Adsorption isotherms in bleaching hazelnut oil
Küçük Resim Yok
Tarih
2003
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Oil Chemists Soc A O C S Press
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Adsorption isotherms in bleaching hazelnut oil were determined to investigate the applicability of the Langmuir and Freundlich equations and to elucidate the adsorption characteristics of oil on bentonite EY-09 (Bensan Co. Ltd., Edirne, Turkey). The degree of bleaching was monitored spectrophotometrically. Absorbance measurements were carried out to investigate the adsorption force of clay during bleaching of hazelnut oil with 0.3, 0.5, 0.7, and 0.9 wt% clay at 50, 60, 70, 80, and 90degreesC. Bentonite EY-09 was used as the bleaching clay (adsorbent). Plots of log(x/m) vs. log X-e (for the Freundlich isotherm) and X-e/(x/m) vs. X-e (for the Langmuir isomtherm) were made (where x is the amount of pigment removed per unit mass of the adsorbent, m, and X-e is the equilibrium concentration of the pigment). The Freundlich constants were found to increase with temperature for a given oil/bleaching agent ratio, showing the formation of more active sites on the adsorbent with a rise in temperature. Since the heat evolved during adsorption (0.32-1.03 kJ mol(-1)) was less than 20 kJ mol(-1), the forces between the adsorbent and adsorbate appeared to be van der Waals forces. This type of adsorption is defined as physical or van der Waals adsorption. The results obtained show good agreement with the Freundlich isotherm, indicating that the adsorption of the pigment from the oil proceeds by monolayer formation on the surface of the adsorbent.
Açıklama
Anahtar Kelimeler
Adsorption Isotherm, Bleaching, Freundlich Equation, Hazelnut Oil, Langmuir Equation, Vegetable-Oils, Adsorbents
Kaynak
Journal Of The American Oil Chemists Society
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
80
Sayı
11
