Horace Heffner
Thu, 20 Mar 2008 09:04:17 -0700
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 + H2so 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/