Reduction of Hexavalent Chromium by Using Immobilized Hibiscus Rosasinensis Leaves

Abstract

Raw agricultural wastes are affordable adsorbents for the removal of heavy metals from aqueous solutions. In this research, the use of Hibiscus rosasinensis leaves (as an eco-friendly and low cost adsorbent) with no treatment having the ability to remove toxic hexavalent chromium (Cr (VI)) from aqueous solutions has been investigated. The influences of several main parameters such as pH value of the solution, sorbent amount, initial metal-ion concentration, and contact time in immobilized batch experiments have been studied. The results revealed that Hibiscus rosasinensis leaves absorbs over 70 to 90 %  with increasing adsorbent dosage from 50 to 200mg. Adsorption isotherms were compared with Langmuir and Freundlich adsorption models and experimental data are found to fit the models. The present study shows that such a low cost material could be used efficiently for the removal of Cr(VI) from aqueous solutions.