Source apportionment of priority PAHs in 11 lake sediment cores from Songnen Plain, Northeast China. (1st January 2020)

• Record Type: Journal Article
• Authors: Bao, Kunshan; Zaccone, Claudio; Tao, Yuqiang; Wang, Jian; Shen, Ji; Zhang, Yifeng
• Is Part Of: Water research. Volume 168(2020)
• Publication Date: 2020-01-01
• Subjects: Polycyclic aromatic hydrocarbons -- Chemical mass balance model -- Daqing oil field -- Anthropocene; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2019.115158
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) have been observed with rapid agricultural and industrial development in the Songnen Plain, Northeast China, but the prospective sources have not been yet apportioned. The concentration of PAHs was measured in 31 sediment samples from 11 Songnen Plain lakes in 2015. The background flux of PAHs in these lake sediments is < 463 μg m −2 year −1 . The maximal concentration of 16 U.S. EPA priority PAHs (599 ng g −1 ) recorded in this study is lower or similar to that found in most of the lake sediments across China, but higher than remote areas, such as North America Rocky Mountains. Both concentration and flux of PAHs increased after the 1950s, which correspond to the industrial development in this area and would probably mark the beginning of the Anthropocene in this region. A chemical mass balance model estimated that straw burning was a major source of Σ13 PAH (3–6 rings) during the past 200 years, with an average contribution of 22.1%, followed by forest fire (21.2%), burning of gasoline (19.1%), coal (12.2%), coke (4.8%) and diesel (3.9%), whereas the contribution from crude oil and natural gas was negligible (<1%). Straw burning (20.2–25.2%) and forest fire (16.7–30.6%) were major sources of PAHs and contributed increasing flux in the past 200 years. The elevated level of PAH recorded after 1950s in this region are also from burning of gasoline (26.1–26.4%), coal (15.3–15.8%), and coke (5.1–9.0%). The contribution of petrogenic sources (e.g., direct oil spill) to the concentration of Σ13 PAH seemed to be ignorable, at least in these lakes. Graphical abstract: Image 1 Highlights: The increased PAH flux after 1950s probably mark the beginning of the Anthropocene. A chemical mass balance model is employed to apportion the prospective sources of PAHs. Straw burning and forest fire are major sources of PAH (3–6 rings) during the past 200 years. The elevated PAH depositions after 1950s are due to pyrogenic sources. The contribution of direct oil spill seems to be ignorable for the priority PAHs.