Removal of malachite green from aqueous solution using the adsorbents produced from the pomegranate

There are significant amount of dyestuffs in industrial wastewaters. One of the most important methods used for the removal of dyes is adsorption. In this study, the removal of malachite green used in industry with adsorbents obtained from pomegranate peel was investigated. For this purpose, the first adsorbent was obtained by carbonizing the pomegranate peel and the second adsorbent with nano iron with zero valent was synthesized by using the previous product. The adsorption studies were carried out with two adsorbent. Characterization of adsorbents was made with FTIR, SEM and BET. The adsorption parameters were determined as amount of adsorbent, initial concentration, contact time, pH of solution and temperature. Langmuir isotherm ensured the best fit to experimental data compared with other isotherms that is commonlly used in aqueous solutions. The adsorption capacity in Langmuir isotherm was found 31,45 and 32,47 mg/g for the first and second adsorbent respectively. The kinetic data were analyzed by pseudo first order, pseudo second order, Elovich and intraparticle diffusion model and it was determined that results were best described with the pseudo-first-order kinetic model and pseudo-second-order kinetic model for the first and second adsorbent respectively. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were calculated and defined that adsorption is spontaneous and endothermic for each adsorbent. The pomegranate peel could be used for both environmental waste evaluation as low cost adsorbent and dye removal from wastewater.