Synergistic and inhibitory reduction of Cr(VI) by montmorillonite, citric acid, and Mn(II)

Purpose Cr(VI) could be reduced in nature by citric acid, Mn(II), and montmorillonite. However, the co-presence of each material could enhance or inhibit Cr(VI) reduction. In this study, the synergistic interaction of citric acid, Mn(II), and montmorillonite on reduction of Cr(VI) was evaluated by experimental design.