Copperas-coated zeolite as an efficient adsorbent for cadmium removal from synthetic wastewater

Water pollution by cadmium is a major global issue as it tends to bioaccumulate and not biodegradable in the environment. Exposure to this heavy metal even at low concentrations can cause many serious health effects to humans. This study aimed to investigate the efficiency of integrated copperas and zeolite as adsorbents for cadmium removal in an aqueous solution. Both materials were integrated by simple immersion and heating methods for 4 h and their properties were each characterized in terms of morphology and functional group analysis via SEM and Fourier-transform infrared spectroscopy, respectively. In the first stage of evaluation, the performance of the adsorbents to remove cadmium was conducted through batch adsorption experiments on natural zeolite and integrated copperas/zeolite. Copperas/zeolite appeared to be a better adsorbent and was selected for further use in batch adsorption experiments at different dosages, initial concentrations, and pH. The highest cadmium removal (99%) was obtained at pH 7, 4.0 g/L dosage, and 0.5 mg/L initial cadmium concentration. The adsorption study was well fitted with the Langmuir and Freundlich isotherm models and indicated both homogenous and heterogeneous adsorption. The findings can provide an essential pathway for developing sustainable and cost-effective adsorbents for cadmium removal in water and wastewater treatment.