Arsenik ve Selenyum İyonlarının Adsorpsiyonunda Anyon Değiştirici Polimerik Adsorbentlerin Kullanımı
Özet
In this thesis, polystyrene modified with N,N-dimethyleneethylenediamine molecules (DMEDA-m-CMS) with anion exchange properties was investigated as an effective adsorbent for As(V) and Se(VI) ions from the aqueous system. The structural and morphological properties of the anion exchange adsorbent material were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effects of pH, contact time, initial concentration, interfering ions and ionic strength on the adsorption of As(V) and Se(VI) ions were systematically investigated by batch adsorption experiments. It has been determined that the adsorption of As(V) and Se(VI) ions on DMEDA-m-CMS adsorbent is fast and 60 minutes is required to reach the adsorption equilibrium. It has been observed that pH 4.00 is optimum for As(V) and Se(VI) ions, and the adsorbent's ability to adsorb these ions is independent of the solution pH. It was determined that the experimental adsorption data obtained for As(V) and Se(VI) ions were in better agreement with the Langmuir isotherm model. The Maximum adsorption capacities from Langmuir isotherm data for As(V) and Se(VI) ions were found to be 114,93 and 78,12 mg/g polymer, respectively. The experimental adsorption kinetic data obtained for As(V) and Se(VI) ions were in good agreement with the pseudo-second order model. It was observed that mono-charged ions such as NO3- and Cl− did not affect the adsorption of As and Se(VI). However, highly charged ions such as SO42- and PO43- were observed to affect the adsorption. DMEDA-m-CMS adsorbent could be effectively regenerated using 3% HNO3, with a desorption efficiency of over 95%. From the results obtained in this study, it was determined that DMEDA-m-CMS adsorbent is applicable for the removal of As(V) and Se(VI) ions from the aqueous medium.
