Adsorption of benzoic acid by CTAB exchanged montmorillonite

Abstract

This paper reports the adsorption of benzoic acid from water on cetyl trimethylammonium exchanged montmorillonite (CTAB-montmorillonite). Important factors are the adsorbent concentration, ionic strength, equilibrium time and pH. The largest adsorption is at pH 9. The adsorption kinetics data fitted the pseudo-second-order equation. The adsorption isotherms at different pH were linear indicating a partition mechanism. Up to about 61% of the dissolved benzoic acid was adsorbed by CTAB-montmorillonite. These results indicate that CTAB-montmorillonite is a potential adsorbent for benzoic acid.

Removal of aqueous toxic Hg(II) by synthesized TiO2 nanoparticles and TiO2/montmorillonite

“…The montmorillonite has also been proved to be suitable host clay material for the controlled syntheses of catalytically active transition metal particles [32,35,46]. Unlike commonly reported microporous pillared structure, a TiO 2 cluster structure in the present study was observed, the purified montmorillonite was firstly modified by cetyltrimethylammonium bromide (CTAB) through an ion-exchange reaction [40,47]. The basal spacing was further expanded by the intercalation of dodecylamine (DDA), and then TiO 2 was dispersed and attached in the structure and surface of montmorillonite by hydrolyzing TiO(OH) 2 sol using Ti(OC 4 H 9 ) 4 as the precursor.…”

“…The possible formation mechanism of mesoporous TiO 2 /montmorillonite includes the intercalated quaternary ammonium cations and neutral amines as co-surfactants to direct the interlamellar hydrolysis and condensation polymerization of neutral inorganic precursor [32,40,41,46]. Thus the pore size becomes controllable, and the thermal stability is improved.…”

“…per 100 g. A mass of 10 g of montmorillonite was saturated with water for half an hour and was firstly modified by cetyltrimethylammonium bromide (CTAB) through an ion-exchange reaction. The basal spacing was further expanded by the intercalation of dodecylamine (DDA) of 20 molar ratio [40]. This was then mixed with a certain amount of TiO 2 sol, stirred for 1 h, followed by a washing-centrifugation procedure to make the supernatant nearly neutral.…”

“…The experiments of Hg(II) removal were carried out in a cylindrical glass reactor The organic matter degradation in the precursor of TiO 2 /montmorillonite is mainly based on C x H y decomposition, and water and CO 2 are continuously released, resulting in increase of the basal spacing in layer structure [39][40][41]. The specific surface area, pore diameter and pore volume for the two materials were determined using nitrogen adsorption/desorption isotherm and multi-point BET analysis, the results of which are shown in Table 1.…”

Modified Bentonite with Dithizone as Nano Clay Mineral Adsorbent for Solid Phase Extraction of Silver Ions

“…[20,21] Due to their highly specific surface area, high cationic exchange capacity (CEC), and high abundance and resulting low price, clay minerals can be used as effective, environmentally friendly adsorbents for metal ions. The adsorption capacity and character of the clay minerals have been modified by treatment with sulfuric acid [22] and humic acid, [23] as well as by immobilization of anionic [24] and cationic [25,26] surfactants. Replacement of natural exchangeable cations with cationic surfactant makes the clay mineral surface more hydrophobic.…”