Phenol Red Adsorption from Aqueous Solution on the Modified Bentonite

Abstract

In the present work, the modified bentonites were prepared by the modification of bentonite with cetyltrimethylammonium bromide (CTAB), both cetyltrimethylammonium bromide and hydroxy-Fe cations and both cetyltrimethylammonium bromide and hydroxy-Al cations. X-ray diffraction (XRD), thermal analysis (TG-DTA), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms were utilized to characterize the resultant modified bentonites. The modified bentonites were employed for the removal of phenol red dye from aqueous solution. Phenol red adsorption agreed well with the pseudo-second-order kinetic model. The equilibrium data were analyzed on the basis of various adsorption isotherm models, namely, Langmuir, Freundlich, and Dubinin‒Radushkevich models. The highest monolayer adsorption capacity of phenol red at 30°C derived from the Langmuir equation was 166.7 mg·g−1, 125.0 mg·g−1, and 100.0 mg·g−1 for CTAB‒bentonite, Al‒CTAB‒bentonite, and Fe‒CTAB‒bentonite, respectively. Different thermodynamic parameters were calculated, and it was concluded that the adsorption was spontaneous (∆G° < 0) and endothermic (∆H° > 0), with increased entropy (∆S° > 0) in all the investigated temperature ranges.

Physicochemical Characterization of Regional Clay: Application to Phenol Adsorption

“…e removal of phenol was maximum and unperturbed when the initial pH of the phenol solution was between 3 and 8; a similar ability of pH effect was observed for the adsorption of phenol on activated carbon prepared from biomass material [4], as well as a similar trend for the adsorption of phenol red from aqueous solution on modified bentonite with maximum uptake at pH 3.0 and a remarkable decrease upon increasing the pH from 3.0 to 9.0 [24].…”

“…Clay materials have a good adsorption capacity of organic pollutants, heavy metals, and dyes to aqueous media [18]. Several studies have been targeted by the use of Moroccan clay adsorbent for the recovery of methylene blue [19], basic yellow cationic dye [20], methyl violet [19], adsorption of amino acids [21], adsorption of gallic acid on montmorillonite [22], adsorption of acid dyes red 1 and acid green 25 [23], removal of phenol and its derivatives by adsorption on petroleum asphalts [3], and adsorption of phenol by modified bentonite [24]. e surface charge of a clay material and its structure and chemical composition are parameters sufficiently capable of determining their adsorption capacity [25].…”

Dye Removal from Colored Textile Wastewater Using Seeds and Biochar of Barley (Hordeum vulgare L.)

“…The apparent equilibrium constant K of the adsorption is calculated by Equation (10). The free energy of Gibbs of the adsorption ∆G • is calculated from Equation (11), the relationship between K and the The Temkin isotherm equation is…”

“…Scientists have successfully removed heavy metals and dyes from wastewater using biosorption [6,7]. Recently, there is interest in producing materials based on natural substances such as agricultural waste; in this sense, the bioadsorbents appear to be a very promising method for the adsorption of several dyes [8][9][10][11][12][13]. Similar research shows that activated carbon derived from the barley (Hordeum vulgare L.) husk can be used as an efficient and cost-effective adsorbent for the treatment of phenol-red-contaminated water.…”

Removal of Anionic and Cationic Dyes Present in Solution Using Biomass of Eichhornia crassipes as Bioadsorbent

“…Phenol red (PR) is presented as a red and odorless powder or crystals whose formula and chemical structure are shown in Figure 1 b. It is used as a fabric dye [ 15 , 16 , 17 ]. PR is widely used in in vitro toxicological studies and culture media it is used as an indicator of pH change (between 6.4 and 8.2) [ 16 , 17 ].…”