[Coral-List] "Growing" calcium-carbonate reefs (Justin Enjo)

Xinping Hu xhu at uga.edu
Thu Dec 10 13:13:29 EST 2009

My apologies to the list, I was missing the point about Justin's question. He wanted to know the effect of electrolysis of seawater on reef building. Indeed electrolyzing seawater produces needed alkalinity, even though it can't be a large scale practice for absorbing atmospheric CO2.
Thanks to Tomas Goreau who pointed out my error.


Message: 5
Date: Tue, 08 Dec 2009 12:50:25 -0500
From: Xinping Hu <xhu at uga.edu>
Subject: Re: [Coral-List] "Growing" calcium-carbonate reefs
To: coral-list at coral.aoml.noaa.gov
Message-ID: <4B1E91E1.8090504 at uga.edu>
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    Perhaps one of the direct "evidence" for your interested subject can 
be found in this paper: Solar-Generated Building Material from Seawater 
as a Sink for Carbon by Wolf H. Hilbertz, Ambio 
<http://www.jstor.org/action/showPublication?journalCode=ambio>, Vol. 
21, No. 2 (Apr., 1992), pp. 126-129). The link is: 
    Although by definition, if using CO2 as a reactant, this reaction 
takes out CaCO3 as the final product, and the solution will end up with 
increased hydrogen ion concentration two times of the lost Ca2+ via 
precipitation (charge balance, Ca(2+) + CO2 + H2O --> CaCO3 + 2H(+)). 
Thus what you get is acidified seawater. Similarly, known biogenic 
carbonate formation processes may all lead to a release of CO2 as 
carbonate precipitates. So I would say that the above mentioned paper is 
likely a false claim with regard to removing CO2 from the atmosphere by 
electrolyzing of seawater, although growing this type of reef may be 
feasible provided that water circulation removes the excess acidity 
efficiently (also supply you with needed Mg and Ca ions).


Message: 4
Date: Mon, 7 Dec 2009 18:13:33 -0500
From: Justin Enjo <jenjo2008 at my.fit.edu>
Subject: [Coral-List] "Growing" calcium-carbonate reefs
To: Coral-List at coral.aoml.noaa.gov
	<ceff7fb90912071513u67ea0ec4p63f7dc38e1388a6a at mail.gmail.com>
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Coral List,

Short anecdote.  If I put a  metallic structure (underwater in the ocean)
and apply an electric potential to it (cathode-anode), I can cause
calcium-carbonate to precipitate out of solution.  In essence, I would be
"growing" a calcium carbonate reef.  If carbon dioxide is being taking out
of solution as well, dissolved oxygen levels near the anodic reaction would
suspect to rise, causing a positive feedback loop for growing my reef.

Can anyone send me peer review journal articles touching on this subject? I
am looking especially for research into "growing" such reefs.  Does anyone
have any documented history with this topic they would be willing to share?


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