Adsorption of cesium from aqueous solution using agricultural residue – Walnut shell: Equilibrium, kinetic and thermodynamic modeling studies

• Published in: Water Research Vol. 47; no. 7; pp. 2563 - 2571
• Main Authors: Ding, Dahu, Zhao, Yingxin, Yang, Shengjiong, Shi, Wansheng, Zhang, Zhenya, Lei, Zhongfang, Yang, Yingnan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2013; Elsevier
• Subjects: Adsorption; Agriculture; analysis; Applied sciences; biosorbents; Cesium; Cesium - isolation & purification; Cesium adsorption; chemistry; correlation; Differential Thermal Analysis; Diffusion; Exact sciences and technology; Ferrocyanides; Ferrocyanides - chemistry; Industrial wastewaters; Integrated analysis; isolation & purification; Isotherms; Juglans; Kinetics; Mathematical models; Microscopy, Electron, Scanning; Models, Theoretical; nickel; Nickel - chemistry; Nickel hexacyanoferrate (NiHCF); Nonlinear Dynamics; Pollution; Residues; scanning electron microscopes; Scanning electron microscopy; Shells; Solutions; sorption isotherms; temperature; thermal analysis; Thermodynamics; Thermogravimetry; Time Factors; Walnut shell; Waste Products; Waste Products - analysis; Wastewaters; Water Pollutants, Chemical; Water Pollutants, Chemical - isolation & purification; Water treatment and pollution; Cesium adsorption; Integrated analysis; Walnut shell; Nickel hexacyanoferrate (NiHCF); Alkali metal Compounds; Adsorption isotherm; Bioadsorbents; Surface structure; Characterization; Agricultural waste; Husk (fruit); Scanning electron microscopy; Adsorption energy; Nickel Hexacyanoferrates; Transition metal Complexes; Adsorption; Walnut; Industrial waste water; Morphology; Crop residues; Cesium Compounds; Physicochemical purification; Thermal analysis; Kinetics; Waste water purification; Thermodynamic properties
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2013.02.014

A novel biosorbent derived from agricultural residue – walnut shell (WS) is reported to remove cesium from aqueous solution. Nickel hexacyanoferrate (NiHCF) was incorporated into this biosorbent, serving as a high selectivity trap agent for cesium. Field emission scanning electron microscope (FE-SEM) and thermogravimetric and differential thermal analysis (TG-DTA) were utilized for the evaluation of the developed biosorbent. Determination of kinetic parameters for adsorption was carried out using pseudo first-order, pseudo second-order kinetic models and intra-particle diffusion models. Adsorption equilibrium was examined using Langmuir, Freundlich and Dubinin–Radushkevich adsorption isotherms. A satisfactory correlation coefficient and relatively low chi-square analysis parameter χ2 between the experimental and predicted values of the Freundlich isotherm demonstrate that cesium adsorption by NiHCF-WS is a multilayer chemical adsorption. Thermodynamic studies were conducted under different reaction temperatures and results indicate that cesium adsorption by NiHCF-WS is an endothermic (ΔH° > 0) and spontaneous (ΔG° < 0) process. [Display omitted] ► Nickel hexacyanoferrate incorporated walnut shell is first fabricated. ► Pseudo second-order kinetic model and Freundlich isotherm fits the data well. ► Ion exchange process between Cs+ and K+ is proved.