The Simulation Study On The Removal Law Of Dissolved Inorganic Carbon (DIC) Of Lijin Section, Yellow River

River system is a key link in the global biogeochemical cycles. The input of the land erosion material is the main channel of the ocean. It records, in response to environmental basin evolution, and spread the human disturbance to coastal land systems and marine systems. The river caused land erosion input about 1Gt carbon to the ocean every year, of which about 60% of inorganic carbon,40% of organic carbon. Flowing through the middle reaches of the Loess Plateau, the Yellow River is the world’s leading high turbidity river because of the intense weathering. Yellow River since the low-latitude flow to the high latitude and it is perfect condition to cause ice flood. Therefore, different tributaries of the Yellow River and the extent of winter ice conditions have the phenomenon, which will also cause great effect to the distribution of dissolved inorganic carbon (DIC) in the river. By the freezing experiments, we discussed the variation of TAlk, DIC and its constituent during freezing. With the combination of 13CDIC it came out that the carbonate precipitation, carbon dioxide degassing were likely to occur during freezing. The main conclusions are as follows:1. The freezing process had a strong removal effect of DIC. Compared to the raw water samples, the DIC content in the ice samples were extremely low. As the largest component of DIC in Lijin Station, HCO3- owned the major removal but it had the lowest rate.2. In closed conditions, the unidirectional remove of CO2 made relatively more CO2 in the remnant water while more CO32- was left in the ice. In opened conditions, the freezing progress was followed by degassing. At this condition, CO2 was enriched in the ice and CO32- was significantly decreased.3. In opened conditions, the vertical DIC distribution of ice was showed high on both faces and low inside. With the progressing of freezing, the DIC concentration of inside ice continues in low values, which represents the continuous removal of salt.4. Environmental temperature was a key to the distribution of DIC during the nature freezing process. First of all. the initial freezing temperature played an important role on both the concentration of DIC and CO2. In low temperature condition, rapid freezing progress made more salt got trapped in ice and so did CO2. Vice versa. Secondly, after the formation of ice, the rose of daytime temperature made the CO2 escaped from the ice and the composition of DIC made carbonate precipitation more likely to occur.