Cr(VI) Adsorption onto Hydrous Concrete Particles from Groundwater

Adsorption of Cr(VI) onto hydrous concrete particles in synthetic groundwater was investigated with batch equilibrium adsorption experiments. Results show marked adsorption under acidic conditions, and the amount of Cr(VI) adsorbed decreases with increasing solution pH and surface loading. A surface complex formation model was employed to describe the adsorption of Cr(VI) onto concrete particles. The adsorptionfree energy of HCrO-4 and CrO2-4 species are -6.16 and -8.53 kcal/mol, respectively. Results also indicate that specific chemical interaction is the major mechanism responsible for the adsorption process.