Ozone as a Disinfectant in Water Filtration

Try Trojan UV Systems in London, Ontario. Siemens also carries UV systems, but I haven't worked with their products.

The Trojan systems I have worked with were anywhere from 1-5 MGD units (skid package) on the outlet of filter beds, to ones that could handle 120 MGD. They have all worked well.

As far as Ozone generators, the only one I am familiar with is Ozonia North America. It has had a few glitches, but overall reliable.

I don't think you will get away from CL2 in the distribution system, but if you use the UV systems you can use less.

Yes, O₃ is far more effective than Cl₂. However, if the water is not to be consumed immediately but is to be stored, then residual protection is recommended. As for removing iron, any oxidizing agent will oxidize soluble Fe(II) to inaoluble Fe(III), so this benefit isn't exclusive to O₃.

Hi cwarner7 11

Congratulations your comment has earned 2GAs, so I thought you and/or who added GAs will be able to back what you stated with more scientific facts. When you utilize ozone to stored water (rainwater or any other) you have to keep adding ozone. Will it not be very costly and what about release of ozone even minute amounts which could be dangerous to brain cells of any operators who pass by the storage?

How does ozone discourage algae growth and mosquito breeding? I hear many people say chlorine is the best for this purpose?

Are your sure about what you stated about cryptosporidium & Giardia spores? Any scientific studies to back up your claim?

By the way my personal experience is Chlorine is an excellent way of reducing iron in well water and it is cheaper too.

My company sell UV systems in my country for point of use systems but I do not think I will ever recommend UV or Ozone for urban water treatment/distribution systems. They are no match for Chlorine!

By the way when I say Chlorine I mean both cl2 and Hypochlorite

There are many issues to consider when using Ozone. I have worked with one of the best companies in this area, and I can tell you that after many years of experience, you do not want to use Ozone alone, rather you want to use it in combination with UV. This combination (when done according to their patented process) produces Hydroxl ions which are much more aggressive than chlorine. This approach not only kills the bacteria and virus but also oxidizes oils, acetone, fertilizers to CO2 and water. If you send me your email address, I will send you some un-retouched photos of actual trials with ozone/UV that will seem unbelievable, but I assure you they are real. Pyrolysis Dan

Dear Achilles, You will find a very interesting write up at http://www.wcponline.com/pdf/1007Dunk.pdf describing a very thought provoking water purification technique of Auburn University using N-halamine chemistry in drinking water treatment. Good luck.

Chloramine is widely used in conjunction with primary disinfection to maintain the residual necessary to protect from post-treatment contamination in the distribution system.

This chemical will not react as aggressively as Cl2 with certain trace organics found in drinking water to produce dangerous compounds and is therefore preferred by many municipal drinking water utilities.

Check out this Site

http://www.epa.gov/safewater/disinfection/chloramine/#eight

Ozone does a good job in small doses (0.5-1.0 ppm or so) to generate a floc to assist in settling things. Once you get the "settleables" out, another small dose of ozone will help with MIB or geosmin (precursosrs for THHM and HAA), making them tastier for BAC (biologically activated carbon) to use as food. Then you have no / fewer problems using chlorine as your secondary sterilant. El Paso, TX USA has a plant that is running on the same lot of GAC for more than 2 years... the ozone seems to reactivate the media (since the biology is doing all the work).

If you contact the International Ozone Association with a plant capacity, and applied dose (figure 2 ppm max), they can give you "budgetary" numbers that will be close enough for estimation purposes. You will find, I suspect, that payback is 10years or so (if you have no problems with MIB/geosmin). But it very much depends on how much ozone your source water requires.

One place in CA, USA was applying more than 20 ppm (buried fossilized redwood forest was well aquifer), and they had all sorts of problems. Ozone too expensive but nothing else seems to do what is required either.

I know that chlorine is best for secondary sterilization, chlorine dioxide is formed from chlorine plus additional chemicals (so higher cost on a 1:1 basis), and I have not heard good things about chloramine.

Using alternative waste water treatment is under 'construction' since the beginning of the XX century, lol. Using chlorine , in combination with UV and /or Ozone is very interesting, but as I know, since 1970 the technology hasn't evolved much. Treating waste water is, as you surely know, complicated process. Pure alternative method to get drinking water is far a big project, but deep waters could be used after treating with ozone. I have seen that people has made on DIY approach mini treating plants of water that is used in fish nursery's. I have found many documents related to your question, but they are all non english - we on Balcanian peninsula just love the alternative methods to find solutions for our problems. If you need more resources, contact me on my mail, and I gonna see what can do with translations. Whatever, post some more deeper details about the question.

.Hi,

my local swimming pool uses Ozone as it's primary treatment which results in a much less agressive environment for the swimmer.

Some Chlorine is used for secondary treatment. Not sure how that part works.

I am sure that others do, reading the thread so far.

I am not sure that I would be happy using Ozone treatment alone for water for drinking. Gut feel. I am sure that others will know more.

The purpose of my contribution is that for costing information etc. you could start with the swimming pool industry. You will then have to factor in size , throughput of water, purifcation level, bacteria tolerance of customers, standards required by each industry and other similar issues. That might be useful as a starter.

Good Luck

Sleepy

I have read that Paris, France, treats their sewage with ozone, which is so effective in destroying pathogens and other organics that the effluent is fed back into the drinking water supply. Try looking to see how they do it.

What is the size of your system? Is this a city disinfection or a small community? I can email you a capital and operations presentation that was presented at an ozone conference in Orlando last year if interested? This was in conjunction with the International Ozone Association (www.io3a.org).

Regards,

John

Hi guest, my email is 5rb32@queensu.ca the system will be 'used' in Kingston On, which has population of 200k people.

Achilles,

Have you looked at the AWWA (American Water Works Association). They have many manuals, standards, guides, and similar sources. They also will have articles in their monthly publications. Their bookstore has an impressive listing.

--John M.

There are over 400 municipal drinking water treatment plants using ozone in North America. The International Ozone Association www.io3a.org and its members have the experience to assist you. There are a number of plants in the Toronto area, Vancouver, St Johns, Montreal etc.

Hi Inventorman

Interesting info. A GA for that.

Would it be feasible to use a 2 stage disinfection - UV + ozone 1st stage with Chlorine or the many derivatives to provide a residual effect?

Obviously good filtration reduces problems as well as the quantity of disinfectant needed.

I believe some filters are capable of removing all bacteria and viruses, so the only need for disinfection is the residual to prevent or minimize reinfection. Have you any info on this, or is it just hype?

If you have a lot of money please do so. May I suggest you also add a RO at the end! If you have a lot more to spare may be donate some to third (my) world charity too. (just joking!)

Otherwise if you are as poor as I am please use chlorine/hypochlorite followed by activated carbon at point of use to remove THMs- so called carcinogens.

Actually, I have written a patent for a two stage system. Furthermore there are technical papers suggesting that two stage systems are always more desirable than single stage treatments.. Generally, monochloroamine is considered to be a good, less expensive second stage treatment because it remains in the distribution system for a considerably long time but it presents the problem of nitrification (in dead areas of the line) and this is not a good thing. UV treatment is a good choice for primary disinfection but it has considerable maintenance issues (as previously stated) and the generation cost is high... Ozone is the best of all disinfectants but it also has short comings (I have overcome the problems associated with the use of ozone in my pending patent). There are valid estimates that my technology will prevent many thousands of waterborne disease deaths each year in the USA alone.