RU138578U1 - DEVICE FOR ELECTROCHEMICAL WASTE WATER TREATMENT FROM IONS OF HEAVY AND NON-FERROUS METALS - Google Patents

Abstract

A device for treating wastewater from heavy and non-ferrous metal ions, comprising a housing divided into sections of preliminary electric processing in the form of anode and cathode chambers of a diaphragm electrolyzer and electroflotation treatment, characterized in that the anode chamber of the diaphragm electrolyzer is equipped with two cation exchange membranes, the space between which is filled with cation exchange resin in the Η-form and connected by a pipeline to the electroflotation cleaning section.

Description

The proposed utility model relates to devices for the electrochemical treatment of wastewater from ions of heavy and non-ferrous metals and can be used at enterprises of non-ferrous and ferrous metallurgy, mechanical engineering, instrument making, radio electronics, and the electrical industry to create water treatment systems and closed water circulation.

A device for electroflotation, including a camera, the body of which is made in the form of two hermetically separated waterproof conductive diaphragm electrodes and a discharge pipe [USSR author's certificate No. 486792 A1, IPC B03D 1/14, decl. 01/04/1974; publ. 08/05/1975. Bull. No. 37].

The disadvantage of this device is its low efficiency in the separation of fine particles.

A known method of wastewater treatment and a device for its implementation, including electroflotation in a device with perforated electrodes and preliminary electric treatment using insoluble anodes (USSR Author's Certificate No. 966025 A1, IPC C02F 1/46, C02F 1/465, claimed. 12.12.1979; publ. 10/15/1982. Bull. No. 38).

The disadvantage of this invention is the low degree of wastewater treatment from suspended and emulsified impurities.

It is known that a device, selected as a prototype, for electrochemical treatment of wastewater from ions of heavy and non-ferrous metals, comprising a housing divided into sections of preliminary electric processing in the form of anode and cathode chambers of a diaphragm electrolyzer and electroflotation treatment, with a set of insoluble horizontal electrodes placed in it, pipes for supplying waste water and withdrawing purified water and a device for removing sludge [USSR Author's Certificate No. 1675215 A1, IPC C02F 1/46, C02F 1/465, decl. 10/13/1989; publ. 08/30/1991. Bull. No. 32].

The disadvantage of this device is the low degree of purification of wastewater from ions of heavy and non-ferrous metals.

The purpose of the claimed utility model is to eliminate this drawback, namely, increasing the degree of wastewater treatment from non-ferrous and heavy metal ions.

The technical result is achieved by the fact that the anode chamber of the diaphragm electrolyzer is equipped with two cation exchange membranes, the space between which is filled with a cation exchange resin in the H-form and connected by a pipeline to the electroflotation cleaning section.

The presence of a cation exchange resin in the H-form provides an increase in the degree of purification of wastewater from all ions of heavy and non-ferrous metals due to their sorption. The cation-exchange membrane located on the side of the anion-exchange membrane provides an increase in the degree of purification of wastewater from heavy and non-ferrous metal ions due to their transfer under the influence of electric current from the treated wastewater, and the cation-exchange membrane located on the side of the anode ensures the transfer of hydrogen ions generated in the process of electrochemical decomposition of water. The presence of hydrogen ions in the purified water ensures the regeneration of the cation exchange resin and its neutralization.

A comparative analysis of the claimed device of the utility model and the prototype shows that the claimed device differs from the known one in that the anode chamber of the diaphragm electrolyzer is equipped with two cation exchange membranes, the space between which is filled with a cation exchange resin in the H-form and connected by a pipeline to the electroflotation cleaning section.

In FIG. 1. shows a General view of the proposed utility model of the device for electrochemical wastewater treatment from ions of heavy and non-ferrous metals.

A device for electrochemical treatment of wastewater from ions of heavy and non-ferrous metals consists of a housing 1, separated by an overflow partition 2 into a diaphragm electrolyzer and an electroflotation treatment section with a set of insoluble horizontal electrodes placed in it 3. The housing of the device is equipped with a nozzle 5 for draining clarified water and a device 6 for collection and withdrawal of flotation sludge.

The diaphragm electrolyzer is made in the form of anode and cathode chambers.

