아산시 송악저수지의 수질오염 현황 및 부영양화 저감방안 연구 = The Status of Water Pollution and the Strategy of Reduction of Eutrophication of Song-ak Lake in Asan City

다국어 초록 (Multilingual Abstract)

This study was conducted to estimate the water pollution load, water quantity and quality of inflow stream, status of water pollution and reduction of eutrophication in the Song-ak lake in Asan city.
Inflow of branch to Song-ak lake has three streams, one is Eu-gok stream which has the most width of inflow area and another is Dong-hwa stream and the other is Ma-gok stream. The sampling numbers for water quality are 30 points from the sediment of bottom in the Song-ak lake from June, 1997 to ay, 1998.
Water quality had been tested for water temperature, pH, dissolved oxygen(DO), chemical oxygen demand(COD), suspended solid(SS), total nitrogen(T-N), total phosphorus(T-P), colony numbers of E. coli, chlorophyll-α. The total nitrogen, total phosphorus and heavy metals(Fe, Pb, Cd) were analyzed by the migration test of the sediment.
The results were as follows;
The rate of water pollution by the livestock wastewater of the total water pollution load for BOD, SS, T-N and T-P were 59.8%, 82.9%, 56.1% and 90.6%, respectively.
Mean daily inflow was 25,369m3. Quantity of inflow was highest at Eu-gok stream.
The mean levels of pH, DO, COD, SS, T-N, and colony numbers of E. coli of the inflow water were 7.52, 10.25mg/ℓ, 2.12 mg/ℓ, 3.03 mg/ℓ, 2.25 mg/ℓ, 0.11 mg/ℓ and 1,795/100㎖, respectively. The worst inflow water quality was observed at Dong-hwa stream.
The mean levels of pH, DO, COD, SS, T-N, T-P, T-N/T-P and colony numbers of E. coli at Song-ak lake were 8.06, 9.32mg/ℓ, 6.83 mg/ℓ, 4.78 mg/ℓ, 1.66 mg/ℓ, 0.115 mg/ℓ, 20.75 and 64/100㎖, respectively. these are higher than class IV by environmental water quality standards for lake. Mean level of trophic state index was 59.4.
The mean levels of T-N, T-P, Fe and Pb by migration test of sediment at Song-ak lake were 259.7ppm, 10.546ppm, 1,704ppm and 8.54ppm, respectively.
As the water pollution was mainly caused by livestock waste, the strategy for the reduction of eutrophication of the Song-ak lake should be concentrated on the control of the livestock waste.