Multiscale Evaluation of Raw Coconut Fiber as Biosorbent for Marine Oil Spill Remediation: From Laboratory to Field Applications

This study provides the first comprehensive multiscale evaluation of raw coconut fibers as biosorbents for crude oil removal, encompassing laboratory adsorption tests, mesoscale hydrodynamic simulations, and field trials in marine environments. Fibers were characterized by SEM, FTIR, XRD, XPS, and chemical composition analysis (NREL method), confirming their lignocellulosic nature, high lignin content, and functional groups favorable for hydrocarbon adsorption. At the microscale, a 25−1 fractional factorial design evaluated the influence of dosage, concentration, contact time, temperature, and pH, followed by kinetic and equilibrium model fitting and regeneration tests. Dosage, concentration, and contact time were the most significant factors, while low sensitivity to salinity highlighted the material’s robustness under marine conditions. Adsorption followed pseudo-second-order kinetics, with an equilibrium adsorption capacity of 4.18 ± 0.19 g/g, and it was best described by the Langmuir isotherm, indicating chemisorption and monolayer formation. Mechanical regeneration by centrifugation allowed for reuse for up to five cycles without chemical reagents, aligning with circular economy principles. In mesoscale and field applications, fibers maintained structural integrity, buoyancy, and adsorption efficiency. These results provide strong technical support for the practical use of raw coconut fibers in oil spill response, offering a renewable, accessible, and cost-effective solution for scalable applications in coastal and marine environments.