Using Nanobubbles for Oxidation?

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Has anyone used nanobubbles to oxidize organic chemicals and heavy metals in water treatment process?

What is the oxidative capacity of nanobubbles and how effective is the method?  

Please share your experiences and give advice on how to get the best of nanobubbles.  

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10 Answers

  1. We have done extensive research on application of nanobubbles technology for waste water treatment. Kindly peruse the enclosed documents. Our PLC controlled nanobubbles Generators produce Nanobubbles of <100 NM size. kindly visit our website https://nanobubblestechnology.com/ fpr more information. We will be happy to answer any query. Kindly mail at jagjit@nanobubblestechnology.com 

  2. Hi Jerome, I can email you case studies here in Australia. My email is andrew@waterandoilsolutions.com.au

    As a tertiary treatment, we were able to lower BOD and COD to within limits over a period of 30 days. What surprised us was the area of effect of the nanobubbles. We had read in research that once they stabilize between 300nm to 1 micron in diameter, they can actually remain suspended in the water for several days. We believe this to be the case with the trial at this particular STP. There is no physical way to measure the presence of nanobubbles in such a large water mass. However, we were able to note fish appearing at the outlet of the 1st tertiary pond after 20 days. This is 100m away from the aerator. Initially, we specified 2 aerators using conventional conservative calculations but due to budgetary constraints, only 1 aerator was used. The effect of the micro and nanobubbles were a surprise because we did not expect to reduce BOD and COD that much.

    Water quality monitoring of this site can be seen at http://www.mpsc.nsw.gov.au/index.php/home/waste/epa-monitoring

    Download the

    Monitoring Data Moree STW Updated 16 May 2017 file and see page 9.

     

     

    Note that the aerator was commissioned on March 31st 2016. It was taken out in late October for servicing and put back in mid-November 2016. Sampling this year should give a better indicator of performance. The STP operators are planning to replace the existing three 75kW aspirator type aerators with three micro and nano bubble generators each 6kW in size. This is a reduction of 92%. 

    SOTR results from University of Southern Queensland show an estimated SOTR of 5kg O2 per hour and SAE of 3.15 O2 per kWH. This does not account for the dissolved oxygen in the form of nanobubbles, we have not found a solution yet in research to measure these accurately. We only know from the decrease in BOD and COD that there is possible a theoretical bank of stored oxygen in the form of nanobubbles. A visual way to detect the presence of nanobubbles is by green laser irradiation which we have confirmed.

    Another interesting test we have done is 100% saturation of ozone in water in the form of nanobubbles. The water turns a pale pink color.

    In terms of oxidation capabilities, we know that the oxidation potential of water can be raised up to 200 mV through hydrodynamic cavitation in a static mixer. As the nanobubbles are generated and collapse they decrease the zeta potential of the water, thus increasing coagulation and flocculation reactions and increasing oxidation potential. This has been tested in swimming pools with water temperatures typically between 30 and 35 degrees C.

    We are currently testing nanobubble suspension and chemistry in salt water, this is of great interest to the prawn industry here in Australia.

    We have also successfully used micro and nanobubble generation in pre-treatment of drinking water to oxidize iron, manganese, and breakdown 91 agricultural chemicals in river water through a micro and nanobubble generator in an aeration tank and a series of static mixers.

    I am happy to answer any questions on micro and nanobubble research and application.

    My email is andrew@waterandoilsolutions.com.au

     

  3. Hello All,

    We produce nano bubbles less than 5 microns in size bubbles and more than 90 percent of it, which in turn implode and form nano bubbles ..Thus effectively producing more nano bubbles than most competitors in the market... The overall dissolution rate is around 95 percent as per our tests but more than that the implosion  of these 5 micron bubbles we create generates heat and thus hydroxyl radicals ... This hydroxyl radical is 7/8 times more powerful than ozone itself and we claim to produce most hydroxyl radicals than any in the world .. The resultant effect on oxidation and disinfection and many other applications due to the size and stability of nanobubbles in waste water along with generation of hydroxyl radicals turns around the whole application of an efficient DOF system and is much better than DAF and is able to achieve excellent results in terms of decrease in ozone capacity needed , oxidation and floculation in same tank giving excellent pre treatment options and wide applicability in aquaculture/ livestock waste water/ textile / tanneries ( chromium also) paper and pulp and any process which requires excellent surface cleaning ( reduces eleiminates need of rinsing thus also resulting in reduction of waste water production) ... All in all the treatment of the future in terms of financial viability / energy requirements and low retention time and odour and colour elimination ....It also helps the memberane bioreactor achieve better results as chains are broken in pretreatment itself....

