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| | | Forum Newbie
Group: Forum Members
Last Login: 1/25/2008 2:51:50 PM
Posts: 5, Visits: 16 |
| | We have an industry that is discharging high levels of BOD (in the form of sugars from jelly and jam processing) into the municipal sewer. Their quarterly surcharge is in the range of $20,000 for their high BOD. They are interested in a pretreatment process prior to discharging to the municipal sewer. Their average daily use is in the of 5000 gpd. What type of system would you expect they would need to install prior to discharge to reduce their BOD?? Simple aeration unit? Would it help to run their restroom drains to this aeration unti as well to help increase the bacteria present? I have hit the resource books, but seem to be spinning my wheels?? Any help is greatly appreciated.
Andy |
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| | | Supreme Being
Group: Forum Members
Last Login: 6/26/2008 4:01:08 PM
Posts: 156, Visits: 1,477 |
| | My experience for a similar type of waste has been with apple cider, juice, and soda. The wastes are high in sugars, and nitrogen deficient. There is a stand-alone plant that uses activated sludge, and has had problems for many years. Influent BODs typically range from 10,000 to 30,000, with occassional spikes much higher. It is about 10,000 to 20,000 gpd, so not too much out of line with what you are seeing. Their total detention time (with eq. tanks, because of slug loading from production), is probably several days. I have seen papers presented on pre-treatment, in which anaerobic processes appeared to do well (I think the one in particular concerned the City of Buffalo). Whichever way you go, it can probably be made to work, but not a simple one. Much will depend on what sort of limits you are trying to meet. The apple plant I mentioned discharges to a small stream, so has very stringent limits. Good luck ! |
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| | | Forum Member
Group: Forum Members
Last Login: 6/16/2008 8:44:25 AM
Posts: 48, Visits: 63 |
| | The BOD is going to be high in soluble BOD, probably in the 90% range. I have a food industry that suffers currently from this issue and they have a pretreatment system. They separte oil from water, have a barscreen, have a rotating solids screen, an equalization tank, a dissolved air flotation unit and several chemical delivery systems. They are having to go back to operating their DAF unit at design parameters flow-wise to even have a chance at meeting the local limits. They are also going to liquid caustic for pH control(leaving behind the old soda ash approach). They may have to increase the volume of their holding tank, and might be installing dissolved air for mixing and microbial reduction of BOD. The basic problem with the soluble BOD is that it takes so much longer for bugs to consume it. My industry is going to be trying to limit how much actually makes it into the holding tank to begin with. Some times the soluble BOD can be oxidized chemically, but not always. Good luck! Egadz |
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| | | Supreme Being
Group: Forum Members
Last Login: 2 days ago @ 12:01:02 AM
Posts: 86, Visits: 550 |
| | MBR would do the trick, they are compact and have come a long way in the last couple of years. |
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