Simulation Ttest Of Endogenous Pollution Releasing And Ecological Restoration In Surrouding River Of Chaohu City

The city of Chaohu located in central Anhui province,near the Yangtze River,surrounded by one of the five largest fresh water Chaohu Lake.The geographical position is superior,and the transportation is convenient.In recent years,the economics of Chaohu city developed rapidly,but the river pollution is more and more serious.In Chaohu,old town,a round-the-city river in the southwest of the Xi'an Qiao Zha into the Chaohu lake,by Xi'an Qiao Zha can water diversion to its.It concludes east and west.In recent years,its west by controlling the measures such as the sediment dredging,water quality improved obviously,but the pollution of east is still severe.This article explores the causes of its east water pollution,(releasing of endogenous pollution)and water ecological restoration.There are two parts of the cause of its pollution in surrounding of Chaohu city,the external cause and internal cause.Analyzing the internal cause is important.External cause is mainly in the urban sewage interception of direct emissions and surface runoff pollution,internal cause is derived from its release of sediment.Based on the laboratory static simulation test,to explore the different temperature,dissolved oxygen concentration and pH value(acidic,alkaline or neutral)under the condition of the east in Chaohu city.The characteristics of releasing COD and NH3-N,TN and TP.And explores the aquatic plant(species,planting density and growth state)on its water ecological restoration,the test to select the varieties of small water lily(floating-leaved plant),crosses floating(floating plant),bitter herb(submerged plant)and hornwort(submerged plant).The tests result: the temperature is 20?,A quantity of releasing is to maximum,the 10? is minimum.A quantity of releasing at 30? is in between;the release of COD in aerobic conditions is greater than the aerobic condition,the quantity of COD in natural is in between;With the rising of the temperature,the release of NH3-N,TN,TP in sediment increase unceasingly;Overlying water dissolved oxygen concentration decreases gradually,sediment NH3-N,TN,TP increase gradually;The change of NH3-N concentrations and TN concentrations were positively correlated in the overlying water;Overlying water body in acidic and alkaline conditions,the quantity of releasing COD,NH3-N,TN and TP is greater than the neutral condition,and in alkaline environment,the quantity of releasing is slightly higher than the acidic environment.In water,the four kinds of aquatic plants can absorb the COD,TN and TP,and can purify the water.The submerged plant(bitter grass and hornworts)stronger than the other two kinds of aquatic plants in absorbing ability,purification effect is better.In the submerged plant,the ability of absorption ability on nitrogen,bitter herb is lower than the hornwort,and on phosphorus absorption ability stronger than hornwort;As the bitter grass planting(plant density)increasing,the ability of absorbing COD,TN,TP increased;The different of growth conditions,the absorptive capacity of COD,TN and TP in water.In a growth phase absorption ability is very strong,the death in the state of the plant would cause overlying the rise of COD,TN and TP,but intends to the equilibrium state,the content of COD,TN and TP in water is lower than the control group without planting.