Impacts Of Bioturbation On Distribution Of Dissolved Oxygen At Sediment-water Interface

With the development of oceanography, sediment-water interface (SWI)becoming an importance research field. Since the SWI is the main interface ofbiogeochemistry circle, the measurement of concentration and distribution ofdissolved oxygen at SWI is very important and helpful. Bioturbation is an importantfactor influencing the distribution of dissolved oxygen, as well as the geochemistry.Bottom-dwelling animals change sediment pellet, sediment stratification andsediment structure during burrowing, feeding, construction of tubes and ventilationactivities, changing concentration of many parameters, which can be used inquantitative analysis.Former dissolved oxygen measuring methods are limited in in-situ measurementdue to low efficiency and accuracy. Since the1970s’, the new developed planaroxygen optodes shows its huge superiority. As one kind of two-dimensionalchemistry-biology sensors, planar oxygen optode can be used to monitor and recordspatial dynamic changing process of goal’s chemical composition, providing aneffective technological method for the revelation of natural science question. In thisthesis, the different methods based on fluorescence intensity, lifetime, ratio andeven the synthesized analysis are provided their principle, and feasibility. Bycombining them with the actual situation, ratiometric method shows greatadvantages and is chose. Using PtOEP as fluorescence indicator and Marcrolex Yellow10GN as donor and antenna, sensor film is made in the lab and used in self-madeplanar optode performing well in the later calibration.With the self-made planar optode, distribution of dissolved oxygen at SWI ismeasured, and combined to the “Fick’s1stlaw” to calculate the diffusion flux ofoxygen.