摘要
A Zr-β-FeOOH adsorbent for both As（Ⅴ） and As（Ⅲ） removal was prepared by a chemical co-precipitation method. Compared with β-FeOOH, the addition of Zr enhanced the adsorption capacities for As（Ⅴ） and As（Ⅲ）, especially As（Ⅲ）. The maximum adsorption capacities for As（Ⅲ） and As（Ⅴ） were 120 and 60 mg/g respectively at pH 7.0, much higher than for many reported adsorbents. The adsorption data accorded with Freundlich isotherms. At neutral pH, for As（Ⅴ）, adsorption equilibrium was approached after 3 hr, while for As（Ⅲ）, adsorption equilibrium was approached after 5 hr. Kinetic data fitted well to the pseudo second-order reaction model. As（Ⅴ） elimination was favored at acidic pH, whereas the adsorption of As（Ⅲ） by Zr-β-FeOOH was found to be effective over a wide pH range of 4-10. Competitive anions hindered the adsorption according to the sequence： phosphate 〉 silicate 〉 bicarbonate 〉 sulfate 〉 nitrate, while Ca2＋ and Mg2＋ increased the removal of As（Ⅲ） and As（Ⅴ） slightly. The high adsorption capability and good performance in other aspects make Zr-β-FeOOH a potentially attractive adsorbent for the removal of both As（Ⅲ） and As（Ⅴ） from water.
A Zr-β-FeOOH adsorbent for both As（Ⅴ） and As（Ⅲ） removal was prepared by a chemical co-precipitation method. Compared with β-FeOOH, the addition of Zr enhanced the adsorption capacities for As（Ⅴ） and As（Ⅲ）, especially As（Ⅲ）. The maximum adsorption capacities for As（Ⅲ） and As（Ⅴ） were 120 and 60 mg/g respectively at pH 7.0, much higher than for many reported adsorbents. The adsorption data accorded with Freundlich isotherms. At neutral pH, for As（Ⅴ）, adsorption equilibrium was approached after 3 hr, while for As（Ⅲ）, adsorption equilibrium was approached after 5 hr. Kinetic data fitted well to the pseudo second-order reaction model. As（Ⅴ） elimination was favored at acidic pH, whereas the adsorption of As（Ⅲ） by Zr-β-FeOOH was found to be effective over a wide pH range of 4-10. Competitive anions hindered the adsorption according to the sequence： phosphate 〉 silicate 〉 bicarbonate 〉 sulfate 〉 nitrate, while Ca2＋ and Mg2＋ increased the removal of As（Ⅲ） and As（Ⅴ） slightly. The high adsorption capability and good performance in other aspects make Zr-β-FeOOH a potentially attractive adsorbent for the removal of both As（Ⅲ） and As（Ⅴ） from water.
基金
supported by the Special Co-construction Project of Beijing Municipal Commission of Education
the National Natural Science Foundation of China (No.51221892,21125731)
