Using Ozone treatment to reduce COD levels

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What are the pros and cons of using Ozone treatment to reduce waste water COD levels prior to introduction into a Waste Water Treatment Plant?

We are looking to reduce the COD levels of grease trap waste following solids and FOG separation and removal.

We would like to investigate using Ozone to eliminate microbes and bacteria present in the waste water prior to release into the works. This would allow the microbes in the works to start work digesting the residual organic matter. Although most large matter has been screened prior to release.

Alternatively we have looked at dosing the wastewater with microbes prior to release into the works. However there are concerns that over time, the microbes we introduce will take over the waste water treatment works microbes and throw the system out.

If anyone has any experience in this we would greatly appreciate their advice.

Sincerely

Chris

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8 Answers

  2. The TITUS Twister mixing aerator with ozone enhancement is specifically designed to deliver ozone into the water column. We can show you how to significantly reduce CBOD, FOG, Disolved sulfides, H2S gasses, and most of all odors without chemicals. Using only O2, and O3 generated on site, and delivered into the water column with our TITUS TWISTER mixing aerator. The TWISTER with ozone is also very effective at disinfection making water safe for re-use. You can contact me at lewis@titusig.com or go to our web site www.titusig.com

  3. Why do you want to eliminate the bacteria?  The bacteria will eliminate the oil and grease, in time. The COD can be lowered with microbes.  We grow them for this use.  A grease separation through flotation and skimming would allow the recovered grease to be sold, if you have a large amount.  Many of the large food processing, and meat processing plants use this method.  Depends on the oil and grease, how you set it up.  I did a steel mill by using both precipitation of heavy tars, and flotation of the light oils.  Both were recovered.  I would have to know more about what else is there and what the full system is about before thinking about using ozone or a halogen: from what you have said, it may not be needed.  

    Problems with Oil and grease have sometimes been solved with pH reversal, take it down and then bring it back up.  A high pH in the alkaline range will turn the oil into a soap. 

    More needs to be known.  It sounds like a salesman just wanted to sell Ozone. You need to get some specifics.  Type of oil, or oils, grease from what?  what is causing the high COD, besides oil, full water analysis including metals, pH, hardnes (total, Ca, Mg), conductance UMOS, etc.   

    Flow rates, and amount of flow, changes in flow, sessional flow, etc. if important.

    I hope that helps. 

    1 Comment

    1. Hello Waymon,

      Thank you very much for the response. We have already have a mechanical process for the removal of the FOG and solids from the grease trap waste, so we don't need the microbes to do this for us. The problem we are trying to solve is reducing the COD levels in the remaining waste water before it is released into the waste water treatment works. These can be anywhere between 4,000-35,000 mg/l.

      We need a process which can reduce the COD quickly, approximately 8 hours, in a storage container of between 10,000-30,000 liters. Ideally we would like to keep the COD levels of the waste water below 5000 mg/l when it released into the treatment works. 

      Best regards

      Chris

  5. Chris, 

    I will contact you on Monday to discuss the matter. We have running a pilot in Trinidad to lower the COD from produced oil. We have had a pilot in Paris for a year (now going to full implementation) for FOG elimination win sewerage (without ozone there). Ozone is indeed expensive but can only be a part of the solution. Creating emulsions for bacteria to eat the FOG with ozone as a supplement is the solution for most problem. Talk to you Monday. 

    Patrice

  6. Hi Chris,

    Although ozone is a strong oxidizer, application of ozone to remove COD for a grease trap -- I assume has high COD -- is inefficient and expensive. A combination of ozone would be a better choice but expensive, nevertheless.

     I would recommend the Fenton process; it is simple to apply, highly effective for the treatment of wastewater with high COD, and the process kills any bacteria present in your wastewater.

    Good Luck

    A. Amiri (a.amiri@cogeco.ca)  

  7. Hello Mr Chris

    Your question is not clear what do you want to achieve? You have to provide source of water type of industry you want to deal with. COD is a VAGUE terminology, you have to clarify where you want to use the water after treatment.

    Biological treatment can be enhanced digesting the residual organic matter by dosing right bacteria culture for FOG. In the grease trap or ahead of the trap.  

    Ozone can be injected 0.4% at the last for complete disinfection.

    Any further clarifications please contact Amdy. mtplimited@gmail.com

  8. Hi Chris,

    AOP are more effective than biological processes but you have to full command the theory and technology, specially with ozone that also will depend of kind of grease and concentration.

    We re-purify any kind and flow of wastewater into potable with zero emissions to environment (air. soil, water) with 95% minimum efficiency and low operating costs between another environmental and economical advantages.

    Regards