Efficiency of pre-treated Moringa oleifera for the removal of Cd2+ and Zn2+ ions from wastewaters

Increased human activities have led to a rise in environmental pollution. Conventional methods of wastewater treatment are costly and sometimes not efficient. Use of Moringa oleifera has been promoted as a cost effective method. Its use as a biosorbent for sequestration of Zn and Cd for both single and mixed systems was investigated. The results show that metal uptake increased with contact time, based on a solid-to-liquid ratio of 1:100 with maximum adsorption occurring at pH 4. However, metal biosorption decreased drastically with increasing pH and Zn2+ ions were more efficiently biosorbed than Cd2+. The data fitted into both the Langmuir and Freundlich adsorption isotherms and Moringa treated with KMnO4 further enhanced heavy metal biosorption by offering better properties.