Study On Characteristics, Distribution, Dredging And Disposal Of Sediment From Sewage River

Dagu sewage river, one of two sewage rivers of Tianjin city, has been discharging the sewage of the sorth city to BohaiBay. In Dagu river rehabilitation project, the most difficult problem is how to deal with 2,300,000m3 sediment. The following content are studied in this paper.1 Study on pollutant distribution discipline of sedimentBy means of sampling along the river, the lengthways & transverse distribution discipline of heavy metal in Dagu sediments is studied, the sediment pollutant situation is evaluated and the sediment is classified. The gist is given for calculating the sediment amount based on different disposal ways and optimizing the design method of river section. Through the pollution source analysis, math simulation and forecasting models of heavy metal distribution and sediment configuration are studied, which not only help point out the key inspecting points, but also help reveal the danger degree of sediment to environment.2 Study on plant distribution discipline along the Dagu bankBy site survey and lab test, the plant distribution discipline along the Dagu bank and heavy metal content in plant is studied for the first time, accordingly, we can find out the suit plant for sediment at every part of the river and absorption degree of aboriginal plant to heavy metal. All of these can help us know how to rehabilitate the sediment by plant and how to choose the plant after the landfill is covered.3 Study on the dewatering method of sedimentThe dewatering methods are studied on the basis of test and pilot-scale trial. The methods include air-drying, belt filter, vacuumizing tank, freeze-thaw (for the first time) and geotextile bag. We can find out the efficiency and affection on the following treatment process for every method. The results help us use the land efficiently, reduce the cost and find out leachate contamination degree for every dewatering method.4 Study on optimizing environmental dredging processThe several sediment disposal methods are offered on the basis of collecting, analyzing and testing. The uncontaminated sediment of Dagu is used in the basis of road. Different aboriginal plants are filtered according to plant distribution discipline along the river for different part and different contamination.Finally, the dredging and disposal integrated process of sediment is optimized...