Intensifying of phenol removal from aqueous solutions using ACTF as a hybrid carbon nanostructure: Isotherms, kinetics and thermodynamics study

Abstract

Activated carbon thin film (ACTF) was prepared via a single-step mixing method through thermal fabrication that was utilized for the removal of phenol in the batch aqueous media. The prepared adsorbent was characterized using TEM, XRD, FTIR, BET, EDX, Raman, and TGA analyses. Batch adsorption experiments were studied by using the effects of different parameters such as pH, temperature, dose, contact time, and initial concentration of phenol solution on adsorption. The maximum phenol removal by ACTF was approximately 89.5% at pH 4, adsorbent dose of 1 g/L, and 50 ppm for the initial concentration of phenol at room temperature through 150 min. Adsorption data were modeled using four adsorption isotherm models (Langmuir, Freundlich, Temkin, and D-R) and three kinetic models (pseudo first order, pseudo second order, and Intraparticle diffusion) using linear and non-linear regression methods. The chi-square (X 2) and the correlation coefficient (R 2) were both used as error analysis techniques to find the best-fitting equations. The results showed that phenol adsorption on ACTF adsorbent fitted more accurately with nonlinear regression models, which is consistent with Freundlich isotherm and pseudo-second order form. Also, thermodynamic results demonstrated that attachment of phenol onto ACTF adsorbent was spontaneous (negative value of ΔG) and exothermic (negative value of ΔH) with decreasing temperature from 55 °C to 25 °C. Synthesized ACTF showed good regeneration capacity with 0.1 M NaOH as the eluent, making it an appropriate adsorbent for the elimination of phenol. This study evidenced the efficacy of ACTF as a phenol adsorbent.