Bakkal Gula C, Bilgin Simsek E, Duranoglu D, Beker U
Chemical Engineering Department, Yildiz Technical University, Istanbul 34220, Turkey E-mail:
Chemical and Process Engineering Department, Yalova University, Yalova 77100, Turkey.
Water Sci Technol. 2015;71(2):203-10. doi: 10.2166/wst.2014.491.
The present paper discusses response surface methodology as an efficient approach for predictive model building and optimization of As(V) adsorption on activated carbon derived from a food industry waste: peach stones. The objectives of the study are application of a three-factor 2³ full factorial and central composite design technique for maximizing As(V) removal by produced activated carbon, and examination of the interactive effects of three independent variables (i.e., solution pH, temperature, and initial concentration) on As(V) adsorption capacity. Adsorption equilibrium was investigated by using Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. First-order and second-order kinetic equations were used for modeling of adsorption kinetics. Thermodynamic parameters (ΔG °, ΔH °, and ΔS °) were calculated and used to explain the As(V) adsorption mechanism. The negative value of ΔH (-7.778 kJ mol⁻¹) supported the exothermic nature of the sorption process and the Gibbs free energy values (ΔG°) were found to be negative, which indicates that the As(V) adsorption is feasible and spontaneous.
本文讨论了响应面法，这是一种用于建立预测模型以及优化利用食品工业废料桃核制备的活性炭对五价砷吸附效果的有效方法。本研究的目的是应用三因素2³全因子设计和中心复合设计技术，以最大化所制备活性炭对五价砷的去除率，并考察三个自变量（即溶液pH值、温度和初始浓度）对五价砷吸附容量的交互作用。采用朗缪尔等温线模型、弗伦德里希等温线模型和杜宾宁-拉杜舍维奇等温线模型研究吸附平衡。用一级动力学方程和二级动力学方程对吸附动力学进行建模。计算了热力学参数（ΔG °、ΔH °和ΔS °），并用于解释五价砷的吸附机理。ΔH的负值（-7.778 kJ mol⁻¹）支持了吸附过程的放热性质，吉布斯自由能值（ΔG°）为负，这表明五价砷的吸附是可行的且是自发的。
