CN114804306A - Three-dimensional electrode wastewater treatment reactor - Google Patents

Abstract

The invention discloses a three-dimensional electrode wastewater treatment reactor. The three-dimensional electrode wastewater treatment reactor includes an electrolytic cell, an anode, a cathode, a particle electrode, a DC power supply, and an aeration device; a liquid inlet is provided at the lower part of the electrolytic cell, and a liquid outlet is provided at the upper part; two cathodes and a liquid outlet are provided inside the electrolytic cell. An anode; the anode and the cathode are respectively connected with the positive and negative electrodes of the DC power supply; the particle electrode is filled between the anode and the cathode; the aeration device feeds air into the electrolytic cell through a microporous aeration pipe. The invention adopts two cathodes and one anode, which increases the specific surface area of the cathode and can produce more strong oxidizing substances such as OH, H ₂ O ₂ , etc.; meanwhile, the distance between the reactant and the electrode is shortened, and the mass transfer effect is enhanced. , thereby improving the wastewater treatment effect. The particle electrode adopts proportionally filled insulating particles and conductive particles, which reduces the short-circuit current in the process of wastewater treatment, improves the degradation efficiency and current efficiency of wastewater, and reduces energy consumption.

Description

A three-dimensional electrode wastewater treatment reactor

technical field

The invention belongs to the field of wastewater treatment, in particular to a three-dimensional electrode wastewater treatment reactor.

Background technique

With the rapid development of the chemical industry, more and more organic compounds are used in electroplating, printing and dyeing, medicine and other industries. Wastewater is large in volume, complex in composition, poor in biodegradability, contains toxic and harmful substances, is difficult to handle, and causes serious harm to the environment. Therefore, the treatment of wastewater has become an urgent problem to be solved.

In recent years, electrocatalytic oxidation technology has made great progress in wastewater treatment due to its high efficiency, good environmental compatibility, and easy operation. However, the traditional two-dimensional electrocatalytic oxidation method has the shortcomings of small surface-to-body ratio, poor mass transfer effect, and low current efficiency, and has obvious defects in practical engineering applications.

In response to this defect, Backhurst proposed the concept of three-dimensional electrode oxidation in the late 1960s. In essence, it is an upgrade and improvement of two-dimensional electrodes. Electrode materials of different shapes, different materials and conductive electrodes are added between the main electrode plates of traditional two-dimensional electrodes as particle electrodes to form three-dimensional electrolysis. The addition of particle electrodes will form many micro-electrolytic cells in the electrolysis reactor to accelerate the electrochemical reaction.

Compared with the two-dimensional electrode, the particle electrode increases the reaction area of the electrode, improves the mass transfer efficiency, and effectively improves the degradation rate of pollutants. Therefore, the use of three-dimensional electrode method has broad prospects in the application of treatment of industrial wastewater pollutants. However, there are still shortcomings in the three-dimensional electrode method. For example, the electrode material is easy to passivate and corrode, and the life is short;

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the deficiencies of the prior art, the purpose of the present invention is to provide a three-dimensional electrode wastewater treatment reactor, which improves the yield of strong oxidizing substances such as OH, H ₂ O ₂ , and effectively improves the waste water Treatment effect; the reactor reduces the short-circuit current in the reaction process, improves the wastewater degradation efficiency and current efficiency, and significantly reduces energy consumption.

In order to achieve the above goals, the present invention adopts the following technical solutions:

A three-dimensional electrode wastewater treatment reactor is characterized in that it comprises an electrolytic cell, an anode, a cathode, a particle electrode, a DC power supply and an aeration device; the electrolytic cell is provided with a liquid inlet at the lower part and a liquid outlet at the upper part; Two cathodes and one anode are arranged inside the electrolytic cell; the anode and the cathode are respectively connected with the positive and negative electrodes of the DC power supply; the particle electrode is filled between the anode and the cathode; Air.

Preferably, the electrolytic cell is a rectangular electrolytic cell.

Preferably, the inner wall of the electrolytic cell is provided with a slot for fixing the anode and the cathode.

Preferably, a fixing plate is provided inside the electrolytic cell, which is located on the side close to the bottom of the electrolytic cell to prevent the particle electrodes from depositing on the bottom of the electrolytic cell.

Preferably, the fixing plate has holes with an opening rate of 30% to 80% and a hole diameter of 1 to 8 mm.

Preferably, the optimal range of the aperture ratio is 60% to 70%, and the optimal range of the aperture is 3 to 5 mm.

Preferably, the anode is a titanium-based coated electrode.

Preferably, the cathode includes a graphite electrode, a stainless steel electrode, an activated carbon fiber electrode, and a titanium electrode.

Preferably, among the cathodes, graphite electrodes and activated carbon fiber electrodes have the best performance.

Preferably, the anode is placed vertically at the center of the electrolytic cell, and a cathode is placed on each side parallel to the anode.

Preferably, the particle electrode is composed of conductive particles and insulating particles, the conductive particles are activated carbon, and the insulating particles are any one of glass beads, ceramsite, quartz sand, and artificial zeolite.

Preferably, among the insulating particles, glass beads and ceramic particles have the best performance.

Preferably, the conductive particles and the insulating particles have similar bulk densities, and the bulk densities range from 0.3 to 0.8 g/cm ³ . .

Preferably, the optimal value range of the bulk density of the conductive particles and the insulating particles is 0.45-0.65 g/cm ³ .

Preferably, the mass filling ratio of the conductive particles to the insulating particles is 1:1 to 5:1.

