• Journal of Environmental Science International
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• v.9 no.4
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• pp.275-284
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• 2000

The studyies on physico-chemical factors and phytoplankton at the 3 rivers in the Taejon city were conducted from November 1997 to May 1998. The Results were as floows; In the water quality, the down streams were generally worse than the upper streams. Water temperature was varied from 2.4$^{\circ}C$ to 23.$0^{\circ}C$; DO from 1.80mg/$\ell$ to 17.6mg/$\ell$ ; pH from 4.7 to 10.4 ; BOD from 0.78mg/$\ell$ to 8.80mg/$\ell$ ; COD from 0.32mg/$\ell$ to 8.26mg/$\ell$ ; SS from 2.0mg/$\ell$ to 43.0mg/$\ell$ ; total phosphate was from 0.001mg/$\ell$ to 0.709mg/$\ell$ ; total nitrogen 0.01mg/$\ell$ to 11.69mg/$\ell$. In phytoplankton species, they were identified as total 191 taxa composed of 8 classes, 18 orders, 35 families, 74 genera, 152 species, 35 varieties and 4 forms. The dominant species were Synedra ulna in Taejon-chon, Diatomavulgare in Yudong-chon, Oscillatioria princeps, Scenedesmus qadricauda, Synedra ulna, and Diatom vulgare in Gap-chon. Standing crops of phytoplankton were from 2,076 cells/$m\ell$ to 97,356 cells/$m\ell$