J. F. Richardson, J. H. Harker and J. R. Backhurst, “Chemical Engineering: Particle Technology and Separation Processes,” 5th Edition, Butterworth Heinemnn, India, 2003.
 W. L. McCabe, J. C. Smith and P. Harriot, “Unit Operations of Chemical Engineering,” 7th Edition, McGraw Hill, New York, 2005.
 R. C. Zielke and T. J. Pinnavaia, “Toxicants: Binding of Chlorophenols to Pillared, Delaminated, and Hydroxy-Interlayered Smectites,” Clays and Clay Minerals Journal, Vol. 36, No. 5, 1988, pp. 403-408.
 R. Goldman, L. Enewold, E. Pellizzari, J. B. Beach, E. D. Bowman, S. S. Krishnan and P. G. Shields, “Smoking Increases Carcinogenic Polycyclic Aromatic Hydrocarbons in Human Lung Tissue,” Cancer Research Journal, Vol. 61, 2001, pp. 6367-6371.
 M. Ghiaci, A. Abbaspur, R. Kia and F. Seyedeyn-Azad, “Equilibrium Isotherms Studies for the Sorption of Benzene, Toluene and Phenol onto Organo-Zeolites and As-Synthesized MCM-41,” Separation and Purification Technology, Vol. 40, No. 3, 2004, pp. 217-229.
 A. M. Mastral, T. Garcia, R. Murillo, M. S. Callen, M. V. Narvarro and J. Galban, “Assessment of Phenanthrene Removal from Hot Gas by Porous Carbons,” Energy Fuels, Vol. 15, No. 1, 2001, pp. 1-7. doi:10.1021/ef000116g
 O. Gok, S. A. Ozcan and A. Ozcan, “Adsorption Kinetics of Naphthalene onto Organo-Sepiolite from Aqueous Solutions,” Desalination, Vol. 220, No. 1-3, 2008, pp. 96-107. doi:10.1016/j.desal.2007.01.025
 J. P. Chen, S. Wu and K. H. Chong, “Surface Modification of a Granular Activated Carbon by Citric Acid for Enhancement of Copper Adsorption,” Carbon, Vol. 41, No. 10, 2003, pp. 1979-1986.
 M. Khalid, G. Joly, A. Renaud and P. Magnoux, “Removal of Phenol from Water by Adsorption Using Zeolites Bain,” Industrial & Engineering Chemistry Research, Vol. 43, No. 17, 2004, pp. 5275-5280. doi:10.1021/ie0400447
 A. S. Ozcan and A. Ozcan, “Adsorption of Acid Dyes from Aqueous Solutions onto Acid-Activated Bentonite,” Journal of Colloid and Interface Science, Vol. 276, No. 1, 2004, pp. 39-46. doi:10.1016/j.jcis.2004.03.043
 A. Ozcan and A. S. Ozcan, “Adsorption of Acid Red 57 from Aqueous Solutions onto Surfactant-Modified Sepiolite,” Journal of Hazardous Materials, Vol. 125, No. 1-3, 2005, pp. 252-259. doi:10.1016/j.jhazmat.2005.05.039
 W. T. Tsai, C. W. Lai and T. Y. Su, “Adsorption of Bisphenol-A from Aqueous Solution onto Minerals and Carbon Adsorbents,” Journal Hazardous Materials, Vol. 134, No. 1-3, 2006, pp. 169-175.
 R. S. Juang, S. H. Lin and K. H. Tsao, “Mechanism of Sorption of Phenols from Aqueous Solutions onto Surfactant-Modified Montmorillonite,” Journal of Colloid Interface Science, Vol. 254, No. 2, 2002, pp. 234-241.
 S. Y. Lee and S. J. Kim, “Adsorption of Naphthalene by Hdtma Modified Kaolinite and Halloysite,” Applied Clay Science, Vol. 22, No. 1-2, 2002, pp. 55-63.
 C. F. Chang, C. Y. Chang, K. H. Chen, W. T. Tsai, J. L. Shie and Y. H. Chen, “Adsorption of Naphthalene on Zeolite from Aqueous Solution,” Journal of Colloid and Interface Science, Vol. 277, No. 1, 2004, pp. 29-34.
