Research Of Volume Control And Emission Reduction Of COD, Nitrogen, Phosphorus In Water Of Pulandian Bay

With the fast pace of the whole basin urbanization in Dalian, land for industrial and urban development is experiencing serious shortage, so that in-land industrials start to migrate into coastal area. At the same time, the rapid development of industrialization and urbanization process also results in major gulf pollutants discharged into the sea. The bay area is severely polluted, which leads to increasing risks of bay ecological security.The quality of marine environment and changes in major bay pollutants have become rising public concerns nowadays.The fundamental way to carry out marine environment protection is to calculate the pollutant holding capacity of the marine environment and to control and assign the pollution discharge.By applying this method, the existing pollution will be cured to certain extent; the spread of future pollution can be prevented; and the sustainable development of marine economy can be eventually achieved.Especially, pollutants containing COD, nitrogen, phosphorus and etc. are the major chemical contaminants monitored by the government.This article focuses on the research about numerical simulation in the pollution holding capacity and distribution by controlling the amount of pollutants under the allowable limit within a certain range of marine environment.The research area for this paper is Pulandian Bay area, which is the forerunner area of Dalian Chemical Industrial Zone and urban construction.It highlights the fact that some of the habitats are so seriously polluted that it is impossible to recover because of the over-urbanization.Based on the data of hydrological and chemical elements of COD, nitrogen and phosphorus inspected by a research group in July 2013, the author observed, analyzed and developed a two-dimensional tidal current mathematical model for Pulandian Bay area in order to further research the exchange capacity of Pulandian B ay water, the marine capacity of holding pollutants, as well as total quantity control and the assignment of discharge reduction.By researching the hydrodynamic exchange information specifically for this area, the exchange capacities of 6 subareas are sorted:Area B> Area E> Area C> Area D> Area A> Area F.As for discharge points, there is no remaining holding capacity for inorganic nitrogen and inorganic phosphorus in the Discharge Point I, so that the pollution emission from land-based sources should be reduced; there is still certain level of environmental capacity for COD, nitrogen and phosphorus in the rest of discharge points.In addition, according to the redistribution program of the index system and the study of the two types of excessive COD and phosphorus, Discharge Point I’can be added for inorganic nitrogen to go through, and a redistribution plan, which is based on the redistribution response factor field, can be developed for Discharge Point I and I’.Moreover, the location of the new discharge point was screened out, so that the outward spread of water contamination can be prevented through physical purification methods.Therefore, based on the above theory and discussion, the total amount of pollutants discharged into the sea can be make sure to be the same as discharge carrying capacity, which will contribute to the enhanced comprehensive pollution control, and the coordinated development of natural resources and the ecological environment.This research also provides critical scientific and technical support for realizing the regional total amount control, distribution and discharge reduction goal in the near future; and ultimately achieving the excellent ecological environment in the habitat, maintaining the maximum biomass growth as well as promoting sustainable development of marine economy in Dalian New Urban Basin area.