title: Fungal biomass with grafted poly(acrylic acid) for enhancement of Cu(II) and Cd(II) biosorption.
abstract: The biomass of Penicillium chrysogenum was modified by graft polymerization of acrylic acid (AAc) on the surface of ozone-pretreated biomass. The sorption capacity for copper and cadmium increased significantly as a large number of carboxyl groups were present on the biomass surface, especially when the carboxylic acid group was converted to carboxylate ions using NaOH. When modeled using the Langmuir isotherm, the sorption capacities were 1.70 and 1.87 mmol g(-1) for copper and cadmium, respectively. The loaded biosorbent was regenerated using HCl solution and used repeatedly over five cycles with little loss of uptake capacity beyond the second cycle. The sorption of the two metals was time-dependent, and the kinetics fitted the pseudo-second-order equation well. The Freundlich, Langmuir, Temkin, and Dubinin-Redushkevich isotherms were used to model the metal sorption isotherms, and the thermodynamic parameters calculated show that the sorption was spontaneous and endothermic under the condition applied and that the biomass has similar sorption affinities for the two metals. Fourier transform infrared and X-ray photoelectron spectroscopy reveal that carboxyl, amide, and hydroxyl groups on the biomass surface were involved in the sorption of copper and cadmium and ion exchange and complexation dominated the sorption process.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.forename: Yen Peng
authors.initials: YP
authors.lastname: Ting
mesh_terms: D000180:Acrylic Resins; D000327:Adsorption; D001692:Biological Transport; D018533:Biomass; D002104:Cadmium / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D005612:Freeze Drying; D010408:Penicillium chrysogenum / Q000254:growth & development* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D002104:Cadmium; C006903:carbopol 940; D003300:Copper