Aplicação de solvente eutético profundo (DES) como solidificante para remediação de derramamento de óleo no mar

Abstract

Due to the incessant exploration of oil, accidents associated with its spillage are increasingly common, triggering a series of consequences, such as animal mortality, damage to marine habitats, economic losses, etc. Currently, existing remediation methods, such as chemical surfactants, present high toxicity and low biodegradability, which demands the search for safer and more effective alternatives. Chemical oil solidifiers operate by forming macroscopic molecular networks within the oil, modifying the liquid oil into a cohesive mass. Thus, a new category of solidifier was developed, based on deep eutectic solvent (DES), a class of ionic liquids, formed through the fusion of two compounds with high melting points, generating a solution with a melting point lower than that of the individual components, resulting in the formation of a mixture with a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD). Due to the moldable characteristics, it is feasible to obtain a DES with good physicochemical characteristics and mainly with low toxicity. In this study, a DES based on lauric acid and acetamide (AAL) was formulated in a ratio of 1:4, respectively. To verify its solidifying power, a solidification test was performed at 25 °C, using DES in different amounts (200-1500 μL), keeping the amount of water (10 mL) and engine oil (1 mL) constant. In the range of 400-1500 μL, the DES showed promising results, the oil was completely solidified, transforming into a cohesive structure that was easy to remove. It was verified through Fourier transform infrared spectroscopy (FTIR) that the solid formed exclusively incorporates the oil and DES. At the same time, the water in the mixture remained unchanged, exactly as before the contamination. This proves that the method not only efficiently captures the oil, but also preserves the purity of the water, standing out as an environmentally safe and highly effective solution for the remediation of spills.