Combined Treatment of Cr(VI)-Contaminated Soils by Reduction, Adsorption, and Solidification

Remediation of Cr(VI)-contaminated soil usually includes reducing Cr(VI) to Cr(III) with sub-sequent solidification. In this paper, a treatment technique that combines reduction, adsorption, and solidification was proposed. By introducing an adsorbent into the reduction process, remediation effectiveness improved amount solidified agent decreased. Synthetic precipitation leaching procedure (SPLP), unconfined compressive strength (UCS) test, scanning electron microscope (SEM) analysis were carried out evaluate effect under different combinations agent-adding procedures. The results SPLP showed reduction/adsorption/solidification significantly reduced leachability Cr. UCS increased increasing dosage cement CaS5, decreased vermiculite. best CaS5 2 times molar stoichiometric ratio Cr(VI), 15% vermiculite, 20% cement. Orthogonal test for low content, most important factor affected Cement vermiculite have greater impact in limiting Cr when content increased.