Method for treatment of oily sewage at bottom of bilge of vessel and method for preparation of magnetic activated carbon for decontamination of oily sewage

Abstract

The invention provides a method for treatment of oily sewage at the bottom of a bilge of a vessel and a method for preparation of magnetic activated carbon for decontamination of the oily sewage. The method for treatment of oily sewage at the bottom of the bilge of the vessel includes steps of feeding magnetic activated carbon into a mixing tank, filtering and retaining suspended particles in sewage at the bottom of the bilge and the magnetic powdered activated carbon with partial oil adsorbed by means of a high-gradient magnetic filter, feeding magnetic powdered activated carbon into an ultra-filtration membrane reaction tank, and deoiling by means of the magnetic powdered activated carbon and an ultra-filtration membrane. The method for preparation of magnetic activated carbon includes the steps of soaking powdered activated carbon into clean water for more than twenty-four hours, taking out the powdered activated carbon and drying the powdered activated carbon for two hours at a temperature higher than 105 DEG C, ultrasonically dispersing the dried powdered activated carbon with ferroferric oxide at the ambient temperature, and filtering by means of a filter screen and drying the filtered activated carbon for more than two hours at a temperature higher than 105 DEG C. More loosened mud cake layers are formed on the surface of the ultra-filtration membrane, filterability is greatly improved, membrane flux is improved, and membrane pollution can be effectively prevented.

Description

technical field [0001] The invention relates to a method for treating sewage, in particular to a method for treating ship bilge sewage and a method for preparing its special medium. Background technique [0002] Ship bilge oily sewage mainly includes oily ballast water, oily tank washing water and engine room bilge water produced during the normal operation of the ship. Typical pollutants include fuel oil, lubricating oil, cleaning agent and foaming agent ( AFFF), paint, etc. The main characteristics of its water quality are: (1) The water quality and water volume change greatly; (2) Only oil and some suspended solids in the oily sewage from ships exceed the specified discharge standards, while other pollutants are less and basically do not exceed the standards; (3) The composition is extremely It is complex, contains many kinds of oil, and due to the use of many chemical agents such as active agents, it has a high degree of emulsification. The traditional oil-sewage separ...

AI Technical Summary

Problems solved by technology

[0004] However, during the separation process of the ultrafiltration membrane, an adhesion layer will be formed on the surface of the membrane or the membrane pores will be blocked, resulting in a decrease in the membrane flux.

Severely polluted membranes, once the membrane surface fouling intensifies, will lead to low membrane flux, and its flux can drop by up to 80%

Membrane fouling seriously affects the separation efficiency of the membrane, shortens the service life of the membrane, and leads to a series of serious problems such as frequent deterioration of effluent quality and frequent cleaning.

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