title: Sorption studies of Cr(VI) from aqueous solution using bio-char as an adsorbent.
abstract: The characteristics of sorption of hexavalent chromium (Cr(VI)) onto bio-char derived from wood chips (spruce, pine, and fir) were evaluated as a function of pH, initial Cr(VI) concentration and bio-char dosage using synthetic wastewater in batch tests. The initial Cr(VI) concentrations were varied between 10 and 500 mg/L to investigate equilibrium, kinetics, and isotherms of the sorption process. About 100% of Cr(VI) was removed at pH 2 with initial Cr(VI) concentration of 10 mg/L using 4 g of bio-char after 5 hours of sorption reaction. The maximum sorption capacity of the bio-char was 1.717 mg/g for an initial Cr(VI) concentration of 500 mg/L after 5 hours. The sorption kinetics of total Cr onto bio-char followed the second-order kinetic model. The Langmuir isotherm model provided the best fit for total Cr sorption onto bio-char. The bio-char used is a co-product of a down draft gasifier that uses the derived syngas to produce electricity. Bio-char as a low cost adsorbent demonstrated promising results for removal of Cr(VI) from aqueous solution. The findings of this study would be useful in designing a filtration unit with bio-char in a full-scale water and wastewater treatment plant for the Cr(VI) removal from contaminated waters.
authors.affiliation: Department of Land and Water Resources Engineering, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
authors.forename: A H M G
authors.initials: AH
authors.lastname: Hyder
authors.affiliation: Department of Chemical Engineering, Tuskegee University, Tuskegee, AL, 36832, USA E-mail: begums@mytu.tuskegee.edu.
authors.forename: Shamim A
authors.initials: SA
authors.lastname: Begum
authors.affiliation: Department of Chemical Engineering, Tuskegee University, Tuskegee, AL, 36832, USA E-mail: begums@mytu.tuskegee.edu.
authors.forename: Nosa O
authors.initials: NO
authors.lastname: Egiebor
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D014874:Water Pollutants, Chemical; C540010:biochar; D014867:Water; D002857:Chromium; D002606:Charcoal