Eco-friendly human hair as a biosorbent for the removal of Non-Aqueous Phase Liquids (NAPLs) from seawater

Abstract Oil spills in the marine environment pose significant ecological and economic threats, requiring a prompt, environmentally sound and cost-effective response. In this study, the use of waste human hair as an eco-friendly organic biosorbent for the removal of lubricating oil and diesel oil spills from seawater was investigated. Through systematic comparison of three distinct physically morphologies - namely intact hair, chopped fibers and fine powder - this work presents a novel structure-function relationship that demonstrates the direct influence of sorbent morphology on surface area availability, inter-fiber capillary action, and oil-water selectivity as a function of fluid viscosity. The chopped hair fibers achieved maximum sorption capacities of 7.18 g/g for high-viscosity lubricating oil and 3.85 g/g for low-viscosity diesel, respectively. Experimental results demonstrated that the sorption mechanism was governed by external surface adsorption and capillary retention within the porous fiber bed, thereby avoiding increased mass-transfer resistance and minimizing the generation of secondary sludge. For statistical reliability, all experimental runs were repeated three times. The results highlight the potential of waste human hair as an economically viable and highly scalable alternative to synthetic sorbents in marine spill recovery, offering a promising approach for sustainable spill management.