2026 Saddat Intensified REE Adsorption and Desorption

Rare earth elements (REE) are critical to 21st-century technology, from electronics and defense applications to renewables and beyond. The processing of REE is primarily based on minerals (bastnasite, monazite, and xenotime), but alternative resources (coal ash, E-waste, and permanent magnets) are also gaining increasing interest. Adsorption remains one of the most efficient, environmentally friendly extraction methods despite its lengthy mixing time. In the present research article, a hemp biochar prepared by vacuum pyrolysis at 700 ◦C was examined for its applicability in the adsorption of selected REE (La3+, Nd3+, Dy3+) from synthetic solutions. An innovative technique, Resonant Vibratory Mixing (RVM), was applied to improve adsorption kinetics, with factors including time (5–30 min) and intensity (30–70%) at room temperature. Using the Thermo Scientific 4000 M shaker for mixing, the maximum adsorption capacities were 77.56 mg/g for Dy3+, 75.85 mg/g for La3+, and 72.65 mg/g for Nd3+ using 100 mg of hemp biochar and 10 mL solutions (1000 mg/L). The adsorption capacity of 100 mg hemp biochar was 79.79 mg/g for Dy3+, followed by 77.61 mg/g for La3+ and 75.75 mg/g for Nd3+, using RVM for only 40 min at 70% intensity. RVM increased the adsorption capacities of all REE in only 40 min.