| 摘要 |
A method of extracting oil from water, particularly spillage water from gasoline stations, including water that emanates from vehicle-washing plants, comprising filters to which contaminated water from the vehicle-washing plant and possibly other contaminated water spillage is passed, and wherein the water is cleansed in one or more mutually sequential filters in the flow direction of the water. The invention is characterized in that the water is cleaned by causing the water to flow through a collection filter (4) in which oil and coarse particles are collected, in a first cleansing or purifying stage; in that the water from the collecting filter (4) is caused to pass through a fine filter (5) which is adapted to lower the oil content of the water to a level below approximately 50-75 mg/l, in a second cleansing or purifying stage; in that the water from the fine filter (5) is caused to flow through a membrane filter (13) which is adapted to filter-off at least 75 % of the oil remaining in the water, in a third cleansing or purifying stage; and in that at least a substantial part of at least the water cleansed in the membrane filter (13) is recycled back (26) to the vehicle-washing plant while any residual part of said water is discharged to a municipal sewage network (23). The invention also relates to a system of apparatus.
|
