CS259915B1 - Method of degradation of organic matter in water - Google Patents

Abstract

A method of degrading organic substances contained in water, expressed by the summary indicator of chemical oxygen demand, by the action of cavitation, whereby the water passes through the cavitation space one to thirty times, preferably two to eight times, with the water passing through one cavitation space, or the cavitation spaces being arranged one after the other. Before or between the cavitation spaces, air is dispersed into the water in an amount of 0.1 to 7 parts by volume per part by volume of water, preferably 0.7 to 2.0 parts by volume of air per part by volume of water, which is treated with ultraviolet radiation before mixing with water. The degradation of endangered organic substances in water is catalyzed by metals with an easily transformable valence, preferably salts and oxides of iron, aluminum, chromium, manganese, molybdenum, vanadium, cerium and copper. The method finds application in water purification both for technological purposes and in wastewater purification before its new use or discharge into a recipient.

Description

The invention relates to the purification of water containing impurities of organic origin by their degradation during passage through areas of cavitation.

Currently, technological processes based on physicochemical, chemical and biological principles are used for water purification, depending on the quantity and quality of dissolved or suspended substances in it. Due to the deteriorated water quality, in some cases it is necessary to combine the above processes in order to obtain water of the required quality.

For example, the following processes are used to purify water containing organic pollution:

Among the physical-chemical methods, ionizing radiation can be mentioned, among chemical methods, catalytic decomposition of peroxides, and among biological methods, the use of mixed cultures of microorganisms in the yield, or anchoring on a solid phase.

All the above-mentioned methods have some drawbacks. The use of ionizing radiation as a source of free radicals capable of oxidizing organic substances entails the construction of expensive equipment and is problematic from the point of view of work safety. As regards the use of peroxides, the main disadvantages of this method are that the oxidation reactions take place effectively in the range of 3 to 5, and that the peroxide simultaneously enters a number of other reactions, which disproportionately increases its required dose. The implementation of biological methods requires the construction of expensive >. f equipment, which requires an enclosed space, and it has also been shown that in some cases the metabolites formed can support the formation of carcinogenic substances during subsequent treatment of these waters.

The above-mentioned shortcomings are eliminated by the method according to the invention, which is based on the fact that the degradation of organic substances contained in water occurs by the action of cavitation one to thirty times, preferably two to eight times, with the water passing through one cavitation area, or the cavitation areas are arranged one after the other. Before, or between the areas of cavitation, air is dispersed into the water in an amount of 0.1 to 7 parts by volume of air per part by volume of water, which is treated with ultraviolet radiation before mixing with water.

The degradation of organic substances contained in water is catalyzed by metals with an easily transformable valence, preferably salts and oxides of iron, aluminum, chromium, manganese, molybdenum, vanadium, cerium and copper.

Another advantage of the method according to the invention is that its use can be used to intensify already operating facilities and that its use does not increase the salt content in the water and creates minimal requirements for auxiliary chemicals.

The use of the method according to the invention is illustrated by the following examples.

Example

Water from the cooling circuit of a chemical plant was purified in a model circulation device with a usable volume of 20 l. The content of organic substances in this water, which was determined by the total indicator of chemical oxygen demand (COD), was 16.7 mg/l. This water was treated under the following regimes:

a) Number of passes through the cavitation point: 1.5; 20; 30;

b) Number of parts by volume of air per part of water: 0; 0.1; 0.5; 7. One part by volume of air that has passed through a source of broadband ultraviolet radiation (UV lamp) before mixing with one part by volume of water.

The cleaning results expressed in the change in COD in mg/1 are shown in the following table /TAB 1/

Table 1

Number of passes Without air Air addition Ord. d. of air + vol. d. of water UV radiation volume air volume/volume d. water / 0.1/1 0.5/1 7.0/1 1.0/1.0 0 16.7 / / / / 1 10.2 9.1 8.5 8.5 6.8 5 4.9 3.9 3.1 2.9 2.4 20 2.1 2.0 1.9 1.8 1.8 30 2.1 1.9 1.8 1.8 1.8 P h o r k law 2 On the device mentioned in the example 1 surface water was treated with COD = 7 .2 mg/l, to which was the following dose administered for each experiment quantity salts of the respective metals/ to water after the mixture contained next quantity effective components. /One component used at a time/

iron 0.2 mg/l aluminum 0.1 mg/l cobalt 0.1 mg/l chrome 0.03 mg/l manganese 0.1 mg/l molybdenum 0.03 mg/l from above 0.01 mg/l cerium 0.02 mg/l copper 0.03 mg/l

The results of the experiments are shown in Table 2. (COD values mg/l)

Table 2

Catalyst Number of passes through the cavitation point values

COD mg/l

5 10

iron 4.7 1.9 1.9 aluminum 4.3 1.9 1.8 cobalt 4.0 2.2 2.2 chrome 4.8 2.1 2.0 manganese 4.8 1.9 1.8 molybdenum 5.4 2.3 2.3 from above 5.3 2.3 2.2 cerium 5.2 2.5 2.5 copper 4.9 2.0 2.0 0 5.4 2.6 2.6

Example 3

In the Js 400 pipeline with a length of 1,800 b.m, through which water with a biochemical oxygen demand (BOD 5) in the range of 750 to 936 mg/l and a chemical oxygen demand (COD) in the range of 1,150 to 1,420 mg/l was supplied to the biological treatment plant, one, three and five cavitation points were implemented. The average results from ten days of monitoring are shown in Table 3.

Table 3 After passing Indicator Entry One place Three places Five places of origin é (mg/1) origin cavitation cavitation 0 cavitation formation ύ COD 1,306 796 mg/1 496 mg/1 365 mg/1

The method according to the invention will find application in water purification both for technological purposes and in wastewater purification before its new use or discharge into a recipient.

Claims (4)

I will invent the subject A method of degrading organic substances contained in water, characterized in that the organic matter is degraded by cavitation, wherein the water passes through the cavitation area from one to thirty times, preferably two to eight times, with water passing through one cavitation area or cavitation areas sequenced. 2. A method according to claim 1, characterized in that air is dispersed in the water in an amount of 0.1 to 7 parts by volume per part by volume of water, preferably 0.7 to 2.0 parts by volume of air, before or between cavitation areas. one volume of water. 3. A method according to claim 1 or 2, characterized in that the dispersed air is treated with ultraviolet radiation before mixing with water. 4. Process according to claim 1, 2 or 3, characterized in that the degradation of the organic substances is catalyzed by the addition of metals with easily transformable valence, preferably salts and oxides of iron, aluminum, chromium, manganese, molybdenum, vanadium, cerium and copper.