Modelling and appraisal of cadmium removal from water by sustainable bio-waste of hen egg shells

Abstract

Hen egg shells powder is investigated as adsorbent for the removal of cadmium (Cd) from water with and without chemical modification. Batch sorption studies were performed at different bio-waste dose, metal ions solution initial concentration, pH, particle size and agitation. Optimal removal efficiency of Cd is noted in 45 minutes, quantifying 86% removal by 2 g optimised dose at 100 rpm. Maximum adsorption occurred at pH 7. The kinetic data is modelled with the help of reaction based equations; the data is well fitted with pseudo second order model. Hydrolysed and oxidised egg shells revealed enhanced remediation of cadmium possibly due to increased lactonic sites. The use of egg shells as value added adsorbent will be thoughtful endeavour of turning waste into commodity.