The effectiveness testing of oil spill-treating agents

Laboratory effectiveness tests have been developed for four classes of oil spill treating agents: solidifiers, demulsifying agents, surface-washing agents and dispersants. Several treating agent products in these four categories have been tested for effectiveness. The aquatic toxicity of these agents is an important factor and has been measured for many products. These results are presented. Solidifiers or gelling agents solidify oil. Test results show that solidifiers require between 16% and 200% of agent by weight compared to the oil. De-emulsifying agents or emulsion breakers prevent the formation of or break water-in-oil emulsions. Surfactant-containing materials are of two types, surface-washing agents and dispersants. Testing has shown that effectiveness is orthogonal for these two types of treating agents. Tests of surface washing agents show that only a few agents have effectiveness of 25 to 55%, where this is defined as the percentage of oil removed from a test surface. Dispersant effectiveness results using the swirling flask test are reported. Heavy oils show effectiveness values of about 1%, medium crudes of about 10%, light crude oils of about 30% and very light oils of about 90%.