B. Afsin

Determination of adsorptive properties of a Turkish Sepiolite for removal of Reactive Blue 15 anionic dye from aqueous solutions

Reactive Blue 15 (RB 15) adsorption on the Turkish Sepiolite was carried out by batch equilibrium technique. IR spectrum and surface area measurement of the composite of dye-sepiolite (Turkish) pointed out that dye species replaced partly the zeolitic water to form hydrogen bond with bound water and adsorbed to the channels sites. The effects of temperature, pH and ionic strength on adsorption of dye molecules were investigated and the nature of adsorption process was determined by calculating DeltaH, DeltaS and DeltaG values. The adsorbed amount increased with increase in temperature, but that for high pH values decreased for the adsorption of reactive dye.

Structural Characterization of Aniline-Bentonite Composite by FTIR, DTA/TG, and PXRD Analyses and BET Measurement

ABSTRACT The aniline species incorporated into the acid-activated bentonite matrices leads to the decay of the skeletal stretches centered at 1041 cm−1 and the rise of new features in the phenyl ring frequency region, 1700–1400 cm−1, demonstrates clearly the influence of the acid activation on the Lewis sites necessary for coordination of aniline to bentonite. The exothermic DTA features at 507, 684, and 725°C indicate the release of both the clusters and the decomposed fragments of the aniline-clay composite, and the highly stable carbonaceous residue, respectively. The basal difference by ∼1.0 nm and the much smaller surface area (33.8 m2/g) than that of the nonintercalated bentonite (129.2 m2/g) prove the presence of the tilted aniline species between the interlamellar grooves of the bentonite framework.

Key words: Sound Diffraction; Lined Duct; Integral Transform; Wiener-Hopf Technique; Expansion Coefficients; Pole Removal Technique

The intercalation of dimethyl sulphoxide (DMSO), pyridine (Py), ethanolamine (Ea), and Nmethyl formamide (NMF) molecules into the kaolinite interlayers led to an appreciable decrease of 3697 cm−1 of the hydroxyl band. The appearance of the peaks at 3662, 3541, and 3504 cm−1 proved that the DMSO species are intercalated between the kaolinite layers through forming H-bonds with internal-surface hydroxyl groups. The intensities of the 942 and 796 cm-1 bending peaks arising from inner-surface hydroxyls decreased and new vibrational features appeared due to the intercalation of the guest species. The d001 value of pure kaolinite was found at 7.18 A° , and the d001 values were seen at 11.26, 11.62, 10.77, and 10.67 °A for kaolinite-dimethyl sulphoxide (K-DMSO), kaolinite-pyridine (K-Py), kaolinite-ethanolamine (K-EA), and kaolinite-N-methyl formamide (K-NMF) composites, respectively. The endothermic differential thermal analysis (DTA) peaks at a temperature of 108 - 334 ◦C reflected the changes in the physicochemical properties of the intercalated species. The thermal stability increase followed the order of K-Py<K-NMF<K-Ea<K-DMSO. Based on the thermal analysis data, the intercalation ratios of the composites above were determined as 80.0, 40.0, 81.6, and 82.0%, respectively. The specific surface areas are affected by the intercalation geometry of the composites within the gallery spacing. The surface areas of the K-DMSO, K-Py, and K-EA complexes increased whereas the surface area of K-NMF decreased with respect to that of untreated kaolinite.