Prosopis Juliflora (Kikar) pods as adsorbent for removal of Cd(II) ions from aqueous streams

Abstract

Cadmium Cd(II) is a heavy metal, the presence of which in an aqueous ecosystem is detrimental to human beings, animals and vegetation due to its mobile, toxic and non-biodegradable nature. Different treatment techniques like neutralization, coagulation and flocculation, oxidation, ion exchange, ozonation, membrane separation and disinfection have been employed, but eco-friendly techniques involving adsorption on natural and bio-degradable adsorbents is the most favourable one as it is the least costly, flexible in design and possesses large removal efficiencies. The present work is based on the adsorptive removal of Cd(II) ions from wastewater streams employing biosorbent prepared from Prosopis Juliflora (kikar) pods. To determine the parametric sensitivity of the adsorptive removal, batch experiments have been carried out by varying the dosage of the adsorbent, initial Cd(II) concentration, pH and the time of contact. The chemical/microstructural composition of adsorbent prepared from raw and carbonized kikar pods has been examined by its proximate analysis, SEM and FTIR. The carbonized kikar pods can act as an economical, eco-friendly and practical adsorbent for Cd(II) from wastewater streams as they displayed a maximum removal efficiency of 82% and a maximum metal uptake capacity of 16 mg g−1 of biosorbent. Further, to comprehend the kinetic data for the adsorptive removal, a pseudo-second order mechanism has been proposed.