Table of Contents Author Guidelines Submit a Manuscript
Journal of Chemistry
Volume 2015 (2015), Article ID 853105, 8 pages
http://dx.doi.org/10.1155/2015/853105
Research Article

Kinetic and Thermodynamic Studies on the Phosphate Adsorption Removal by Dolomite Mineral

School of Metallurgy and Material Engineering, Chongqing University of Science and Technology, Chongqing 401331, China

Received 26 November 2014; Revised 15 January 2015; Accepted 26 January 2015

Academic Editor: Apostolos Giannis

Copyright © 2015 Xiaoli Yuan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The efficiency of dolomite to remove phosphate from aqueous solutions was investigated. The experimental results showed that the removal of phosphate by dolomite was rapid (the removal rate over 95% in 60 min) when the initial phosphate concentration is at the range of 10–50 mg/L. Several kinetic models including intraparticle diffusion model, pseudo-first-order model, Elovich model, and pseudo-second-order model were employed to evaluate the kinetics data of phosphate adsorption onto dolomite and pseudo-second-order model was recommended to describe the adsorption kinetics characteristics. Further analysis of the adsorption kinetics indicated that the phosphate removal process was mainly controlled by chemical bonding or chemisorption. Moreover, both Freundlich and Langmuir adsorption isotherms were used to evaluate the experimental data. The results indicated that Langmuir isotherm was more suitable to describe the adsorption characteristics of dolomite. Maximum adsorption capacity of phosphate by dolomite was found to be 4.76 mg phosphorous/g dolomite. Thermodynamic studies showed that phosphate adsorption was exothermic. The study implies that dolomite is an excellent low cost material for phosphate removal in wastewater treatment process.