Aramanızda 9 sonuç bulundu.

Tez notu: ABSTRACT Six bentonite samples, three of which were activated with phosphoric acid (H3PO4) were obtained from Nigeria and Turkey. The samples were compared in terms of methylene blue adsorption capacity and kinetics. The raw bentonites had a pHzpc of 9, 9 and 8 while pHzpc of the activated bentonite samples were 2, 2 and 7. The results showed that raw bentonites (A and B) from Turkey achieved the highest MB mass adsorbed as 210 mg/g and 215 mg/g respectively. Lower equilibrium time of 90 min was achieved with raw sorbents compared to their activated forms with an equilibrium time of 2760 min. Raw bentonites (A and B) were selected from six bentonites based on superior characteristics in terms of adsorption capacity and kinetics. X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) analysis were conducted in order to understand the interaction mechanisms between methylene blue dye and bentonite (A and B). Among the solution pH tested (pH2-11), the highest dye mass adsorbed was obtained at pH 11 and this is because of the decrease of positive sites on MB with increasing pH and increase of negative adsorption sites on Bentonite. When the sorbent concentration varied from 0.5g/L to 2.0g/L, the largest adsorption capacity was obtained with 0.5 g/L. The sorption kinetics data were explained well by the pseudo second order model for both Bentonite A and B. The freundlich isotherm described MB adsorption on bentonite A well with an R2 of 0.9299 while linear isotherm had the best fit to the adsorption data for bentonite B with an R2 of 0.9458. Key words: Methylene Blue, Raw Bentonite, Activated Bentonite, Adsorption