Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

Abstract

h i g h l i g h t sWe assess the fate of atmospheric PAHs in the air-water interface of BS and YS. The volatilization fluxes of three-ring PAHs were higher than the deposition fluxes. Petrogenic inputs contribute PAHs in the dissolved phase and sustain volatilization. The input to and output from the water reached equilibrium for four-ring PAHs. Five to six ring PAHs were introduced into the water primarily through deposition. In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three-and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266e1454 ng/m 2 / d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The airesea exchange fluxes of the threering PAHs were 2-to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five-and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere.

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

“…Consequently, there is significant transport of PAHs from the mainland to coastal oceans due to the influence of the East Asian monsoon [ Lang et al ., ]. These PAHs in the upper air can bind to fine particles and are deposited into the ocean due to gravity and precipitation, such as rain, snow, hail [ Chen et al ., ]. Following deposition in the ocean, most PAHs are easily absorbed onto suspended particles, due to their high hydrophobicity and lipid solubility [ Li et al ., ].…”

“…[], and is described in detail in supporting information Text S1. Data on PAHs concentrations in the atmosphere and rivers were collected from published materials [ Wang et al ., ; Chen et al ., ; Qi et al ., ; C. Wang et al ., ] and detailed information is provided in supporting information Tables S1 and S2.…”

“…The U.S. Environmental Protection Agency has identified 16 PAHs as priority pollutants. Anthropogenic PAHs are omnipresent in environmental matrices and are found in the atmosphere, soil, water, ice, sediment, and food web [ Chen et al ., ; C. Wang et al ., ; Lohmann et al ., ; Yuan et al ., ; Stout and Graan , ; Huang and Batterman , ], due to the global distribution of sources and the resistance of PAHs to degradation. Marine sediments usually act as important sinks for anthropogenic PAHs through two major pathways, riverine discharge and atmospheric deposition [ Wang et al ., ; Mulder et al ., ; González‐Gaya et al ., ].…”

“…The ECMSs are adjacent to one of the world's most heavily populated and densely developed regions (Changjiang [Yangtze] River basin with 400 million inhabitants) [ Zhao et al ., ], and receive large amounts of terrestrial pollutants [ Lin et al ., ; Zhong et al ., ; Li et al ., ]. In the early 21st century, several ECMSs‐related studies focused on the PAHs cycle, important factors that regulate PAHs budgets, fate of PAHs in the marine environment [ Liu et al ., ; Lin et al ., ; Li et al ., ], deposition flux of sedimentary PAHs [ Guo et al ., ; Qin et al ., ; Lin et al ., ], and air‐seawater exchange of PAHs [ Wang et al ., ; Chen et al ., ]. However, PAHs research efforts have concentrated on specific compartments and regions due to the complexity and size of the ECMSs region.…”

Shifts in the Distribution and Fate of Sedimentary Polycyclic Aromatic Hydrocarbons Within the Estuarine‐Inner Shelf Areas of the East China Sea: Response to Human‐Induced Catchment Change

“…PAHs are mainly derived from anthropogenic activities such as incomplete combustion of biomass and fossil fuels (Yunker et al, ) or natural processes such as forest fires, volcanic activity, and petroleum seeps (Lima et al, ). PAHs are omnipresent in environmental matrices and are found in the atmosphere, soil, water, and sediment (Chen et al, ; Lin et al, ; Lohmann et al, ; Wang et al, ), due to ubiquitous combustions and resistance of PAHs toward degradation. Marine sediments usually act as important sinks for PAHs through two major pathways, riverine discharge and atmospheric deposition (Chen et al, ; Mulder et al, ; Wang et al, ).…”