Removal of antimicrobial compounds from water by gac and natural minerals

Abstract

The widespread and unrestricted use of antimicrobials resulted in accumulation of them in the environment and due to their adverse effects they can be considered as an emergent pollutant group. Development of antimicrobial resistance in microorganisms is the major adverse effect of antibiotic pollution in the environment. In order to remove sulfonamide and tetracycline group antibiotics namely, sulfamethazine (SMZ), sulfamethoxazole (SMX), and oxytetracycline (OTC) batch experiments have been performed by granular activated carbon (GAC). Adsorption kinetics and equilibrium studies were performed by GAC. Additionally, the adsorption performance of some natural minerals (perlite, pumice, and zeolite) was evaluated for SMZ. The effects of contact time, initial antimicrobial concentration, and pH on the adsorption were investigated. While the highest adsorption capacity of natural minerals for SMZ was obtained with zeolite with a value of 1.42 mg/g, about nine fold higher adsorption was obtained with GAC. Experimental equilibrium data indicates that the isotherms for these antimicrobials on GAC can be satisfactorily described by Temkin isotherm equation. Four different mathematical models proposed in the literature were used to describe kinetics and the adsorption of all antimicrobials could be described more favorably by the pseudo-second order kinetic model. Batch adsorption experiments indicate that the sorption is a pH dependent process.