Adsorption of Dye from Wastewater by Zeolites Synthesized from Fly Ash： Kinetic and Equilibrium Studies

• Published in: Chinese journal of chemical engineering Vol. 17; no. 3; pp. 513 - 521
• Main Author: 王春峰 李健生 王连军 孙秀云 黄佳佳
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2009
• Subjects: adsorption; dye; fly ash; kinetic; zeolite; 动态平衡; 废水处理; dye; fly ash; zeolite; adsorption; kinetic
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60239-6

The removal performance of a basic dye, methylene blue （MB）, in aqueous solution was investigated by adsorption process on single-phase and high-crystalline zeolite A （FA-ZA） and X （FA-ZX）. Both adsorbents FA-ZA and FA-ZX were synthesized from fly ash prepared aluminosilicate gel followed by the hydrothermal treatment at 100°C with the control of Si/Al molar ratio, respectively. The properties of the synthetic zeolites and commercial grade zeolites, such as thermal stability, elemental composition, and cation exchange capacity, were investigated for comparison. Batch method was used to study the influential parameters, such as initial pH value of the solution, temperatures, and adsorbents dosage, on the adsorption process. The experimental data were well fitted by Ho’ pseudo-second-order model and liquid film diffusion model. The suitability of Langmuir and Freundlich isotherms to the equilibrium data was investigated in the solid-liquid system while the Langmuir model produces the best re-sults. Thermodynamic data （△H, △S, and △G） corresponding to the MB uptake were evaluated from the Langmuir model. In all the adsorption experiments, the adsorption capacity followed the order as follows： FA-ZX 〉 FA-ZA. In addition, attempts were also made to regenerate the adsorbents.