Dissolution and Photodegradation of Two Crude Oils in Seawater

Abstract

The fate of oil spilled on seawater is an important issue for marine environment. This paper studied the dissolution of two crude oils and the photodegradation of their water-soluble fraction (WSF). The relationship between the solubility and the component of the crude oils was studied by gas chromatograph, UV absorption and synchronous fluorescence spectrum, and the result indicated that the aromatic hydrocarbon was liable to dissolve in water and the dissolved organic matter (DOM) in seawater enhanced the dissolution of crude oils. Moreover, the photodegradation of WSF accorded with the pseudo-first order reaction, and the reaction rate constants for WSF 1 and 2 were 0.088 and 0.121 h-1, respectively. This investigation is helpful for better understanding the transformation of crude oil spilled on the sea.

Photochemistry of oil in marine systems: developments since the Deepwater Horizon spill

“…The results of the linear regression analysis obtained in this study indicated that, for most of the oil compounds, light intensity had the largest effect on their degradation rates. Liu et al 64 conducted an experiment to examine the dissolution and photodegradation of two types of crude oil in seawater by exposing a solution containing the water-soluble fraction to radiation from a 300 W Mercury lamp in a cylindrical reactor. The lamp was enclosed by a quartz jacket and a water-cooling system was used to regulate the temperature at 20 ± 1 °C.…”

“…[27][28][29] Dissolution and evaporation commence immediately, while photooxidation begins as soon as the oil is exposed to solar irradiation, increasing its compositional complexity. [30][31][32][33][34] Increased water solubility and elevation of boiling points both result from production of more oxygen functionalized compounds through biological, thermal, or photochemical reactions. The onset of emulsication is considered a secondary process that begins several hours aer the spill occurs and may continue for a year or longer.…”