The Distribution and Source Analysis of Main Organics in Sediments from Laizhou Bay
|School||Ocean University of China|
|Keywords||Surface sediments N-alkanes Polycyclic aromatic hydrocarbons Distributed Source Analysis|
Marine sedimentary organic matter is mainly to study the composition of organic matter in marine sediments, distribution characteristics, biological sources and biogeochemical conversion of organic matter in the early diagenesis stage. N-alkanes is widespread in modern marine sediments, can reflect the relative abundance of n-alkanes of different carbon sources and thermal maturity of organic matter in the sediments. Aromatic compounds in environmental pollution control focused on the most modern marine surface sediments aromatics little research, which comes mainly from forest fires, coal-fired fuel, vehicle exhaust and oil spills. N-alkanes in the sediment and the PAHs to go through a specific extraction method pretreatment spectra obtained by instrumental analysis method, the spectrum analysis, calculations, etc. to determine the content thereof, as well as distribution and origin. N-alkanes in the sediments is easy to change with the change of environmental conditions, therefore, the n-alkanes are widely used in organic geochemistry, to illustrate the impact of organic matter accumulation and transport on the environment. Polycyclic aromatic hydrocarbons (PAHs) are mainly derived from the man-made pollution, the distribution characteristics of polycyclic aromatic hydrocarbons in sediments can strengthen its source pollution control. Laizhou Bay sediment n-alkanes and polycyclic aromatic hydrocarbons, while investigating the Laizhou Bay land-based sources of pollution of the rivers into the sea, the study results show that: the Laizhou Bay surface sediments (1) n-alkanes in the waters east of and southwestern waters were a high-value area, the input with Yellow River, Xiaoqinghe and other rivers as well as the Bohai fishing operations related. Mainly three sources of n-alkanes in the surface sediments of the Laizhou Bay, terrigenous input dominant type, land-based sources and marine endogenous type of mixed type, and oil pollution. Isoprenoid hydrocarbons pristane and phytane analysis, Pr / Ph (pristane / phytane) changes in the 0.62-1.43 between indicating the Laizhou Bay oxidation - reduction depositional environment. (2) The concentration distribution of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Laizhou Bay presents the eastern waters of the west coast, followed by the middle of the waters, in descending order by the estuary shore distribution trend, with the Little Yellow River, Qinghe The rotation of the middle of the river input Laizhou Bay trend. Qualitative source analysis of polycyclic aromatic hydrocarbons in the surface sediments of the Laizhou Bay, the analysis showed that exhibit the characteristics of mixed origin of polycyclic aromatic hydrocarbons, including oil pollution, the burning of fossil fuels and wood and coal burning. Meanwhile, polycyclic aromatic ring number composition as the the Laizhou Bay polycyclic aromatic hydrocarbons main source of oil pollution. (3) 11 Laizhouwan terrigenous stations petroleum hydrocarbon concentration exceeds III quality standard (1m / L), Yuhe and Mihe, petroleum hydrocarbons concentrations up to 40.01mg / L and 39.82mg / L. The most stations COD concentration meet the the I quality standard (2m / L) slightly exceeded the Wang River and the offshoot River II water quality standard (4m / L), Ze River beyond the Grade III standard (6m / L). Laizhou Bay rivers into the sea, high concentrations of petroleum hydrocarbons in the coastal waters of the n-alkanes and polycyclic aromatic hydrocarbons in one of the main sources of these rivers, and sediment is rich in organic matter, sea terrigenous input source. Petroleum hydrocarbons enter the main river Yuhe, Mi River and the Xiaoqing River.