On Mar 20, 2008, at 4:12 AM, R C Macaulay wrote:
Howdy Vorts,
As some are aware, one of our companies build water treating and
wastewater disinfection chem feed inductors. We have depended on
our industry to produce the remainder of the systems including the
chemicals for this purpose. We are not chemists or physicists. We
need systems that can produce quantities of "in situ"ozone gas at a
lower cost and safer methods.
There are new "exotics" entering the nation's water supply that we
believe can be destroyed via ozone treatment but the existing
processes for making ozone are both expensive and troubling.
There are Vorts here that have an idea on the subject that may
help our industry.
Richard
I'm only an amateur, but here is some food for thought for you. I
expect if you mix the ozone with water, an apparently necessary step
for water or wastewater treatment, you are going to get mixed
oxidants, especially hydrogen peroxide:
O3 + H2O -> O2 + HOOH
O3 + H2O -> O2 + 2 HO
O3 + HO -> O2 + HOO
and a host of other reactions depending on the water chemical contents.
One option is to simply buy commercial hydrogen peroxide and mix it,
but that doesn't meet your criteria for "in situ" generation.
I posted earlier about commercial MIOX treatment equipment, which
electrolyses brine, i.e. NaCl mixed with de-ionized (softened with
ordinary water softener using NaCl flushed resins) water, and then
mixes small amounts of that with the water to be treated (the water
to be treated does not have to be de-ionized):
On Jun 9, 2007, at 8:49 AM, Horace Heffner wrote:
About the practical side of things, electrolysis of saltwater is
now used commercially and very effectively to make a water
decontaminate called "MIOX" which stands for "mixed oxidents". See:
http://www.miox.com/
A google search on "miox" shows lots of other references. MIOX is
the stuff that accumulates about the cathode when electrolysing
NaCl brine. MIOX is mostly HOCl, hypochlorous acid, but also lots
of other oxy-chloro compounds and also H2O2, hydrogen peroxide.
The process requires de-ionized water, otherwise the reaction
product mix can vary substantially. It is far more effective than
chlorine or bleach, and far safer, but requires very careful flow
and/or concentration regulation to keep it that way. With holding
times of a couple hours or more, even in concentrations with almost
no residual taste, it is even effective against viruses. MIOX
decontamination units are made in many sizes for use by water
companies. At local state well operator classes I've seen an
actual demonstration of a MIOX pocket pen run by AA batteries. The
MIOX is produced in the pen by electrolysis and then mixed with a
much larger volume of water to be decontaminated. The pen was
produced for the military.
The above MIOX stuff has multiple patents, and is fairly expensive,
so you would need means of producing oxidants that avoid the patents,
and a very reliable means of mixing the water with the oxidants at a
fixed ratio (e.g. a fixed ratio flow rate pump, which should be a
public domain method) and achieving a sufficient holding time for the
oxidants to do their job. Many oxidants don't last long at
concentration, so have to be generated on site, which is in your
specification anyway.
One means of beating the patents, while improving energy efficiency
at the same time, might be to use electrode-less electrolysis. I
suggest trying a thin layer of brine between dielectric covered
capacitor plates as a capacitor in a resonant tank circuit. Brine
could flow between the plates at a slow rate. I would start out with
a very small capacitor initially, and small inductance, so as to get
the frequency as high as possible. Based on recent data regarding
the Kanzius process, a frequency of around 13.5 MHz may be optimal or
desirable. This may be effective at generating HOOH, HO, HOO, as
well as OH-, and OOH- radicals in addition to sodium hypochlorite,
and other similar chlorine based decontaminants and mixed oxidants.
The basic process would be:
2H2O -> HOOH + H2
so hydrogen gas would evolve and would either need to be vented or
maybe used to help drive the process, maybe as auxiliary fuel for a
generator or fuel cell.
I do have to wonder if ordinary electrolysis (as opposed to electrode-
less electrolysis) is sufficient and can be done without patent
violation, but it is expensive because Pt anodes are probably
necessary. Use of a cheap thin high dielectric constant corrosion
resistant dielectric, like alumina, as an AC electrode surface might
do the job much cheaper Salt is still pretty cheap too.
I hope this gives you some useful ideas.
Horace Heffner
http://www.mtaonline.net/~hheffner/
