Basic Blue Dye Adsorption from Water Using Polyaniline/Magnetite (Fe3O4) Composites: Kinetic and Thermodynamic Aspects

Abstract

Owing to its exciting physicochemical properties and doping–dedoping chemistry, polyaniline (PANI) has emerged as a potential adsorbent for removal of dyes and heavy metals from aqueous solution. Herein, we report on the synthesis of PANI composites with magnetic oxide (Fe3O4) for efficient removal of Basic Blue 3 (BB3) dye from aqueous solution. PANI, Fe3O4, and their composites were characterized with several techniques and subsequently applied for adsorption of BB3. Effect of contact time, initial concentration of dye, pH, and ionic strength on adsorption behavior were systematically investigated. The data obtained were fitted into Langmuir, Frundlich, Dubbanin-Rudiskavich (D-R), and Tempkin adsorption isotherm models for evaluation of adsorption parameters. Langmuir isotherm fits closely to the adsorption data with R2 values of 0.9788, 0.9849, and 0.9985 for Fe3O4, PANI, and PANI/Fe3O4 composites, respectively. The maximum amount of dye adsorbed was 7.474, 47.977, and 78.13 mg/g for Fe3O4, PANI, and PANI/Fe3O4 composites, respectively. The enhanced adsorption capability of the composites is attributed to increase in surface area and pore volume of the hybrid materials. The adsorption followed pseudo second order kinetics with R2 values of 0.873, 0.979, and 0.999 for Fe3O4, PANI, and PANI/Fe3O4 composites, respectively. The activation energy, enthalpy, Gibbs free energy changes, and entropy changes were found to be 11.14, −32.84, −04.05, and −0.095 kJ/mol for Fe3O4, 11.97, −62.93, −07.78, and −0.18 kJ/mol for PANI and 09.94, −74.26, −10.63, and −0.210 kJ/mol for PANI/Fe3O4 respectively, which indicate the spontaneous and exothermic nature of the adsorption process.

Effective Adsorption of Hexavalent Chromium and Divalent Nickel Ions from Water through Polyaniline, Iron Oxide, and Their Composites

“…The intensity of the peak at 378.11 nm increased when Cr(VI) came in contact with the surface of composite materials as shown in Figure 3h. In our already published work, it was explained that doping of PANI with Fe3O4 caused an increase in the surface area of the composite resulting in the enhancement of adsorption [42].…”

“…PANI, Fe 3 O 4 and their composites were synthesized as per our previous reports [41,42]. Solutions of both Cr(VI) and Ni(II) in different concentrations in the range of 5-100 mg•L −1 were prepared in 20 mL volumes from stock solution.…”

Preparation and characterization of novel polyoxometalate/CoFe2O4/metal–organic framework magnetic core–shell nanocomposites for the rapid removal of organic dyes from water

“…The primary pH of the solution is a very important variable in the adsorption system, which can inuence the charges of the POM/CFO/MIL-101(Cr) adsorbent, the ionization, and stability of the dyes. 44 As such, the inuence of primary pH was investigated in the elimination of MB (Fig. 5c) and RhB (Fig.…”

Acid Red 66 Dye Removal from Aqueous Solution by Fe/C-based Composites: Adsorption, Kinetics and Thermodynamic Studies

“…The Langmuir isotherms show that the temperature increment is not favorable to the adsorption process (Figure 7), as an intrinsic characteristic of the exothermic adsorption process. (1 ) e e bC + where qe (mg•g −1 ) and Ce (mg•L −1 ) are the equilibrium adsorption capacity of the adsorbate and the equilibrium concentrations of the adsorbent, respectively. qo is the maximum amount of the adsorbent per unit mass of sorbent to form a complete monolayer on the surface bound at high Ce.…”

“…The synthetic dyes are widely used by several industries such as textile, painting, leather and printing. The discharge of the dyes in water effluents continues to be one of the greatest health problems worldwide, affecting human health and the environment [1][2][3]. Of particular importance, the textile dyes are typically composed by organic molecules from colored fabrics, which uses large amounts of these organic compounds for textile production to fulfill the consumer needs [2,3].…”