Magnetic human hair nanocomposites as an innovative adsorbent for removal sodium fluorescein dye: Batch and fixed bed column studies

This study explores the removal of sodium fluorescein (SF) dye using magnetite nanoparticles loaded human hair (MNLHH) bio-composite through batch and fixed-bed column adsorption. The composite was characterized using zeta potential, TEM, FTIR, and XRD. Batch experiments examined the effects of contact time (2–70 min), pH (1–10), adsorbent dosage (0.05–0.25 g), and dye concentration (5–20 ppm). Optimal conditions (pH 3, 0.2 g adsorbent, 60 min contact time, and 20 ppm dye concentration) achieved 82% removal efficiency and 3.8406 mg/g adsorption capacity. The adsorption followed the Langmuir isotherm model and pseudo-second-order kinetics, indicating monolayer chemisorption. Fixed-bed studies evaluated initial dye concentration (20–40 ppm), flow rate (2–3 mL/min), and bed height (0.3–1 cm), with a maximum adsorption capacity of 13.058 mg/g at 0.5 cm bed depth. The uniqueness of this study lies in the integration of human hair as a sustainable biopolymer matrix, functionalized with magnetite nanoparticles, providing enhanced adsorption performance. Unlike conventional bio-adsorbents, MNLHH offers magnetic separation capability, high surface area, and abundant functional groups, facilitating strong dye interactions. Compared to past studies on natural and synthetic adsorbents, this work introduces a novel bio-based composite with improved efficiency, regenerability, and economic feasibility. KEY WORDS: MNLHH, Adsorption, Sodium fluorescein dye, Fixed bed column, TEM; FTIR; and XRD, Isotherm Bull. Chem. Soc. Ethiop. 2025, 39(9), 1747-1763. DOI: https://dx.doi.org/10.4314/bcse.v39i9.8