To: Aquatic-Plants at actwin_com
Subject: Re: ammonia
From: Charley Bay <charleyb at hpgrla_gr.hp.com>
Date: Tue, 17 Oct 95 8:53:19 MDT
In-Reply-To: <199510161939.PAA20560 at looney_actwin.com>; from "Aquatic-Plants-Owner at actwin_com" at Oct 16, 95 3:39 pm
Mailer: Elm [revision: 70.85]
> Helen Nash (HNH2Ogar at aol_com) wrote:
> ...claims that aeration breaks the bond of ammonia. He says that
> "water in its entirety has more affinity to oxygen than it does to ammonia.
> Ammonia is pushed out with the introduction of oxygen, with the water being
> cold during the winter the chain reaction from cracking the ammonia loose is
> one benefit, the other is the actual cracking of the ammonia molecule itself
> into the two gasses that it is made up of. The byproduct of this is plain
> old nigrogen which is gobbled up by the first algae bloom in the spring,
> before the bio-filter kicks in. Cold water holds more air and less ammonia
> by nature. The introduction of the air forces out the ammonia, the
> instability of the ammonia from the separation causes it to crack again into
> the two gasses which are carried out by the water bubbles to the outside."
> He has stated that he has smelled ammonia in the water, tested positive for
> ammonia, heavily aerated, then retested negatively. What is the scientific
> explanation of why or why not aeration breaks the bond of the ammonia
> molecule and allows its removal from the water naturally?
> Thanks for your help with this quest for some real science!
Hmmmm. This is quite interesting, and I would like to get some other
feedback on this. I'm not familiar with ammonia (NH3) "cracking"
or splitting into its components of N2 and H2, but that makes sense.
I believe what you just said (aerating decreases ammonia in solution)
for the following reasons:
(1) Assuming nothing else, aerating the water effectively "washes"
other gasses from the system. By super-saturating the solution
with gasses (which aeration does), some must be displaced from
the solution. Even if water has a higher affinity to NH3, it
will eventually be removed from the system because other gasses
are introduced to displace it.
(2) "Burning" is merely another term for "rapid oxidation". Those
little oxygen atoms want to bond with some thing RIGHT NOW when
they find themselves free in solution (why do you think O2 must
be present for fires? :-) Since NH3 (ammonia) is as good a
target as anything else to a free oxygen atom (probably a better
target for equilibrium than H20), it makes sense to me that
the little guy would break up NH3 just to have something to
I'm not a chemist, but it would seem to me that:
4NH3 + 3O2 <=> 6H20 + 2N2
as opposed to:
4NH3 + 7O2 <=> 4NO2- + 6H2O
4NH3 + 8O2 <=> 4NO3- + 6H2O
Yep. I think this is quite interesting. Is this what those
those electrical "de-nitrators" are supposed to do?
--charley Fort Collins, Colorado 80526
charleyb at gr_hp.com or charley at agrostis_nrel.colostate.edu