还原剂添加的矿物聚合物对Cr(Ⅵ)的解毒/固化  

Detoxication and immobilization of chromium( VI)with geopolymers added by reducing agent

作　　者：陈方明[1] 陈洁渝[2] 

机构地区：[1]湖北大学资源环境学院,武汉430062 [2]中国地质大学(武汉)材料科学与化学工程学院,武汉430074

出　　处：《环境工程学报》2015年第4期1963-1969,共7页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(41102025);中国地质大学生物地质与环境地质国家重点实验室开放基金(GBL21310)

摘　　要：在对现有Cr(Ⅵ)污染控制方法分析的基础上,提出用还原剂添加的矿物聚合物对Cr(Ⅵ)进行解毒/固化的研究思路。以煤矸石为原料,以水玻璃和Na OH为碱性激发剂,合成矿物聚合物;以Fe Cl2·4H2O为还原剂,用还原剂添加的矿物聚合物对Cr(Ⅵ)进行解毒/固化实验,并采用XRD、TEM/EDS、XPS对固化体进行检测。当添加的Fe(Ⅱ)与Cr(Ⅵ)的摩尔比≥3∶1时,矿物聚合物中总铬的浸出浓度小于1 mg/L,铬固化率大于99%。还原剂添加的矿物聚合物对Cr(Ⅵ)最大固化量为0.8%。在合成过程中,Fe(Ⅱ)和Cr(Ⅵ)添加的矿物聚合物发生了氧化还原反应,Fe(Ⅱ)被氧化成了Fe(Ⅲ),Cr(Ⅵ)被还原成了Cr(Ⅲ),随后Fe(Ⅲ)和Cr(Ⅲ)同时被矿物聚合物中的—OAl(-)(OH)3吸引,并固化在非晶质结构中。On the basis of analysis of the controlling methods for Cr( Ⅵ) pollution,the research method about detoxification and immobilization of chromium( VI) was proposed with geopolymers added by reducing agent. The geopolymers were synthesized with gangue as raw materials,water glass and sodium hydroxide as alkaline excitated agents. Fe Cl2·4H2O was used as reducing agent. The geopolymers added by reducing agents were used for detoxification and immobilization of Cr( Ⅵ). Then geopolymers were tested by XRD,TEM / EDS and XPS. When the molar ratio of Fe( Ⅱ) and Cr( Ⅵ) was more than 3 ∶ 1,the leaching concentrations of total chromium were less than 1 mg / L and the fixation rates of chromium were above 99%. The best fixation capacity of Cr( Ⅵ) was 0. 8%. The mechanism of detoxification and immobilization of Cr( Ⅵ) was oxidation-deoxidation reaction. Fe( Ⅱ) was oxidized to Fe( Ⅲ) and Cr( Ⅵ) was deoxidized to Cr( Ⅲ) during the synthesis of the geopolymers added by Fe( Ⅱ) and Cr( Ⅵ). Then Fe( Ⅲ) and Cr( Ⅲ) was attracted by-OAl(-)( OH)3in the geopolymers and fixated in the non-crystaline structures.

关 键 词：矿物聚合物 Cr(Ⅵ) 解毒 固化 

分 类 号：X505[环境科学与工程—环境工程]