RU2297980C1 - Method of the electroactivation of the water solutions - Google Patents

Abstract

FIELD: technology of treatment of the water solutions; methods of electroactivation of the water solutions.

SUBSTANCE: the invention is pertaining to the technology of treatment of the water solutions and may be used for production of the electroactivated solutions. The water solution of the sodium the sodium sulfate, either sodium acetate, or ammonium chloride with concentration of 0.50...0.95% is treated with the direct electric current in the flow diaphragm electrolyzer at the ratio of the catholyte and the anolyte of 0.744-0.942, the specific consumption of the electric power of 0.370-0.448 ampere-hours per one liter of the summed the catholyte and then anolyte. The technical result of the invention is reduction of consumption of the salt and the amount of the utilizable spent solutions at the preset parameters of the electroactivation.

EFFECT: the invention ensures the reduced consumption of the salt and the amount of the utilizable spent solutions at the preset parameters of the electroactivation.

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Description

The invention relates to a technology for processing aqueous solutions and can be used to obtain electroactivated solutions.

The processes of electroactivation of water and aqueous solutions are used in agriculture, medicine, industry. Electroactivation is carried out by processing solutions in a diaphragm electrolyser-activator with direct electric current. At the same time, in the cathode chamber of the activator, an alkaline solution — catholyte — is obtained with a pH of 8-12, and in the anode chamber, an anolyte with a pH of 2-5 — an acid solution. Catholyte, along with alkali, contains substances possessing reducing properties with redox potential (ORP) of -200 ...- 900 mV (relative to silver chloride reference electrode, CSE), anolyte, along with acids, are oxidizing substances with an ORP of +300 ... +1000 mV.

Catholyte has detergent properties, anolyte has disinfecting properties [1], the methods of their application are mainly based on these properties. As a solvent, distilled or tap drinking water can be used.

A method is described for the electroactivation of aqueous solutions of sodium chloride — an initial solution with a concentration of 5 ... 10 wt.% At the STEL type electroactivation unit, which is produced commercially by NPO Ekran (Moscow) (prototype) [2].

The installation kit includes a diaphragm electrolyzer-activator, tanks for the initial solution, for collecting catholyte and anolyte, a rectifier, connecting tubes with fittings. The electrolyzer of the vertical type includes a coaxially located inner rod anode, a cylindrical outer cathode, a ceramic diaphragm between them, which are fixed in the lower and upper bushings, with channels for supplying and discharging liquid with gaskets and a water-jet pump at the inlet for supplying liquid from the initial container to the cathode and anode chamber. The electrodes are made of corrosion resistant materials. At the STEL-MT-1 type installation - one set of TEM type electrodes. The surface of the cathode is 88 cm ² , the anode is 50 cm ² . To produce anolyte disinfectant solution, a 5-10% sodium chloride solution is used as the initial solution. After flushing the system, the inlet hose is connected with a tap of water, the suction hose is connected to the capacity of the initial solution, voltage is applied to the electrodes, the current strength is set to 5.0 ... 7.5 A, and at the flow rate of catholyte and anolyte, 10 l / h are generated anolyte and catholyte with a pH of 2 ... 3 and 11 ... 12, respectively. Anolyte contains up to 300 mg / l of oxidizing agents (oxidants) based on active chlorine. Anolyte is used for its intended purpose, for example, for disinfection of livestock buildings, food production equipment.

The disadvantages of the method: high consumption of salt of sodium chloride and, accordingly, the need for disposal of a large number of waste solutions and sodium chloride.

EFFECT: development of a method for electroactivation of aqueous solutions with a lower consumption of various salts and a low amount of utilized waste solutions at given technological parameters of electroactivation.

This is achieved by the fact that a 0.50 ... 0.95% solution of the available salts — sodium chloride, sodium sulfate, sodium acetate, ammonium chloride — is used as the initial solution, with the flow rate ratios of catholyte and anolyte 0.744 ... 0.942 with specific consumption of the amount of electricity 0.370 ... 0.448 ampere-hours (Ah) per 1 liter of total catholyte and anolyte. It receives anolyte with a pH of 1.8 ... 5.0 and an ORP (CSE) of +903 ... 1189 mV and a catholyte of pH 9.2 ... 12.4 and an ORP of -726 ...- 894 mV.

Example 1. On the installation of the type "STEL-MT-1" using a 0.90% solution of sodium chloride, an electric treatment is carried out at a current strength of 5 A at a temperature of +20 ... 25 ° C. Anolyte and catholyte are accumulated at flow rates of 7.1 and 6.4 l / h (catholyte / anolyte ratio 0.901) with the following quality indicators:

pH ORP, mV anolyte 1.8 +1189 catholyte 12,4 -892

with a specific consumption of electricity Q 0.370 A · h / l.

The results of other experiments are presented in the table.

Experience number Type of stock solution Catholyte / anolyte flow rate ratio Catholyte Anolyte Q, A · h / l pH ORP, mV pH ORP, mV 2 0.5% sodium sulfate 0.840 12.1 -894 2,3 +1027 0.402 3 0.95% sodium acetate 0.744 11.9 -855 5,0 +903 0.320 four 0.8% sodium chloride 0.942 9.2 -726 1.8 +1160 0.448

Anolytes contained up to 400 mg / l of oxidants. The current strength can vary within the regulated values (5-7.5 A) at the STEL-MT-1 installation, but with a ratio of flow rates and specific consumption of electricity.

Thus, in the proposed method, the consumption of salt in the concentration is reduced from 5 ... 10% to 0.50 ... 0.95%, the number of utilized-spent solutions is reduced for the given technological parameters of electroactivation.

Changes in the proposed parameters of electroactivation lead to an increase in the consumption of electricity or to a decrease in the quality of catholyte and anolyte.

Information sources

1. Bahir V.M. Modern technical electrochemical systems for disinfection, purification and activation of water. M .: VNIIMT, 1999, 84 pp.

2. Installation of STEL-MT-1. Operator's manual with a regimen-technological map, NPO Ekran, Moscow, 1993.

Claims (1)

The method of electroactivation of aqueous solutions, including the processing of the initial solutions with direct electric current in a flow diaphragm electrolyzer with separate input into the cathode and anode chambers and the conclusion from them, characterized in that 0.5-0.95% chloride solution is used as the initial solutions sodium, or sodium sulfate, or sodium acetate, or ammonium chloride with a ratio of catholyte and anolyte flow rates of 0.744-0.942 with a specific electricity consumption of 0.370-0.448 Ah per 1 liter of total catholyte and anolyte.