Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
J Environ Manage. 2017 Dec 15;204(Pt 1):424-435. doi: 10.1016/j.jenvman.2017.09.010. Epub 2017 Sep 12.
Adsorption, a popular technique for removing azo dyes from aqueous streams, is influenced by several factors such as pH, initial dye concentration, temperature and adsorbent dosage. Any strategy that seeks to identify optimal conditions involving these factors, should take into account both kinetic and equilibrium aspects since they influence rate and extent of removal by adsorption. Hence rigorous kinetics and accurate equilibrium models are required. In this work, the experimental investigations pertaining to adsorption of acid orange 10 dye (AO10) on activated carbon were carried out using Central Composite Design (CCD) strategy. The significant factors that affected adsorption were identified to be solution temperature, solution pH, adsorbent dosage and initial solution concentration. Thermodynamic analysis showed the endothermic nature of the dye adsorption process. The kinetics of adsorption has been rigorously modeled using the Homogeneous Surface Diffusion Model (HSDM) after incorporating the non-linear Freundlich adsorption isotherm. Optimization was performed for kinetic parameters (color removal time and surface diffusion coefficient) as well as the equilibrium affected response viz. percentage removal. Finally, the optimum conditions predicted were experimentally validated.
吸附是一种从水溶液中去除偶氮染料的常用技术，受到多种因素的影响，如 pH 值、初始染料浓度、温度和吸附剂用量。任何旨在确定涉及这些因素的最佳条件的策略，都应该考虑到动力学和平衡方面，因为它们会影响吸附的速率和去除程度。因此，需要严格的动力学和准确的平衡模型。在这项工作中，使用中心组合设计（CCD）策略对活性炭吸附酸性橙 10 染料（AO10）进行了实验研究。确定影响吸附的显著因素是溶液温度、溶液 pH 值、吸附剂用量和初始溶液浓度。热力学分析表明，染料吸附过程是吸热的。在将非线性 Freundlich 吸附等温线纳入后，使用均匀表面扩散模型（HSDM）严格地对吸附动力学进行了建模。对动力学参数（脱色时间和表面扩散系数）以及平衡影响的响应（即去除百分比）进行了优化。最后，对预测的最佳条件进行了实验验证。
