Industrial & Engineering Chemistry Research, Vol.51, No.34, 11226-11235, 2012
Adsorptive Removal of 2,4-Dichlorophenoxyacetic Acid (2,4-D) from Aqueous Solutions Using MIEX Resin
Batch experiments are carried out to evaluate the adsorption performances of 2,4-D from aqueous solutions by MIEX resin. The initial 2,4-D concentration, adsorption time, adsorbent dosage, inorganic ions, natural organic matter, and initial pH of solution have considerable effect on the removal of 2,4-D, but temperature has less effect. The isotherm experiments show the Redlich-Peterson and Sips models are the most appropriate models to simulate the equilibrium data at 293 K. The kinetic study demonstrates the pseudo-second-order model gives a best fitting to the adsorption of 2,4-D on the resin and the intraparticle diffusion is not the only rate-controlling step. The thermodynamic parameters are calculated. The results show that the adsorption of 2,4-D on the resin is a thermodynamically spontaneous and endothermic process. Accordingly, it can be concluded that MIEX resin can potentially be employed as an adsorbent for removing 2,4-D from raw water.