Simulation Of Concentration Distribution Of Major Pollutants And Growth Of Algal In Dalian Bay

Seasonal three-dimensional hydrodynamic water quality model can simulate more than 20 water quality variables of physical, chemical, biochemical reaction. At the same time, it takes into account many factors, such as geographical location, topography, hydrology and natural marine meteorological conditions and so on. Based on the historical reference and monitoring data, the model can reproduce overall situation of water pollution in Dalian Bay and average relative error is inside 20%.Ammonium nitrogen and phosphate as major pollutants was studied in detail. Simulation results showed that load of ammonium nitrogen and phosphate was mainly concentrated on the top of the sewage outfall location in Dalian Bay. When the load of pollutants added, the pollutant concentration would increase rapidly.In water quality management and objectives planning, reduction of emission of ammoniacalal nitrogen and phosphate, as well as change of sewage outfall location can influence the growth of algal. Simulation results illustrated that phosphate was the main factor to influence algal growth near the sewage outfall in Dalian Bay. So the growth of algal can be controlled by reduce the discharge load of phosphate. But away from the sewage outfall location, the growth of algal can be controlled by reducing the discharge load of ammonium nitrogen and phosphate with a certain ratio. In other words, by taking into account the ratio of nitrogen to phosphate, ammonium nitrogen was the major factor and phosphate was necessary to be considered in Dalian Bay.