Biosorption of Cadmium from Water using Surfactant Impregnated Egg Shell

 Abstract —Cadmium (Cd) is regarded as one of the most toxic elements and it causes water pollution when it exceeds the permissible limit. It is currently present in the Mooi River above these permitted levels, and must therefore be removed using effective methods. In this study, egg shell adsorbent was prepared through physico-chemical treatment including impregnation with an anionic surfactant, namely sodium dodecyl sulphate; the resulting adsorbents were characterized using FTIR spectroscopy. The prepared adsorbents were then used for the removal of cadmium from solution. The results showed that there were additional binding groups on the egg shell following impregnation, this contributed to increase the adsorption capacity of the adsorbent. The adsorption of cadmium by the pristine egg shell membrane (ESM) and the impregnated egg shell membrane (SDS-ESM) fitted the pseudo second order kinetic model which allowed to predict adsorption capacities of 16.56 mg/g and 20.4 mg/g, respectively. In can therefore be concluded that the impregnation of the ESM is a suitable approach to improve its adsorption capacity.