Date: November 23, 1998
From: Adrian Desbarats <adesbara@ns.sympatico.ca>
To: aqua-l@killick.ifmt.nf.ca
QUESTION:
Does anyone have information regarding nitrification rates rates at
temperatures of 1-6C? I expect it would be negligible but any empirical data on the subject would be much appreciated.
Adrian Desbarats
<adesbara@ns.sympatico.ca>
***************
COMMENTS 1:
Fred Wheaton may have some data on that in Aquaculture Engineering. I seem to recall a temperature vs nitrification graph in that source. This would also depend upon the species of nitrifying bacteria- I recall the optimum is around 75 to 85 F. For freshwater systems we have the usual Nitrosomonas and Nitrobacter nitrifying bacterial, but there are relatively less well known marine species of Nitrococcus.
I don't know what size system you may be considering, but if you are
seeking to design a biological filter for a small to medium size system,
have you considered algal turf scrubbers?
Ted Ground
<ground@thrifty.net>
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COMMENTS 2:
You could try estimating the rates below 5 degrees using the data from
Speece below, probably have to verify them experimentally. Nitrification seems to be possible at a wide range of temperatures but optimums are higher 22C+.
1) Speece, R.E. (1973), Trout metabolism characteristics and the rational design of nitrification facilities for water reuse in hatcheries.
Transactions of the American Fish Culturist. 36:8-15
Shows a linear relationship between nitrification capacity and area of
substrate per day (g/sqm/d) over 5 to 22.5 degrees C. These data can be used to calculate rates at any temperature over that range.
eg Nitrification g/sqm/d = Temperature (C) x 0.05368 - 0.0859
Assumes all other factors controlling nitrification are optimal, eg
limiting factors include DO, pH, alkalinity, temperature, light, free ammonia, nitrite, salinity, therapeutants.....etc
2) Engineering Aspects of Intensive Aquaculture (1991). Proceedings from the Aquculture Symposium, Cornell University. North East Regional Agricultural Engineering Service. 152 Riley Robb Hall. Cooperative Extension. Ithaca, New York. 14853-5701.
Contains reviews and discussions of nitrification and biofilter design.
Including pH, temperature optima for some species of nitrifying bacteria. It seems some species are able to oxidise ammonia down to -5 degrees. Many references.
3) Creswell. R. (1993). Aquaculture desk reference. AVI books. Van Nostrand Reinhold. Tables of temperature optima for nitrifiers and inhibitory compounds/pH's, with references.
David Brown <dbrown@mozart.inet.co.th>
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COMMENTS 3:
In trials with fluidized bed biofilters in a cold seawater system for cod,
we found stable nitrification rates of 0.7g of TAN/sqm/day at 10 C.
Gerrit Quantz
BUTT Marine Fischfarm
D-24229 Strande, Germany
Tel. +49-4349-383
Fax +49-4349-506
e-mail butt.fischfarm@t-online.de
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