生物质炭对单一与复合污染土壤中铜、铅、铬的钝化作用  

Immobilization of Copper, Lead and Chromium in Single and Multiple Contaminated Soil with Biochar

作　　者：夏鹏[1] 王学江[1] 张晶[1] 王鑫[1] 宋靖珂[1] 陈杰[1] 

机构地区：[1]同济大学环境科学与工程学院污染控制与资源化研究国家重点实验室,上海200092

出　　处：《土壤通报》2016年第1期192-197,共6页Chinese Journal of Soil Science

基　　金：国家"863"计划项目(2012AA063608-03);国家国际合作专项项目资助

摘　　要：外源投加重金属硝酸盐制得铜、铅、铬单一和复合三级污染土壤(800 mg kg^(-1)、1000 mg kg^(-1)、800 mg kg^(-1)),以热解制备的生物炭为钝化剂,根据重金属钝化率对钝化剂投加量进行优化,并通过改进的BCR(European Communities Bureau of Referent)分级提取方法研究最佳钝化剂投加量下土壤中重金属形态变化。结果表明:施入生物质炭后,单一与复合污染土壤重金属有效浓度均显著降低,确定2%和10%为单一和复合最佳投加量。最佳投加量下,单一与复合过程Cu、Pb、Cr钝化率分别为26.2%、10.9%、36.5%与12.7%、6.0%、37.6%。生物质炭的施入能促进金属离子从可交换态向残渣态和可还原态转变,比较单一与复合污染,Cu、Pb、Cr可交换态减少量分别从18.4%、20.5%、37.5%变为10.5%、18.2%、46.5%,残渣态增加量分别从138.1%、64.2%、41.6%变为37.4%、58.5%、48.2%。生物炭对土壤中Cr的钝化效果最佳,在复合污染土壤中更为明显。This study used single and multiple contaminated soil（800 mg kg-1, 1000 mg kg-1, 800 mg kg-1, respectively）,obtained by the addition of copper（Cu）, lead（Pb） and chromium（Cr） nitrate, as the tested soil samples, used biochar produced by wood pyrolysis as the immobilizing agent, optimized dosage according to the passivation rate, and analyzedthe morphology of heavy metals under optimum agent cast by improved BCR（European Communities Bureau of Referent） Extraction Method. The results showed that： after applying biochar into single and combined contaminated soils, available concentration of heavy metals significantly decreased, 2% and 10% were determined to be the optimal dosage for single and combined pollution. Under the optimal dosage, passivation rates of Cu, Pb and Cr in single and composite process were, respectively, 26.2%, 10.9%, 36.5% and 12.7%, 6.0%, 37.6%. Biochar obviously promoted the metal ions transform from the exchangeable state to residual and reducible state. Comparing single and combined pollution, the decrease amount of exchangeable Cu, Pb and Cr changed, respectively, from 18.4%, 20.5%, 37.5% to10.5%, 18.2%, 46.5%, while the increasement of residual Cu, Pb and Cr changed, respectively, from 138.1%, 64.2%,41.6% to 37.4%, 58.5%, 48.2%. Biochar showed better performance on immobilizing Cr in soils, especially in the combined contaminated soil.

关 键 词：生物质炭 铜、铅、铬 钝化 BCR 

分 类 号：X131.3[环境科学与工程—环境科学]