RU1822970C - Method of potentiometric water quality control - Google Patents

Abstract

Usage: purification of natural and waste water, environmental protection, in particular to the control of water quality by potentiometric methods. SUMMARY OF THE INVENTION: the method includes the continuous withdrawal of a portion of controlled water into a flow measuring system, measuring the physical parameters of the redox potential and then comparing their values with the control ones. Before measuring the redox potential and physical parameters, water is ozonized with a constant dose of ozone, which pre-installed on controlled water that meets sanitary and environmental safety standards, as processed roll index water quality indicator using rH2. which is determined by the formula gH2 + 2pH, where Eb and pH are the current values of the redox potential in MW and the water index in pH units, respectively, and the dose for ozonation of controlled water is set during the adjustment of the measuring system with a gradual increase in ozone consumption to values at which the highest growth rate of the redox potential and the gH2 index are achieved. 3 ill. Ј

Description

The invention relates to the control of the quality of water taken for the needs of water supply and of wastewater discharged after treatment into water bodies. The invention provides environmental safety when using water in various technological processes, for example, in ship water supply and sewage systems, as well as in public utilities.

The purpose of the invention is to expand the range of analyzed objects and increase the reliability of control.

This goal is achieved by the fact that according to the method of potentiometric control of water quality, including continuous supply of it to the flow measuring system and measurement of the redox potential, the dependence of the redox potential (ORP) on the ozone consumption in a controlled genus corresponding to the norms is removed sanitary and environmental safety, choose the value of ozone consumption corresponding to the maximum rate of change of ORP, after which continuous ozonir vanie water selected dose of ozone with simultaneous measurement of the pH value. and water quality is determined by the formula:

gN2-- | Ј- 2RN,

where gH2 is an integral indicator of water quality,

E is the current ORP value, mV, and pH is the current pH value in pH units.

In FIG. 1 schematically shows a flow measuring system for implementing the proposed method: in FIG. 2 shows the dependence of the redox potential (ORP) of water on the dose of ozone (D); in FIG. 3 - a change in time of the current values of the quality indicators of controlled water in comparison with the control value of the integral indicator.

The measuring system for implementing the method comprises a water supply pipe 1 directly from the controlled object, a controlled water supply pipe 2 that has been processed to environmental safety standards, a switching device 3, an ejector 4, an ozonizer 5 with an ozone flow controller 6, a chamber 7 for separating the gas phase from the liquid, a pipe 8 in which a flowmeter 9 is installed, a pH meter 10, a measuring cell 11 with electrodes for measuring redox potential (ORP), a device 12 for registration of the gH2 indicator and the discharge pipe 13.

The method is carried out as follows. At the beginning, controlled water is supplied to the measuring system through pipeline 2, which has been processed to environmental safety standards. With a gradual increase in the flow rate of the regulator 6 through the ejector 4 into the water (dose) ozone and remove the dependence of the ORP from the flow (dose) of ozone D (Fig. 2). When the maximum ORP change rate is reached, a reference dose of ozone D is selected and the corresponding gH2 value is determined. The reference dose of ozone is fixed by the flow regulator 6. and the corresponding gH value is taken as the control. Then, using the switching device and, -, the measuring system supplies water from the pipeline 1 directly from the controlled object. This water is continuously ozonated with a fixed dose of ozone with simultaneous measurement of pH and ORP. Water quality is determined by the formula

gN2

§L 29

2рН,

where: gH2 is an integral indicator of water quality; E - current ORP value, mV;

pH is the current pH value in pH units.

The deviation of the current values of gH2 from the control indicates a change in the organic or mineral composition of the controlled water (Fig. 3). Exceeding the current values of hHa and their equality with the control indicates that all ozone has entered the oxidation reaction, i.e. in terms of the quality of its composition, controlled water satisfies the requirements of sanitary and environmental safety. A decrease in the current values of gH2 below the control indicates the appearance of additional pollution in water, which

entailed a decrease in ozone in water and a corresponding decrease in gH2.

When controlling drinking water quality

The reference value of the gH2 index can be determined in advance from the standard water quality indicators.

Example. Household wastewater is subjected to quality control

after shore treatment facilities. In order to carry out monitoring, the wastewater is known to first meet the requirements of sanitary and environmental safety in a flow measuring system. This is verified by laboratory analysis of treated effluents. In particular, this water has the following quality indicators: BP "5 - 10 mg / l, potassium index 1000 pcs / l, suspended solids - 10 mg / l.

By gradually increasing the ozone consumption, the dependence of the redox potential of the redox potential on the ozone consumption is removed. At the maximum rate of change in the ORP in the area 1-2 determine

and record the ozone consumption in the measuring system. At the same time, the Eh and pH values of the water are measured and the integral gH is calculated; , 0 i-d in.; 4tMuie

WHICH TAKE,.} ,,, and 1 AND, 1

Fig. 3, this reference value is indicated by a horizontal dashed straight line 1, which complies with sanitary and environmental safety standards.

Then, wastewater from the same facility is supplied to the measuring system to continuously monitor its quality. In this case, water is ozonized with a selected (fixed) dose of ozone and, by measuring the Eb and pH indicators, the current values of the integral indicator of gH2 are determined by the formula:

rH2-fЈ- + 2pH.

where gH2 is an integral indicator of water quality;

Eh - current ORP value, mV;

pH - current pH value in pH units.

The results of the time variation of the gH2 value of the controlled water are shown by curve 2 in FIG. 3. At current gH2 values greater than or equal to the control water, it is guaranteed to meet sanitary and environmental safety standards, i.e. BPKb quality indicators - 10 mg / l, potassium index - suspended solids do not exceed the maximum permissible values. When the current values of the integral indicator gH2 decrease below the control value, a signal is sent to the treatment plant to intensify the treatment of effluents.

The proposed method provides reliable continuous quality control

waters of a wide range are analyzed. oOektov, including treatment facilities for water treatment for technological needs and drinking quality, air pollution and soil pollution control systems based on the dissolution of pollutants in water.

Claims (1)

SUMMARY OF THE INVENTION A method for potentiometric monitoring of water quality, comprising continuously supplying it to a flow measuring system and measuring a redox potential, characterized in that, in order to expand the range of objects to be analyzed and increase the reliability of control, the dependence of the redox potential (ORP) on the ozone consumption in controlled water that meets sanitary and environmental safety standards, the value of ozone consumption corresponding to m ksimalnoy AFP rate of change, and then carried out the continuous ozonization of water selected dose of ozone with simultaneous measurement of the pH, and water quality is determined by the formula gN2 §I 23 2 pH where gH2 is an integral indicator of water quality; Her - current ORP value. mV; pH - current pH value. FIG. - / ll / od twenty 3 T.rf FIG. 2