Adsorptive Removal of Aromatic Compounds Present in Wastewater by Using Dealuminated Faujasite Zeolite

Abstract

The adsorption of aromatic compounds (nitrophenols, nitroaniline, chlorophenols, chloroanilines) present in wastewater using dealuminated faujasite zeolite has been investigated. The adsorption capacity of faujasite zeolite depends on the pH, (the neutral form of the pollutants is more easily adsorbed into zeolite than the dissociated form), and on the solubility in water of the aromatic compounds. The adsorption capacity for a family of compounds increases with decreasing water solubility. In this study, we have shown that the pollutant acidic character enhances their adsorption into the zeolite. Thus, the changeover of phenol to aniline decreases the adsorbent−adsorbate interaction, as well as in the substitution of the NO2 group by a Cl group. The adsorption data was analyzed using the Fowler−Guggenheim isotherm. The sorption mechanism of nitrophenol in faujasite zeolite was investigated using Raman spectroscopy and through a thermodesorption kinetic study. The relative affinity of the phenolic compounds toward the surface of the dealuminated faujasite was related to the electron donor−acceptor complex formed between the basic sites on the zeolite (oxygen) and the hydrogens (acidic site) of the aromatic ring and of the phenols and anilines functions.

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

“…Adsorption by zeolites appears to be also pH dependent in many cases [210,216,226,232]. The state of ionization of the adsorbate is naturally determinant for the extent of ion exchange with zeolite cations (in which case a cationic state is favored) or adsorption/partition to the surfactant (a neutral form is usually more efficiently removed from the liquid in such cases).…”

“…A zeolite with a higher content of the more hydrophobic silicon can show higher affinity for nonpolar organics [223,224]. Some of the synthetic zeolites for which studies can be found in the literature are the beta (BEA) zeolite [221,223,225], ZSM-5 [211,[221][222][223], hydroxysodalite [226], zeolite A (LTA) [224,227], zeolite P [226], zeolite X [224,227], zeolite Y [222,224,228,229] and dealuminated Y (DAY) zeolite [230][231][232].…”

“…Among some of the organic compounds that have been observed to be successfully removed by zeolites are phenolic compounds [208,[210][211][212]223,225,228,232,238], PAHs [209,231], BTEX [209][210][211]236], other aromatics such as nitrobenzene, bisphenol A, aniline and aniline derivatives [208,210,226,232,235], dyes [146,[213][214][215]230,233], pesticides [219,227] and pharmaceuticals [220][221][222]229].…”

Design, synthesis and characterization of MOF-199 and ZIF-8: Applications in the adsorption of phenols derivatives in aqueous solution

“…Among them it is worth mentioning cases reported in the literature such as adsorption [4][5][6][7][8][9][10][11][12][13][14][15]26], oxidation [19][20][21][22][23][24][25][26][27][28][29], membrane separation [20][21][22][23][24][25][26], and extraction [24][25][26][27][28][29]. Among these technologies, adsorption is recognized as the most applicable one for single-design, easy-operation, and highefficiency [18,[25][26][27] and in the adsorption process, activated carbon is popularly employed as adsorbent for its large specific surface area and high adsorption capacity [1,3,4,8,17,28]. Even though activated carbon material is considered one of the best materials to solve environmental pollution problems, it ...…”

“…Among these technologies, adsorption is recognized as the most applicable one for single-design, easy-operation, and highefficiency [18,[25][26][27] and in the adsorption process, activated carbon is popularly employed as adsorbent for its large specific surface area and high adsorption capacity [1,3,4,8,17,28]. Even though activated carbon material is considered one of the best materials to solve environmental pollution problems, it has limitations including poor mechanical strength and difficult-regeneration [3,26,28,29].…”