Bilge oily water is bilge sediments, which are formed on all types of vessels as a result of leakage of water, oil and fuel of ship equipment, feed pumps. Bilge water includes sea water that ensures operation of the equipment aboard. Getting into ship’s service area it mixes with the contaminants. Waste bilge water gradually accumulates in the engine rooms of ships. Bilge water is also formed in various industries, as well as at tank farms and filling stations.
Bilge water is denoted by the second class of environmental risk along with cement dust, electrolytes, sulfuric acid and other aggressive substances. Petroleum products being in the water in different phase-dispersed states, gradually lead to the formation of “dead zones” in which the oxygen level is considerably reduced. Discharge of bilge water into the environment is prohibited by law in Russia and all civilized countries.
Many methods of bilge treatment have been invented and used. The most effective of them are:
- Flotation treatment
- Multistage cleaning with pressure aeration by purified recirculating water
- Ultrasonic cavitation
- The method of thermal oxidation of emulsified petroleum products
- Centrifugal purification
- Separation precipitation
The methods available in the market have one common disadvantage: inefficiency and inability to re-use oil products.
The photo shows a double-stage mobile installation (70 kg) with the capacity of 1 cubic meter/ hour.