Biosorption of hexavalent chromium from paint industrial effluent by Saraca indica leaves using with and without gel entrapment method

Raw agricultural wastes are affordable adsorbents for the removal of heavy metals from aqueous solutions. In this research, the use of Saraca indica leaves (as an eco-friendly and low cost adsorbent) having the ability to remove toxic hexavalent chromium (Cr(VI)) from paint industrial effluent has been investigated. Parameters such as biosorbent quantity, initial metal-ion concentration, and contact time in with and without immobilised batch experiments have been studied. The results revealed that Saraca indica leaves absorb over 86% of Cr (VI) ions from solutions with increasing adsorbent dosage. Adsorption isotherms were compared with Langmuir and Freundlich adsorption models and experimental data were found to fit the models. Also adsorption kinetic models were studied and found to best fit the pseudo second order model. The present study showed that such a low cost material could be used efficiently for the removal of Cr(VI) from paint industrial effluent.