title: Removal of hexavalent chromium by biosorption process in rotating packed bed.
abstract: Removal of hexavalent chromium ions from an aqueous solution by crude tamarind (Tamarindus indica) fruit shell was examined in a rotating packed bed contactor by continuously recirculating a given volume of solution through the bed. Reduction of Cr(VI) to Cr(III) within the biosorbent appeared to be the removal mechanism. Depletion rate of Cr(VI) from, and release of reduced Cr(III) ions into the aqueous phase, was influenced by mass transfer resistance besides pH and packing depth. A mathematical model considering the reduction reaction to be irreversible and incorporating intraparticle and external phase mass transfer resistances represented the experimental data adequately. The study indicated that the limitations of fixed bed contactor operating under terrestrial gravity in intensifying mass transfer rates for this system can be overcome with rotating packed bed due to liquid flow under centrifugal acceleration.
authors.affiliation: Department of Chemical Engineering, Jadavpur University , Kolkata 700032, India.
authors.forename: M
authors.initials: M
authors.lastname: Panda
authors.forename: A
authors.initials: A
authors.lastname: Bhowal
authors.forename: S
authors.initials: S
authors.lastname: Datta
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002857:Chromium / Q000302:isolation & purification*; D003198:Computer Simulation; D052918:Environmental Restoration and Remediation / Q000295:instrumentation* / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D012212:Rheology; D012399:Rotation; D029861:Tamarindus / Q000737:chemistry
chemical_list: D002857:Chromium; C074702:chromium hexavalent ion