Influence Of Temperature And Precipitation On Nitrogen And Phosphorus Pollution In Nanfei River Water

Nanfei River is one of the most important river into Chao Lake,throughout the Hefei,over the years accepting life sewage and industrial wastewater in Hefei,of which nitrogen and phosphorus pollution is very serious.After repeated silting,the water quality was not significantly improved.This paper studied the main factors influencing nitrogen and phosphorus pollution in Nanfei River,which is of great significance to the effective control of eutrophication of water and the management of river channel.Temperature and precipitation are important to the input,migration and transformation of nitrogen and phosphorus.This article select temperature and precipitation,through actual investigation and statistics,to study the temperature,precipitation,precipitation of river water,rainwater samples before and after the change of the concentration of nitrogen and phosphorus pollutants in characteristics,through the correlation analysis and data fitting and other statistical methods to analyze the effect of the temperature and precipitation on nitrogen and phosphorus pollution and contribution to river.Its results show that:?1?temperature in addition to a significant correlation between TN and TN/TP?P<0.05?,and other correlation between nitrogen and phosphorus pollutants were not significant?P<0.05?.?2?When the temperature below 15?,the concentration of nitrogen and phosphorus pollutants in the water with a linear temperature change,and in addition to the TP and weak positive correlation to the temperature,NH₃-N,TN and COD_Cr are negatively related with temperature.When the temperature is higher than 15?,the water of NH₃-N and COD_Cr concentration and temperature between the effect of using the quadratic polynomial fitting is relatively good?R2>0.40?,with the rise of temperature of"rise after the first decreases,"trends,namely,when the water temperature of 25?or so NH₃-N and COD_Cr concentrations fell to the lowest;And the concentration of TP and TN is worse than the fitting effect of temperature.?3?the rainfall that falls directly into the river has a certain dilutive effect on the nitrogen and phosphorus concentration in the river.And the larger the rainfall,the stronger the dilution.In 2014,the highest concentration of nitrogen and phosphorus in the water was in February,April,June,July,August and November,mainly in summer?June-August?.In 2014 and 2015 in Hefei city two snow of nitrogen and phosphorus pollutants are mainly composed of TN pollution,reached the"surface water environment quality standard"?GB3838-2002?of?class and worse?the level below,and TP in the snow,NH₃-N and COD_Cr concentration is relatively low.?4?The average concentration of nitrogen and phosphorus in the surface runoff of the urban artery?UR?is slightly higher than that of the region?SR?;Rainwater?Sr?of nitrogen and phosphorus pollutants concentrations were significantly high in surface runoff,river water,TN,TP and NH₃-N and COD_Cr of the average concentration of 22.40 mg/L respectively,2.46 mg/L,12.33 mg/L and 188.07 mg/L.Rainwater nitrogen and phosphorus pollutants concentration in river downstream and upstream of the compared with obviously increased,the TN concentration increased 14.14%on average,TP concentration increased1.75%on average,NH₃-N concentrations increased 66.67%on average,COD_Crr concentration increased 41.69%on average.?5?the contribution of temperature to TN in the river is approximately equal to the amount of precipitation,about 1 mg/L.And temperature on the river in the contribution values of TP significantly more precipitation is high,that temperatures contributed to the release of TP in the sediments,the phosphorus pollutants carried by rainfall and surface runoff is relatively low.However,the contribution of the NH₃-N and COD_Cr,the precipitation is obviously higher than the temperature,which indicates that the sewage system may be merged into the sewage,and the surface contaminant is more.