Cation resin fixed-bed column for the recovery of valuable THAM reagent from the wastewater

Two commercial available cation resins, i.e. Amberlite IR-120 and Dowex HCR-W2, were tested as ion exchange adsorbents to investigate their isotherms, kinetics, breakthrough characteristics and regeneration on removal and recovery of tetra-methyl ammonium hydroxide (TMAH) from wastewater. Batch and column experiments were investigated to obtain experimental data for theoretical modelling and verify the column performance of the ion exchange process. The Langmuir isotherm represents better equilibrium behavior of both resins on TMAH uptake. The ion exchange kinetics follows the pseudo second order rate law also for both resins. Furthermore, breakthrough characteristics study shows the breakthrough curves follow the Thomas model and Yoon-Nelson model very well. The recovery efficiencies of TMAH were obtained as 99.6 and 98.0% from wastewater by ion exchange resin column by using 9 N HCl regeneration for Amberlite IR-120 and Dowex HCR-W2 resins, respectively. The comparative study on TMAH ion exchange removal by Amberlite IR-120 and Dowex HCR-W2 resins in fixed bed column suggested that Dowex HCR-W2 demonstrates higher ion exchange capacity than that of Amberlite IR-120 resin.