The Reasearch Of Denitrification And Its Influent Factor In Typical Sea Area

With the increasing let of waste water and sewage in human industrial and agricultural production, nitrogen and phosphorus element in estuary and in shore sea area go up year after year, and cause Eutrophication in ocean environment and Frequent cause of red tide phenomenon. It forms serious pollution for ocean environment. So, the biology rehabilitate technic about inorganic nitrogen contamination is becoming one of the important research field in current ocean pollution disposal. Study denitrification in sediment-water interface, understand circle characteristic of nitrogen, depth studieson coastal nitrogen is of great significance for the research of nitrogen.In this paper we study the denitrification rate in part of north yellow sea area in summer using Acetylene Inhibition Technique and Local Static State. It find that the denitrification in this sea area is between 2.5～5.8μmol/m2·h, and its average value is 4.85μmol/m2·h. The denitrification rate shapes a high obvious value area in Bohai channel nearby, and gradually reduce off to north yellow sea and both sides. The main factors affecting denitrification rate is dissolved oxygen, followed by temperature.This paper study the ification rate in Yellow River estuary using Acetylene Inhibition Technique and Local Static State. It find that he denitrification rate in Yellow River estuary is 3.8～19.3μmol/(m2·h), and its average value is 10.27μmol/(m2·h). The denitrification rate shapes two high value areas in frontage sea area of Yellow River estuary and the sea area near Laizhou Bay. It gradually reduces from the two high value areas and shapes a lowest value areas extended to Bohai sea. The number of denitrification bacteria keeps high relevance with denitrification rate and it is one of the important factors affecting denitrification rate in yellow River estuary. Other environmental factors have no significant correlation with denitrification rate. Denitrification rate in Yellow River estuary is below the estuary of the Pearl River, Yangtze River and the gulf abroad. This paper studies the effect of oxygen,nitrate concentrations,different carbon source and carbon content, temperature for the rate of denitrification. The results show that single factors have significant influence on the denitrification rate. Among them, dissolved oxygen and carbon have the greatest impact, and under certain conditions, the ratios of removing nitrate are over 50﹪. Therefore dissolved oxygen,nitrate concentrations,different carbon source and carbon content,the temperature are important factors for the denitrification rate. Their extent of the impact is dissolved oxygen,carbon source,carbon content,temperature and nitrate concentration in turn.