The available data have shown that acid-leached clays had sites for adsorption of impurities in oils. Data obtained on residual impurities in cotton and sunflower-seed oils bleached with the same clay materials produced linear Langmuir and Freundlich isotherms. The increase in constant, k with increase in both temperature of thermal activation and concentration of acid used to leach the clay, suggests that bleaching efficiency increased. The value of n decreased with increase in temperature of activation and concentration of acid used to leach the clay suggesting that bleaching capacity increased. The mineral compositions of the clays influenced their surface, structural and bleaching properties.
References
[1]
Sabah, E.C. and Sabri, M. (2005) Sepiolite: An Effective Bleaching Adsorbent for the Physical Refining of Degummed Rapeseed Oil. Journal of the American Oil Chemists’ Society, 82, 911-916.
[2]
Langmuir, I. (1916) The Constitution and Fundamental Properties of Solids and Liquids. Part I. Solids. Journal of the American Chemical Society, 38, 2221-2295. http://dx.doi.org/10.1021/ja02268a002
[3]
Freundlich, H.M.F. (1906) Uber die Adsorption in Losungen. Zeitschrift für Physikalische Chemie, 57, 385-470.
[4]
Laidler, K.J. (1987) Chemical Kinetics. Harper and Row Publishers, New York.
[5]
Boki, K.M. and Kawasaki, N. (1994) Bleaching of Rape Seed and Soybean Oils with Synthetic Adsorbents and Attapulgites. Journal of the American Oil Chemists’ Society, 71, 595-601. http://dx.doi.org/10.1007/BF02540585
[6]
Achife, J. and Ibemesi, J. (1989) Applicability of Freundlich and Langmuir Adsorption Isotherms in Bleaching of Rubber and Melon Seed Oils. Journal of the American Oil Chemists’ Society, 66, 247-252. http://dx.doi.org/10.1007/BF02546069
[7]
Topallar, H. (1998) Adsorption Isotherms of the Bleaching of Sunflower-Seed Oil. Turkish Journal of Chemistry, 22, 143-148.
[8]
De Greyt, W.F., Kellens, M.J. and Huyghebaert, A.D. (1999) Effect of Physical Refining on Selected Minor Components in Vegetable Oils. Lipid, 101, 428-432. http://dx.doi.org/10.1002/(SICI)1521-4133(199911)101:11<428::AID-LIPI428>3.0.CO;2-T
[9]
Rossi, M., Gianazza, M., Alamprese, C. and Stanga, F. (2001) The Effect of Bleaching and Physical Refining on Color and Minor Components of Palm Oil. Journal of the American Oil Chemists’ Society, 78, 1051-1055. http://dx.doi.org/10.1007/s11746-001-0387-8
[10]
Ng, M.H., Choo, Y.M., Ma, A.N., Chuah, C.H. and Mohd. Ali, H. (2004) Separation of Vitamin E (Tocopherol, Tocotrienol and Tocomonoenol) in Palm Oil. Lipids, 39, 1031-1035. http://dx.doi.org/10.1007/s11745-004-1327-y
[11]
Puah, C.W., Choo, Y.M., Ma, A.N. and Chuah, C.H. (2007) The Effect of Physical Refining on Palm Vitamin E (Tocopherol, Tocotrienol and Tocomonoenol). American Journal of Applied Sciences, 4, 374-377.
[12]
Zchau, W. (1981) Chapter 9: Bleaching. In: O’brien, R.D., Farr, W.E. and Wan, P.J., Eds., Introduction to Fats and Oils Technology, Second Edition, AOCS Press, Champaign.
[13]
Goh, E.M. (1991) Palm Oil Composition and Quality. Proceedings of the PORIM International Palm Oil Conference (Chemistry and Technology), 268-278.
[14]
Car, R.A. (1978) Refining and Degumming Systems for Edible Oils and Fats. Journal of the American Oil Chemists’ Society, 55, 765-771. http://dx.doi.org/10.1007/BF02682645
[15]
Sadia, M.A. (1992) Degumming of Soybean Oil. Fasc., 45, 11-17.
