Stages and methods for treatment of oil contaminated water

Treatment of oil contaminated water

Purpose of Reverse Osmosis Systems is to support and help treatment of oil contaminated water to recover petroleum oils that are found in water bodies at several stations

  • Free non-emulsified oils
  • Emulsified oils and stable in the water
  • Insoluble solids

The principles of the separation, recovery and treatment of oil contaminated water depends on characteristics and properties of these oils; the nature and existence, solid materials and non-emulsified oils are physically separated while emulsified oils are chemically separated. Finally, small emulsions and organic dissolved material which were not treated with previous means are being treated biologically.

Stages and methods for treatment of oil contaminated water
Contaminated water are being processed by three phases depending on the method of processing which are:

  • Physical treatment
  • Chemical processing treatment
  • Biological treatment stage

Physical treatment

Solid matters and non-emulsified oils are separated based on the principle of gravity, where design breaks is returned to the American Petroleum Institute, which the design depends on the principle of the difference in density between the water and oils properties, whether free or solid. Free oils float on the surface of the water and taken by a certain abrasive raze to a special hole to be returned again after layering to the production lines while the solid matters settle at the bottom of these basins are taken through a private in the form of sludge sockets to private places where follow up treatment and disposal

Chemical processing treatment

Emulsified oils can not be separated physically so it needs to be separated chemically which allows to remove the case of emulsification and stability emerging between oil and water in the middle surrounding the second phase

Where external water are brought from external basins after adding some coagulated materials such as iron sulfate which is less expensive than other coagulated materials and because they in fact do two jobs

Forms (after oxidation by dissolved oxygen moiety) hydroxide compound of iron gelatin textures and surface, which has a capacity that helps adsorption of emulsified oil droplets on the surface and the air with the help of the dissolved

The addition of iron sulfate helps in getting rid of hydrogen sulfide gas dissolved and compounds which may be contained with oily water, which have seriously damaged the subsequent biological treatment work, where the presence of iron sulfide is a moiety with ion iron deposit is a black iron sulfide

After the formation of the raw material adsorption (ferric hydroxide) a polymer is added with high molecular weights that carries an electric positive charge on the surface collects iron hydroxide particles on the surface compounds the problem so volumes and surfaces wide capable of dissolved air flotation, which will inject later assisted.

Complete chemical treatment of so-called phase flotation stage, a very important and very critical stage in the improvement of the final specifications for water treatment and symbolized by the acronym of the dissolved air flotation.

The principle of this method depends on the density change problem solids by adding the previous chemicals by joining the air bubbles injected by a private network at the bottom of the tub to the surfaces of these pendants and its contribution to the expansion of the relative surfaces and thus reduce the intensity of which will allow its flotation.

In other words, what is meant by flotation in fact is the updraft of adsorption materials that will contribute to the adsorption of emulsified oil droplets at the same time also pick up solid natural pendants which we call water turbidity collected on the surface of the flotation tanks.

Then to be taken by a special raze gathered in private protectors called flotation sludge pit

Biological treatment stage

Emerging from the flotation stage water enters the biological treatment providers basins mechanical mixers are secure ventilation of these basins and providing oxygen required for processes of oxidation where this method is the most common and successful way in converting organic material, whether decadent or sizes minutes impossible separated previous stages to non-material decadent through oxidized by microorganisms (bacteria) that are converted via vital metabolism to carbon dioxide and to new microorganisms called bacterial midwife to be placed at the bottom attached to the biological reactors settling basins and described in the third stage in the scheme

Many of the microorganisms can feed on organic material dissolved or suspended and disassembled condition of maintaining the appropriate conditions of her life and, in particular, needs oxygen.

And measured the water content of organic material degradable bacteria, including the requirement we call organic oxygen: BOD Biochemical Oxygen Demand.

This standard represents the amount of oxygen consumed by bacteria to represent this organic material and can be called organic pregnancy basin biological When this pregnancy is fairly low and if there is sufficient tracts of land are designed in this case the biological basins Allagoonat system or open pits where believes bacteria which need oxygen directly from the natural air

But if the high organic load must in this case from those basins oxygen supply mechanical means which are periodically required to secure for the entire basin ventilation