Sludge bulking (filamentous bacteria) in SBR municipal sewage

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Hello,
I'd like to know how to eliminate filamentous bacteria, and how to prevent it from re-growing, in a SBR plant that treats 3400 m3/d of municipal sewage.

The effluent quality meets the environmental norms, however, the excess sludge handling has increasing costs because of the bulking.
Thanks in advance

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13 Answers

  1. The city waste management cannot be separated from the mud, and if the installation is like a UF or some kind of RO, it must be very heavy. Pre-treatment is needed to process such large municipal wastewater. Bacteria and heavy metal solutions are only via pre treatment. Here I offer a formula that will be used for pre treatment. Regarding cost, I think it will be covered by savings in the fields, electricity, maintenance, human power and the quality of the output water later. Take a look at my post on LinkedIn about water treatment. thanks.

    Answered on by

  2. We, at Amalgam Biotech are one of the leading manufacturers of Bio culture in India. Our product Bacta Cult - MLSS Debulking shall help resolve the problem of filamentous bacteria. please mail me your plant details on rajesh@amalgambiotech.com. I shall send you the offer.

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  4. Hello ,

    Best way to control filamentous microbes is by setting appropriate environment in the SBR basin. DO level in the tank plays an important role and it is required to be set so that you control filamantous microbes without compromising the effluent quantity . DO level of 1 to 1.5 mg/l during aeration cycle and should be OK. Time of anoxic cycle is also to be adjusted to control filamantous growth 

  5. Hello Felipe, I agree with some of the content of the other answers to your question so far, but not all!  First let's keep things simple here.  Sequencing Batch Reactors (SBR) is just another variation of the biological activated sludge treatment process.  True there are many different types of filamentous bacteria, but they are all common in all activated sludge systems.

    Identification of the actual type of filament is very important, as it can assist you in determining the source of the filaments.  Eliminating the filaments at the source, so they don't enter your system is always the best method of filament elimination, but may actually be the most difficult.   I agree that there is a good likelihood that your filaments are from an industrial source, that has been my experience as well.  If you can determine the source then depending on the wastewater regulations in your area of Mexico, you may have some authority behind you to force the industry to control the filaments at the source.  That is not always successful however and depends a lot on how large your collection system is and of course how well you know all of your different industrial sources and also the relationship you have established with them.

    As for control of filamentous bacteria at your facility, I do not recommend you waste any money on any of the "snake oil" concoctions out there, freeze dried bacteria, or any "special" systems out there!  You will spend a lot of money with questionable results.  Yes, process control adjustments to your system are critical, so that you eliminate or minimize the conditions that are allow the filaments to thrive.  However, no two SBR systems are the same.  So I would never recommend specific process control adjustments based on my experience with my system.  Use the ranges established in all the manuals, only adjust one parameter at a time, and waaaiiittt long enough to see a change before making another adjustment or parameter change.   Every treatment system has a "sweet spot" and your main job is to find it! 

    True, too high of a DO concentration can increase filament growth, but not all treatment systems will allow for large decreases or fluctuations in DO.  The quality and turbidity of your effluent may suffer and you could find yourself exceeding your discharge limitations very quickly, so be very cautious.  Again, very small adjustments over time.  Go at least one full MCRT or SRT cycle (two if possible) between adjustments.  Patience, my friend, patience!

    Chlorine is the most common and most successful method of controlling (killing) filaments growing out of control in your system.  Again you must be very careful using chlorine.  In order to not kill too many of your viable organisms, you need to start with a small dosage and gradually increase the dosage (don't forget the 1 or 2 MSRT/SRT cycle rule!)  Also remember, that as you kill the filamentous organisms they will appear in your effluent and show as increased turbidity, so you don't want to kill them all off at once!  The starting dosage is critical (so many lbs of chlorine for every 1000 mg/l MLSS), but I will not quote it now, because I am not 100% positive that I remember it correctly, without referring to the "bible"!   What is of the second highest importance is the application point.  For chlorination to be affective you must have good mixing.  An excellent point of injection is directly into a Return Activated Sludge(RAS) pipeline, and make sure that is has enough time in the pipe to mix thoroughly.  Don't just try to drip the chlorine into your activated sludge tank or RAS channel! 

    The regional expert on filamentous bulking and control, at least in California and arguable in the entire United States is Dr. David Jenkins, out of Berkley, CA.  Dr. Jenkins has written several books and papers on the subject.  He co-authored a book with Michael G Richard and Glen T Daigger, which in my 36 years of experience and universally agreed upon, is the "authority" on the subject.  "Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and other Solids Separation Problems", publication date 2003/8/27, Publisher Crc Press.

    I hope this was helpful, good luck and take care,

    Mark B. Gingras                                                                                                                                                   "The Ribeye Guy"

    Wastewater/Water Recycling Operations Manager                                                                         Presently Retired 

     

    2 Comments

    1. Thank you very much Mark, this information was definitely useful, I'll begin doing one trial at a time, doing long runs as you say, and waiting for small but consistent changes hopefully. The book will definitely help. Thanks again!

    2. One of the best comments I have read. Patience, don't know how many times I have had to remind myself. Have used Dr. Michael Richard for filament analysis.

  6. I wish you all the best.  My experience of SBR is that it can be difficult.  I have seen to SBR tanks working side by side with the same feed.  One suffered from severe filamentous growth while the other didn't.  There are various things you can use but they may not work.  You could try chlorination starting at a low concentration and increase the strength slowly.  This can break up the filaments.  There are freeze-dried bacteria available, which can outgrow the filamentous bacteria.  The question is why have the filamentous bacteria developed.  My experience is with industrial and food wastes, so I am able to identify the source of the problem and produce a solution but with sewage, you may not the cause.  There are two main references on filamentous growth and control.  The first is Eikelboom and the second is RIchards.  I am afraid that the solution may not be easy.

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  8. Solution depends on what kind of filament. We get M. parvicella (think I spelled it right) and use Pax 14 to combat. This filament is a specialist in that it uses medium to long chain fatty acids for food, most like short chain, stores food, and faciltative so selectors don't work.

    There are labs that can check to see what kind of filament you have, I would start there.

  9. Biological and biochemical treatment are based in bacterial oxidation, synthesis and endogenous processes, so your influent was not well characterized or its waste content has increased quantity or potential contaminant for your installed capacity.

    Let me suggest our wastewater purification ionic system or zero emissions for any kind and flow of wastewater into potable with 95% minimum efficiency and low operating costs between another advantages; experience since 2003.

  12. Have looked at:-

    D.O. control. Don't over or under aerate. We get complete nitrification with average DO of 0.5 mgl. You don't need 1.5 mg/l.

    Have you checked the F:M ratio? Try and maintain at least 0.1. Do you measure MLSS daily?

    Is the incoming sewage quality consistent? You can't control, but it could be a factor.

    Have you tried increasing the static fill time? Say 30 minutes? This has worked for us.

     

    Let us know how you get on.