Modeled Direct Photolytic Decomposition of Polybrominated Diphenyl Ethers in the Baltic Sea and the Atlantic Ocean

摘要

In this study, tetra- (#47), penta- (#99), and decabrominated (#209) diphenyl ethers were exposed (in isooctane) to summer sunlight at 60° N, where their photochemical half-lives ranged from 0.6 to 203 h. Apparent quantum yields, ranging from 0.16 to 0.28, were applied to optical models to calculate the rates of direct photochemical decomposition at the surface (depth of 0 m) and in the mixing layer of the ocean. The calculated photolytic half-lives were 4-100 times as long in the mixing layer of the Baltic Sea and the North Atlantic Ocean as at the surface of 0 m. Calculation of seasonal photochemical half-lives for the mixing layer of the North Atlantic Ocean from 0° N to 60° N showed that the solar photolysis effectively decomposes the congeners in the tropics.