Preparation Of Magnetic Humic Acid/Conductive Polymer Composites And Their Adsorption For Cr(?) Ions In Aqueous Solution

In order to effectively avoid environmental pollution caused by heavy metal ions in wastewater,the waste water can be discharged after strict treatment.At present,adsorption treatment is one of the most common methods of treatment.With many advantages,it has been widely studied and applied.In this paper,a series of micro / nano structures of magnetic humic acid / conductive polymer composites were synthesized by two step polymerization with Pickering emulsion drop lets as templates,and the adsorption properties of composites for Cr(?)ions in water were studied systematically.The results of the study are as follows:(1)Based on the solubility of humic acid in the alkaline environment and the easy precipitation of humic acid in the acidic environment,oil in water Pickering emulsion with p H response were prepared with the precipitated humic acid colloid particles as the stabilizer,the water as the continuous phase and the hydrophobic oil as the dispersed phase.The effects of types of oil phase and amount of humic acid on Pickering emulsion were investigated.It is found that humic acid colloid particles can stabilize many different types of oil phase,and the stability of emulsion becomes stronger as the amount of humic acid increases.Styrene was used as polymerizable dispersed phase to achieve the green cyclic polymerization of the emulsion,and the pure polystyrene microspheres were successfully prepared.(2)Magnetic humic acid / polypyrrole / polystyrene composite microspheres(PPy/PS/HA/Fe3O4)and magnetic humic acid / polyaniline / polystyrene composite microspheres(PANI/PS/HA/Fe3O4)were prepared by two step polymerization using Pickering emulsion droplets as the template.The Pickering emulsions were stabilized by humic acid colloid particles with cyclohexane magnetic fluid,styrene and two vinyl benzene as the oil phase.When the p H value of Cr(?)solution is 2,the adsorption properties of the composite microspheres are the best.The maximum adsorption capacity is 151.52 mg/g(PPy/PS/HA/Fe3O4)and 117.10 mg/g(PANI/PS/HA/Fe3O4),respectively.The adsorption behavior could be well described by the quasi-two-order kinetics model and the Langmuir isothermal model.(3)Magnetic humic acid / montmorillonite / polypyrrole / polystyrene composite microspheres(P-MSHn)and magnetic humic acid / montmorillonite / polyaniline / polyphenylene composite microspheres(A-MSHn)were prepared by two step polymerization using Pickering emulsion droplets as template.The Pickering emulsions were stabilized by humic acid colloid particles / montmorillonite with the dimethylbenzene magnetic fluid,styrene and two vinyl benzene as the oil phase.When the p H value of Cr(?)solution is 2,the adsorption properties of the composites are the best.The maximum adsorption capacity is 49.74 mg(P-MSHn)and 76.74 mg/g(A-MSHn),respectively.The adsorption behavior well followed the quasi-two-order kinetics model and the Langmuir isothermal model.