Application of PMF receptor model merging with PAHs signatures for source apportionment of black carbon in the continental shelf surface sediments of the Bohai and Yellow Seas, China

Abstract

Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are byproducts generated from the incomplete combustion of organic materials, including fossil fuels and biomass. The similar production processes shared by BC and PAHs provide the possibility to infer the BC sources using the PAHs signatures. This study successfully utilized data sets of BC and PAHs analyzed from the continental shelf surface sediments of the Bohai and Yellow Seas to a standard receptor model of positive matrix factorization (PMF) to apportion the sources of BC in the sediment matrix. Results showed that combustion of fossil fuels (i.e., coal and oil/petroleum) accounted for an average level of 83 ± 5% of the total BC preserved, which was significantly higher than that from the biomass burning (17 ± 5%). The spatial distributions of the fossil BC concentrations and percentages differed significantly from those of the biomass BC, implying their different geochemical behaviors in the continental shelf regimes and further emphasizing the importance to effectively differentiate between fossil BC and biomass BC. In addition to the relative proportions of the BC subtypes (char‐BC/soot‐BC), the regional‐specific hydrodynamic conditions, including the cold cyclonic eddy, resuspension and coastal current, also exerted a significant influence on these spatial variations.

Cycling and Budgets of Organic and Black Carbon in Coastal Bohai Sea, China: Impacts of Natural and Anthropogenic Perturbations

“…The East Asian monsoon and associated hydrodynamic conditions also plays an important role in sorting sedimentary BC from various combustion sources with distinct physical properties (especially particle size), as reported in our recent study (Fang et al, 2016). In that study, we found that within 5-30 km away from the Yellow River estuary, the fossil fuel combustion-derived BC increased exponentially from 10% to 80%, and the biomass burning-derived BC accordingly declined exponentially from 90% to 20%.…”

“…The Yellow River was of particular interest in this study, because it is the world's second largest river in terms of sediment load, and its sediment export has a dramatic impact on the BS ecosystem. It is estimated that more than 80% of Yellow River sediment discharges into the BS in summer (Bi et al, ; Fang et al, ). During this period, the water column in LZB is highly stratified and vertical mixing is remarkably weakened.…”

Distribution pattern and mass budget of sedimentary polycyclic aromatic hydrocarbons in shelf areas of the Eastern China Marginal Seas

“…[] demonstrated that origins of PAHs in the surface sediment of the BS and YS were similar to those of the PAHs in PM 2.5 aerosols from the upwind area, highlighting the significant influence of atmospheric deposition of PAHs in the ECMSs. As for outputs, nearly 88.4% (494 t) of the input PAHs were buried in the bottom sediments, indicating that sequestration is the dominant PAHs output pathway, consistent findings for black carbon in the BS, as they are derived from coemitting sources [ Fang et al ., ]. Therefore, the continental shelf sediments of the ECMSs act as sinks, and play an important role in preserving PAHs originating in China.…”

Concentration, source identification, and exposure risk assessment of PM2.5-bound parent PAHs and nitro-PAHs in atmosphere from typical Chinese cities

“…The detailed background and applications of the PMF model for source apportionment were described in EPA PMF 5.0, Fundamentals and User Guide ( http://www.epa.gov/heasd/research/pmf.html ). In recent years, PMF has been successfully applied to spatially distributed datasets to determine the sources of parent PAHs in aerosol and sediment 24 , 62 – 64 . In this study, the datasets used for PMF analysis included 26 species (14 parent PAHs and 12 nitro-PAHs, Table S2 ), which were input to the model using EPA PMF5.1 to determine the contributions of primary emissions and secondary formation sources of nitro-PAHs.…”