Program
 
General Session 2: Marine & estuarine biogeochemistry
 
 
 
Poster
Distribution of particulate organic carbon and elemental carbon in the Jiulong River-Estuary and their correlations with persistent organic pollutants
GS2-47-S
Yuling Wu* , State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University
Xinhong Wang, State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University
Miaolei Ya, State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University
Yongyu Li, State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University
Presenter Email: ylwu@xmu.edu.cn
Organic carbon (OC) and elemental carbon (EC), ubiquitous in organic matter of suspended particulate matter (SPM), are considered to be important factors for influencing on the transport and fate of persistent organic pollutants (POPs) in water environment. Surface water samples were collected from the Jiulong River-Estuary, filtered through pre-baked quartz-fiber filters, then pretreated with hydrochloric acids to remove inorganic carbon. The filters were analyzed for OC and EC on a Desert Research Institute Model 2001A Thermal/Optical Carbon Analyzer following the IMPROVE (Interagency Monitoring of Protected Visual Environments)-A protocols. The concentrations of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticide (OCPs) in the SPM were also measured. Total concentration of OC and EC ranged from 328-4137 (mean 1367£©µg C L-1, 75~2712 (mean 467) µg C L-1£¬EC accounted for 23¡À10% to total organic carbon. OC/EC concentrations in riverine SPM had a distinct spatial distribution, an increasing trend of OC/EC was found from the upstream to downstream of the watershed, while a declining trends appeared in the estuary area, which was mainly influenced by emission from point sources, nature of river and seawater diluting. Correlation was found to be significant between OC and EC in the West Stream and estuary (except the North Stream), suggesting that they possibly came from same sources, e.g. soil erosion and anthropogenic activities. The ratios of OC/EC increased in the estuary area, indicating the input sources was from the upper reach. A standard receptor model of positive matrix factorization (PMF) to apportion the sources of EC in the SPM matrix, results showed that combustion of fossil fuels (i.e., coal and oil/petroleum) accounted for an average level of 78% of the total EC preserved, which was significantly higher than that from the biomass burning (22%). The spatial distributions of the fossil EC concentrations and percentages differed significantly from those of the biomass EC, implying their different geochemical behaviors in the Jiulong River In addition,a good correlation between EC (rather than OC) and PAHs or OCPs was reported in the river estuarine waters, inferring that sorption of POPs in water is more significantly controlled by EC, which provides new knowledge on the behavior of POPs in the Jiulong River, and the study on the influence of EC to the fate of POPs in water environment should pay more attention.