超细粉煤灰吸附Cr^6＋机理和动力学  

Cr^(6+) Adsorption Mechanism on Ultrafine Coal Fly Ashes and Its Kinetics

作　　者：刘转年[1] 杨志远[2] 

机构地区：[1]西安科技大学地质与环境工程系,陕西西安710054 [2]西安科技大学化学与化工系,陕西西安710054

出　　处：《中国矿业大学学报》2008年第4期478-482,共5页Journal of China University of Mining & Technology

基　　金：中国博士后科学基金项目(20070411124);陕西省工业攻关项目(2006k07-G19);陕西省教育厅产业化培育项目(06JC11);西安市工业攻关项目(GG06074)

摘　　要：以陕西渭河电厂粉煤灰(WFA),灞桥热电厂粉煤灰(BFA)和西郊热电厂粉煤灰(XFA)为原料,经球磨分级得到超细粉煤灰WUFA,BUFA和XUFA.研究了粉煤灰与超细粉煤灰对Cr6+的吸附机理.结果表明,3种超细粉煤灰对Cr6+的吸附性能有一定的差别,其顺序为:WU-FA>BUFA>XUFA,影响吸附的因素为粉煤灰中的Al2O3含量.超细粉煤灰在25,35和45℃对Cr6+的吸附均符合Langmuir吸附等温式.超细粉煤灰对Cr6+吸附的ΔG0和ΔH0为均负值,吸附为自发放热过程.与原粉煤灰相比,吸附时间为150 min时,WUFA,BUFA和XUFA对Cr6+的吸附量分别提高43.27%,11.14%和28.69%.原粉煤灰和超细粉煤灰对Cr6+的吸附均符合二级吸附动力学模型.Using three kinds of ultrafine coal fly ashes WFA, BFA and XFA from three coalfired power stations as raw material, three ultrafine coal fly ashes WUFA, BUFA and XUFA were prepared by milling and classification, respectively. The Cr^6＋ adsorption mechanism on ultrafine coal fly ashes was studied. The results show that the adsorption capacities of three ultrafine coal fly ashes are different and follow the order of WUFA〉BUFA〉XUFA. Al2O3 content in coal fly ash is the most important factor influencing Cr^6＋ adsorption. The three adsorption isotherms all accord with Langmuir isotherms at 25, 35 and 45℃. △G^0 and △H^0 are negative, which show that the adsorption processes are spontaneous and exothermic. Comparing with the adsorption capacities of WFA, BFA and XFA, that of WUFA, BUFA and XUFA increased by 43.27%, 11.14% and 28.69% when adsorption of 150 min, respectively. The Cr^6＋ adsorption on coal fly ashes and ultrafine coal fly ashes all follow the second-order kinetic equation.

关 键 词：超细粉煤灰 吸附 CR^6+ 动力学 

分 类 号：X075[环境科学与工程]