Adsorption of 2,4-dinitrophenol and 2,6-dinitrophenol onto organoclays and inorganic-organic pillared clays

Victor K. Tchieda1,2,4, Ignas K. Tonle3, Mihaela-Claudia Tertis2,4, Emmanuel Ngameni3, Maria Jitaru2,4

1 Laboratory of Analytical Chemistry, Faculty of Science, University of Yaound 1, P.O. Box 812 Yaounde, Cameroon
2 Research Center LAF-INT-ECOL, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, 11 Arany Janos Street, 400028, Cluj-Napoca, Romania
3 Laboratory of Mineral Chemistry, Faculty of Science, University of Dschang; P.O. Box, 67 Dschang, Cameroon
4 Research Center LAF-INT-ECOL, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, 11 Arany Janos Street, 400028, Cluj-Napoca, Romania

Abstract


The adsorption of two substituted nitrophenols, 2,4-dinitrophenol and 2,6-dinitrophenol on smectite clay modified by intercalation of hexadecylpyridinium bromide (O-Sa01) or hexadecylpyridinium bromide and complex hydroxy-aluminum (IO-Sa01) were studied. The adsorption experiments were conducted in batch mode. The results obtained show that adsorption increases with the initial concentration of the nitrophenols and equilibrium is reached within a short period of time (20 min). The maximum capacity uptake from waste water was 28.07 and 28.58 mg g-1 for O-Sa01 and IO-Sa01 respectively for an initial concentration of 18.40 mg L-1 of 2,4-dinitrophenol, and 24.65 and 26.62 mg g-1 of 2,6-dinitrophenol for O-Sa01 and IO-Sa01, respectively, for the same initial concentration as in the case of 2,4-dinitrophenol. Separation factor RL indicates that the adsorption of the nitrophenol compounds studied is more favorable on IO-Sa01. Adsorption was modeled by the equations of Langmuir, Freundlich, and Temkin. Kinetic data were described by the pseudo-first order and pseudo-second order equations. Based on the linear correlation coefficient (>0.97), the Langmuir model better represented the data.

Keywords


adsorption; isotherm; modified clays; nitrophenols

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