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Group: Forum Members Last Login: 11/1/2007 1:40:20 PM Posts: 26, Visits: 34 |
| Woodie is the man. It makes me crazy when us engineers are getting ready to do a design and go sample for the routine stuff including ammonia but ignore the organic fraction which is only going to be recognized with the TKN test. Thank you Woodie!! Depending on the nature of the carbon (how readily bioavailable it is) you can get in trouble if your ammonia fraction is low and your organic fraction is more complex and slower to ammonify. ie, the bug can go to town on the carbon (believe theres quantities of acetate and glycol in soaps and shampoos ) but not have enough ammonia for cell synthesis. They dont like this at all and have seen on several occasions the mixed liquour turn snotty - stringy - almost like putting your hand in a polymer tank. This situation is of course not typical to normal doemestic wastewater but is in industrial wastes including some food process wastes. I havent read about any settling problems on this one and its highly unlikely there wouldnt be settling problems so I'm thinking there is likely high TKN that shows itself in excess ammonia at the butt end of the process.
and the bug knows best |
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Group: Forum Members Last Login: 6/12/2008 2:25:55 PM Posts: 34, Visits: 46 |
| | Right, I would agree with those folks who responded that Organic N conversion to ammonia is likely cause. You should be able to confirm as was recommended by getting influent and effluent TKN data and looking for reduction of organic N component of TKN over to N. High F/M would indicate likely potential for only partial nitrification of ammonia produced from breakdown of organic N. Fact that the system is working implies plenty of organic N as ratio of ammonia to BOD is too low to facilitate BOD breakdown unless the nitrogen is there in another form, so it's likely there as ammonia N. A full nitrogen balance would be interesting to trace it all through but seems pretty likely you'll see what's happening from testing for reduced forms in influent and effluent (TKN, organic, ammonia)... Wiff Peterson
Wiff Peterson |
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Group: Forum Members Last Login: 6/12/2008 2:08:59 PM Posts: 2, Visits: 6 |
| | I would add to the list of things to watch: Alkalinity - well known culprit when lacking; Nutrients, especially phosphate. Industrial wastes will often be out of balance when compared to domestic in which bacteria thrive.
Chemist |
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Group: Forum Members Last Login: 6/12/2008 2:25:55 PM Posts: 34, Visits: 46 |
| | I would agree with Woody's suggestion. The organic N component of influent BOD is being converted to ammonia as BOD is broken down. Running influent and effluent TKN (which will give you ammonia N and organic N which combined equal TKN) will likely confirm the conversion of organic N in the influent to ammonia N in the effluent. At these F/M's you'd expect that! Wiff Peterson
Wiff Peterson |
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Group: Forum Members Last Login: 2 days ago @ 1:37:32 PM Posts: 481, Visits: 1,437 |
| | It may be spending to much time in the clarifier and getting anaerobic. Try increasing the return rate. The usual number is 100 % return rate of the influent flow. |
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Group: Forum Members Last Login: 6/20/2008 8:55:11 AM Posts: 6, Visits: 49 |
| | Too little data for answer. Key data are in the mass balance of the total nitrogen; inflow (before and after primary clarifier) - in kg/d. Also the external flows - externa substrate in the digestion, dosing of nutrients into biological stage. |
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