Abstract
The arsenic adsorption properties of a new iron hydroxide synthesized from ferrous sulfate, sodium hypochlorite, and sodium hydroxide were examined. The main constituents of the new compound were iron, sulfur, chlorine, and sodium. It was confirmed by X-ray, TG/DTA, and SEM analyses that the new compound is amorphous. Arsenic adsorption obeyed the Langmuir isotherm, and a high adsorption ability was observed at low to high arsenic concentrations. At an arsenic concentration of 20 mg·L-1 and an adsorbent amount of 10 g·L-1, As(III) and As(V) were adsorbed rapidly so that the arsenic concentration decreased to below the detection limit within 1 min. Under the same conditions as described above, As(III) and As(V) were almost completely removed at pH of 3.0 to 9.0 within 1 h. Coexisting ions, SO42-, Cl-, NO3-, and HCO3-, did not affect the arsenic adsorption by the new iron hydroxide. The arsenic adsorption ability was also satisfactory in the column continuous experiment.
