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RE: KwH per pound of BOD removed

Deerfield Wastewater — Wed, 19 Mar 2008 15:56:36 GMT

Interesting question. Ours is 1.1-1.2 kwh/lb BOD but that's for the whole plant, not just aeration. We have floating mechanical aerators and just one electrical meter for the whole plant. We have also been tracking sludge disposal cost per pound of BOD treated in case anybody is interested. For us that's about $60/lb BOD.

RE: KwH per pound of BOD removed

TerryF — Wed, 02 Jan 2008 16:08:34 GMT

Mickey,

Keeping such data is useful as a historical record of performance within your own plant , but unless you are comparing yourself to a plant with similar characteristics in terms of configuration , operating parameters , effluent goals and influent characteristics , then it maybe of limited value. For example a plant with surface aeration might use substantially more energy than one with fine bubble diffusers for the same throughput and effluent goal.

Nonetheless in the big picture such data from a large number of plants is useful to see trends in the industry in terms of efficency , impacts of licence changes , the effects of technology change etc.

I did a quick calculation and on average we are doing about 0.9kwh/lb BOD removed operating for low levels of N and P with fine bubble diffusers.

Regards

TerryF

KwH per pound of BOD removed

Mickey Nowak — Wed, 02 Jan 2008 14:50:08 GMT

Does anyone keep track of this? I am trying to track energy used by the secondary treatment process. I have some calculations that show 0.5 to 1.0 KwH per pound of BOD removed. Does that sound right?