A filter system for receiving an oil-in-water emulsion contaminated with an emulsified contaminant oil, and separating the emulsified contaminant oil from the oil-in-water emulsion includes a filter media for receiving the oil-in-water emulsion and emulsified contaminant oil, having an inner filter element formed from a 95 percent single pass efficiency 48 micron (5 micron nominal) filtering material of needle punch polypropylene felt, an outer filter element formed from a 95 percent single pass efficiency 19 micron absolute filtering material of a polypropylene microfiber material and a porous spunbond polypropylene sandwiching the outer filter media. The filter element de-emulsifies the emulsified contaminant oil from the oil-in-water emulsion into the contaminant oil and the oil-in-water emulsion, separates the de-emulsified contaminant oil from the oil-in-water emulsion, coalesces the separated contaminant oil and passes both the coalesced de-emulsified contaminant oil and the oil-in-water emulsion. A first tank supports the filter element and is further configured to hold a quantity of the separated coalesced contaminant oil and the oil-in-water emulsion. The first tank has an overflow passing to a second tank. The second tank has an oil separation assembly for removing the oil-in-water emulsion from the contaminant oil and passing the oil-in-water emulsion therefrom. A method for separating the emulsified contaminant oil from the oil-in-water emulsion and recovering the oil-in-water emulsion is also disclosed.
1. A method for separating an oil-in-water emulsion formed from micelles from a liquid system having an oil-in-water emulsion contaminated with a contaminant oil and suspended particulate material, comprising the steps of:
introducing the liquid system containing the oil-in-water emulsion contaminated with the contaminant oil attached to the outside of the micelles into one end of a coiled, tubular composite filter media;
introducing the oil-in-water emulsion, contaminant oil attached to the micelles and suspended particles into the side wall of the filter media;
retaining particulate material greater than a predetermined size within the filter media;
temporarily adsorbing the contaminant oil from the micelles on the fibers of the filter media;
entraining particulate material less than the predetermined size in the adsorbed contaminant oil;
migrating the contaminant oil with the entrained particulate material and transforming them into droplets;
passing the oil-in-water emulsion through the filter media; and
trapping and containing the contaminant oil with entrained particle droplets while passing the filtered oil-in-water emulsion on.
2. The method in accordance with claim 1 wherein the trapping and containing step is carried out in a container that retains the trapped contaminant oil with the entrained particulate material and wherein the method includes the step of passing the oil-in-water emulsion from the container.
3. The method in accordance with claim 1 including the step of recovering the oil-in-water emulsion.
4. The method in accordance with claim 1 including the step of reusing the oil-in-water emulsion.