chromium contaminated soils stabilized/solidified by CGB was better than that of chromium contaminated soils stabilized/solidified by OPC.Though the water content, pH and unconfined compressive strength of OPC stabilized/solidified soil was better than those of the CGB stabilized/solidified soil. But the chromium concentration in leach test of the OPC stabilized/solidified soil was exceedSto the identification standards for hazardous wastes of China.While the CGB stabilized/solidified soil with 20% dosage was accordance with the identification standards for hazardous wastes of China.Sequential extractions test showed that the weak acid soluble fraction of Cr was translated to the oxidizable fraction in CGB stabilized/solidified soil,while the weak acid soluble fraction of Cr was translated to the reducible fraction with OPC stabilized/solidified.