Nutrient Removal from Wastewaters using Treated Incineration Residues of Expired Medications: Kinetics, Thermodynamics and Isotherm Modeling

AbstractIncineration residues of expired medications (IREM) were chemically treated (IREM-T), by a combination of mixed salts (CaCl2, MgCl2) and thermal treatments with NaOH. They were characterized and used for simultaneous ammonia and phosphates adsorption from wastewater. Batch experiments were carried out to investigate the effect of contact time, adsorbent dose, initial concentration, pH and temperature. The maximum adsorption capacity for phosphate and ammonium on IREM-T was found to be 24.68 mg g−1 and 34.30 mg g-1, respectively at the same initial concentration of 50 mg L−1 on 5 g L−1 of IREM-T. Langmuir, Freundlich, Temkin and Dubinin – Radushkevich adsorption models were applied to analyze adsorption data. The equilibrium data fitted well with Langmuir isotherm. To examine the adsorption mechanism, pseudo first-order, pseudo second-order and intraparticle diffusion models were applied to analyze the experimental data. All the linear correlation coefficients of the second-order model were found t...