江苏省某城市河流自净状态研究

Study on the Self-purification Status of an Urban River in Jiangsu Province

以江苏省某城市河流为研究对象,用原位调查的方法对其自净状态进行了研究。研究发现,该河流超标最严重的指标是BOD5（9.0~16.2mg/L）和氨氮（1.07~4.78mg/L）。溶解氧、氮元素形态和有机物浓度等都能较好地指示河流的自净状态。在河流自净状态较健康的河段,河流溶解氧含量较高,处于好氧状态,氮元素形态以硝氮为主（60%）,有机物含量相对较低;在河流自净状态较差的河段,河流溶解氧较低,进入厌氧状态,氮元素以氨氮为主（80%）,有机物形成积累。所研究河流的自净状态并不稳定,尤其下游河段进入了厌氧状态,有发生黑臭的风险。该研究可为今后该河流的进一步治理提供科学依据。

Taking an urban river in Jiangsu province as study object, the article researches on its state of self-- purifieationby the in--situ investigation. The study shows that the among all the pollutants which exceed the national standard, the most serious are BODs （9.0to16.2 mg/L）and ammonia--nitrogen （1.07to 4.78mg/L）. The dissolved oxygen, nitrogen form and organic content can well indicate the self--purification of a river. In the part that the river has a healthy self--purification, the dissolved oxygen remains at a high level and the river is under an aerobic condition. The nitrogen is the in main form of nitrate nitrogen（60%） And the organic content is at a low level relatively. On the contrary, in the part that the river has an unhealthy self--purification, the dissolved oxygen is quite low and the river is in an anaerobic condition. The nitrogen is in the main form of ammonianitrogen（80%） and the organic content is accumulated. The self--purification of this urban river is not stable, especially the downstream gets into anaerobic condition and has a high risk of becoming black and smelly. This study providesscientific references for the further management of this river.