title: Sorption of lead, cadmium, and zinc on sulfur-containing chemically modified wastes of fluted pumpkin (Telfairia occidentalis Hook f.).
abstract: We have tested the applicability of regular as well as sulfanylacetic acid (SA) modified fluted pumpkin waste biomass as adsorbents for Pb2+, Cd2+, and Zn2+ aqueous solutions by means of the batch-sorption technique. The data revealed that SA modification produces a larger surface area, enhancing the metal-ion binding capacity of the biomass. The sorption process was examined by means of Freundlich and Langmuir models. The kinetic study showed that the sorption rates can be described by a pseudo-second-order process. The rate constants for the control biomass (CB) were 2.2x10(-2), 4.4x10(-2), and 1.6x10(-2) mg g(-1) min(-1) for Pb2+, Cd2+, and Zn2+, respectively; and the corresponding rate constants for the SA-modified biomass were 4.0x10(-2), 4.7x10(-2), and 1.7x10(-2) mg g(-1) min(-1), respectively. Thermodynamic considerations indicated a spontaneous exothermic process, which implies that physisorption is the main mechanism in the sorption process.
authors.affiliation: Department of Pure & Industrial Chemistry, University of Port Harcourt, Uniport P.O. Box 402 Choba, Port Harcourt, Nigeria. horsfalljnr@yahoo.com
authors.forename: Michael
authors.initials: M
authors.lastname: Horsfall
authors.forename: Ayebaemi I
authors.initials: AI
authors.lastname: Spiff
mesh_terms: D018533:Biomass; D002104:Cadmium / Q000737:chemistry*; D028464:Cucurbita / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007854:Lead / Q000737:chemistry*; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry*
chemical_list: D002104:Cadmium; D007854:Lead; D015032:Zinc