As(Ⅲ) Adsorption Effects of Montmorillonite, Iron Oxides and Their Complex

A modified montmorillonite complex was prepared out of montmorillonite and FeCl₃·6H₂O, and used in comparison between montmorillonite, iron oxide and the modified complex in adsorption of As(Ⅲ). Results show that the kinetics of the three adsorbents adsorbing As(Ⅲ) in water fit the Lagergren speed equation, and all belong to the sort of Freundlich sorption isotherm. The modified complex is obviously superior to the other two in setting efficiency. Besides, it is capable of regulating pH of the arsenic solution. Competitive adsorption experiments on some common ions come to the conclusion that calcium ion has some positive effect, while magnesium and sulfate has little on removal efficiency of arsenic, and nitrate and phosphate competes vigorously with As(Ⅲ) for adsorption.