Eco-Friendly Surfactants Based on Fatty Acids and Monoethanolamine for Efficient Oil Spill Remediation

Environmental concerns surrounding the use of toxic chemical dispersants in oil spill remediation have prompted the development of safer, more sustainable alternatives. Surfactants derived from fatty acids offer advantages such as low toxicity, biocompatibility, and cost-effectiveness. In this study, two novel surfactants based on monoethanolamine/lauric acid (MEA-LA) and monoethanolamine/oleic acid (MEA-OA) were evaluated for their potential in oil spill cleanup applications. To this end, measurements of surface tension, emulsification index, crude oil dispersion, and motor oil removal from sand were conducted. MEA-LA and MEA-OA reduced surface tension to 21.7 ± 0.03 mN/m and 25.2 ± 0.00 mN/m, with CMC values of 8.5 and 1.2 mmol/L, respectively. Emulsification assays revealed stable emulsions after 24 h, with indices of 52.6% ± 1.0 (motor oil) and 74.4% ± 2.0 (kerosene) for MEA-LA and 50% ± 2.0 (motor oil) and 67.1% ± 3.0 (kerosene) for MEA-OA, consistently outperforming sodium dodecyl sulfate (SDS). Both surfactants demonstrated hydrocarbon removal from sand, achieving efficiencies of 57.03% ± 0.03 (MEA-LA) and 61.67% ± 0.05 (MEA-OA) at 3 × CMC. In addition, low-energy dispersion confirmed their ability to produce fine, stable oil droplets, favoring biodegradation. Acute toxicity assays with <i>Artemia salina</i> showed lethal concentration values (LC₅ ₀) of 2057 μg/mL (MEA-LA) and 1956 μg/mL (MEA-OA), classifying both as nontoxic. These results suggest that fatty acid-based surfactants are promising candidates for replacing conventional dispersants in oil spill response, contributing to the reduction of environmental and socioeconomic impacts.