Equilibrium and Kinetic Studies on Removal of Crude Oil from Polluted Water by Magnetite-Enhanced Plantain Pseudostem Fiber Biosorbent Char

Abstract

Crude oil pollution poses significant environmental and health challenges, particularly in Nigeria's Niger Delta region where frequent spillages contaminate aquatic ecosystems. The objective of this paper was to investigate the equilibrium and kinetic studies on the removal of crude oil from polluted water by magnetite-enhanced plantain pseudostem fiber (PPSF-Mt) biosorbent char using appropriate standard procedures. Data obtained shows that the proximate composition of the synthesized hybrid nano biosorbent incorporating magnetite (Fe₃O₄) nanoparticles onto biochar derived from plantain pseudostem fiber revealed successful magnetite incorporation with enhanced surface area (658 m²/g), pore volume (0.96 cm³/g), and functional groups favorable for crude oil adsorption. Batch adsorption experiments demonstrated that oil removal efficiency was significantly influenced by adsorbent dosage, contact time, initial oil concentration, pH, and temperature. Equilibrium studies revealed that the Temkin isotherm model (R² = 0.9889) provided the best fit, indicating multilayer adsorption on a heterogeneous surface with presence of adsorbent-adsorbate interactions. Kinetic analysis showed that the first-order model (R² = 0.9873) best described the adsorption process, suggesting a concentration dependent process. Thermodynamic parameters indicated that the adsorption process was spontaneous (ΓG° < 0), endothermic (ΓH° > 0), and resulted in increased randomness (ΓS° > 0) at the solid-liquid interface. This study establishes magnetite-enhanced plantain pseudostem fiber as an effective, sustainable, and eco-friendly biosorbent for crude oil remediation, contributing to agricultural waste valorization and the achievement of multiple Sustainable Development Goals (SDGs 6, 12, 13, and 15).