粉煤灰超细改性及对Cr^(6+)的吸附热力学  

Modification of ultra-fine coal fly ash and its thermodynamics of Cr^(6+) adsorption

作　　者：刘转年[1] 

机构地区：[1]西安科技大学地质与环境工程系,陕西西安710054

出　　处：《化工进展》2008年第4期569-572,576,共5页Chemical Industry and Engineering Progress

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

摘　　要：将3个不同电厂的粉煤灰球磨后得到超细粉煤灰,选择HCl、H2SO4、NaOH、Ca(OH)2和Na2CO3等对超细粉煤灰进行化学改性。结果表明,采用Ca(OH)2改性效果最好,经过Ca(OH)2改性的3种超细粉煤灰对Cr6+的去除率提高2.01～2.44倍。Ca(OH)2改性超细粉煤灰对Cr6+的吸附热力学研究表明,3种改性超细粉煤灰在25℃、35℃和45℃对Cr6+的吸附符合Langmuir吸附等温式,吸附过程为自发、放热过程。同时,分析了Ca(OH)2改性超细粉煤灰的机理,研究了吸附饱和改性超细粉煤灰的脱附再生方法。Three kinds of coal fly ash were collected from three thermal power plants. Raw coal fly ash was ball milled and ultra-fine coal fly ash was obtained. The ultra-fine coal fly ash was modified by HCl, H2SO4, NaOH, Ca（OH）2 and Na2CO3, respectively. The results showed that Ca（OH）2 was the best modifier and the removal rates of Cr^6＋ increased by 2.01-2.44 times after modification. The isotherms of Cr^6＋ adsorption onto three kinds of modified ultra-fine coal fly ash all could be descibed by the Langmuir isotherms at 25 ℃, 35 ℃ and 45 ℃, and the adsorption process was spontaneous and exothermic. The modification mechanism of Ca（OH）2 and methods of regeneration by desorption were also discussed.

关 键 词：超细粉煤灰 改性 吸附 CR^6+ 

分 类 号：X075[环境科学与工程]