摘要
通过逐步加入抗坏血酸与硫酸亚铁盐到蒙脱石浆液,制备了一种环境友好型抗氧化型还原功能矿物材料（AFe（II）-Mt）;同时制备了单独加入Fe（II）离子改性的蒙脱石Fe（II）-Mt,比较这2种还原功能材料对Cr（VI）的去除性能.结果表明：p H为2~7时A-Fe（II）-Mt去除效果最好,最大去除量为34.9 mg/g,而Fe（II）-Mt为26.8 mg/g.反应在90 min内趋于平衡,符合假二级动力学方程.其中,A-Fe（II）-Mt对Cr（VI）的去除过程：首先Cr（VI）阴离子被吸附到亚铁改性蒙脱石表面,接着被还原为低毒的Cr（III）,之后Cr（III）可能形成氢氧化物或被蒙脱石吸附而固定.这种去除六价铬的治理方法对于铬的稳定化处置具有高效和安全性,应用前景广泛.
An environmentally friendly reductive function mineral material, termed as antioxidant-Fe （II）-montmorillonite （A-Fe （II）-Mt） , is prepared using stepwise addition of ferrous ion and ascorbic acid （vitamin C ） with desired concentrations into the montmorillonite dispersion. An Fe-Mt is also prepared by adding ferrous ion alone. These two materials are investigated systematically to compare their ability of removing Cr（VI） from aqueous solutions. The experimental results show that the optimum pH condition for the Cr（VI） removal is in the range of 2.0 7.0 with the maximum Cr（VI） removals of 34. 9 mg/g and 26.8 mg/g for A-Fe（II）-Mr and Fe（II）-Mt, respec- tively. The relevant reactions reach equilibrium within 90 min and can highly follow the pseudo-second-order kinet- ic model. The Cr（VI） removal process associated with A-Fe（II）-Mr may be concluded that hexavalent chromium anion is first adsorbed onto the material surfaces, followed by the Cr （VI） reduction to the low toxic species of Cr（III）. After that, the Cr（III） ion is found to form chromic hydroxide, i.e. Cr（ OH）3 and/or to be adsorbed onto montmorillonite. The treatment approach for the Cr（VI） removal is efficient and safe to the chromic stabilization, and its application is wide promising.
出处
《华南师范大学学报（自然科学版）》
CAS
北大核心
2015年第6期63-71,共9页
Journal of South China Normal University(Natural Science Edition)
基金
国家自然科学基金项目(41372050)
