The Eutrophication Condition and the Pollutant Fluxes Entering the Sea via the Rivers in the Haihe River Basin

Through an investigation of the nutrients and organic pollutants entering the sea via nine rivers in the Haihe river basin in the summer of 2005,we found that there were three rivers in which the key pollutants were petroleum,in one river the key pollutant was CODMn and the remaining fiver rivers whose were rich in nutrients.The rivers were evaluated by the comprehensive trophic state index with the following results: the Tuhaihe river was meso-eutrophic,the Luanhe、Majiahe and Daqinghe rivers were eutrophic,particularly the Haihe、Jiyunhe、Chaobaixinhe、Duliujianhe and Ziyaxinhe rivers were extremely-eutrophic.According to a survey of organic pollutants,the average TOC value for the nine rivers was 20.57 mg/L,and the average CODMn was 6.70 mg/L.The pollutant fluxes entering the sea via the rivers in the Haihe river basin were 52174 t in the summer of 2005,of which CODMn and NH4+-N,which approximately accounted for 77.1% of the total played a leading role.