RU2252919C1 - Drinking water electric-activation process - Google Patents

Abstract

FIELD: processes for treating water in centralized systems for supplying drinking water, possibly preparation of electrically activated water.

SUBSTANCE: method comprises steps of unipolar treatment of drinking water in flow-through diaphragm-type electrolyzer having separate inlet and outlet at predetermined relation of speeds of catholyte and anolyte flows in range 0.94:1 - 1.50:1 at passing specific quantity of electricity in range 0.071 -0.083 A-hours for 1 l of catholyte and anolyte.

EFFECT: lowered specific consumption of electricity quantity and electric energy.

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Description

The invention relates to a technology for the treatment of drinking tap water and can be used to produce electro-activated water.

In recent years, electroactivated water has been increasingly used in agriculture, medicine, industry, including for detergents, disinfectants.

Electroactivated water is obtained by unipolar treatment in a diaphragm electrolyser-activator in the form of catholyte and anolyte. An alkaline catholyte with a pH of 8-12 is obtained in the cathode chamber, and an acid anolyte with a pH of 2-5 is obtained in the anode. In addition, catholyte contains, along with alkali, substances possessing redox properties with a redox potential (ORP) of -200 ...- 900 mV (relative to a silver chloride reference electrode = ChSE), and the anolyte, along with acids, contains oxidizing agents with redox potential of +300 ... + 1000 mV (CSE) [1].

Any natural water is a diluted solution of inorganic compounds - cations and anions - and trace amounts of organic pollutants.

Drinking tap water of the region (Volga River) contains mainly sodium, potassium, calcium, magnesium, chloride, sulfate ions after water treatment facilities with a total salinity of 200 to 430 mg / l and a total hardness of 2.8-3.2 mEq ./l and trace elements impurities within the requirements of sanitary norms and rules [2]. The process of electroactivation is carried out both in periodic and continuous mode.

The method of electroactivation in periodic mode has several disadvantages, including uneven properties along the height of the electrodes [3].

A method for the electroactivation of water and aqueous solutions in a flow-through electrolyser-activator [4], which is included in the installation kit of the STEL-MT-1 type, is described. The unit is equipped with plastic tubes with fittings and water vessels.

The electrolyzer is made of vertical coaxially located outer cylindrical, inner rod electrodes and between them a ceramic diaphragm, which are installed in the lower and upper dielectric bushings, and in the bushings there are channels for supplying and discharging the treated water with fittings, as well as a water-jet pump for supplying water with their separation by electrode chambers. The electrolysis device allows you to adjust the flow rate in the cathode, anode chamber and the suction fluid from the original tank.

The surface of the outer cylindrical cathode is 88 cm ^{2 the} inner anode is 50 cm ² .

The electrolyzer is a typical flow-through electrochemical TEM module of various modifications. A common electrolyzer can contain several TEM-type modules in STEL-type plants, in particular, in the simplest case, the STEL-MT-1 installation includes one TEM module.

At the STEL-MT-1 installation, catholyte and anolyte based on tap water and an aqueous solution of sodium chloride (in the initial solution of 5-10% wt. Nacl) can be produced. When treating tap water in an installation with 6 TEM modules with a total mineralization of 220 mg / l, pH 7.3 by redox potential (ORP) +280 mV (rel. CSE), catholyte and anolyte with the following values were obtained [4]:

pH ORP catholyte 11.3 -800 anolyte 3.3 +1000

with a ratio of catholyte to analyte flow rates of 3.4: 1 and a specific consumption of electricity of 0.28 A · h / l (1000 kul / l), a specific consumption of electricity of 1.4 W · h / l (based on 1 l of total catholyte and anolyte).

The disadvantages of the process are the relatively high specific consumption of the amount of electricity and electricity.

The technical result is the development of a method of electroactivation of water with lower specific consumption of the amount of electricity and electricity.

This is achieved by the fact that in the proposed method, for a given ratio of catholyte and anolyte flow rates of 0.94: 1 ... 1.50: 1 and a specific consumption of electricity amount of 0.071 ... 0.083 Ah-l / specific power consumption is reduced to 0 , 36-0.42 W · h / l while maintaining the quality of activation by pH and ORP.

With a ratio of catholyte to anolyte flow rates of 0.94: 1 ... 1.50: 1, catholyte with a pH of 11.1 ... 11.2 and an ORP of 671 ...- 792 MB and anolyte with a pH of 3.3 are obtained ... 4.2, ORP +861 ... + 890 mV (CSE).

Example 1. At the STEL-MT-1 installation, an inlet hose is connected to a tap of tap water, tap drinking water with a total salinity of 300 mg / l is poured into the source liquid tank, the water supply is turned on, the flow rate of catholyte and anolyte is set at 3.5 l / h (1: 1 ratio), a voltage is applied to the rectifier and a current strength of 0.5 A is installed on the cell (current density at the anode is 0.01 A / cm ² ) at a voltage of 5 V, catholyte and anolyte samples are generated, analyzed, and the following are obtained indicators:

pH ORP, mV specific consumption: the amount of electricity, A · h / l the amount of electricity W · h / l catholyte 11.1 -792 0,071 0.36 anolyte 4.4 +875

The results of other experiments are presented in the table.

No. p / p Type of fluid Flow rate, l / h The ratio of catholyte: anolyte duct velocities Beats electricity consumption, A · h / l Ud.consumption of electricity, W · h / l pH ORP mV (HSE) 2 Catholyte 3.2 0.94: 1 0,076 0.38 11.2 -788 Anolyte 3.4 4.2 +861 3 Catholyte 3.6 1.50: 1 0,083 0.42 11.1 -671 Anolyte 2,4 3.3 +890

Thus, in the proposed method, the specific costs of the amount of electricity and electricity are reduced.

Sources of information

1. Bahir V.M. Modern electrochemical systems for disinfection, purification and activation of water. M., VNIIIMT, 1999, pp. 17-21.

2. Chemical Encyclopedia, Volume I, M., SE, 1988, p. 394.

3. Pat. Russian Federation № 2221753, 2002, IPC C 02 F ^_1/46.

4. Electrochemical activation: water purification and obtaining useful solutions, ed. Bakhira V.M., M., VNIIIMT, Ed. “Marketing Support Services,” 2001, p.17.

Claims (1)

The method of electroactivation of drinking water by unipolar treatment with constant electric current in a flow diaphragm electrolyzer with separate input into and exit from the cathode and anode chambers, characterized in that the electric treatment is carried out at a given ratio of catholyte to anolyte flow rates in the range of 0.94: 1 ÷ 1.50: 1 and transmitting a specific amount of electricity in the range of 0.071-0.083 ampere-hours per 1 liter of catholyte and anolyte.