Adsorption study for removal of Congo red anionic dye using organo-attapulgite
Adsorption study for removal of Congo red anionic dye using organo-attapulgite
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DOI：
10.1007/s10450-009-9155-z
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发表时间：
2009-08-01
影响因子：
3.3
通讯作者：
Zhao, J.
中科院分区：
文献类型：
--
作者：
Chen, H.;Zhao, J.
以十六烷基三甲基溴化铵（HTMAB）为原料，加入十六烷基三甲基溴化铵（HTMAB）与十六烷基三甲基溴化铵（CEC）的等比，制备了有机凹凸棒土，作为吸附剂用于去除刚果红（CR）阴离子染料。利用红外光谱和x射线衍射对吸附剂进行了表征。考察了接触时间、温度、pH和初始染料浓度对有机凹凸棒土吸附CR的影响。结果表明：CR在有机凹凸棒土上的吸附量随染料浓度、温度和ph的增加而增加。采用拟一级、拟二级和颗粒内扩散模型研究了CR在有机凹凸棒土上的吸附动力学，并计算了吸附速率常数。研究发现，染料/有机凹凸棒土体系的吸附机制符合准二级动力学，膜扩散对其有重要贡献。与Freundlich等温模型相比，平衡数据与Langmuir等温模型拟合较好，吸附剂的最大吸附量为189.39 mg g（-1）。动力学和解吸研究均表明，化学吸附是有机凹凸棒石去除CR的主要方式。结果表明，htmab改性凹凸棒土可作为低成本的材料用于废水中刚果红阴离子染料的脱除。
The organo-attapulgite was prepared using hexadecyltrimethylammonium bromide (HTMAB) with equation equivalent ratio of HTMAB to CEC of attapulgite added and then used as adsorbent for the removal of Congo red (CR) anionic dye from aqueous solution. Adsorbent characterizations were investigated using infrared spectroscopy and X-ray diffraction. The effects of contact time, temperature, pH and initial dye concentration on organo-attapulgite adsorption for CR were investigated. The results show that the amount adsorbed of CR on the organo-attapulgite increase with increasing dye concentration, temperature, and by decreasing pH. The adsorption kinetics was studied with the pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and the rate constants were evaluated. It was found that the adsorption mechanisms in the dye/organo-attapulgite system follow pseudo-second-order kinetics with a significant contribution of film diffusion. Equilibrium data fitted perfectly with Langmuir isotherm model compared to Freundlich isotherm model, and the maximum adsorption capacity was 189.39 mg g(-1) for the adsorbent. Kinetic and desorption studies both suggest that chemisorption should be the major mode of CR removal by the organo-attapulgite. The results indicate that HTMAB-modified attapulgite could be employed as low-cost material for the removal of Congo red anionic dye from wastewater.