Hexavalent chromium or Cr(VI) in drinking water presents a serious human health risk. It has been identified as a by-product in industrial processes and found in hazardous waste sites, although natural sources have been reported. Common methods to remove Cr(VI) employ adsorption, filtration, ion exchange technologies and redox reactions. The organic reagent, Biotage® MP-Carbonate has been extensively used for the acid neutralizations of chemical reactions or scavenge acidic organic molecules such as carboxylic acids or phenols from reaction mixtures. We report on its ability to effectively adsorb Cr(VI). The macro-porous polystyrene anion exchange resin, a solid-supported equivalent of tetra-alkyl ammonium carbonate removes Cr(VI) from synthetic wastewater by bidentate or monodentate coordination of chromate with the ammonium ions. Chromate sorption is pH independent as seen by the adsorption capacity of 332, 161 and 163 mg CrO42- per gram of MP-Carbonate at pH 2.0, 6.8 and 10.0, respectively. Experimental data indicate an exergonic and endothermic adsorption process. Density functional theory calculations supports the preferential bidentate binding of the larger CrO42- ion compared to CO32- with the ammonium ions. These studies identify the potential uses of MP-Carbonate in the remediation of Cr(VI) wastewater unrelated to the pH of the water source.

Switching an old organic reagent for a new water remediation strategy:  Adsorption of hexavalent chromium with biotage MP-carbonate

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.