Removal of Synthetic Heavy Metal (Cr⁶⁺,Cu²⁺,As³⁺,Pb²⁺) from Water Using Red Mud and Lime Stone

Abstract

This study examined the removal rate of heavy metals from synthetic control water using red mud and lime stone. Overall, the percent of absorption obtained in this study for the red mud treatment was 94.0% (), 67.1% (), 37.5% (), and 36.6% (), while that of lime stone was (30.8%), (16.5%), (11.5%), and (8.9%). The kinetic data presented that the slow course of adsorption follows the Pseudo first and second order models, the equilibriuim adsorption of and obeys Freundlich isotherm model, while the adsorption of obeys only Langmuir model. The results also showed that adsorption rate slightly increased with increasing pH from 5 to 9. Interestingly, this trend is similar to results obtained as function of loading amount of red mud. Meanwhile, an unit adsorption rate was slightly decreased. For lime stone, it did not much change in adsorption as function of treatment amount. Consequently, it was concluded that the absorbents can be successfully used the removal of the heavy metals from the aqueous solutions.