Efficient Adsorption of Methyl Orange on Nanoporous Carbon from Agricultural Wastes: Characterization, Kinetics, Thermodynamics, Regeneration and Adsorption Mechanism

Abstract

Nanoporous carbon derived from Moringa oleifera seed waste was synthesized by an original process of flash pyrolysis followed by zinc chloride impregnation. The N2-adsorption–desorption results of the optimized sample revealed a BET surface area of 699.6 m2/g and a pore size of 2 nm. It was evaluated for the adsorption of a mono azo dye, methyl orange (MeO), from aqueous solution. Four isothermal models (Langmuir, Freundlich, Dubinin–Radushkevic and Temkin) were applied to fit the experimental data. The results revealed that Langmuir is the most appropriate isothermal adsorption model to describe the adsorption process (X2 = 1.16); with an adsorption capacity 367.83 mg/g at 298 K, the interaction of MeO dye with the nanoporous carbon surface is a localized monolayer adsorption. The adsorption kinetics was consistent with the pseudo-second-order model and found to correlate well with the experimental data (X2 = 9.06). The thermodynamic study revealed a spontaneous and endothermic adsorption process, and the substances are adsorbed in a random manner. The desorption of MeO dye from MOC-ZnCl2 by sodium hydroxide solution was achieved to a level of about 84%, and the nanoporous carbon was recycled and reused at the fifth cycle. This work demonstrates that MOC-Zncl2 could be employed as an alternative to commercially available activated carbon in the removal of dyes from wastewater.

High Performance of Ni-Al/magnetite Biochar for Methyl Orange Removal in Aqueous Solution

“…Adsorption has numerous benefits that make it a efficient approach for treating water and wastewater. These advantages encompass easy implementation with simple equipment needs, the lack of detrimental by-products, a substantial capacity for extracting contaminants from water solutions, and suitability for small-scale applications (Raji et al, 2022) . Various adsorbents, such as activated carbon (El Maguana et al, 2020) , zeolites (Radoor et al, 2021) , and LDHs (Zaghloul et al, 2019) , can be successfully utilized for eliminating dye contaminants.…”

Model‐based design of stratified packings for enhanced mass transfer using optimal control theory

“…In Case B, the mass transfer occurs in the opposite direction. Initially, an unloaded stationary phase is flowed by a fluid phase containing a target component to load the solid phase with this target component or to remove the target component from the liquid phase 29–31 …”

“…Initially, an unloaded stationary phase is flowed by a fluid phase containing a target component to load the solid phase with this target component or to remove the target component from the liquid phase. [29][30][31] The approach presented has a high degree of generality from utilizing the classical continuum approach combined with established constitutive relationships. Furthermore, well-established parametrization strategies are available.…”