Distribution Of Particulate And Dissolved N-Alkanes In The Changjiang And Its Adjacent Sea

In the present thesis, particulate and dissolved n-alkanes in water were detected by gas chromatography. The samples were collected from sampling locations in Changjiang drainage basin, Xuliujing, Changjiang estuary area, East China Sea, and Yellow Sea. The main purposes of the current study are to elucidate the distributions, the transportation and variation of n-alkanes in the land-sea systems from Changjiang drain basin to East China Sea. Furemore, the n-alkanes flux, which is depleted from Changjiang runoff by the turbidity maximum zone in its estuary, is also estimated.Chapter 1 introduced the importance of n-alkanes in organic geochemical study and the proposed main factors that affected the concentration of particulate or dissolved n-alkanes.The first section of Chapter 2 dealed with the climate, geography and hydrology of the areas. The second one summarized the materials, chemicals, instruments and methods of experiments.The results and discussion part are shown from Chapter 3 to Chapter 6:In Chapter 3, based on the results of the particulate samples collected from Changjiang drain basin in water, we found that the concentrations of particulate n-alkanes decreased in the direction from upriver of Changjiang 13 μg·mgC^-1 to its estuary 2.5 μg·mgC^-1 . The maximal n-alkanes concentration appeared in the sample from Jinshajiang. Comparison with the results from other study areas, the concentrations of terrigenious n-alkanes in Changjiang drain basin were lower than results from Torrid Zone, but higher than those from Frigid Zone.In Chapter 4, it was found that the molecule carbon indexes of n-alkanes in samples from Xuliujing were ranged from 15 to 36. There were three distribution patterns of n-alkanes in Xuliujing, i.e. a high carbon number predominance, a bimodal distribution, and a petroleum contaminated distribution. According to the total...