Mg-Al Layered Double Hydroxide (LDH) as an Adsorbent for Removal of Itaconic Acid from Aqueous Solutions: Equilibrium and Kinetic Study

Abstract

This study aims to remove itaconic acid, one of the important members of carboxylic acids, fromits aqueous solutions by using an adsorption method. Recently the Layered Double Hydroxide (LDH), whichhas attracted attention in many areas, was synthesized by the co-precipitation method and used as anadsorbent. The effects of the adsorption time, LDH amounts, adsorption temperature, and initial acidconcentration changes on the adsorption efficiency were examined. In one-stage batch adsorptionexperiments performed under different conditions, approximately 70% of itaconic acid was removed fromthe aqueous phase using 1 g of LDH. Various adsorption isotherm models such as Langmuir, Freundlich, andTemkin were applied to the obtained experimental data. Since R2 values are greater than 0.98, it can be saidthat the experimental data fit all three isotherm models. Kinetic studies were carried out using timedependent measurements. Adsorption behavior was kinetically investigated using pseudo-first-order,pseudo-second-order, and Elovich models. The kinetics of the adsorption of itaconic acid by LDH was foundto be the best defined by the pseudo-second-order model.