TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

fastest absorption of nutrients from water in experiment 1. Therefore Pistia stratiotes seems
the best for denitrification purpose among the plants tested for the IBK system.
In the present experiment initial planting was so thin that the spatial potential to grow the
plants was not fully utilized. Therefore if we had started the plant growing much intensely
from the first, the production would have been more than double or triple the present results of
15 g nitrogen synthesis. Thus the amount of nitrogen synthesis by Pistia stratiotes would have
been more than 30 to 45 g on an area of 2 m 2 for 30 days.
The amounts of crude fat and ash synthesized were also highest in Pistia stratiotes (457 g
and 492 g, respectively) followed by Hygrophila angustifolia (328 g and 271 g), Eichhornia
crassipes (152 g and 178 g) and Hydrocotyle leucocephala (160 and 125 g).
Conclusion
Some aquatic plants such as Eichhornia crassipes, Hydrocotyle leucocephala,
Hygrophila angustifolia, and Pistia stratiotes, are used for denitrification process in
recirculating aquaculture systems by some fish farmers in Korea. The removal of NH4-N,
NO2-N, and NO3-N from the water of IBK system by these four aquatic plants was compared.
Weight gain of, and nitrogen synthesized by, these plants in the system were evaluated. Pistia
stratiotes appeared much more effective than the other three plants both in terms of total
synthesis and the removal of inorganic nitrogen nutrients from the water of IBK system.
Acknowledgement
The Art and Science Promotion Foundation in Pukyong National University supported
this work
References
AOAC. “Official method of analysis. 16 th ed.” Association of Official Analytical Chemists.
Arlington, Virginia. 1995.
Colt, J. and D.A. Armstrong. “Nitrogen toxicity to crustaceans, fish and mollusks”.
Proceedings of the Bio-Engineering Symposium of Fish Culture. American Fisheries
Society: 1981.
Dunigan, E.P., R.A. Phelen, and Z.H. Shamsuddin, Use of water hyacinths to remove nitrogen
and phosphorus from eutrophic waters. Hyacinth Control Journal, (1975) 13: 59-61.
Hrubec, T.C., S.A. Smith, and J.L. Robertson. “Nitrate toxicity; a potential problem of
recirculating system”. G.S. Libey, and M.B. Timmons, Eds. Successes and Failures in
Commercial Recirculating Aquaculture.(1996): 41-48 .
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