Adsorption of o-, m- and p-nitrophenols onto organically modified bentonites

作者：Koyuncu Hulya^*; Yildiz Nuray; Salgin Ugur; Koroglu Fatmanur; Calimli Ayla

来源：Journal of Hazardous Materials, 2011, 185(2-3): 1332-1339.

DOI：10.1016/j.jhazmat.2010.10.050

• Adsorption
• HDTMAB
• PEG
• Nitrophenols
• Organobentonites

Experiments were conducted on the adsorption characteristics of o-, m- and p-nitrophenols by organically modified bentonites at different temperatures. Two organobentonites (HDTMA-B and PEG-B) were synthesized using hexadecyltrimethylammonium bromide (HDTMABr) and poly(ethylene glycol) butyl ether (PEG). Synthesized HDTMA-B and PEG-B were characterized by XRD, FTIR and DTA-TG analyses and their specific surface area, particle size and pore size distributions were determined. BET surface areas and basal spacings (d(001)) of the HDTMA-B and PEG-B were found to be 38.71 m(2) g(-1), 69.04 m(2) g(-1) and 21.96 angstrom, 15.17 angstrom, respectively. Increased adsorption with temperature indicates that the process is endothermic for o-nitrophenol. On the other hand m- and p-nitrophenols exhibited lower rates of adsorption at higher temperatures suggesting a regular exothermic process taking place. Results were analyzed according to the Langmuir, Freundlich and Dubinin-Redushkevich (D-R) isotherm equations using linearized correlation coefficient at different temperatures. R-L separation factors for Langmuir and the n values for Freundlich isotherms showed that m- and p-nitrophenols are favorably adsorbed by HDTMA-B and, p-nitrophenol is favored by PEG-B. Adsorption of o-, m- and p-nitrophenols as single components or from their binary mixtures on HDTMA-B and, p-nitrophenol on PEG-B are all defined to be physical in nature.

• 出版日期2011-1-30