微波辐射在二氧化锰诱导下对六氯苯污染土壤的修复研究

以二氧化锰为微波吸附剂,在密封体系中研究了微波辐射技术对六氯苯污染土壤的修复效果。分别以不同浓度的酸碱水溶液添加到土壤中,在模拟含水率为20%情况下,硫酸(50%)介质下六氯苯处理效果最好,10min的微波辐射即可使50mg/kg的六氯苯达到完全去除;但是在纯水和10mol/L氢氧化钠介质下,六氯苯基本上没有去除;随着硫酸浓度的降低,六氯苯的去除率显著降低。气相色谱/质谱联用(GC/MS)分析没有检测到新物质。六氯苯去除机理推测为,直接矿化或者HCB及其分解的中间产物同土壤发生化学结合而被固定起来,以致难以萃取出来。

Studies on the Remediation of HCB Contaminated Soil with Microwave Induced by MnO2

Using MnO_2 as adsorbent,the decomposition of hexachlorobenzene(HCB) in soil using microwave(MW) technology was studied in a sealed vial.In the presence of manganese dioxide(MnO_2),a strong oxidant and MW-Absorbent,a complete removal of HCB was obtained by addition of H_2SO_4(50%),while no significant removal was observed for NaOH and H_2O with 10 min MW.With the decrease of H_2SO_4 concentration,the removal of HCB decreased sharply.Gas chromatography/mass spectrum(GC/MS) analysis revealed no intermediates formed in all the processes.The fate of HCB was proposed to be mineralized to CO_2 and H_2O directly,or bounded to the soil tightly together with its decomposition intermediates.