Abstract

This study on the removal of cobalt ions from aqueous solutions by red mud was conducted in batch condition. Its objective was to investigate the possibility of using red mud waste material as an alternative to high cost commercial adsorbent materials for the removal of cobalt from aqueous solution. In this study, batch experiments were carried out for the adsorption of cobalt onto red mud industry waste. The red mud waste material was successfully used for the removal of cobalt ion from aqueous solution and the technique appears industrially applicable and viable. The potential of economically cheap waste materials like red mud was assessed for cobalt adsorption from aqueous solutions. The operating variables studied were contact time, initial solution pH, initial metal concentration, temperature and adsorbent dosage. The experimental investigation results show that activated red mud has a high level of adsorption capacity for cobalt ion. The adsorption data was correlated with the Langmuir and Freundlich isotherm models. It was found out that the Langmuir and Freundlich isotherms fitted well to the data. Consequently, it was concluded that the red mud can be successfully used for the removal of the cobalt ions from the aqueous solutions with heavy metals.

Key words: Red mud, cobalt removal, aqueous solution, adsorption isotherms.