 J. M. Hwu, G. J. Jiang, Z. M. Gao, W. Xie and W. P. Pan, “The Characterization of Organic Modified Clay and Clay-Filled PMMA Nanocomposite,” Journal of Applied Polymer Science, Vol. 83, No. 8, 2002, pp. 1702-1710.
 S. A. Boyd, M. M. Mortland and C. T. Chiou, “Sorption Characteristics of Organic Compounds on Hexadecyl Trimethy-Ammonium-Smectite,” Soil Science Society of America Journal, Vol. 52, No. 3, 1988, pp. 652-657.
 N. Xu, C. Christodoulatos and W. Braida, “Adsorption of Molybdate and Tetrathiomolybdate onto Pyrite and Geothite: Effect of pH and Competitive Anions,” Chemosphere, Vol. 62, No. 10, 2006, pp. 1726-1735.
 K. M. Spark and R. S. Swift, “Effect of Soil Composition and Dissolved Organic Matter on Pesticside Sorption,” Science of the Total Environment, Vol. 298, No. 1-3, 2002, pp. 147-161.
 X. Wu, B. Xiao, R. Li, C. Wang, J. Huang and Z. Wang, “Mechanisms and Factors Affecting Sorption of Microcystins onto Natural Sediments,” Environmental Science & Technology, Vol. 45, No. 7, 2011, pp. 2641-2647.
 M. Ahmedna, M. Johnson, S. J. Clarke, W. E. Marshall, and R. M. Reo, “Potential of Agricultural By-Products Based Activated Carbon for Use in Raw Surge Decolorization,” Journal of the Science of Food and Agriculture, Vol. 75, No. 1, 1997, pp. 117-124.
 O. Huerta-Pujol, M. Soliva, F. X. Martinez-Farre, J. Valero and M. Lopez, “Bulk Density Determination as a Single and Complementary Tool in Composting Process Control,” Bioresource Technology, Vol. 101, No. 3, 2010, pp. 995-1001. doi:10.1016/j.biortech.2009.08.096
 J. A. Lori, A. O. Lawal and E. J. Ekaem, “Characterisation and Optimization of Deferration of Kankara Clay,” Journal of Engineering and Applied Sciences, Vol. 2, No. 5, 2007, pp. 60-74.
 U. S. Sree Ramulu, “Principles in the Quantitative Analysis of Water, Fertilizers, Plant and Soils,” Scientific Publishers, India, 2003.
 W. E. Marshall, L. H.Wartall, D. E. Boler, M. M. Johns, and C. A. Tolea, “Enhanced Metal Adsorption by Soyabeans Hulls Modified with Citric Acids,” Bioresource Technology, Vol. 69, No. 3, 1999, pp. 263-268.
 A. Gajo and B. Loret, “The Mechanics of Active Clays Circulated by Salts, Acids and Bases,” 2007.
 P. Malakul, K. R. Srinivasan and H. Y. Wang, “Metal Toxicity Reduction in Naphthalene Biodegradation by Use of Metal-Chelating Adsorbents,” American Society of Microbiology, Vol. 64, No. 11, 1998, pp. 4610-4613.
 J. Q. Jiang and C. Cooper, “The Removal of Humic Substance with Modified Clay Adsorbents,” Environ Engineering Science, Vol. 20, No. 6, 2003, pp. 581-586.
 M. E. Chukwuedo and F. E. Okieimen, “Enhanced Metal Adsorption by Groundnut Husks Modified with Citric Acid,” Journal of Chemical Society of Nigeria, Vol. 33, No. 2, 2008, pp. 50-53.
 T. Abood, A. B. Kasa and Z. B. Chik, “Stabilization of Silt Clay Soil Using Chloride Compounds,” Journal of Engineering Science & Technology, Vol. 2, No. 1, 2007, pp. 102-110.
 M. F. Delbem, S. V. Ticiane, R. V. Francisco and R. D. Nicole, “Modification of a Brazilian Smectite Clay with Different Ammonium Salts,” Química Nova, Vol. 33, No. 2, 2010, pp. 309-315.
 C. N. Owabor, S. E. Ogbeide and A. A. Susu, “Adsorption and Desorption Kinetics of Naphthalene, Anthracene and Pyrene in Soil Matrix,” Petroleum Science and Technology, Vol. 28, No. 5, 2010, pp. 504-514.