Mechanistic investigation into sunlight-facilitated photodegradation of pyrene in seawater with oil dispersants

TitleMechanistic investigation into sunlight-facilitated photodegradation of pyrene in seawater with oil dispersants
Publication TypeJournal Article
Year of Publication2017
AuthorsFu J., Gong Y.Y, Cai Z.Q, O'Reilly S.E, Zhao D.Y
JournalMarine Pollution Bulletin
Volume114
Pagination751-758
Date PublishedJan
ISBN Number0025-326X
Accession NumberWOS:000393931700014
KeywordsOil and Gas Degradation
AbstractThis study investigated the effects of 3 model oil dispersants (Corexit EC9500A, Corexit EC9527A and SPC 1000) on photodegradation of pyrene under simulated sunlight. Both Corexit dispersants enhanced photodegradation of pyrene, while SPC1000 slightly inhibited the reaction. Span 80 and Tween 85 were the key ingredients causing the effects, though the underlying mechanisms differed. Span 80 enriches pyrene in the upper layer of water column, whereas Tween 85 induces a photosensitization process. Two reactive oxygen species, O-1(2) and O-2(center dot-), were found responsible for pyrene photodegradation, though the presence of EC9500A suppressed the O-1(2) pathway. In terms of photodegradation products, EC9500A enhanced generation of polyaromatic intermediates, i.e., phenaleno[1,9-cd][1,2]dioxine, 1-hydroxypyrene, and 1,8-pyrenequinone, but did not alter the classical photodegradation pathway. The Corexit dispersants were more prone to photochemical decomposition, with multiple by-products detected. The information aids in our understanding of the effects of dispersants on photochemical weathering of oil compositions. (C) 2016 Elsevier Ltd. All rights reserved.
DOI10.1016/j.marpolbul.2016.10.077