Dye Adsorption on Expanding Three-Layer Clays - Green Chemistry for Dyes Removal from Wastewater - page 353

effect. A high pH value is preferred for cationic dye adsorption, and a low
pH value is preferred for anionic dye adsorption. Increased ionic strength
generally enhances adsorption due to the compression of the diffuse dou-
ble layer on the adsorbent. Langmuir and Freundlich isotherms have been
used extensively by many researchers, with the Langmuir isotherm being
the most predominant. Langmuir models also give good R L values, and
they confirm a favorable adsorption process for all systems. Kinetic data
usually follows the pseudo-second-order model, and thermodynamic data
usually indicates an endothermic process. Anionic dye adsorption is some-
times exothermic. From the economic point of view, clay can be consid-
ered an efficient adsorbent when compared to activated carbon.
References
1. A. Baban, A. Yediler, and N. K. Ciliz, Clean , Vol. 38, No. 1, p. 84-90, 2010.
2. P. A. Soloman, C. A. Basha, V. Ramamurthi, K. Koteeswaran, and N.
Balasubramanian, Clean , Vol. 37, No. 11, p. 889-900, 2009.
3. C.I. Pearce, J. R. Lloyd, and J. T. Guthrie, Dyes and Pigments , Vol. 58,
p. 179-196, 2003.
4. G. McMullan, C. Meehan, A. Conneely, N. Kirby, T. Robinson, P. Nigam, I. M.
Banat, R. Marchant, and W. F. Smyth, Appield Microbiological Biotechnology ,
Vol. 56, p. 81-87, 2001.
5. T. Robinson, G. McMullan, R. Marchant, and P. Nigam, Bioresource
Te c h n o l o g y , Vol. 77, p. 247-255, 2001.
6. D. Suteu, C. Zaharia, D. Bilba, A. Muresan, R. Muresan, and A. Popescu,
Industria Textila , Vol. 60, No. 5, p. 254-263, 2009.
7. C. Zaharia, D. Suteu, A. Muresan, R. Muresan, and A. Popescu, Environmental
Engineering and Management Journal , Vol. 8, No. 6, p. 1359-1369, 2009.
8. S. Chatterjee, D. S. Lee, M. W. Lee, and S. H. Woo, Bioresource Technology ,
Vol. 100, p. 3862-3868, 2009.
9. A. Bhatnagar, and A. K. Jain, Journal of Colloid Interface Science , Vol. 281,
p. 49-55, 2005.
10. Q. Sun, and L. Yang, Water Resource , Vol. 37, p. 1535-1544, 2003.
11. M. N. V. Ravi Kumar, T. R. Sridhari, K. D. Bhavani, and P. K. Dutta, Colorage ,
Vol. 40, p. 25-34, 1998.
12. G. Crini, Bioresource Technology , Vol. 97, p. 1061-1085 2006.
13. F. Derbyshire, M. Jagtoyen, R. Andrews, A. Rao, I. Martin-Gullon, and
E. Grulke, Carbon materials in environmental applications, in: L. R. Radovic,
ed., Chemistry and Physics of Carbon , Vol. 27. Marcel Dekker, New York,
pp. 1-66, 2001.
14. S. Babel, and T. A. Kurniawan, Journal of Hazardous Materials , B97,
p. 219-243, 2003.