Synthesis Of Hydroxylamine Modified Polyacrylonitrile Metal Ions Complexes And Their Properties Of Catalytic Oxidation And Removal For Arsenic

The loose and porous polyacrylonitrile(PAN) was prepared using acrylonitrile as raw material by suspension polymerization, then polyacrylonitrile containing amidoxime(AO/PAN) was got by modification of hydroxylamine. Using AO/PAN as adsorbent, three kinds of Polymeric ligand exchangers(PLEs)-hydroxylamine modified polyacrylonitrile metal ion complexes were obtained by adsorbed Cu(II),Fe(III) and Cu(II)/Fe(III) respectively, named as AO/PAN-Cu(II), AO/PAN-Fe(III) and AO/PAN-Cu(II)/Fe(III). The structure of these PLEs were characterized by Fourier infrared spectrum(FT-IR), thermo-gravimetric analysis(TG), scanning electron microscope analysis(SEM), X-ray photoelectron spectroscopy(XPS) and specific surface area pore size analysis. The catalytic oxidation ability of three kinds of polyacrylonitrile metal ion complexes to As(III) and arsenic removal performancce in the presence of H2O2 were studied in detail, including catalytic oxidation kinetic experiment, thermodynamics, the influence of solution pH, H2O2 concentration,adsorbent dosage and coexisting anions to the catalytic oxidation of As(III) and removal of As(T), and the dynamic experiment. The results of experiments showed that:(1) Kinetic experiments showed that the system of H2O2- AO/PAN-Cu(II) on the oxidation of As(III) removal rate constant was 16.3 and 18 times faster than used alone of H2O2 and AO/PAN-Cu(II) system, respectively. Thermodynamics experiments showed that the adsorption behavior of AO/PAN-Cu(II) for As(T) conformed to Freundlich isothermal. Cl-, NO3-, SO42-, HCO3-, SiO32- and H2PO4- had little influence on the oxidation of As(III), As(III) removal was up to 88%. When the concentration of Cl-, NO3-, SO42-, HCO3- and SiO32- was 0.1 mmol/L, As(T) removal could reach to 85%.Column experiment showed that AO/PAN-Cu(II) had good purifying effect for the simulated wastewater containing arsenic in the presence of H2O2, the breakthrough volume was 95 Bed volume(BV).(2) Kinetic experiments showed that the system of H2O2-AO/PAN-Fe(III) on the oxidation of As(III) removal rate constant was 53 and 5.3 times faster than used alone of H2O2 and AO/PAN-Fe(III) system, respectively. Thermodynamics experimentsshowed that the adsorption behavior of AO/PAN-Fe(III) for As(T) conformed to Langmuir isothermal and the theoretical maximum adsorption capacity was 33.75mg/g. Coexisting ions had little influence on the oxidation of As(III), As(III) removal was up to 89%. When the concentration of Cl-, NO3-, SO42- and HCO3- was 0.1 mmol/L,As(T) removal could reach to 98%. Column experiment showed that AO/PAN-Fe(III)had good purifying effect for the simulated wastewater containing arsenic in the presence of H2O2, the breakthrough volume was 130 BV.(3) Kinetic experiments showed that the system of H2O2-AO/PAN-Cu(II)/Fe(III)on the oxidation of As(III) removal rate constant was 85 and 17 times faster than H2O2 and AO/PAN-Cu(II)/Fe(III) system, respectively. Thermodynamics experiments showed that the adsorption behavior of AO/PAN-Cu(II)/Fe(III) for As(T) followed to R-P isothermal. Coexisting anions had little effect on the As( â…¢) oxidation, As(III)removal was up to 95%. When the concentration of Cl-, NO3-, SO42- and H2PO4- was0.1 mmol/L, As(T) removal could reach to 86%. Column experiment showed that AO/PAN-Fe(III) had good purifying effect for the simulated wastewater containing arsenic in the presence of H2O2, the breakthrough volume was 130 BV.