【摘要】 利用漂白粉(Ca(ClO)2)、H2O2、二氧化氯消毒剂(ClO2)作为氧化剂,处理氰化物污染的土壤,使其分解成低毒物或无毒物,据此建立了二氧化氯消毒剂(ClO2)处理含氰土壤的新方法.结果表明,漂白粉大大提高了土壤的pH值,改变了土壤原有的理化性质,H2O2有较好的处理效果但是氧化效率低,综合考虑,选择低浓度ClO2强氧化剂来修复氰化物污染的土壤.同时研究了温度、反应时间、ClO2浓度对反应的影响.结果显示,常温下,0.1%的ClO2为氧化剂,反应时间为45min时,去除率可以达到55.57%;当ClO2浓度仍为0.1%,将温度升高为65℃,反应时间为30min时,去除率即能够达到98.85%.研究结果表明,该方法对氰化物污染的土壤处理是一种可行的和有效的选择,具有实用意义.更多还原

【Abstract】 In this study,the efficiency of oxidants(Ca(ClO)2,H2O2 and ClO2) for cyanide removal from soils was investigated.The results indicated that the addition of bleaching powder(containing Ca(ClO)2 as oxidant) may cause abrupt changes of pH values and physico-chemical characteristics of the soil.The oxidation efficiency of hydrogen peroxide was the lowest compared with the other oxidants.The addition of ClO2 did not cause abrupt changes of pH values of the soil,and had the highest oxidation efficiency among the three oxidants.Thus,a low concentration of ClO2 was chosen as the most suitable oxidant,and the effects of reaction time,ClO2 dosage and temperature on cyanide removal efficiencies were further studied.The results showed that the removal rate of cyanide increased with the reaction time and temperature,and it reached a maximum of 55.57% in 45 min at room temperature with 0.1% ClO2 as oxidant.When the temperature was increased to 65 ℃,the removal rate reached a maximum of 98.85% in 30 min.Based on the above results,a new chemical method was set up to remediate the cyanide contaminated soils with chlorine dioxide.This study suggests that chemical oxidants may be a feasible option for cleaning soils contaminated with cyanide.更多还原