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.
Research Article|March 22 2014
Sorption studies of Cr(VI) from aqueous solution using bio-char as an adsorbent
A. H. M. G. Hyder
Shamim A. Begum
A. H. M. G. Hyder, Shamim A. Begum, Nosa O. Egiebor; Sorption studies of Cr(VI) from aqueous solution using bio-char as an adsorbent. Water Sci Technol 1 June 2014; 69 (11): 2265–2271. doi: https://doi.org/10.2166/wst.2014.143
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