Preparation, characterization and sorption performance of supported ionic liquid phase (SILP) systems

The main objective of this study is to investigate the preparation and characterization of supported ionic liquid phase (SILP) materials by using different preparation methods such as simple impregnation and sol–gel method. By using these methods, synergistic effect are aimed due to the combination of high ligand-making ability of ionic liquids with the porous properties of silica based sorbents. Chemical morphological characterization and surface area of the prepared adsorbents are invenstigated by using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Brunauer Emmett Teller (BET) Surface Area analysis. The thermal stability of the adsorbents is also evaluated by Thermogravimetric Analysis (TGA). Potential usage of SILP materials as sorbents is determined by a series of batch and continuous studies. Moreover, Cr(VI) ion sorption performances of the prepared adsorbents are investigated regarding the thermodynamic and kinetic aspects. Results part has two sections according to the preparation methods of materials. In Section A, physical impregnation method is discussed. The removal percentages of Cr(VI) ions are found as almost 100 % for all adsorbents prepared. Sorption isotherms are fitted with Langmuir equation and they exhibit favorable sorption behavior. The packed bed column mode sorption performances of modified particles exhibit high breakthrough capacity. In Section B, sol gel method is performed. The sorption performances of the modified particles are enriched by impregnation up to 99 % in the aqueous solution. Sorption of Cr(VI) onto modified particles follow the Langmuir isotherm model with the maximum sorption capacity of 31.74 mg/g. The results of sorption kinetic studies show that the sorption process of Cr(VI) ions followed pseudo second order. The calculated thermodynamic parameters indicate that endothermic and spontaneous nature of the adsorption process under operating conditions. Also, desorption efficiency is achieved 100% using 1 M HNO3.