Characteristic analysis and countermeasure research of Yuqiao reservoir's eutrophication process

The present paper intends to introduce our research of analysis and countermeasure research of yuqiao reservoir' s eutrophication process.As is known,Yuqiao reservoir is located in the northern part of Tianjin,and in turn the main drinking water supply base of Tianjin city.For its importance for the city survival,we have adopted the water quality monitoring data from 1999 to 2007 of Guoheqiao section,that is,the upstream section of the reservoir,to monitor the frequencies and ratio of the dominant pollution indices in accordance with the national standard pollution-control value.Then, Mann-Kendall method was introduced to analyze the monthly trend of the 6 pollution indices.Furthermore,these index-changing trends were studied respectively in the wet seasons,normal seasons,dry seasons and the whole year.Through our analysis of the chief contaminants beyond the national pollution-control standard situations, we have obtained the reservoir's eutrophication characteristics.Based on our investigation results of the pollutant sources,we have put forward some countermeasures to change the situation of the of Yuqiao reservoir's eutrophication.The characteristic analysis of its eutrophication shows that the restraint factors of the reservoir' s eutrophication process was phosphorus.Moreover,water algal blooms in Yuqiao reservoir during the period of the two months from July through September were chiefly caused by the release of phosphorus in the reservoir s mud,whose release from the reservoir was controlled by the Oxidation-Reduction of ferro(Fe) ingredients.And,therefore, the Ferro in the upstream may have an important effect on the water algal bloom of the reservoir.To prevent the water from the algae eruption,we have taken two key countermeasures to inhibit the release of phosphorus in its sediment: one is to strictly control the sewage rich in Fe and the iron mine's activities to contaminate the water from the upstream inflow,the other is to apply the technology of sediment oxidation or artificial aeration so as to restrict the phosphorus effect on the reservoir s sediment.Thus,it can be concluded from the characteristic analysis and countermeasures research that the reservoir' s eutrophication process has had great significance for the water supply safety of the whole Tianjin city.