药剂复配对含铬污染土壤的稳定化效果

Stabilization Effect of Composite Medicament on Soil Contaminated with Cr

工业的快速发展使得高毒性的铬(Cr)广泛存在于土壤中,给生态及人类带来了严重威胁。目前,固化/稳定化技术是铬污染土壤处置的有效手段。单一药剂的使用不仅效果及稳定性差且易造成二次污染,因而,采用将还原剂、吸附剂及固化剂进行复配的策略,通过正交试验对加药顺序及最佳药剂配方进行了研究。最终得到复合药剂的最佳组分为多硫化钙、弱碱性阴离子交换树脂和生石灰,最佳加药方式为"吸附还原-固化剂"。对处置前后铬污染土壤的红外测试进行分析,发现复合药剂成功将土壤中Cr(Ⅵ)进行了还原,有效降低了铬的毒性和迁移性,实现了在低药剂投加量的情况下对含铬污染土壤的稳定化处置,处置效果满足《生活垃圾填埋场污染控制标准》中关于总Cr和Cr(Ⅵ)浸出液的限量标准,为含铬污染土壤的处置提供了行之有效的方法。

With the rapid development of industry,chromium(Cr)with high toxicity is widely existed in the soil,which brings serious threat to the ecology and human beings.Presently,curing/stabilization technology is an effective method for treating Cr contaminated soil.The use of single agent not only has poor effect and stability but also easily causes secondary pollution.Therefore,reducing agent,adsorbent and curing agent were compounded.Orthogonal test was used to study the dosing sequence and the optimum formulation.Ultimately,it was concluded that the best composition of the compound was calcium polysulfide,weak base anion exchange resin and quick lime,and the best dosing method was"adsorption reduction-curing agent".After evaluating the infrared test of chromium contaminated soil before and after treatment,it was found Cr(Ⅵ)in the soil was reduced successfully by the compound agents,effectively reduce the toxicity of Cr as well as the mobility.Implements in the case of low drug dosing quantity of chromium contaminated soil stabilization treatment and disposal effect meet the pollution control standards for domestic waste landfills about the standard limitation of liquor leaching for total Cr and Cr(Ⅵ).An effective method for the disposal of chromium contaminated soil was provided.