Adsorption of Petroleum Monoaromatics from Aqueous Solutions Using Granulated Surface Modified Natural Nanozeolites: Systematic Study of Equilibrium Isotherms

Abstract

Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant-modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models namely, Langmuir, Fruendlich, Elovich, Temkin, and Dubinin-Radushkevich models. It was concluded that the Langmuir model fits the experimental data. The measured adsorption capacities were 3.89 and 4.08 mg of monoaromatics per gram of hexadecyltrimethylammonium-chloride and n-cetylpyridinium bromide (CPB)-modified granulated nanozeolite, respectively. Considering the type of surfactant, adsorbents modified with CPB showed greater tendency for the adsorption of the adsorbates.

Adsorption of BTEX on Surfactant Modified Granulated Natural Zeolite Nanoparticles: Parameters Optimizing by Applying Taguchi Experimental Design Method

“…By comparing these results it can be concluded that the granulated nanosized adsorbents exhibit considerably better efficiency comparing to the natural parents. Furthermore, the CPB modified adsorbents show higher adsorption capacity in comparison to the HDTMA-Cl modified adsorbent which is in accordance with our previous studies [11][12][13]. The combination of factors in the experiments 8, 2, and 5, in which the q e was the highest, showed the best adsorption results.…”

“…In addition by further grinding of natural clinoptilolite to finer nanosized particulates; its surface area will be increased remarkably. Furthermore, granulated natural zeolite nanoparticles exhibit a drastically increase in the adsorption capacity toward BTEX compounds [12,13]. The pseudo-second-order kinetic represented the equilibrium data very well.…”

Study of the Adsorption of Bright Green by a Natural Clay and Modified

“…The first approach: the surfactant molecules interact with clay through their non-polar (alkyl) groups; hence the positive head of the surfactants points toward the bulk of the solution. The second approach [26]: in this approach, the adsorption of the cationic surfactant onto the negatively charged surface of the adsorbent can be considered to be controlled by two steps; (1) the formation of surfactant monolayer through the ion exchange and electrostatic attraction and (2) the formation of surfactant bilayer via hydrophobic interactions [30][31][32]. As a matter of fact, firstly, the positive head of the surfactants are exchanged with the interlayer exchangeable cations within the clay, thereby forming a surfactant monolayer with outward pointing head groups.…”

Charaterization of Pore Structure and Surface Chemistry of Activated Carbons – A Review

“…Usually, there are many types of synthetic or artificial adsorbents (convential adsorbents) such as activated carbon (AC) (Li, et al, 2010b), resin (Vinodh, et al, 2011), zeolite (Seifi, et al, 2011), and so on used in adsorption operation, but AC is the most widely used adsorbents for removal of inorganic and organic compounds from wastewaters or waste gases because they have excellent capacities for adsorption of compounds derived from their huge surface area, developed pore texture, as well as easy availability (Khan, et al, 1997a, Khan, et al, 1997b, Okolo, et al, 2000, Viraraghavan&De Maria Alfaro, 1998). …”