Preparation of modified kermes oak (Quercus coccifera l.) adsorbents and As(v) removal from aqueous solutions

In this study, the effectiveness of adsorbents obtained from raw and modified kermes oak biomass for the removal of Arsenate (V) ions from aqueous solutions by adsorption method was investigated. In the study, firstly, two different solid adsorbents were obtained after acid modification (A-KMB) and iron oxide coating on the surface (DOKMB) of kermes oak biomass. The structures of the obtained solid adsorbents were characterized by FTIR, XRD, EDX and BET surface area analysis methods and the changes in their surface morphologies were characterized by SEM images. In the second stage of the study, the effects of the initial solution pH, initial solution As(V) concentration, contact time, adsorbent dose and ambient temperature parameters, which are effective in the removal process of As(V) ions of KMB, A-KMB and DOKMB solid adsorbents, were investigated. For this purpose, the batch method was used and the optimum removal conditions were determined. According to the results obtained in the study, it was determined that DOKMB was the most effective adsorbent among the three adsorbents examined in the removal of As(V) ions from aqueous solution. The maximum adsorption capacity and removal efficiency for DOKMB were obtained as 1.84±0.02 mg/g and 91.78±0.79%, respectively. The thermodynamic parameters ΔH, ΔG and ΔS were calculated in the process of removal of As(V) ions from aqueous solution using DOKMB solid adsorbent. It was determined that the adsorption process had an endothermic character. The compatibility of the experimental adsorption data with the Langmuir, Freundlich and D-R isotherms was investigated. It was determined that the Langmuir isotherm model of the removal of As(V) ions with DOKMB adsorbent was more compatible than the other isotherms. It was determined that DOKMB solid adsorbent was effective in real samples prepared from tap water containing low concentration As(V) ion in the range of 25-200 µg/L. In the study, it was suggested that DOKMB solid adsorbent, a low-cost material obtained from the modification of kermes oak biomass, is a promising alternative material in the removal and preconcentration of As(V) from aqueous solutions by adsorption method.