RU2315298C1 - Method of testing purity of water - Google Patents

Abstract

FIELD: medicine; ecology; hygiene.

SUBSTANCE: method can be used for analysis and differentiation of degree of pureness of water on purpose of revealing of effect of water onto human health, as well as for checking pureness of water in laboratory tests. Tested sample of water in amount of 2-5 ml is placed into dish of chemiluminometer. Flash is measured and ozone is supplied to dish through waterproof light-protected capillary gas-duct at speed of up to 10 mcg ozone/sec. Intensity and dynamic changes in chemiluminescence are measured during 1 minute. Computer automatically processes result of measurements and it is presented in form of graph of changes in chemoluminescence. Maximal signal (peak meaning) is calculated and total number of flashes is calculated within 1 minute (light sum of pulses during 60 seconds).

EFFECT: high sensitivity of method; reduced lower limit of measurement range; reduced amount of water necessary for tests.

1 tbl, 2 dwg

Description

The present invention relates to medicine, namely hygiene and ecology, can be used to analyze and differentiate the degree of purity of water in order to prevent the effect of water on human health. Also, the proposed method can be used to determine the purity of the water used in laboratory analyzes.

The standard method for analyzing water purity is currently the permanganate oxidation method, which is based on measuring the amount of oxygen (using potassium permanganate) required for the oxidation of organic and easily oxidized inorganic substances contained in water [1].

The disadvantages of this method are the low sensitivity, the need for a large amount of analyzed water and the high dependence of the analysis result on the conditions of its implementation.

There are modified methods for determining the purity of water based on measuring the chemical consumption of oxygen, in particular an accelerated method for determining the chemical consumption of oxygen with aqueous solutions containing organic compounds in water, which involves oxidizing organic substances contained in water with potassium dichromate in the presence of sulfuric acid, mercury sulfate, indicator of ferroin, followed by titration of an excess of potassium dichromate 0.25 N. Mohr's salt solution [2].

The disadvantages of this method are the use of highly hazardous substances as reagents, the need for specific equipment - a homogenizer, a multi-blade mixer having sharp edges, with a speed of 14000 rpm. Also, for this analysis, a sufficiently large volume of the investigated water is required - 100-150 ml. In addition, the known method has a high lower limit of the measuring range and can only be used to measure the purity of highly polluted waters.

The principle of the proposed method is based on measuring the intensity of chemiluminescence in the test water induced by ozone.

The proposed method is as follows.

The studied water sample in a volume of 2-5 ml is placed in a chemiluminometer cuvette, the background glow is measured, then ozone from the ozonizer is fed into it through a sealed light-proof capillary gas pipeline at a rate of up to 10 μg of ozone per second, and the intensity and dynamics of chemiluminescence are measured for 1 min. The result is automatically processed on a computer and expressed as a graph of the dynamics of chemiluminescence intensity, the maximum signal (peak) and the total number of flashes for 1 min (light sum, pulses for 60 s) are calculated.

For example, figure 1 shows the comparative dynamics of ozone-induced chemiluminescence of tridistilled water with oxidizing agents (especially pure water for chemical analysis) - graph A, bidistilled water - graph B, distilled water - graph B and water purified through a membrane filter - graph B The measurements were carried out under the same conditions - the first 10 s - the background chemiluminescence of the test water, ozone is supplied to the water for 10 seconds, then the ozone-induced chemiluminescence is recorded for 60 s.

Figure 2 shows the comparative dynamics of the chemiluminescence of artesian water - graph A and tap water from a surface source - graph B. The measurement conditions are similar.

Quantitative results of the measurement data of these samples are given in table 1.

Drinking water (artesian and tap water from a surface source) has ozone-induced chemiluminescence values of 1-2 orders of magnitude higher than 60-120 thousand pulses in 1 min compared to pure prepared waters - 1.5-6 thousand pulses. However, there are significant differences between drinking water. Tap water from a surface source has a chemiluminescence value of 1.8 times higher compared to artesian, which corresponds to the values of pollution of these waters, determined by analogue and prototype. There is also a difference between pure waters prepared in different ways: the chemiluminescence of highly pure water for chemical analysis is 1.8 times less than the chemiluminescence of bidistilled water and 4 times less than the chemiluminescence of distilled water and water purified using a membrane filter. Using analog and prototype methods, these differences cannot be detected.

The advantages of the proposed method are the reduction in the amount of water required for analysis to 2-5 ml; expressness of analysis - the time required to analyze 1 sample, from 1 to 5 minutes; No need to use highly hazardous chemicals and sample preparation for analysis. A significant reduction in the lower limit of the measuring range and the high sensitivity of the method makes it possible to detect trace amounts of contaminants, thus measuring the purity of pure and very pure water used in chemical analysis. In addition, the proposed method can be fully automated.

Literature

1. ISO 8467-93. Water quality. Definition of permanganate index - analogue.

2. RF patent BSh 2265212 C2 from 01/23/2003 - prototype.

Table 1 Ozone Induced Chemiluminescence Results in Various Water Samples Try Light sum, impulses for 60 s Peak chemiluminescence Highly pure water for chemical analysis 1477.4 108.7 Bidistilled water 2668.1 332.1 Distilled water 5874.7 733.2 Membrane Filter Purified Water 5652.0 434.2 Artesian water 57444.0 4653,4 Tap water from a surface source 102896.6 6945.9

Claims (1)

A method for studying water purity, including the oxidation of pollutants by ozone supplied to the test water sample at a rate of up to 10 μg / s, and measuring the intensity of chemoluminescence induced by ozone, and for artesian and tap water from a surface source, the intensity of chemoluminescence is 6-120 thousand pulses per 1 min, and for pure prepared water - 1.5-6 thousand pulses.

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