Removing dyeing from aqueous solution using vermiculite

In this study, raw vermiculite (RV) and expanded vermiculite (EV) were used as adsorbent. The series of characterization analyzes were performed for identification of the samples. As a result of the analysis by using the X- Ray Fluorescence (XRF) method, information about the composition of the RV sample was obtained. The peaks observed in XRD pattern which was obtained from the RV sample with X- Ray Diffraction (XRD) method confirmed that the T-O-T structure of the vermiculite and the presence of water between the layers. Moreover, it also showed the presence of mica and potassium feldspar in the structure. The surface areas of the RV and EV samples were determined as 2,90 m2 /g and 2,89 m2 /g, respectively with the Brunauer-Emmet-Teller (BET) method. The cumulative surface areas of BJH adsorption pores for RV and EV were determined by the BarrettJoyner-Halenda (BJH) method as 2,25 m2 /g and 3,04 m2 /g, respectively. It has been determined that RV and EV adsorbents have micropores. Morphological analysis of RV and EV samples was performed using Scanning Electron Microscopy (SEM). The plate structure was seen in the taken images for both adsorbents. The Maxilon® Blue GRL (300%), a textile dye, removal behavior of both adsorbent materials from aqueous solution was investigated under varying initial dye concentration, time, pH and temperature conditions. The maximum adsorption capacity values were obtained at a maximum dye concentration of 20 mg/L at room temperature as 4,44 mg/g for RV and 5,97 mg/g for EV. The maximum dye removal value was obtained at pH 7,0. In the adsorption kinetics studies, it was revealed that the adsorption process proceeds with pseudo-first order kinetics. In the thermodynamic evaluation, it was concluded that the adsorption phenomenon occurs spontaneously and proceeds by taking heat, which has endothermic properties. From the adsorption isotherm evaluation, it was understood that the adsorption phenomenon complied with the Langmuir adsorption isotherm.