     

    Thanks

    Harish Anantharaman

    1 Comment

    1. Hi Harish, please clarify if you mean micro- (fine) or nano- (ultrafine) bubbles. I believe the definition of a nanobubble according to the Fine Bubble Industries Association and in research documented in Hideki Tsuge's Micro- and Nanobubbles: Fundamentals and Applications is bubble size between 300nm and 1 micron. 

      I find the claim of 7/8 times more powerful than ozone hard to believe. How exactly do you measure this? 

      I agree nanobubbles will significantly reduce energy costs for gas to liquid transfer and should be investigated in this regard.

       

  4. Algae produce oxygen bubbles in micro and nano size.

    We are promoting the use of Diatom Algae for Phyco-remediation of wastewater and eutrophic lakes. 

    Diatoms consume some of the heavy metals and the oxygen produced does oxidise some of the metals. We have not studied the details.

    Our focus at present is on consumption of nutrients, Nitrogen and Phosphorus and production of Oxygen, to satisfy the BOD and COD and increase DO and on providing fish with live feed. Thus the Carbon in the water is converted into fish biomass and water becomes clean and well oxygenated. 

    We too are looking for scientists who would like to research micro and nano-bubbles and their impact on all chemicals in the water. 

    1 Comment

    1. Hi Bhaskar, I would be interested to see what you are working on. I am currently involved in nanobubble research for the prawn industry here in Australia. My company also produces a fine and ultrafine bubble generator that we use for wastewater treatment.

      My email is andrew@waterandoilsolutions.com.au

  5. If the question is about TiO2 nano-tubes, it has been used in conjunction with UVA to oxidize organic in aqueous solution. for the oxidation. The UV/TiO2 process can oxidize a variety of organics and reduce various metals as long as the background COD is low and the water is noyt contaminated with dissolved iron. The nanotubes oxidative capacity and effectiveness depends on water quality parameters. The background COD competes with target contaminants for the hydroxyl radicals and and iron can deactivate TiO2.  

  6. The Australian National Uni. - Canberra I believe has had success in using micro bubbles.

    Might be an idea to have a chat with them.

    Hugh.

    1 Comment

    1. There is also research being conducted at the University of Southern Queensland. I am happy to answer in questions regarding nanobubbles and refer you to researchers that I have been working with in Australia. 

      My email is andrew@waterandoilsolutions.com.au

  8. Are nanobubbles likely to have different chemistry, or just better solubility and contact because there is more surface exposed? Is it just aeration on steroids? Is it worth the cost?

    1 Comment

  10. Dear Jerome,

    I have asked for years nuno bible device manufacturers to provide dissolved gas efficiency test data and still did not get any reply.

    So if you are looking to oxidize water contaminants using oxidizers like oxygen, ozone, etc., an inexpensive Venturi ejector will offer you much better results for fraction of the cost.

    As en example: with Absolute Ozone® generator Venturi injector is dissolving more than 90% of ozone injected, so why use expensive devices that require a lot of service and maintenance if even if you can gain only a percent of two of efficiency. However most of the test data I have seen does not show higher dissolved gas efficiency than about 10% for nano bubbling devices.

    That said, the bubbles as you understand could get attached to solid particles and theoretically bring them to the surface where they could be skimmed out.

    The movement of bubbles in water offers agitation and lift of the particles that could be mildly beneficial for water treatment, but I did not see any serious test data that indicated that this method is anything else but wasteful, if compared to bio-filiation followed by polishing with ozone, or some other oxidant.

    3 Comments

    2. nano bubbles of Ox (not as effective as O3 but less destructive) can, if their negagtive charge is enhanced with rare earth are enormously effective in cleaning up organic compounds, phosphates and nitrates both

    3. Misha, thank you for the insights and experience.  Can you share a couple useful resources I can review to get up to speed on the nanobubbling devices/technology?  Thanks.

      1 Comment reply

      1. While a simple venturi device can generate the micro/nano bubble ... without the enhanced negative charge bubbles tend to clump ... we are about to launch a major effort in cleaning up infected oysters and the environment in which they exist.