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...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.展开更多
基金Key Project of uclear Safety and Advanced Nuclear Technology,China(No.2019YFB1901002)Project supported by the State Key Laboratory of Powder Metallurgy,Central South University,China。
基金supported by the Special Co-construction Project of Beijing Municipal Commission of Educationthe National Natural Science Foundation of China (No.51221892,21125731)
文摘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.