title: Characterization of adsorption of aqueous arsenite and arsenate onto charred dolomite in microcolumn systems.
abstract: In this work, the removal of arsenite, As(III), and arsenate, As(V), from aqueous solutions onto thermally processed dolomite (charred dolomite) via microcolumn was evaluated. The effects of mass of adsorbent (0.5-2 g), initial arsenic concentration (50-2000 ppb) and particle size (<0.355-2 mm) on the adsorption capacity of charred dolomite in a microcolumn were investigated. It was found that the adsorption of As(V) and As(III) onto charred dolomite exhibited a characteristic 'S' shape. The adsorption capacity increased as the initial arsenic concentration increased. A slow decrease in the column adsorption capacity was noted as the particle size increased from>0.335 to 0.710-2.00 mm. For the binary system, the experimental data show that the adsorption of As(V) and As(III) was independent of both ions in solution. The experimental data obtained from the adsorption process were successfully correlated with the Thomas Model and Bed Depth Service Time Model.
authors.affiliation: a Department of Mechanical Engineering, Faculty of Engineering and Architecture , American University Beirut , Beirut , Lebanon.
authors.forename: Yousef
authors.initials: Y
authors.lastname: Salameh
authors.forename: Ala'a H
authors.initials: AH
authors.lastname: Al-Muhtaseb
authors.forename: Hasan
authors.initials: H
authors.lastname: Mousa
authors.forename: Gavin M
authors.initials: GM
authors.lastname: Walker
authors.forename: Mohammad N M
authors.initials: MN
authors.lastname: Ahmad
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000737:chemistry*; D018053:Arsenites / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D008962:Models, Theoretical; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001149:Arsenates; D018053:Arsenites; D014874:Water Pollutants, Chemical; D002119:Calcium Carbonate; D008274:Magnesium; C015001:arsenite; C025657:arsenic acid; C028042:calcium magnesium carbonate
keywords: adsorption; arsenic; charred dolomite; dolomite; microcolumn; water treatment