Removing or Treating Edible Oil from Waste Stream 2

Jp316:

I believe you posed this question on the Water and Wastewater Forum.

Contact ECP International, LLC for an effective electrolytic-catalytic system, at water@infoecp.com, or 514-557-4108.

Orenda

yes. Thanks Orenda. A colleague and I will be investigating a solution to this problem and we will seriously consider all options presented.

I did some testing on oil absorbent bag filter media. The product I tested could absorb approximately 50 grams of machine cutting oil per sqft of material from a 0.25% water emulsion. The filter elements I worked with could process at least 10L of your liquid at this rate. It would cut down on your TSS, and oil adsorption would increase by using your TSS as an adsorptive filter aid. Putting in a filter aid in a slurry upstream of the filters may could also help. Alas, bag filters and filter aids are consumable materials, which you may wish to avoid if you can help it.

Polypropylene felted media (needlepunch) has a natural tendency to remove oil from aqueous systems. It is a great side benefit when filtering in recirculated wash and rinse systems for machined parts. 10L per element is not a lot, I know, but it may be the reduction you need for oil and TSS . Using an oil skimmer upstream would be a great way to further reduce the oil level.

ChemE, M.E. EIT
"The only constant in life is change." -Bruce Lee

Thanks aspearin1 for your input. Merry Christmas.

jp316,

Would you like to recover the 3% oil or decompose it insitu? Do the solids float or sink?

If the oil and water are in separate phases (not an emulsion), then a simple hydrocyclone density separator will work just fine.

If you want to completely oxidize the oil when it reaches the center of the hydrocyclone see the WhirlArc at:


Sincerely,
Todd Foret

Todd

The traditional method for removing the oils is a DAF (issolved air flotation). There are thousands of applications of these usits operating (unlike the methods listed by the previous posts). Contact komline sanderson for further information. They are a manufacturer of this type of equipment.

Jp316:

Regarding the 1/4/2005 post by Bimr, he (and you) should be aware that DAF's rarely provide discharge criteria water on their own. I would also suggest that aeration alone will not sufficiently remove the residual oil and TSS from the DAF effluent, hence my earlier suggestion that you contact ECP International at 514-557-4108 to achieve discharge quality effluent.

Orenda

Yes, orenda, saw your post but would have to politely disagree. ECP International is not a major player in the waste treatment market. Show me how many units that ECP has installed for this appliction. I will be waiting....

A DAF unit is the most cost effective method to remove this oil.

Bimr:

Yes, you are correct that ECP is not a major player in this market....yet! The fact remains that a DAF in almost all cases will not produce an effluent of discharge quality. Therefore additional organic removal treatment will be required to meet discharge criteria....the ECP process is exceptionally capable of doing this.

Orenda

If you will review the original post, I believe that jp316 is only looking for pretreatment for his existing aeration basin.

DAF will certainly be likely to work, as will an inclined plate separator, providing the oil is not substantially emulsified, and has a density reasonably dissimilar from water.

The inclined plate separator will treat the effluent more cheaply in terms of both running and capital costs that a DAF unit. Both sinking or floating solids and oil can be recovered by such a unit.

Seán

My experience has been that a plate separator will clog when it being used with oils, sticky wastes, and materials that will precipitate. It is difficult to clean these materials from between plates that are only 100 mm apart. So, use of a plate separator is questionable on this type of wastewater.

I've installed five of these, with parallel plate separators followed by coalescing media, giving very high degrees of oil removal.

Settlement of sludges is allowed for in sizing the tank following the plates.

The design can be seen at the following link:


Seán

The poster says he has 94,100 TSS (mg/l) in addtion to the 3% oil in water. If the 94,100 TSS wasn't there and the oil remained warm enough so it wouldn't solidify, your plate separators would probably work.

If you have an installation of edible oils, maybe you can share the details.