Re: Denitrator

[Paul Sears <psears at nrn1_NRCan.gc.ca>]

> From: Kevin.Buckley at uk_neceur.com
> Subject: Re: Aquatic Plants Digest V6 #66
> 
> 
> I understood that I also have:
> 
> 2)   4 NO3 + 3 S = 2 N2 + 3 SO4

	I'm pretty sure it's not that simple, particularly as that
equation doesn't balance when you include the charges (as you must)
(NO3-  and SO4--).  Nitrate is pretty inert, which is why removing
it is not a trivial job.  I think the bacteria do the job, and they
require the sulphur.  I'm not a microbiologist - I would be interested
to hear from someone who knows about this.

> If so, is (2) a necessary requirement for (1) to occur (i.e. are bacteria
> using energy from (2) to enable (1) to occur - so KH erosion should be
> proportional to Nitrate removal)?

	I wouldn't count on proportionality.
> 
> Is it likely that other xxx'ates are also consumed (Phosphates for
> example)?

	If bacteria are multiplying in there, I wouldn't be at all
surprised if other things are consumed, particularly trace metals.
The point about the KH reduction is that it is a result of H2SO4
production.

> To be honest, using the denitrator is mainly out of curiosity to see what
> happens rather than a determined attempt to control Nitrates.

	I already had that impression..    :)

> Maybe all I've done is swap a Nitrate problem for a slightly smaller
> Sulphate (& KH) problem!

	That is if the nitrate is a significant problem - I rather
doubt that it is.  I've heard of lots of people with 50 ppm in their
water (the usual limit for human consumption).

-- 

Paul Sears
psears_at_nrn1.nrcan.gc.ca, 613-996-4171, facsimile / télécopieur 613-996-9400
Natural Resources Canada, 1, Haanel Drive, Nepean, Ontario K1A 1M1
Ressources naturelles Canada, 1, Haanel Drive, Nepean, Ontario K1A 1M1
Government of Canada / Gouvernement du Canada