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Demulsification of effluent

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We have some dissolved oil in our factory effluent, and this is causing tertiary treatment of effluent. Are there any methods to separate dissolved oil of the the order of 50ppm. Any demulsifiers? Physical separation methods?

G.Murali Mohan
- Hyderabad, India

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Hi Murali,

You can aerate (bubble) the effluent by passing compressed air from the bottom of the tank, the oil (suspended in the effluent) will come to the top surface and form froth ... then you can effectively skim the oil out. This is just an idea.. I have not tried it out.. you can try in lab before you apply or You can have a oil collection tank or filtration prior to collecting the effluent in the main collection tank.

Good luck ..

Karthik
- Singapore

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First of two simultaneous responses -- ++

It depends on what is making the oil soluble. 50 ppm is a low level. Clay is used to absorb oils and will settle out with your other sludge. Powdered activated carbon should also work but is usually more expensive than clay.

The US auto industry historically used calcium chloride and alum to physically bind up oils. The Unipure process using ferrous iron will probably work fine since it physically entraps oils.

Ed Cote
- Bloomfield Hills, Michigan

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Second of two simultaneous responses -- ++

WE HAVE A CHEMICAL PRODUCT WHICH SHOULD BE ADDED TO THE EFFLUENT AND STIRRED; SUSPENDED OIL WILL BE SEPARATED AND WILL FLOAT ON THE TOP OF THE TANK. THIS OIL MAY BE REMOVED BY SUITABLE METHOD: OVERFLOWING, SKIMMING ETC.

S. M. SUBRAMANIAM
CHENNAI, TAMIL NADU, INDIA