Cr(VI) removal from aqueous solutions by hydrothermal synthetic layered double hydroxides: Adsorption performance, coexisting anions and regeneration studies

The LDHs exhibit different adsorption capacity of Cr(VI) by the influence of coexisting anions due to the competitive adsorption on surface and anions exchange relative preference. Because the carbonate anions (CO32−) have strong affinity for laminates of LDHs and small ion radius, they showed the greatest impact on the adsorption capacity and the degree of effect is in the sequence CO32− > HCO3− > SO42− > H2PO4− >Cl− > NO3−.