RU2058264C1 - Method for cleaning up waste waters after washing metallurgy products - Google Patents

Abstract

FIELD: cleaning waste waters comprising oil products. SUBSTANCE: mechanical separation of impurities using centrifuges. Filtering is carried out through 1.25 m bed height composed of depleted rock of coal mines of 0.5 - 1.3 mm grain size at up to 9 m/h speed. Then ultrafiltration is carried out. EFFECT: high quality of water. 2 tbl

Description

 The invention relates to the field of chemical technology for the treatment of aqueous solutions, for example, wastewater treatment containing oil products, oils.

 A known method of purification of wash water, in which the wash water is fed into the neutralization tank, into which acid or alkali is dosed to create a constant pH value of the solution. Next, the process water passes through mechanical filters, on which coarse particulate matter is removed, and is collected in a collection tank. After this tank, water is supplied to the reverse osmosis unit, and then passed through a filter filled with activated carbon. Then the process water is divided into two streams for washing in technological processes where water with a minimum concentration of impurities (pickling, galvanization, etc.) is required. Process water with a high concentration of impurities and the concentrate after installing reverse osmosis is sent to a special neutralizer tank, from which it is supplied to the evaporator. The vapor from the evaporator is discharged into the atmosphere, and the concentrate in the form of sludge is discharged from the evaporator.

 The disadvantage of this method is that a large number of chemical reagents are used in the cleaning process, useful substances are irretrievably lost, the cleaning method is unsuitable for a large concentration of oils, oil products and requires the use of additional processing methods. Polar substances, usually obtained from oil and mineral sources, as a rule, are not biodegradable, and their concentration above 100 mg / l impairs the operation of sewage treatment plants, therefore only chemical processing can be additional processing methods.

 The purpose of the invention is to increase the degree of purification, simplify the treatment of wastewater containing oils, oil products, as well as the reuse of recovered useful substances.

To implement the method, at the first stage, the averaging and mechanical removal of oil, light and partially medium oil products, hydrocarbons, coarse particulate matter and other organic compounds with a low specific gravity are carried out on a centrifuge separator, which prevents clogging of the collectors with oils, greases and oil products. The surfaced sludge is fed to the recovery of oils and other useful substances for reuse, and the settled sludge is fed to vacuum filters for dehydration. The centrate is added to the purified water and passed through filters with a granular layer from the coal mines. The resulting cake is used as an additive in the manufacture of building materials. Due to the low cost of granular rock layer is not regenerated and after calcination at a temperature of ^about 550-600 C, is used for purification of waste water containing heavy metal ions. Wash water after the filter is fed to ultrafiltration. The filtrate after ultrafiltration after disinfection is fed to washing machines, where a lower consumption of detergents is required. The concentrate is used in the manufacture of building materials.

 A distinctive feature of the method is to change the technology of treatment wash water, use a new filter material, ease of maintenance and treatment of wastewater without cooling it, without additional neutralization before treatment, a significant reduction in water, reagent consumption used in the cleaning process, recovery of useful substances that impede ultrafiltration, which extends the life of the membranes.

 The studies were carried out on the wash water of a car repair plant and the experimental-instrumental Darnitsa Repair Plant. The results of the purification of wash water using the proposed method are shown in table 1.

 For ultrafiltration, a UPM-55P (polysulfoyamide) membrane η≈450Å was used; for filtering, a load from the rock with a grain size of 0.5-1.3 mm and a height of 1.25 m was used.

Hot water washings at 80 ^{° C} centrifuged for 5 min n 2500 rev / min, then filtered through a rock centrate fraction 0.5-1.3 mm at a speed of 7.5 m / h. The filtrate is fed to ultrafiltration at a pressure of 4 atm. Treated water is suitable for reuse rinsing. The concentrate is used to make bricks instead of water when making dough. After saturation of the absorption capacity, the filter load of the rock is also used for the preparation of bricks and wall panels.

 Table 2 shows comparative with a known method data on the quality of purified water.

 Wastewater treatment according to the proposed method makes it possible to completely purify water from oils, oil products and reduce the consumption of detergents by 35-45%. The filtering load from the rock can be used as an additive in the manufacture of ceramic products, and also as a filler in ordinary concrete, for example, wall blocks of clay slag concrete M 75-200 during autoclaving.

If the filter loading rocks saturated burn at a temperature of 550-600 ^C and pass therethrough electroplating effluent, the content of metal ions in the wastewater is reduced by 35-65% without additional processing.

Claims (1)

 METHOD FOR CLEANING WASHING WATERS OF METAL PRODUCTS containing oils, petroleum products, including averaging of effluents, mechanical separation of impurities, cleaning by the membrane method and filtering, characterized in that, in order to increase the degree of purification, simplify the method and ensure the reuse of the recovered substances, cheaper method, mechanical separation of impurities is carried out by centrifugation, filtering is carried out through a layer 1.25 m high of spent rock of coal mines with a grain size of 0.5 1.3 mm at a speed of up to 9 m / h, and thereby carry out ultrafiltration.

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