Facile one-pot electrosynthesis of Al(OH)3 - kinetics and equilibrium modeling for adsorption of 2,4,5-trichlorophenoxyacetic acid from aqueous solution

This study presents a Al(OH)(3) synthesis in a facile one-pot process by an electrodissolution method. This process is a novel process, where the adsorbents are generated in an in situ, efficient and cost-effective way for removing organic pollutants. The adsorption performance of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) onto Al(OH)(3) was systematically investigated and the experimental results indicated that Al(OH)(3) showed an excellent adsorption capacity toward 2,4,5-T. To optimize the removal efficiency of 2,4,5-T, different experimental parameters like the effect of current density, pH, temperature, different anodes and inter-electrode distance were carried out. The results showed that the maximum removal efficiency of 86.0% was achieved at a current density of 0.10 A dm(-2) and a pH value of 7.0. The adsorption kinetics could be well described by the pseudo-second-order model and the Langmuir isotherm model showed a better fit with experimental data than the Freundlich and D-R model. Moreover, thermodynamic parameters indicate that the adsorption of 2,4,5-T on aluminum hydroxides was feasible, spontaneous and endothermic. The adsorbed Al(OH)(3) was characterized by different techniques, such as SEM, EDAX, XRD and FTIR measurements.