Nitrifying Activated Sludge Design

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Hi

I wanted to ask if anyone has setup an activated sludge design sheet that they can share? I am teaching myself how to do a detail design and it would be really helpful to compare my calculations against someone else's. 

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2 Answers

  1. What type of design?  There are a myriad of AS designs, but you have to include your primary treatment, because it will be different for each scheme and industry.  What you take out initially that could be toxic or recalcitrant dictates the influent to the secondary biological system for sure.  Then you have to acclimate the bacteria, which is an important for a flawless start-up.  Seeding the bacteria is also a concern if you are getting it from a local POTW and using it in an industrial application.  Normally, you will lose about 70% of your biomass like that, because they are not acclimated.  You use some of the POTW sludge (known age by microscope), and then addition of freeze-dried bacterial cultures mixed in an acclimator (basically a conical shape tank that mixes and aerates the bactterial cultures with added influent of whatever you are treating, then it gets pumped into the new sludgee.  If you want a straight AS system with aeration basins and secondary clarifiers with recirculation back to the aeration basin and wasting to the presses, then that is easy and there are about a million pics of these diagrams on line.  Why don't you tell us what you want to treat, first.  This will help everyone to decide which systems are correct for your particular design.  This is way too open ended, because of MBR, MBBR and IFAS, SBRs, etc.  Looking forward to seeing water data prior to any primary treatment.  If you have a prmary system in place, then let us know what you are using mechanically and chemically, because it makes a big difference in choices for downstream.  There are also some bells and whistles that you may want to consider keeping on hand, if this is an industrial application with any challenges.  Won't know that until we see the water analysis.  If you just want a site with the different designs, it really doesn't tell you when to use what technology.  There are always going to be situations of decisions that have pluses and minuses, so expertise and experience goes a long way, but again we all need a water quality prior.  Anyone that simply sends you a design is doing just that; sending you one of a million iterations of the possible plant layout.  Much more involved than that.  I have designed and started many facilities in my 30+ year tenure, and I am happy to assist, but have to have the basics to even begin.  Then you use a decision tree to pick and choose the lesser evils and build in some fail safes.  Hope this helps, Sean L. Roop

  2. Newer have more than 8 promille fall on pipes and and design uýour inlet bassin big ennogh due to more rain and as water gets thined by rain the airination by musrooms is a good idea

    Also the use og Gas engines from BB from tanks decomponating  waste will help if CO2 and CH4 is seperated can make hot water from cooling and el power from generators also an exhaust boiler is a good idea