錦江에서의 Chlorophyll a와 BOD 및 COD와의 상관관계 硏究 - 배양실험 -

The correlationship among Chlorophyll a, BOD and COD in the Keum river - Culture laboratory work -

Biochemical oxygen Demand(BOD) is considered a major parameter to control the water quality of river. The concentration of BOD in the river is affected not only by the organic load from inflow but also by the phytoplankton biomass under the eutrophication state. The purpose of this study is to clarify the correlationship between Chlorophyll a and BOD in the Keum river. The intensive field survey was conducted in the Keum river in July, 1997. The correlations between Chlorophyll a and BOD. Chlorophyll a and COD were obtained through the culture work of phytoplankton in the laboratory. The culture work of phytoplankton was conducted to two type. One type was conducted with adding nutrients as N o.6ppm, P 0.15ppm. Other type was conducted with not adding nutrients. In the case of culture laboratory work, the concentration of BOD varied with the concentration of Chlorophyll a which was increased by the multiplication of phytoplankton. The correlation coefficients between Chlorophyll a and BOD through the laboratory work of culture were found to be 0.940 and 0.937 in the case adding nutrient and not adding nutrient, respectively. The correlationship between Chlorophyll a and COD showed that the correlation coefficients were found to be 0.928 and 0.898 during the culture laboratory work adding nutrient and not adding nutrient, respectively. Therefore, it is proved through laboratory work that there are good correlationship among Chlorophyll a, BOD and COD. This shows that phytoplankton cause to increase the concentration of BOD. It is possible to estimate the BOD quantitatively using the correlation between Chlorophyll a and BOD. to reduce the concentration of BOD under eutrophication state like the Keum river, we should reduce the amount of phytoplankton biomass as well as the BOD load from inflow.