Bacteria Growth

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What are the possible ways of growing bacteria in the aeration tank? 

(except Urea adding, Biofilms, and proper air)

 

Taxonomy

10 Answers

  1. I agree with Don Sharpe.  The question is rather open ended.  The specific question would what you want to do with the bacteria gorwing in the tank, and why you want to gorw bacterian in an aeration tank.  Yes, it is easy to do, as a school project.  In industry, there is always a purpose: are you trying to get rid of something, such as an industrial waste, or a food waste, or a cleanup before discharge.   Maybe you are trying to grow something to sell.  

  2. Depends on what kind of bacteria. You will need a food supply, and aeration source for aerobic bacteria; anerobic bacteria don't require this. You may also need nitrogen and phosphorus sources if your waste is deficient in these.

  3. I mainly agree with Waymon Hofheins with certain provisos.  It depends entirely on what you are trying to digest.  The theoretical ratio is 100 ppm Carbon: 5 Nitrogen: 1 of phosphate.  Different sources provide different ratios.  Sewage will provide a higher proportion of nitrogen due to the presence of urine.  Certain others will have a higher proportion of phosphate.  I am an advocate of using ammonia oxidising bacteria instead of adding urea.  These fix their carbon from an inorganic  source of bicarbonate and may need carbonate or bicarbonate added to assist them.  They are strictly aerobic but they are effective and once present is a less expensive way of adding nitrogen than urea.  The nitrite eventually produced is used by bacteria removing the carbon.  The pH range can be critical.  The growth rate at pH 7.5 is far higher than at pH 6.5 although a plant may become adapted to that pH.  If the plant is phosphate limiting, then phosphoric acid may be used.  In other cases nitric acid may be used.  It is important in an aerated activated sludge plant to ensure that the plant is well mixed as well as aerated.  The best solution is fine-bubble aeration directed to the bottom of a tank which is angled so as to stir the tank.  Others have aeration at the base of the tank.  Oxygen is inferior to the use of air.  This is for the simple reason that air is 70% Nitrogen which helps drive off the Carbon dioxide, which helps balance the pH to between 7 and 8.  Oxygen does not have this benefit so the pH drops to 6-7 and this impacts the bacteria.  Although we have referred to bacteria, it is desirable to have protozoa and rotifers feeding on the bacteria and this aids oxygen transfer into the floc, which forms and helps reduce sludge levels.  

  4. I mainly agree with Waymon Hofheins with certain provisos.  It depends entirely on what you are trying to digest.  The theoretical ratio is 100 ppm Carbon: 5 Nitrogen: 1 of phosphate.  Different sources provide different ratios.  Sewage will provide a higher proportion of nitrogen due to the presence of urine.  Certain others will have a higher proportion of phosphate.  I am an advocate of using ammonia oxidising bacteria instead of adding urea.  These fix their carbon from an inorganic  source of bicarbonate and may need carbonate or bicarbonate added to assist them.  They are strictly aerobic but they are effective and once present is a less expensive way of adding nitrogen than urea.  The nitrite eventually produced is used by bacteria removing the carbon.  The pH range can be critical.  The growth rate at pH 7.5 is far higher than at pH 6.5 although a plant may become adapted to that pH.  If the plant is phosphate limiting, then phosphoric acid may be used.  In other cases nitric acid may be used.  It is important in an aerated activated sludge plant to ensure that the plant is well mixed as well as aerated.  The best solution is fine-bubble aeration directed to the bottom of a tank which is angled so as to stir the tank.  Others have aeration at the base of the tank.  Oxygen is inferior to the use of air.  This is for the simple reason that air is 70% Nitrogen which helps drive off the Carbon dioxide, which helps balance the pH to between 7 and 8.  Oxygen does not have this benefit so the pH drops to 6-7 and this impacts the bacteria.  Although we have referred to bacteria, it is desirable to have protozoa and rotifers feeding on the bacteria and this aids oxygen transfer into the floc, which forms and helps reduce sludge levels.  

  5. Areobic bacteria require air, a lot of it.  All living things require Carbon, Nitrogen, and Phosphate. The suprise is that they require it in the same proportions.  The usual limiting factor is phoshate, but not always.  For example, when trying to digest certain food products with bacter the limiting factor was nitrogen: so we added urea.  Phosphate was also limiting so we used a small amount of phosphoric acid. There was a lot of carbon present in the product so no problem.  The pH range for most bacteris is about 6.5 (better to thin 7.5) to 8.5 (better to think 8).  I know, there a lot of bacteia that don't follow this.  But for the most part you will also see the algae species growing above 8.2 pH  so we have different growing conditions that will generally follow pH, which you can drive down with a little phosphoric acid. 

    Anerobic bacteria are different. 

    For the large part, this all depends upon what you are trying to do.

  6. Hey JAHANZEB MUSHTAQUE SOOMRO we actually made a video tutorial for this topic. Enjoy and if you like it we would appreciate your subscription on YouTube: 

    https://youtu.be/1YKeLMXuBoU

    1 Comment

  7. If the objective is to increase the number of CFUs (colony forming units) in an aeration tank you can add a very durable packing media with high surface area for bacteria to grow. We use various media in our bioreactors when we have difficult substances to degrade such as formaldehyde which otherwise would kill off beneficial bacteria. We also had a bacteriologist culture a strain specific for the Formaldehyde degradation.

  10. Aeration in an activated sludge process is based on pumping air into a tank, which promotes the microbial growth in the wastewater.The supplied oxygen is utilized by bacteria in the wastewater to break down the organic matter containing carbon to form carbon dioxide and water. Without the presence of sufficient oxygen, bacteria are not able to biodegrade the incoming organic matter in a reasonable time

     The microbes feed on the organic material; forming flocks and removing organic nutrients and finally settled down as sludge. This can easily settle down.

     Carbon source material is following

    1. Add Molasses as a carbon source.
    2. Carbon source like methanol
    3. Circulation of the bacteria by circulation amount of water.” The portion returned to the aeration tanks is called Return Activated Sludge.”
    4. Add phosphoric acid to promote bacteria.
    5. Backwash water can be taking.
    6. Air given by sparser for equal and better distribution.

    Monitoring dissolved oxygen in the water ensures that the Blowers are supplying enough oxygen for microorganisms to survive and carry out aeration wastewater treatment