Original paper
Urea decomposition associated with the activity of microorganisms in surface waters of the North Han River, Korea
Mitamura, Osamu; Cho, Kyu Song; Hong, Sa Uk
Archiv für Hydrobiologie Volume 131 Number 2 (1994), p. 231 - 242
33 references
published: Aug 2, 1994
DOI: 10.1127/archiv-hydrobiol/131/1994/231
ArtNo. ESP141013102006, Price: 29.00 €
Abstract
The rate of urea decomposition in relation to activities of microorganisms was measured in surface water of the North Han River, Korea. The decomposition rate of urea was 0.2 to 3.1µmol urea· m-3· hr-1 in the light. Much higher decomposition rates were observed in the polluted eutrophic waters, which were affected by sewage from a large city. The urea decomposition rates in the upper reaches of the river were obviously higher in the light condition than in the dark, while the polluted waters showed no such difference. Whereas only a negligible level in the phase of carbon incorporation was observed in the upper reaches, a significant value was obtained in the polluted areas. The present results indicate that in unpolluted waters the decomposition of urea occurred in connection with the photosynthesis of phytoplankton rather than bacteria activity. In polluted eutrophic waters, on the other hand, urea seemed to decompose under the competitive action of bacteria and phytoplankton.
Keywords
North Han River • Korea • phytoplankton