机械力化学法活化铝系硅酸盐矿物降解六氯苯机理研究  

Mechanism of Degradation of Hexachlorobenzene by Activating Aluminum Silicate Minerals usingMechanochemical Method

作　　者：何晓曼[1] 许新成 姚真真 张其武[1] 杨巍[2] HE Xiaoman;XU Xincheng;YAO Zhenzhen;ZHANG Qiwu;YANG Wei(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;Sinosteel Wuhan Safety And Environmental Protection Research Institute Co.,Ltd.,Wuhan 430081,China)

机构地区：[1]武汉理工大学资源与环境工程学院,湖北武汉430070 [2]中钢集团武汉安全环保研究院有限公司,湖北武汉430081

出　　处：《金属矿山》2023年第11期67-73,共7页Metal Mine

基　　金：国家自然科学基金项目(编号:41701351,51878523)。

摘　　要：针对六氯苯(HCB)在土壤中长期存在难以降解的问题,本研究基于机械力化学法,系统地探究土壤中固有成分铝系硅酸盐(高岭土、白云母和膨润土)对HCB的降解效果,讨论了球磨转速、球磨时间、HCB初始浓度等条件对HCB降解效率的影响。在HCB浓度为50 000 mg/kg的条件下,600 r/min球磨2 h后,铝系硅酸盐矿物对HCB去除能力由大到小依次为高岭土、白云母、膨润土,高岭土和白云母对HCB的去除率分别为90.13%、85.72%,膨润土几乎不降解HCB。HCB的去除率随着球磨时间增加而增加,与转速呈正相关。HCB初始浓度的降低有利于HCB的降解和脱氯效率,当HCB处于高浓度水平50 000 mg/kg时,高岭土和白云母的脱氯效率较低;当HCB处于低浓度水平2 500 mg/kg时,高岭土和白云母的脱氯效果提高,高岭土的脱氯效果优于白云母。利用ESR检测自由基信号发现,高岭土在机械力化学作用下产生了高活性氧类自由基,而白云母和膨润土未产生自由基。利用GC-MS分析HCB降解中间产物,当高岭土作为添加剂时,产生的自由基导致HCB的C—Cl发生断裂,经过连续脱氯过程,HCB的稳定结构被打破,形成了一系列不稳定的含Cl中间产物。综上所述,铝系硅酸盐矿物在机械力化学作用下能够高效降解HCB,而且便宜易得,不会造成二次污染,具有广泛的应用潜力。In view of the long-term problem that hexachlorobenzene(HCB)is difficult to degrade in soil,based on mechanochemical method,this study systematically investigated the degradation effect of aluminum silicate(kaolin,muscovite and bentonite)in soil,and discussed the influence of milling speed,milling time and initial concentration of HCB on the degra-dation efficiency of HCB.When the concentration of HCB is 50000 mg/kg,after 2 h ball milling at 600 r/min,the HCB re-moval ability of aluminoid silicate minerals is ranked as follows:kaolin,muscovite and bentonite.The removal rates of HCB by kaolin and muscovite are 90.13%and 85.72%,respectively,and the bentonite hardly degrades HCB.The removal rate of HCB increased with the increase of milling time and was positively correlated with the rotational speed.The decrease of the initial concentration of HCB is conducive to the degradation and dechlorination efficiency of HCB.When HCB is at a high concentra-tion level of 50000 mg/kg,the dechlorination efficiency of kaolin and muscovite is low;When HCB is at a low concentration level of 2500 mg/kg,the dechlorination effect of kaolin and muscovite is improved,and the dechlorination effect of kaolin is better than that of muscovite.Using ESR to detect the free radical signal,it was found that kaolin produced high reactive oxygen species free radicals under mechanochemical action,while muscovite and bentonite did not produce free radicals.GC-MS was used to analyze the degradation intermediates of HCB.When kaolin was used as an additive,the free radicals generated caused C—Cl of HCB to fracture.After continuous dechlorination process,the stable structure of HCB was broken and a series of un-stable Cl-containing intermediates were formed.In summary,aluminum silicate minerals can degrade HCB efficiently under me-chanical and chemical action,and are cheap and easy to cause no secondary pollution,which has a wide range of application potential in the field of soil remediation.

关 键 词：机械力化学法 铝系硅酸盐 六氯苯 土壤修复 脱氯 降解机理 

分 类 号：X53[环境科学与工程—环境工程]