SU903302A1 - Method and electrolyzer for electrochemical purification of aqueous solutions - Google Patents

Description

(5t) METHOD FOR ELECTROCHEMICAL CLEANING OF AQUATIC

SOLUTIONS AND ELECTROLISER FOR IT

I

This invention relates to a process for the treatment of water and aqueous solutions by an electrochemical method, based on the performance of electrode redox reactions,

The known method of electrochemical purification of aqueous solutions with the imposition of a magnetic field in which a uniform magnetic field is used. The method is carried out in an electrolyzer comprising a housing with electrodes and magnets f1} placed in it.

The disadvantages of this method are high energy consumption and low degree of purification.

The purpose of the invention is to reduce energy consumption and increase the degree of purification.

The goal is achieved by the fact that according to the method of electrochemical purification of aqueous solutions with the imposition of a magnetic field using a polygradient magnetic field. IMPLEMENTATION

With a intensity of 0.07-0.8 T and a gradient of intensity of 0.1-1.5 T / cm.

The proposed method is carried out in an electrolyzer, including a housing with electrodes and magnets placed in it, the magnets being connected to the electrodes by different poles and located outside the interelectrode space at a distance from each other.

The magnets are made in the form of an errit plate with alternating magnetic and non-magnetic zones.

Zones are made in the form of squares placed in a checkerboard pattern.

Magnetic zones can also be made in the form of circles.

The advantage of a polygradient inhomogeneous magnetic field over a homogeneous one is based on the fact that the intensity of the circulation of an electrically conducting solution placed in a crossed electric and magnetic field under the action of the Lorentz volume force is determined by the degree of heterogeneity of one of these fields. Therefore, the imposition of a poly gradient magnetic field on an electrochemical cell leads to the emergence of a variety of macro and microvortex convection currents along the surface of the electrodes, which increases the intensity of the electrode oxidative redox reactions and, consequently, the efficiency of electrochemical treatment, and the superimposed polygraded magnetic field only on the near electrodes. the processed solution of technical electrodes, on which the O) flow of the redox reactions is inhibited This or that kind of polarization allows to significantly reduce the energy and material costs of creating a magnetic field. The drawing shows schematically a device that implements the proposed method. The device includes a housing 1 through which the treated solution flows, a source of electric current 2, electrodes 3 and, as well as magnets 5 in the form of plates. When pairing magnets 5 with electrodes, the arrangement condition is magnetic;); systems outside the interelectrode space (between two electrodes of the same sign 3 and a hollow two-sided electrode of the other sign 4), and a poly gradient magnetic field is created in the electrode layers of these electrodes. In the electrolyzer, cadmium is extracted from the spent electrolyte (from the sulfuric acid, cadmium treatment) process by reducing Cd to the metallic state on a flat titanium cathode. Graphite is used as an anode, and the cathode and anode spaces of the electrolyzer are separated by a chlorin diaphragm, P 1 and p 1, the process of cathodic reduction of Cd ions is inhibited by concentration polarization due to the diffuse nature of the kinetics of this electrode process. A polygradient magnetic field at the cathode is created by pairing the cathode with a ferrite plate, in which magnetic and non-magnetic zones are created as a result of preliminary magnetization. The thickness of the magnetic and non-magnetic zones change during the experiments in such a way that on the surface of the cathode the magnetic field strength varies within 0.08-0.1 T with the gradient of the magnetic field intensity between the magnetic zones 0.05-0.3 T / cm. Comparative results of the treatment of spent electrolyte from the cadmium plating process in various ways are presented in tab.1. Table 1

1.6 2.5 0.06 1.62 W, 0.07 1.62 3.7 .0.10 1.69, 6.

0.03-0.06 0.05-0.092.5

0.07 0.12.15

0.10 0.12.08

Claims (3)

0.07 0.32.0 Example 2. The electrocoagulation treatment of oil-containing sewage consists of introducing coagulum (Fe ions) into waste water by anodic dissolution of steel electrodes. This process slows down the passivation of anodes over time, which leads to the need to provide for the polarity reversal of the electrodes with a certain frequency. By imposing anodic or polygradient magnetic fields by placing the electrolyzer in a solenoid, it is possible to intensify the process of anodic dissolution of the electrodes by preventing their passivation. A polygradient magnetic field at the anode is created by pairing. As can be seen from the above examples, the imposition of a polygradient magnetic field on the electrode layers of the treated solutions of those electrodes on which the course of redox reactions is inhibited by the presence of one or another type of polarization increases the the efficiency of the near-electrode processes (to increase the current efficiency or, in other words, to increase the degree of purification) by 15-26 S, as well as to reduce the specific energy consumption for 20-55. Accordingly, the economic effect of using a ferrite plate, and which, as a result of preliminary magnetization, creates magnetic zones in the form of squares alternating in a staggered order, separated by nonmagnetic zones. Neighboring magnetic zones on each of the ferrite plates are anti-polar polarity, and the axes of the magnetic zones are perpendicular to the working nnocKoctM electrode. The dimensions of the magnetic and nonmagnetic zones change during the experiments in such a way that on the anode surface the magnetic field strength between the magnetic zones is 0.05-0.3 T / cm. Comparative data on anodic dissolution of iron during electrocoagulation treatment of oil-containing wastewater are presented in Table 2. Table 2 of the proposed method will be added when processing a particular aqueous solution from the savings in production space, from energy savings and savings in capital costs of creating a magnetic system. Claim 1. Investigation of the method of electrochemical purification of aqueous solutions with the imposition of a magnetic field. the fact that, in order to reduce energy consumption and increase the degree of purification, when cleaning, polygradient is used a magnetic field with a intensity of 0.07 0.08 T and a gradient of intensity of 0.1-1.5 T / cm. 2. An electrolyzer for carrying out the method of Claim 1, comprising a housing, with electrodes and magnets placed in it, characterized in that they are magnetically connected to electrodes with different poles and placed outside the interelectrode space at a distance from each other, 3. Electrolyzer according to Clause 1, which is based on the fact that the magnets are made. in the form of a ferrite plate with alternating magnetic and non-magnetic zones, The electrolyzer according to claim 3, about tl and the fact that the zones are made in the form of squares placed in a checkerboard pattern, 5, The electrolyzer in accordance with claim 3, about tl and in that the zones are made in the form of a circle. ((information taken into consideration during the examination 1. The lime of the Academy of Sciences of the Latvian SSR "Series of physical and chemical sciences, 1967, And 6, p. 55-62,