农业环境科学学报2009，Vol.28Issue(10)：2057-2063,7.
海泡石表面化学特性及其对重金属Pb~(2+)Cd~(2+)Cu~(2+)吸附机理研究
Surface Chemical Characteristics of Sepiolites and Their Adsorption Mechanisms of Pb~(2+), Cd~(2+) and Cu~(2+)
摘要
Abstract
The surface characteristics of natural and acid-activated sepiolites were studied through surface acid-base reactions. The adsorp-tion experiments of Pb~(2+), Cd~(2+) and Cu~(2+) on natural and acid-activated sepiolites were performed and the adsorption mechanisms were investi-gated. The maximum adsorption capacities were 32.06 mg·g~(-1)Pb~(2+), 22.10 mg·g~(-1) Cu~(2+), and 11.48 mg·g~(-1) Cd~(2+) for natural sepiolite, and 35.28 mg·g~(-1) Pb~(2+), 24.36 mg·g~(-1) Cu~(2+), and 13.62 mg·g~(-1) Cd~(2+) for acid-activated sepiolite, respectively. The adsorption capabilities of natural and acid-activated sepiolites for Pb~(2+), Cd~(2+) and Cu~(2+) calculated from the amount of substance were in the order: Cu~(2+)>Pb~(2+)Cd~(2+). Langmuir isotherm could describe the sorption data of Cu~(2+) and Cd~(2+) on natural and acid-activated sepiolites with a good fitness. The XRD patterns and IR spec-tra indicated that acid treatment made CaCO_3 in natural sepiolite decomposed and increased the surface area. The pHzpc of acid-activated sepiolite decreased compared with the natural sepiolite, which suggested that acid treatment increased the surface acidity of sepiolite and the surface available sites for heavy metal adsorption. It could be concluded that isomorphous substitution and surface complexation coexist dur-ing the adsorption processes of Pb~(2+), Cd~(2+) and Cu~(2+) onto natural and acid-activated sepiolites. Meanwhile surface precipitation could also occur for the adsorption of Pb~(2+) on the natural and acid-activated sepiolites, especially in basic solutions.关键词
海泡石/酸处理/重金属/吸附Key words
sepiolite/ acid treatment/ heavy metals/ adsorption分类
资源环境引用本文复制引用
徐应明,梁学峰,孙国红,孙扬,秦旭,王林..海泡石表面化学特性及其对重金属Pb~(2+)Cd~(2+)Cu~(2+)吸附机理研究[J].农业环境科学学报,2009,28(10):2057-2063,7.基金项目
国家高技术研究发展计划(863计划)项目(2008AA06Z334):天津市自然科学基金项目(08JCYBJC02200) （863计划）
中央级公益性科研院所基本科研业务费专项资助 （）
