Modificações em espumas de poliuretano pós-comercializadas para sorção de óleos derramados em água do mar

Abstract

The exploration, transportation, and refining of oil are fundamental to the global economy. Occasionally, oil spills in the ocean are reported. Rapid containment and remediation are essential to prevent oil from being carried to the coasts by wind and wave action. The methods currently used to remove oils in water are not free of flaws, and because of that, constant research to develop alternative methods is necessary. In this context, this work proposed the use of post-consumer polyurethane foams to recover oils spilled in seawater. Surface modifications were carried out to increase the selectivity of foams for oils and resulted in increases up to 611% and 991% for modifications with molybdenum disulfide (MoS2) and zinc oxide (ZnO) in systems with S46 lubricating oil and 20W40 engine oil, respectively. These results show the success of hydrophobization and lipophilicity added to the foams through the modifications made. The reuse and resistance to mechanical compression tests showed that even after 10 sorption/desorption cycles, the foams kept their oil recovery capacity without a statistically significant difference. This result demonstrates the economic potential of modified foams thanks to their high reusability capacity. Kinetic studies on seawateroil systems showed that the saturation speed depends on the viscosity of the oil, but that the foam pores are saturated with fluids practically instantly and reach equilibrium in less than 40 seconds of exposure. The pseudo-second order (Ho and McKay) and logistic (Richards and Verhulst) kinetic models were those (among all kinetics models studied) that most adequately described the behavior of the experimental data in all cases. In continuous sorption, the modifications favored oil selectivity, but the vacuum pumping operating mode was the most relevant factor, achieving recovery of up to 99% of the oils initially spilled.