Lamella Clarifier Applied at Pre-sedimentation Tank?

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Hello everyone!

I'm searching for a solution to increase the sedimentation rate of TSS at the pre-sedimentation tank. I'm using a WWTP composed by a conventional settler as pre sedimentation tank+buffer tank with function of equalizing, absorb the max daily flow, hydrolise part of BOD and pre settle part of TSS after has the MBBR+Lamella secondary settler, at the secondary settler, works very well, but I'm thinking to use the lamella at pre settler tank to reduce the footprint of the tank increasing the sedimentation rate.

My question is if have contraindication and considerations in using this technology with this type of application, considering raw waste water? 

I already know that will going to have problems with clogging of lamella caused by biomass growth at the tubes, has any suggestion to avoid that?

Has any other technology that can increase the rate?

Huge thanks in advance!!!

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9 Answers

  1. Rafael,

    We did CFD of an activated sludge application of lamella sedimentation and found that lamellas did not perform better than the tank without the lamellas. I have attached a poster that we presented at the IWA conference in Busan in 2012. I wouldn't propose that this is the last word in investigation of the effectiveness of lamella clarifiers, but it was a pretty alarming result. I very much look forward to seeing confirmation by field test and additional CFD. Let me know if you find anything more.

    Regards,

    Randal

  2. I think I understand your problem.  If you want to increase the sedimenation rate you need to reduce the zeta potential of the particles so that they will agglomerate and settle.  A lamella can help, but they are expensive to build and will plug if not maintained.  I believe that with a minor addition of a cationic polymer you may achieve the same result without the pre-clarifier.  There are a number of clarification aides which can help you, including alum and lime in small doses.  These chemicals will also help precipitate the phosphorous in the effluent.

    1 Comment

  3. We have unique process,which can replace lamellar clarifier,we called it as SSF (Suspended Sludge Filtration),it is high efficient,small foot print,and concentrating sludge.We can discuss SSF with you in details.

  4. We have unique process,which can replace lamellar clarifier,we called it as SSF (Suspended Sludge Filtration),it is high efficient,small foot print,and concentrating sludge.We can discuss SSF with you in details.

  5. We have unique process,which can replace lamellar clarifier,we called it as SSF (Suspended Sludge Filtration),it is high efficient,small foot print,and concentrating sludge.We can discuss SSF with you in details.

  6. Going to probably be a trade off on additional opex to apply biocides and cleaning vs considering a circular 60 degree Dortmund type tank, deep but smaller footprint to conventional rectangular tanks?

  7. Clearify is design and having exactly load. Lamello is the additional equipment to increase settling down of SS. So I think you have to go back and recal from existing system and if you want to try more in new system..pls do not fear for the bad or good result. Good luck

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    1. Thanks for the advice! This project it's for exportation from my country (Brazil) so i'm trying to reduce the amount of equipments that will be transported from here and turn the business more viable

  9. Hey Rafael Castillo we are a engineering and sales company for fill media applications such as lamella clarifiers. We have used lamella clarifiers in a primary clarifier before in Mexico with success. The key is to choose the right lamella clarifier type with equidistant channels and wide channel distances. Furthermore the right position of the lamellas in the tank is very important as well as baffle walls and cleaning systems can be beneficial. Biofilm growth won't be a big problem thus if you have a lot of BOD coming in the material of the lamella can be mixed with anti-legionella additives to prevent growth. If you need more information or engineering support please contact us