[16]
Patterson, H.B.W. (1992) Chapter 3: Adsorbents. In: List, G.R., Ed., Bleaching and Purifying Fats and Oils: Theory and Practice, American Oil Chemists’ Society, Champaign.
[17]
Boki, K.M., Kubo, T. and Tamura, N. (1992) Bleaching of Alkali Refined Vegetable Oils with Clay Minerals. Journal of the American Oil Chemists’ Society, 61, 233-236.
[18]
Mbah, B.J.M., Kamga, J.F., Nguetnkam, J. and Fanni, J. (2005) Adsorption of Pigments and Free Fatty Acids from Shea Butter on Activated Cameroonian Clays. European Journal of Lipid Science and Technology, 107, 387-394. http://dx.doi.org/10.1002/ejlt.200501149
[19]
Hui, Y. (1996) Bailey’s Industrial Oil and Fat Products. John Wiley and Sons Inc., New York, 281-282.
[20]
Rich, A.D. (1964) Some Basic Factors in the Bleaching of Fatty Oils. Journal of the American Oil Chemists’ Society, 41, 315-321.
[21]
Temuujin, J., Senna, M., Jadambaa, T., Burmaa, D., Erdenechimeg, S. and MacKenzie, K.J.D. (2006) Characterization and Bleaching Properties of Acid-Leached Montmorillonite. Journal of Chemical Technology & Biotechnology, 81, 688-693. http://dx.doi.org/10.1002/jctb.1469
[22]
Gregg, S.J. and Sing, K.S.W. (1997) Adsorption, Surface Area and Porosity. Academic Press, London, 197-199.
[23]
Yuksel, B. (2003) Adsorption Isotherms in Bleaching Hazelnut Oil. Journal of the American Oil Chemists’ Society, 80, 1143-1146.
[24]
Siddiqui, M.K.H. (1989) One of These Physico-chemical Properties Is Surface Acidity. Clay Minerals, 37, 385-395.
[25]
Christidis, G.E. and Kosiari, S. (2003) Decolorization of Vegetable Oils: A Study of the Mechanism of Adsorption of β-Carotene by an Acid-Activated Bentonite from Cyprus. Clays and Clay Minerals, 51, 327-333. http://dx.doi.org/10.1346/CCMN.2003.0510309
[26]
Travis, C.L. and Etnier, E.L. (1981) A Survey of Sorption Relationships for Reactive Solutes in Soil. Journal of Environmental Quality, 10, 8-17.
[27]
Fried, N. and Shapiro, R.E. (1956) Phosphate Supply Patterns of Various Soils. Soil Science Society of America Journal, 20, 471-475. http://dx.doi.org/10.2136/sssaj1956.03615995002000040007x
[28]
Olsen, R.S. and Watanabe, F.S. (1957) A Method to Determine a Phosphorous Adsorption Maximum of Soils as Measured by Langmuir Isotherms. Soil Science Society of America Journal, 21, 144-149. http://dx.doi.org/10.2136/sssaj1957.03615995002100020004x
[29]
Hundal, H.S. (1988) A mechanism of Phosphate Adsorption on Narrabri Medium Clay Loam Soil. Journal of Agricultural Science, 111, 155-158. http://dx.doi.org/10.1017/S0021859600082952
[30]
Alemdaroglu, T. (2003) Investigation of the Surface Acidity of a Bentonite Modified by Acid Activation and Thermal Treatment. Turkish Journal of Chemistry, 27, 675-683.
[31]
Kothawala, D.N., Moore, T.R. and Hendershot, W.H. (2008) Adsorption of Dissolved Organic Carbon to Mineral Soils: A Comparison of Four Isotherm Approaches. Geoderma, 148, 43-50. http://dx.doi.org/10.1016/j.geoderma.2008.09.004
[32]
Vandenbruwane, J., De Neve, S., Hofman, G., Sleutel, S. and Hofman, G. (2007) Isotherm Models for Desired Organic Carbon (DOCS) and Nitrogen Sorption to Mineral Soil. Geoderma, 139, 144-153. http://dx.doi.org/10.1016/j.geoderma.2007.01.012
[33]
Jaroniec, M. and Kruk, M. (1999) Standard Nitrogen Adsorption Data for Characterization of Nanoporous Silica. Langmuir, 15, 5410-5413. http://dx.doi.org/10.1021/la990136e
[34]
Allen, S.J., Khader, K.K.H. and McKay, G. (1988) Mathematical Modeling of the Adsorption of Dyes. Environmental Pollution, 52, 39-53.
