Biosorption of Chromium (VI) From Single Ion Solutions on Cotton Stalks and Rice Straw Wastes

Abstract

Industrial activities discharge their effluents containing heavy metals without treatment. The removal of hexavalent chromium (Cr VI) from wastewater is necessary as it is a carcinogen. The aim of this work is to study the removal of (Cr VI) from single ion solution using adsorption technique. Some plant based biomass wastes were tested as biosorbents for Cr (VI) from aqueous solutions. These wastes are cotton stalk wastes (CSW), and rice straw wastes (RSW). Batch scale experiments using Cr (VI) individual single ion solutions were carried out to test the main biosorption parameters such as pH, adsorbent concentration, initial adsorbate concentration, adsorbent particle size and the kinetics of biosorption. The process was pH dependant with an optimal at pH 2 for the tested biosorbents. The capacity of the studied biosorbents to bind chromium (VI) from individual solution was 17.13 and 7.47 mg g -1 for CSW and RSW respectively at 5.0 g l -1 adsorbent concentration and 300 mg l -1 adsorbate initial concentration. Experimental equilibrium data were fitted to Langmuir and Freundlich adsorption isotherms. r 2 for the relation was 0.9677 and 0.9220 for CSW and RSW