HEXAVALENT CHROMIUM REMOVAL FROM AQUEOUS SOLUTIONS BY PLEUROTUS OSTREATUS SPENT BIOMASS.

The Pleurotus ostreatus spent biomass after the harvest, is a waste which was used as a potential sorbent after coating it with chitosan an deacetylated derivative from chitin the most abundant carbohydratesecond to cellulose .The study is an attempt to elaborate and justify the optional utility of Spent Pleurotus ostreatus biomass for hexavalent chromium removal from aqueous industrial effluents. The effect of experimental parameters such as pH, biosorbent dosage, biosorbent dosage, initial metal concentration, temperature and sorption time is very striking from the obtained results .The Freundlich isotherm and Langmuir isotherm fitted well to the data of Cr (VI) sorption capacity of Spent Pleurotus biomass. The intraparticle diffusion plot suggest that the sorption process proceeds by surface adsorption alone in case of activated spentbiomass but when coated with chitosan the process is sorption along with intra particle diffusion or pore diffusion. The overall adsorption process was endothermic and spontaneous innature.EDX analysis indicated the presence of hexavalent chromium ions on the surface of chitosan coated spent Pleurotus biomass. The resultssuggest that the enhanced spent biomass could be employed as an efficient adsorbent for the removal of hexavalent chromium from industrial effluents as well as from contaminated water sources.