[35]
Srinivasan, K.R. and Fogler, H.S. (1990) Adsorption of Toxic Organics on Modified Montmorillonite. Clay and Clay Minerals, 38, 287-293.
[36]
Dandy, A.J. (1965) Bleaching Vegetable Oils with Kajansi, Koki and Mutaka Clays. Proceedings of the East African Academy, 3, 2-8.
[37]
Balaras, P.K., Lezou, P. and Seiragakis, G. (1999) Mineralogical Society of London. Clay Minerals, 34, 221-312.
[38]
Boyd, S.A., Shaobai, S., Lee, J.F. and Mortland, M.M. (1988) Pentachlorophenol Sorption by Organo-Clays. Clays and Clay Minerals, 36, 125-130.
[39]
Hassan, H.M. (2006) Structural and Chemical Alteration of Glauconite under Progressive Acid Treatment. Clay Minerals, 54, 491-499.
[40]
Madejova, J., Andrejkovicová, S., Bujjdak, J., Ceklovsky, A., Hrachova, J., Valuchova, J. and Komadel, P. (2007) Characterization of Products Obtained by Acid Leaching of Fe-Bentonite. Clay Minerals, 42, 527-540.
[41]
Proctor, A. and Toro-Vazquez, J.F. (1998) The Freundlich Isotherms in Studying Adsorption in Oil Processing. Journal of the American Oil Chemists’ Society, 73, 1627-1633. http://dx.doi.org/10.1007/BF02517963
[42]
Nodvin, S.C., Driscoll, C.T. and Likens, G.E. (1986) Simple Partitioning of Anions and Dissolved Organic Carbon in Soil. Soil Science, 142, 27-36. http://dx.doi.org/10.1097/00010694-198607000-00005
[43]
Norris, F.A. (1964) Bailey’s Industrial Oil and Fats Products. Interscience, New York.
[44]
Kaufmann, H.P. and Mukherjee, K.D. (1967) Neuzeitliche Technologie der Fette und Fettprodukte CXVI: Die Raffination der Fette. Chemische Revue über die Fettund Harz-Industrie, 69, 463-472.
[45]
Bijay, K.D.J., Jignesh, B.P., Vijay, K.P. and Vinay, R.P. (2000) Activated Clay. Journal of Oleo Science, 58, 257-263.
[46]
Gadzekpo, V.P.Y. and Mensah, S.G. (1991) Bleaching Palm Oil and Shea Butter Oils Using Acid-Leached Ghanaian Clays. Ghana Journal of Chemistry and Industry, 1, 197-201.
[47]
Ujeneza, E., Njenga, H.N., Mbui, N.D. and Kariuki, D.N. (2014) Optimization of Acid Activation Conditions for Athi River Bentonite Clay and Application of the Treated Clay in Palm Oil Bleaching. IOSR Journal of Applied Chemistry (IOSR-JAC), 7, 29-38. www.iosrjournals.org
[48]
Dandy, A.J. (1968) Bleaching Cotton Seed Oils with a Sepiolite. The Journal of Physical Chemistry, 72, 334-339.
[49]
Fahn, R. (1976) Bleaching Earths-Preparation, Properties, Practical Applications. Proceedings of the International Symposium, Brussels, 28-29 April 1976.
[50]
Onal, M., Sarikaya, Y., Alemdaroglu, T. and Bozdogan, T. (2002) Effect of Acid Activation on Some Physico-Chemical Properties of Clays. Turkish Journal of Chemistry, 409-416.
[51]
ECGA, European Clay Group Association (2002) Newsletter No.5, July 2002, 57-78.
