Biosorption of cadmium and copper ions from industrial wastewaters by waste activated sludge

ABSTRACT

In this study, the removal of cadmium and copper ions from aqueous solutions was investigated by waste activated sludge (WAS) under three conditions: (1) without any aeration and feeding, (2) by aeration without feeding and (3) by simultaneous aeration and feeding. The initial concentration, temperature, contact time, aeration and feeding had influence in Cd²⁺ and Cu²⁺ removal. The maximum removal of Cd²⁺ and Cu²⁺ was obtained with an initial concentration of 5 mg/L of each heavy metal that occurred in the third step (aeration and feeding of activated sludge) with removal efficiency of 75.45% and 76.91% for Cd²⁺ and Cu²⁺, respectively. This study showed that WAS has a high biosorption removal capacity for Cd²⁺ and Cu²⁺ and can be used as an effective biosorbent for the removal of cadmium and copper and/or other types of heavy metals from industrial wastewaters.

KEYWORDS:

• Biosorption
• Cu²⁺
• Cd²⁺
• waste activated sludge

Acknowledgments

The authors are most grateful to the laboratory staff of the Department of Environmental Health Engineering School of Public Health, Tehran University of Medical Sciences, Tehran, Iran, for their collaboration in this research.

Disclosure Statement

No potential conflict of interest was reported by the authors.