花生壳制活性炭及其脱六价铬研究  

Removal of chromium from aqueous solution by activated carbon made from peanut shells

作　　者：俞力家[1] 孙保帅[1] 王天贵[1] 

机构地区：[1]河南工业大学化学化工学院,河南郑州450001

出　　处：《化学工程师》2009年第8期8-12,共5页Chemical Engineer

基　　金：河南省教育厅自然科学研究计划项目(2009B530002)

摘　　要：本文研究了用花生壳制备活性炭和用此活性炭去除水溶液中的C(rⅥ)。采用化学活化法,即用H2SO4、H3PO4、ZnCl2、KOH活化花生壳中的炭。同时研究了这些活化剂的浓度和用量、热解时间和温度对活性炭性能的影响。采用亚甲基蓝吸附实验评价活性炭的性能。结果表明H3PO4和ZnCl2是良好的活化剂,KOH和H2SO4效果较差。溶液的pH值对活性炭吸附C(rⅥ)的能力有很大影响。活性炭的吸附能力随着pH值的降低而升高,同时在不同的pH值下,炭的吸附速率也不同。pH值越低,C(rⅥ)被吸附的越快。等温实验结果表明,在pH值等于2时,用H3PO4和ZnCl2活化的活性炭对C(rⅥ)的吸附能力分别达到125.0和83.3mg·g-1。花生壳活性炭吸附C(rⅥ)的机理比较复杂,与溶液的pH值有关。在pH值等于2时,等温吸附可以用Langmuir模型模拟;在pH值等于2～7时,可以用Freundlich模型模拟。Preparation of activated carbons from peanut shells and removal of Cr（VI） from aqueous solution by the activated carbons were studied in this article. Chemical agents, H3PO4, ZnCl2, KOH and H2SO4 were used to activate the peanut shell carbon. The effects of activating agents, their concentrations and amounts, pyrolysis time and temperature, on the performance of the activated carbons were investigated. Adsorption experiments of methylene blue were adopted to evaluate the performance of the activated carbons. The results show that H3PO4 and ZnCl2 are excellent activating agents but NaOH and H2SO4 are poor ones. The solution pH has considerable influence on the adsorption of Cr（Ⅵ） onto the activated carbons. Adsorption capacity of the carbons increases with pH decreasing. Adsorption rate of the carbons differ at different pH as well. The lower the pH, the faster the Cr（Ⅵ） adsorption. Isotherm experiments show that Cr（Ⅵ） adsorption capacity of the carbons activated by H3PO4 and ZnCl2 reach to 125.0 and 83.3 mg·g^-1 at pH 2, respectively. The results can only be modeled by Langmuir isotherm at pH 2, and by Freundlich isotherm at pH 2 and 7, which means that the mechanism of Cr （Ⅵ） adsorption is complex and related with solution pH.

关 键 词：Cr(Ⅵ) 吸附 花生壳 活性炭 

分 类 号：TQ424.1[化学工程]