The studies are conducted in laboratory to determine the adsorption-desorption behavior of BTX (benzene, toluene and o-xylene) in gas phase on Fe, Fe-Al pillared clays adsorbents. In experimental conditions of constant atmospheric pressure, initial concentrations with an increasing volume (0.5 - 2 ml) injected benzene (2.25), toluene (1.89) and o-xylene (1.66) μmol/L at T (40℃, 60℃ and 80℃), and the adsorption increases with increase of temperature, indicating that the adsorption process would be a chemical adsorption rather than physical one. The results are shown that the BTX adsorption data fitted very well (R2 > 0.999) to the both equations Langmuire and Elovitch for the three samples: bentonite (B), Fe-bentonite () and Fe-Al/bentonite (). At 80℃, the BTX adsorption capacity increased in the following order: . The maximum adsorption capacity () at 80℃ is 175.13, 171.84 and 171.81 μg/g respectively for benzene, toluene and o-xylene for ; the last is a good adsorbent of BTX removal. The benzene diffuses faster than toluene and o-xylene. Thermodynamic parameters, such as ,and are also discussed and the results suggested that the BTX adsorption on all samples used is a spontaneous and endothermic process. Desorption studies show that BTX is very easily desorbed with .
References
[1]
U.S. Environment Protection Agency Office of Air Quality (2000) National Air Toxics Program: The Integrated Urban Strategy. Report to Congress, EPA 453-R-99-007. http://www.epa.gov/urban-air-toxics
[2]
Kuran, P. and Sojak, L. (1996) Environmental Analysis of Volatile Organic Compounds in Water and Sediment by Gas Chromatography. Journal of Chromatography A, 733, 119-141. http://10.1016/0021-9673(95)01121-8
[3]
Alice, O.R. and Emil, D. (2003) Destruction of Volatile Organic Compounds by Catalytic Oxidation. Environmental Engineering and Management Journal, 4, 273-302. http://omicron.ch.tuiasi.ro/EEMJ/
[4]
Daifullah, A.A.M. and Girgis, B.S. (2003) Impact of Surface Characteristics of Active Carbon on Adsorption of BTEX. Colloids and Surfaces A: Physicochemical and Engineering, 214, 181-193. https://doi.org/10.1016/S0927-7757(02)00392-8
[5]
Blocki, S.W. (1993) Hydrophobic Zeolites Adsorbent: A Proven Advancement in Solvent Separation Technology. Technology Environmental Progress, 12, 226-230.
https://doi.org/10.1002/ep.670120312
[6]
Egbuchunama, T.O., Obia, G., Okieimenb, F.E. and Tihminliogluc, F. (2016) Removal of BTEX from Aqueous Solution Using Organokaolinite. International Journal of Applied Environmental Sciences, 11, 505-513.
http://www.ripublication.com
[7]
Carvalho, M.N., Da Motta, M., Benachour, M., Sales, D.C.S. and Abreu, C.A.M. (2012) Evaluation of BTEX and Phenol Removal from Aqueous Solution by Multi-Solute Adsorption onto Smectite Organoclay. Journal of Hazardous Materials, 240, 95-101. https://doi.org/10.1016/j.jhazmat.2012.07.057
[8]
Jaynes, W.F. and Vances, G.F. (1999) Sorption of Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) Compounds by Hectorite Clays Exchanged with Aromatic Organic Cations. Clays and Clay Minerals, 47, 358-365.
https://doi.org/10.1346/CCMN.1999.0470312
[9]
Moura, C.P., Vidal, C.B., Barros, A.L., Costa, L.S., Vasconcellos, L.C.G., Dias, F.S. and Nascimento, R.F. (2011) Adsorption of BTX (Benzene, Toluene, o-Xylene, and p-Xylene) from Aqueous Solutions by Modified Periodic Mesoporous Organosilica. Journal of Colloid Interface Science, 363, 626-634.
https://doi.org/10.1016/j.jcis.2011.07.054
[10]
Sharmasarkar, S., Jaynes, W.F. and Vance, G.F. (2000) BTEX Sorption by Montmorillonite Organoclay. Water Air Soil Pollution, 119, 257-273.
https://doi.org/10.1023/A:1005167524630
[11]
Nourmoradi, H., Nikaeen, M. and Khiadani, M. (2012) Removal of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) from Aqueous Solutions by Montmorillonite Modified with Non-Ionic Surfactant: Equilibrium, Kinetic and Thermodynamic Study. Chemical Engineering Journal, 191, 341-348.
https://doi.org/10.1016/j.cej.2012.03.029
[12]
Méçabih, Z., Kacimi, S. and Bouchikhi, B. (2006) Adsorption des eaux usées urbaines sur la bentonite modifiée par Fe(III), Al(III) et Cu(II). Revue Sciences Eaux, 19, 23-31. http://10.7202/012261ar
[13]
Méçabih, Z., Rose, J. and Borschneck, D. (2014) Urban Wastewater Treatment by Adsorption of Organic Matters on Modified Bentonite by (Iron-Aluminium). Journal of Encapsulation and Adsorption Sciences, 4, 71-79.
https://doi.org/10.4236/jeas.2014.43008
[14]
Rauquerol, F., Rauquerol, J. and Sing, K. (1999) Adsorption by Powders and Porous Solids: Principles, Methodology and Application. Academic Press, San Diego.
[15]
Barrett, E.P., Joyner, L.G. and Halenda, P.P. (1951) The Determination of Pore Volume and Area Distributions in Porous Substances. I. Computations from Nitrogen Isotherms. Journal of American Chemical Society, 73. 373-380.
https://doi.org/10.1021/ja01145a126
[16]
Bankovic, P., Milutinovic, N.A., Jovic, J.N., Dostanic, J., Cupic, Z., Loncarevic, D. and Jovanovic, D. (2009) Synthesis, Characterization and Application of AlFe-Pil- lared. Acta Physica Polonica A, 4, 811-815.
https://doi.org/10.12693/APhysPolA.115.811
[17]
Hernandez, M.A., Corona, L., Gonzalez, A.I., Rojas, F., Lara, V.H. and Silva, F. (2005) Quantitative Study of the Adsorption Aromatic Hydrocarbons (Benzene, Toluene, and p-Xylene) on Dealuminated Clinoptiloties. Industrial Engineering Chemistry Research, 44, 2908-2916 https://doi.org/10.1021/ie049276w
[18]
Song, H., Cheng, W., Jing, H., Fuxing, G. and Ho, Y.S. (2009) Adsorption Thermodynamics of Methylene Blue onto Bentonite. Journal of Hazardous Materials, 167, 630-633. https://doi.org/10.1016/j.jhazmat.2009.01.014
[19]
Fei, Y., Jie, M. and Yanqing, W. (2011) Adsorption of Toluene, Ethylbenzene and m-Xylene on Multi-Walled Carbon Nanatubes with Different Oxygen Content from Aqueous Solutions. Journal of Hazardous Materials, 192, 1370-1379.
https://doi.org/10.1016/j.jhazmat.2011.06.048