Original Articles
Ashwin Shenoy*, Jagadish H. Pa
Abstract
The current work was performed to search the likeli hood of using the water menace, water hyacinth as b iosorbent for the removal of hexavalent chromium ions from sy nthetic water containing chromium. All the biosorpt ion experiments were carried out in batch operation mod e with crude and pyrolysed water hyacinth. The impa ct of key physico-chemical factors pH, temperature, initial c hromium ion concentration and biosorbent dosage on chromium removal has been studied. The experiments reveal th at the maximum chromium removal can be achieved fro m an aqueous solution at low pH, less chromium concentra tion, moderate temperature (40 o C) and maximum biomass loading. Adsorption isotherms at equilibrium were e xamined. The experimental data obtained were analyz ed with Langmuir, Freundlich and Temkin adsorption isotherm models. The data fits well to all the three isothe rms as regression coefficient R 2 is more than 0.9 in all the cases. The crude and p yrolysed water hyacinth had mono layer adsorption with capacity of 2.7964 mg/g and 2.9438 mg/g respectively while the separation factor (S f ) for crude and pyrolysed water hyacinth is found to be 0.0102 and 0.0077 respectively. This indicatesthat performanc e of water hyacinth in pyrolysed form is marginally better tha n crude form. However taking economics in to consid eration water hyacinth in crude form is better as removal o f hexavalent chromium is less by 0.52%.