SU886946A2 - Method of cleaning water by filtering - Google Patents

Description

(54) METHOD FOR CLEANING WATER BY FILTERING

I

The invention relates to methods for purifying water by filtration, used in the process of purification of household drinking and purification of wastewater.

According to the main auth. No. 738,638, a filtration method for water purification is known, which is used in the process of purification of household drinking and waste water purification flj. This method is based on filtering water through granular loading from slags of nickel production containing oxides of iron, silicon, calcium, magnesium.

The known method is characterized by increased productivity due to the filtering properties of granulated nickel production slags.

However, when this method is implemented over time, the filtering properties of the load deteriorate due to the deterioration of the shape factor of the granules due to accumulation.

nor on their surface residual impurities, predominantly aluminum hydroxide and organic compounds, as well as hardness salts.

The organic and inorganic contaminants in the process of loading create a shell on the surface of the granules, the insulated internal porosity of the load from contact with the purified water containing flake coagulum, which reduces the filtration performance of the load, resulting in a shortened filter cycle.

The aim of the invention is to increase the duration of the filter cycle.

This is achieved by the fact that in the method of water purification, filtering on auth.St. N "738638 through granular loading periodically pass

20 water, acidified to pH 4,, 5.

Claims (2)

The water is acidified, preferably with aluminum sulfate, or a chlorine-containing reagent. In the process of regeneration of the load with an acidified aqueous solution of aluminum sulphate, not only does the insulating granule shell dissolve, but also the charge porosity is restored by partially dissolving the surface layer of the granules. Acidification of water to a pH of 4, 2-4.5 is optimal, since. at pH above 4.5, hydrolysis of aluminum sulphate begins with the formation of flakes of aluminum hydroxide and basic aluminum sulphates, as a result of which the granules overgrow with coagulum flakes. Acidification of water to a pH below 4.2 is impractical, since this leads to intensive dissolution of the surface of the granules . Water acidified with aluminum sulphate or chlorine-containing reagent is passed through a filter pshak of nickel production, which worked for a time at the water treatment plant. Filtration with acidified water is conducted by upward flow of water. After regeneration, the load is washed with an upward flow of water and the filtration cycle is repeated. Example. Through the slag of nickel production - loading of a contact clarifier - water purification with a particle size of 3.0-0.5 mm, equivalent to a diameter of 1.12 mm and a loading layer height of 1.6 m, water is passed, acidified: with aluminum sulphate to pH 4.3. Filtration is carried out by an upward flow of water at a speed of 7 m / h. Filtration time 20 min. After that, the load is washed for 5 min with an upward flow of water of 26.2 l / CM intensity. The duration of the filter cycle after regeneration is 19h. The table shows the performance of filters loaded with nickel-made slag production and regenerated by industrial water and regenerated with acidified water, followed by water. 6 As can be seen from the table, additional regeneration of the load with acidified water provides an increase in the duration of the filter cycle by 30-50% while reducing the initial pressure loss in the load by 15-17%. Increasing the duration of the filter1) helps to increase the productivity of the process by saving regeneration time and makes the process more economical. The claims of the invention: 1. A method of water purification by filtering according to av1.cv. No. 738638, characterized in that, in order to increase the duration of the filter cycle, water is periodically passed through the granulated load, acidified to a pH of 4.2-4.5. 2. Method pop, 1, distinguished by the fact that water is acidified with alcumin sulfate or chlorine reagent. . Sources of information taken into account during the examination 1. USSR Author's Certificate No. 738638, cl. B 01 O 37/00, 1980.