| This research effort investigated chemical countermeasure use in near-shore environments. Currently, there are regulatory constraints on the near-shore use of dispersants, one type of countermeasure. Shoreline cleaners, another countermeasure type, were also investigated. There has been minimal shoreline cleaner testing in wetlands and sandy beaches. More scientific research is needed to address these issues.; A fundamental laboratory-scale study investigated hydrocarbon solubility in petroleum/water systems. The predominant mechanisms were dissolution and colloidal oil. The aqueous dissolution of petroleum hydrocarbons was much lower than published solubilities and could be predicted using a modified Raoult's law. A second laboratory study examined the potential of a biosurfactant and a synthetic surfactant for enhancing the solubility of aromatic hydrocarbons in crude oil. The biosurfactant treatment significantly increased solubility (one to two orders of magnitude), as compared to the synthetic surfactant treatment.; The dispersant research was conducted in a surf-zone setting (Shoreline Environmental Research Facility, wave tank facility) and in a wetland (San Jacinto Wetland Research Facility). The experimental design simulated a dispersed-oil plume. In the surf-zone experiment, a materials balance on the oil was calculated. In the dispersed-oil treatment, no oil accumulation was evident. The wetland study monitored chemically-dispersed oil concentrations in the sediments, analyzing the data for biotic and abiotic oil removal. When compared to the control treatment, there were no significant differences in biodegradation rates for the dispersed-oil treatments, but the amount of physical removal (flushing) was significantly different.; The shoreline cleaner studies were also conducted at both research facilities. For the surf-zone experiment, the beaches were systematically oiled, two cleaners were tested for effectiveness, and an oil mass balance was determined. In one cleaner treatment, 75% of the oil from the beach substrate while in the second cleaner treatment, 25% of the oil was removed. Beach erosion factored in the effectiveness of the first cleaner. A shoreline cleaner was also tested on oiled wetland sediments. There were no significant differences in effectiveness or biodegradation rates, when compared to the control.; Research is needed in field-scale dispersant effectiveness tests in near-shore environments; additional quantitative shoreline-cleaner tests in beach settings is also recommended. |
