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

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