The cathode chamber is equipped with a vertical insoluble electrode (cathode) 9 and a pipe 4 for introducing wastewater, which is located in the lower part of the cathode chamber.

The anode chamber of the diaphragm electrolyzer is equipped with a vertical insoluble electrode (anode) 8, two cation-exchange membranes 12 and 13, the space between which is filled with cation-exchange resin 14 in the H-form and nozzles 10 and 11 for introducing clarified water and removing purified water.

The device is equipped with a pipe 15 connecting the electroflotation cleaning section with the space of the anode chamber of the diaphragm electrolyzer formed by cation exchange membranes.

The device operates as follows. Wastewater with a pH of 5-7 containing individual ions of heavy and non-ferrous metals (Cd ²⁺ , Cu ²⁺ , Ni ²⁺ , Cr ³⁺ , Zn ²⁺ , Pb ²⁺ , Fe ²⁺ , Fe ³⁺ ) or the mixture enters through the pipe 4 into the cathode chamber of the diaphragm electrolyzer. As a result of electrolysis at the cathode 9, a discharge reaction of water molecules occurs, accompanied by the release of hydrogen bubbles and the formation of hydroxyl ions (2H ₂ O + 2ē = H ₂ ↑ + 2OH ^- ). The presence of an anion exchange membrane 7 provides alkalization of wastewater to a pH of 8-10, at which particles of sparingly soluble compounds in the form of hydroxides of heavy and non-ferrous metals (Me ^{n +} + nOH ^- = Me (OH) _n ) are formed. At the same time, flotation of the formed particles occurs with hydrogen bubbles.

Next, the wastewater from the cathode chamber is poured through the partition 2 and enters the electroflotation treatment section, where particles of hydroxides of heavy and non-ferrous metals are extracted on the surface of the wastewater due to the operation of the electrode unit 3 generating gas bubbles of hydrogen and oxygen.

In the section of electroflotation treatment, a downward movement of water is provided with its removal from under the electrode block 3. At the same time, an additional cleaning effect is observed associated with filtering wastewater through a dense filter of electrolytic bubbles.

Particles of non-ferrous and heavy metals hydroxides that have surfaced during electroflotation onto the water surface are formed into a foam layer (flotation sludge), which is removed by device 6.

The clarified water with a pH of 8-10 flows from the electroflotation purification section through the nozzle 5 and through the pipe 15 enters through the nozzle 10 into the space of the anode chamber of the diaphragm electrolyzer, formed by two cation exchange membranes 12 and 13, and filled with cation exchange resin 14 in the H-form.

When clarified water passes through a layer of cation exchange resin in the H-form, the resin absorbs all the ions of heavy and non-ferrous metals remaining in it, and an equivalent amount of hydrogen ions passes into the water, which is accompanied by neutralization of the pH of the purified water to a pH value of 7-9.

As a result of the discharge of water molecules, in the anode chamber of the diaphragm electrolyzer on anode 8, hydrogen ions H ^{+ are formed} and oxygen gas O _{2 is released} (2H ₂ O = O ₂ ↑ + 4H ⁺ + 4ē). Hydrogen ions migrate through the cation exchange membrane 13 into the space filled with the cation exchange resin under the action of an electric current. With a decrease in the sorption capacity of the cation exchange resin, it absorbs hydrogen ions from the clarified water, and heavy and non-ferrous metal ions pass into the water, which migrate from the clarified water through the cation exchange membrane 12 under the influence of electric current.

The presence of hydrogen ions in the purified water ensures continuous regeneration of the cation exchange resin without replacing it and without the use of additional regeneration reagents and special devices.

Purified water with a pH of 7-8 is discharged from the installation through the pipe 11.

The proposed utility model allows to increase the degree of purification of wastewater from ions of heavy and non-ferrous metals up to 99.99%.

Claims (1)

A device for treating wastewater from ions of heavy and non-ferrous metals, comprising a housing divided into sections of preliminary electric processing in the form of anode and cathode chambers of a diaphragm electrolyzer and electroflotation treatment, characterized in that the anode chamber of the diaphragm electrolyzer is equipped with two cation exchange membranes, the space between which is filled with cation exchange resin in the Η-form and connected by a pipeline to the electroflotation cleaning section.

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