K. Friesen, and Myrosia M. Foga, M. Loewen
Jul 25, 1996
Citations
0
Influential Citations
41
Citations
Journal
Environmental Science & Technology
Abstract
The aquatic photochemistry of 2,3,7,8-tetrachlorodibenzofuran (T4CDF) and 2,3,4,7,8-pentachlorodibenzofuran (P5CDF) was studied in the laboratory using a xenon light source and under sunlight conditions at 50° N latitude at the Experimental Lakes Area of northwestern Ontario, Canada. Under midsummer sunlight conditions 3H-T44CDF and 14C-P5CDF photolyzed slowly in 25:10 (v/v) distilled water/acetonitrile solutions with rate constants of 0.11 ± 0.01 and 0.015 ± 0.007 d-1, respectively. Both congeners experienced enhanced degradation rates in lake water, with rate constants of 0.58 ± 0.05 and 3.6 ± 0.3 d-1. Photoproduct analysis confirmed reductive dechlorination as a degradative pathway for both PCDFs in lake water. Three T4CDFs were detected as photoproducts of 23478-P5CDF, with two of these products identified by GC/MS as 2368- and 2348-T4CDF. Similarly, one T3CDF was detected in the photolysis of 2378-T4CDF, although the specific congener was not identified. One polar photoproduct was detected in the pho...