Evaluating Surface Washing Agent Performance

Surface washing agents (SWAs) can be used to enhance removal of spilled oil from shoreline surfaces and structures. There are two classes SWA products, “lift float” products which remove the create an slick recovered mechanically disperse” emulsify disperse into water column, more difficult mechanically. Therefore, information regarding ability a product lift surface its mechanism action once has been removed is important for spill responders. The effectiveness (SWAE) 15 (conducted reported blind) listed on NCP Product Schedule was evaluated by applying sand substrate, allowing time adhere treating with SWA, artificial seawater release any that lifted substrate surface. efficiency SWAs calculated based mass remaining relative total applied. Dispersant Effectiveness (DE) determined using Baffled Flask Test sort their (“lift rather than float”). Using basket approach, amount in varied 10 95% various tested, where lower percent signifies better SWA. DE between 8 81%. Though previous studies have concluded good poor dispersants vice versa, results this study demonstrate not general rule. A stoplight decision framework developed considers relationship SWAE, serves identify whose primary float.” Results suggest regardless test evaluate SWAs, coupling findings provide useful decisions during response operations.