Efficient Removal of Eriochrome Black T Dye Using Activated Carbon of Waste Hemp (Cannabis sativa L.) Grown in Northern Morocco Enhanced by New Mathematical Models

Abstract

In the present work, the adsorption behavior of Eriochrome Black T (EBT) on waste hemp activated carbon (WHAC) was examined. The surface of the WHAC was modified by H3PO4 acid treatment. The surface and structural characterization of the adsorbents was carried out using Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analysis. The effect of influential adsorption parameters (pH, contact time, dosage, and initial concentration) on the adsorption of EBT onto WHAC was examined in batch experiments; some adsorption parameters such as pH, concentration and dose were improved by new mathematical models. The adsorption behavior of EBT on the surfaces of WHAC was evaluated by applying different isotherm models (Langmuir, Freundlich, Temkin and Dubinin–Radushkevich) to equilibrium data. The adsorption kinetics was studied by using pseudo-first-order, pseudo-second-order, Elovich and intraparticle models on the model. Adsorption followed the pseudo-second-order rate kinetics. The maximum removal of EBT was found to be 44–62.08% by WHAC at pH = 7, adsorbent dose of 10–70 mg, contact time of 3 h and initial dye concentration of 10 mg.L−1. The maximum adsorption capacities were 14.025 mg.g−1 obtained by calculating according to the Langmuir model, while the maximum removal efficiency was obtained at 70 mg equal to 62.08% for the WHAC. The adsorption process is physical in the monolayer and multilayer.

Hemp Fibres: Essentials, Composites or Nanocomposites and Technical Applications

“…In this regard, sustainable sorbents that are based on hemp fibres have been studied with high dye sorption features [107], [108]. The commonly studied dye for sorption properties of hemp fibres is methylene blue dye [109]. Viscusi et al [110] reported hemp fibres for methylene blue dye adsorption from aqueous media.…”

Removal of Dye from Aquatic Environments: State-of-the-Art and Future Perspectives

“…Another effective method for the removal of dye, due to its low cost and easy installation, is adsorption [15]. El Mansouri et al [16] removed up to 62% of Eriochrome Black T (EBT) using H 3 PO 4 -modified activated carbon (derived from Cannabis sativa L.) at a pH of 7, a contact time of 3 h, and an initial concentration of dye at 10 mg•L −1 . Moreover, in this study, the maximum adsorption capacity was 14.02 (mg•g −1 ) in terms of the Langmuir isotherm study.…”