Preparation Of Different Series Adsorption Materials Based On Iron And Investigation Of The Adsorption Performance On Arsenic (?)

In this thesis,activated carbon,aluminium oxide and silicon dioxide were used as raw materials to prepare several kinds of eco-friendly and low-cost adsorbents by different iron series modification.The adsorption behavior and mechanism for As???were investigated.The research results are summarized as follows:Iron hydroxide/manganese dioxide doped straw activated carbon?FeOOH-MnO₂-SAc?was synthesized for As???adsorption.The adsorbents were characterized by means of XRD,PZC,FTIR,XPS and the adsorption properties were compared.0.05 % NaOH were used as eluent and the elution rate exceeded 90 %.It was found that the adsorption capacity of FeOOH-MnO₂-SAc for As???was 75.82 mg·g-1,which may be attributed to electrostatic interaction and complexation reaction between the adsorbent and the absorbate.The adsorption process for As???in FeOOH-MnO₂-SAc fitted Langmuir isotherm model.In order to study the adsorption properties for As???in Fe-hydroxyl functional groups,Aluminium oxide were used as raw materials to prepare Fe₂O₃-MnO₂-Al₂O₃ by iron sesquioxide/manganese dioxide modification.The adsorption capacity for As???in Fe₂O₃-MnO₂-Al₂O₃ at pH = 1 was higher than that at the other pH values.The mechanism for As???in Fe-Mn-SAc was that MnO₂ on the surface of Fe₂O₃-MnO₂-Al₂O₃ can oxidize As????H3AsO3?into As?V??H2AsO4–?,then the complexation reaction between H2AsO4– and the reaction sites?hydroxyl groups?of Fe₂O₃ was conducted by electrostatic interaction.In consideration of the adsorption capacity for As???in different iron series and in order to improve the adsorption capacity for As???,silicon dioxide was used as raw materials to prepare Fe⁰-CS-SiO₂ by Fe⁰/chitosan modification.The effects of the M-hydroxyl functional groups for As???adsorption properties were investigated.The optimum proportion of raw materials during the adsorbent synthesis process was also explored.Results showed that the adsorption performance for As???in Fe⁰-CS-SiO₂ was relatively high at pH = 3-11 and the maximum adsorption capacity was 100.01 mg·g-1.There is generally no adsorption for other impurities ion such as Ge?IV?,Fe???,Mn?II?,Zn?II?and Cu?II?.Cyclic experiments verified the reproducibility of the adsorbent.