Preparation of bentonite-steel slag composite particles and copper ion adsorption.

To improve the conditions of powder bentonite-steel slag forming, the composite adsorption particles were prepared from calcium-based bentonite and steel slag with the help of cross-linking of sodium alginate and calcium chloride. The post-adsorption morphology, elemental and physical phases of the composite particles were characterized by SEM-EDS and XRD analysis. The effect of composite adsorption particles on the adsorption of Cu (11) at different slag mass ratios, dosing amounts, pH, temperature and initial concentration was investigated by static adsorption experiments. The results showed that the removal rate of Cu(II) reached 92.95% at a compound particle dosage of 30 g/L, pH 5.2 and an initial Cu(II) concentration of 100 mg/L. The kinetics of Cu(II) adsorption by the composite particles is in accordance with the proposed first-order kinetic model, the adsorption thermodynamics is in accordance with the Lang-muir adsorption isotherm model, and the thermodynamically relevant parameters indicate that the adsorption of Cu(II) by the composite particles is a spontaneous, heat-absorbing procees. [ABSTRACT FROM AUTHOR]