Preparation of poly(1-vinylimidazole) grafted polymeric adsorbent used in adsorption of arsenic ions

In this thesis, the new polystyrene-based anion exchanger (PS-VIM) adsorbent material with tertiary amine functional groups was synthesized by ATRP graft polymerization reaction on chloromethyl polystyrene polymeric particles of 1-vinyl imidazole. The degree of grafting of the 1-vinylimidazole monomer on chloromethyl polystyrene polymeric particles was found to be 83,65%. Structural and morphological properties of polymeric adsorbent material were analyzed by using FTIR, SEM and EDX. As (V) adsorption properties of 1-vinylimidazole grafted polystyrene-based polymeric particles were investigated. Solution pH, contact time, As(V) initial concentration, ionic strength and effects of interfering anions on adsorption were investigated at 25 °C by batch adsorption experiments. It was found that adsorption of As(V) ions depends on pH and maximum adsorption occurs at pH 5,00. Kinetic studies have shown that the adsorption process of As(V) ions on PS-VIM polymeric particles fits to the pseudo second order reaction model (R2=0,9902). The adsorption isotherm of the PS-VIM adsorbent for As (V) ions was found to fit the Langmuir model. The maximum adsorption capacity of As(V) ions was determined as 90,10 mg/g adsorbent at pH 5,00 from Langmuir isotherm. Increasing the ionic strength of the solution with NaCl has been observed to affect the adsorption of As(V) ions. The interaction between adsorbent and adsorbate has been found to be electrostatic interaction. The adsorption of As(V) ions was examined in the presence of interfering ions such as Cl-, NO3-, SO42- and ve PO43-, and it was found that SO42- ions significantly affected the adsorption of As(V) ions, but Cl- ions had the least effect. Ten adsorption-desorption cycles have shown that the polymeric material is suitable for efficient removal of As(V) ions from the aqueous solution. PS-VIM polymeric particles used as adsorbents have been shown to remove arsenic ions from tap waters containing As(V) ions at high concentrations. From the results obtained in this thesis study, it was concluded that PS-VIM polymeric particles can be used as an effective adsorbent material for removing As(V) ions from aqueous solutions.