Calculation of oxygen consumption of Artemia nauplii
According to "Coulometric measurement of oxygen consumption during development of marine
invertebrate embryos and larvae" (Guldberg, Manahan 1994) an Artemia nauplius consumes
oxygen @ 1nmol/h (1 nano-mol per hour).
The atomic mass of oxygen is 16g/mol, so we can calculate the total intake of oxygen
for one animal per hour:
1nmol/(h*animal) * 16g/mol = 16*10-9g/(h*animal) = 16ng/(h*animal)
So we have nice number here, of 16 nano grams per hour and animal oxygen consumption.
In order to know how much regular air we must pump into the tank, we need to calculate
the weight of oxygen per volume:
The major components of air are (list contains only components with >0.01%):
Oxygen: 20.99%
Nitrogen: 78.03%
Carbon Dioxide: 0.03%
Argon: 0.93%
With:
22.4 liters of any gas at STP (standard temperature and pressure) contains 6.02214199*1023 atoms (Avogadro number) = 1mol
and
1m3 = 1000liters
we get
1000l/m3 => 44.642857mol/m3
Now we calculate the amounts of each element in air in the unit of mol/m3:
O2: 44.642857mol/m3 * 20.99% = 9.370535714mol/m3
N2: 44.642857mol/m3 * 78.03% = 34.834821429mol/m3
CO2: 44.642857mol/m3 * 0.03% = 0.013392857mol/m3
Ar: 44.642857mol/m3 * 0.93% = 0.415178571mol/m3
From the periodic system we get the atomic weights:
O 16.00g/mol (oxygen)
N 14.01g/mol (nitrogen)
C 12.01g/mol (carbon)
Ar 39.98g/mol (argon)
and finally we can calculate the weights of each element (atom/molecule) in regular air:
O2: 9.370535714mol/m3 * 16g/mol * 2 = 299.857142848g/m3
N2: 34.834821429mol/m3 * 14.01g/mol * 2 = 976.071696441g/m3
CO2: 0.013392857mol/m3 * (12.01g/mol + 16g/mol * 2) = 0.589419637g/m3
Ar: 0.415178571mol/m3 * 39.98g/mol = 16.598839269g/m3
This leads to a total mass of one cubic meter of air to 1293.117098195g/m3.
If we have 16ng/(h*animal) and roughly 300g/m3 we can calculate the volume of
air needed by one animal per hour:
16ng/(h*animal) * 1/300g/m3 = 0.053333*10-9 m3/(h*animal) = 0.053333 mm3/(h*animal)
That is about
~1.3mm3/(day*animal)
Conclusions:
PENDING
Not all oxygen is dissolved in the water. I'm currently researching the amount of oxygen
which is actually dissolved - it is obvious that this depends on the oxygen saturation
and seems to range from 2% (no oxygen in the water) to 0% (if the water is 100% saturated).
Determining the mass of oxygen, in a bubble, transported to the surrounding liquid (water)
is pretty difficult. It depends mainly on the saturation of oxygen of the water and on
the diameter of the bubbles. The lower the saturation of oxygen in the water, the
higher the transfer of oxygen to the water. The lower the diameter of the air bubbles,
the higher the transfer of oxygen to the water.
A rought value for the ratio of oxygen intake and dissolved oxygen in the water is about
1%. So if we have
~1.3mm3/(day*animal)
of air and 1 percent gets actually dissolved in the water, we need to multiply the value
with 100:
~130mm3/(day*animal)
of air.
MORE DETAILS SOON
Last-Modified: Fri, 09 Feb 2007 22:32:27 GMT |
