Reaearch On Nitrogen Spatial And Temporal Changes Of Huiji River In Kaifeng

This article selects the major river named Huiji river in Kaifeng as the research object,respectively in September2012（summer） and December2012（winter） to HuiJiHe’s main road and itstributaries, typical outlet has carried on the field investigation. Water samples were analyzed TN、filteredTN、NH₄⁺-N、NO-2-N、NO-3-N indoor, the several conclusions followed:（1） The contents of TN、filtered TN、NH+-4-N、NO₂^-N and NO-3-N have obvious spatial variationcharacteristics both in summer and winter. The contents of TN、filtered TN、NH₄⁺-N has good consistencyin the summer and winter, the overall trend is similar. Specific for before entering the downtown content isslowly rising, after entering the city rapidly rise and peak, then falling rapidly. After out of urban areas, itscontent is increased. The content of NO-2-N ups and downs is big, there is no obvious change characteristic;NO-3-N has been in a low level, only in the downtown has a sudden increase and then slow decrease.（2） The contents of TN、filtered TN、NH+-4-N、NO₂^-N and NO-3-N have present a certain amountof time in the same point. The content of TN before entering the city, in summer is less than in winter.Flows through the urban area Bin He bridge of maximum value appeared in summer, winter maximumvalue appears on the Da Liang bridge, the maximum value is higher than the maximum in winter, summerout of urban areas after rising rate is more than in winter, summer content more than winter. The content ofNH₄⁺-N, before flow into the city for two season content is basically the same, shows the tendency ofincrease gradually. Maximum after entering the city, the summer and winter respectively in Bin He bridgeand Da Liang bridge, the summer maximum value is higher than the winter maximum. Look from the rateof change, the summer is higher than winter. The content of NO₂^--N in the overall trend is obvious different,the summer maximum occurred at source, the winter maximum occurred in out of city. In summer thecontent of NO-2-N range is larger, winter basically stable at a level. The content of NO-3-N change trend isbasically the same as a whole.（3） The high nitrogen in sanitary sewage and industrial wastewater is the main cause for Huijiriver nitrogen pollution. Based on the different forms of nitrogen and nitrogen content in the outlet of atypical tributaries, found that when the content of N has great changes in space and time, the waste waterdischarged into or tributary import, main sources and tributaries of the river for sewage and industrial wastewater. Main reason for the difference between the different seasons of nitrogen is caused by thetemperature and different season drainage way.（4） Before the main Huiji river into the city, NO--2-N and NO3-N is the main form of TN, alongwith the flow of the river, proportion of NO₂^--N and NO₃^-N gradually decreases, and proportion ofNH₄⁺-N gradually rising, NH₄⁺-n become the main existence form of TN after entering city. When out ofurban areas, proportion of NO-2-N and NO-3-N in a short rise, become the main form, and soon NH₄⁺-Nbecome the main existence form again.（5）The pollution of TN, NO-3-N in Huiji river are seriously polluted. According to "surface waterenvironment quality standard （GB3838-2002）" â…¤ standards, TN in summer and winter maximum exceedthe multiples is26.2and18.4, over standard rate both is100%.NH₄⁺-N in summer, winter maximumexceed the multiples is20.2and17.1, over standard rate both is66.7%.