Adsorption studies on the removal of Malachite Green from aqueous solutions onto halloysite nanotubes
Adsorption studies on the removal of Malachite Green from aqueous solutions onto halloysite nanotubes
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DOI：
10.1016/j.clay.2011.07.008
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发表时间：
2011-11-01
影响因子：
5.6
通讯作者：
Khataee, Ali R.
中科院分区：
文献类型：
--
作者：
Kiani, Gholamreza;Dostali, Mohammad;Khataee, Ali R.
采用高岭土纳米管（HNTs）作为纳米吸附剂，对阳离子染料孔雀石绿（MG）进行了脱除。通过批量实验研究了染料的吸附性能。采用红外光谱（FT-IR）和透射电镜（TEM）对天然HNTs进行了初步表征。考察了吸附剂用量、初始pH、温度、初始染料浓度和接触时间对吸附效果的影响。吸附量随吸附剂剂量、初始pH和温度的增加而增加。接触时间30分钟后迅速达到平衡。采用伪一阶、伪二阶和颗粒内扩散模型计算速率参数。吸附符合准二级动力学模型，相关系数大于0.999。对吸附过程的控制因素进行了计算和讨论。在pH = 9.5时，mg的最大吸附量为99.6 mg g（-1）。G度、H度和S度的热力学参数表明吸附过程是自发的吸热过程。(C) 2011 Elsevier B.V.版权所有
Halloysite nanotubes (HNTs) were used as nano-adsorbents for removal of the cationic dye, Malachite Green (MG), from aqueous solutions. The adsorption of the dye was studied with batch experiments. The natural HNTs used as adsorbent in this work were initially characterized by FT-IR and TEM. The effects of adsorbent dose, initial pH, temperature, initial dye concentration and contact time were investigated. Adsorption increased with increasing adsorbent dose, initial pH, and temperature. Equilibrium was rapidly attained after 30 min of contact time. Pseudofirst-order, pseudo-second-order and intraparticle diffusion models were considered to evaluate the rate parameters. The adsorption followed pseudo-second-order kinetic model with correlation coefficients greater than 0.999. The factors controlling adsorption process were also calculated and discussed. The maximum adsorption capacity of 99.6 mg g(-1) of MG was achieved in pH = 9.5. Thermodynamic parameters of Delta G degrees, Delta H degrees and Delta S degrees indicated the adsorption process was spontaneous and endothermic. (C) 2011 Elsevier B.V. All rights reserved.