Preferably, the optimal mass filling ratio of the conductive particles to the insulating particles is 1:1 to 3:1.

Preferably, the microporous aeration pipe is located at the bottom of the electrolytic cell, below the fixed plate, and the microporous aeration pipe is connected to the aeration device through a flowmeter, and the aeration volume is adjusted by the flowmeter. The adjustment range is 0～180L/h.

Preferably, the aeration rate is 60-120L/h.

Compared with the prior art, the beneficial effects of the present invention are as follows:

(1) The present invention uses a graphite electrode or an activated carbon fiber electrode as a cathode, and its surface can generate more H ₂ O ₂ , thereby increasing the yield of OH and improving the degradation efficiency; at the same time, its hydrogen evolution potential is high, which can effectively reduce occurrence of side reactions.

(2) The present invention adopts two cathodes and one anode, which increases the specific surface area of the cathode and can generate more strong oxidizing substances such as OH, H ₂ O ₂ and the like. At the same time, the distance between the reactant and the electrode is shortened, the mass transfer is enhanced, and the treatment effect is improved.

(3) The particle electrode of the present invention selects proportionally filled insulating particles and conductive particles, which reduces the short-circuit current in the degradation process of the three-dimensional electrode reactor, improves the degradation efficiency and current efficiency of wastewater, and reduces energy consumption; insulating particles and The packing density of the conductive particles is similar, which avoids the problem of delamination of the insulating particles and the conductive particles during the reaction.

(4) the present invention adopts aeration device to introduce air to the electrolytic cell, on the one hand, the concentration of O in the wastewater system is improved _; on the other hand, under the action of aeration, the particle electrode in the three-dimensional electrode reactor is in a suspended state, and the The increase of the contact area between the electrode and the wastewater system can enhance the mass transfer, which is beneficial to improve the current efficiency.

Description of drawings

Fig. 1 is the structure diagram of the three-dimensional electrode wastewater treatment reactor of the present invention;

In the figure: (1) electrolytic cell; (2) anode; (3) cathode; (4) particle electrode; (5) DC power supply; (6) aeration device; (7) flow meter; (8) microporous aeration Trachea; (9) Fixed plate; (10) Liquid inlet; (11) Liquid outlet.

Detailed ways

The three-dimensional electrode wastewater treatment reactor of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

Example 1:

As shown in FIG. 1 , a three-dimensional electrode wastewater treatment reactor includes an electrolytic cell 1 , an anode 2 , a cathode 3 , a particle electrode 4 , a DC power supply 5 and an aeration device 6 . The lower part of the electrolytic cell 1 is provided with a liquid inlet 10, and the upper part is provided with a liquid outlet 11. The liquid inlet 10 is used to introduce the wastewater to be treated, and the liquid outlet 11 is used to discharge the treated wastewater; the inner wall of the electrolytic cell 1 There is a card slot for fixing the anode 2 and the cathode 3; the inside of the electrolytic cell 1 is provided with a perforated fixing plate 9, which is located close to the bottom side of the electrolytic cell 1 to prevent the particle electrode 4 from being deposited on the bottom of the electrolytic cell 1; Anode 2 and The cathode 3 is placed in the electrolytic cell 1 vertically, and is parallel to each other, the anode 2 is connected to the positive pole of the DC power supply 5, the cathode 3 is connected to the negative pole of the DC power supply 5, and the particle electrode 4 is filled between the anode 2 and the cathode 3; 8. At the bottom of the electrolytic cell 1, below the fixed plate 9, the microporous aeration pipe 8 is connected to the aeration device 6 through a flow meter 7, and the aeration amount is adjusted through the flow meter 7.

The anode 2 is a titanium-based coating electrode, which can be selected from a ruthenium-iridium-coated titanium electrode, a tin-antimony-coated titanium electrode, or an iridium-tantalum-coated titanium electrode.

The cathode 3 is a graphite electrode, a stainless steel electrode, an activated carbon fiber electrode or a titanium electrode, among which, the graphite electrode and the activated carbon fiber electrode have the best performance.

The distance between the anode 2 and the cathode 3 is 4-8 cm.

The particle electrode 4 is composed of conductive particles and insulating particles, the conductive particles are activated carbon, and the insulating particles are any one of glass beads, ceramsite, quartz sand, and artificial zeolite. Among the insulating particles, glass beads and ceramsite have the best performance. ; The bulk density of conductive particles and insulating particles is similar, the range of bulk density is 0.3～0.8g/cm ³ , and the optimum value range of bulk density is 0.45～0.65g/cm ³ ; The mass filling of conductive particles and insulating particles The ratio is 1:1~5:1, and the optimal quality filling ratio is 1:1~3:1.

The adjustable aeration volume range of the flow meter 7 is 0-180L/h; wherein, the optimal value range of the aeration volume is 60-120L/h.

The aperture ratio of the fixed plate 9 is 30%-80%, and the aperture is 1-8mm; wherein, the optimal range of aperture ratio is 60%-70%, and the optimal range of aperture is 3-5mm.

Using two cathodes 3 and one anode 2 increases the specific surface area of the cathode 3 and can produce more strong oxidizing substances such as OH, H ₂ O ₂ . At the same time, the distance between the reactant and the electrode is shortened, the mass transfer is enhanced, and the treatment effect is improved.

The particle electrode 4 uses proportionally filled insulating particles and conductive particles, which reduces the short-circuit current in the degradation process of the three-dimensional electrode reactor, and improves the degradation efficiency and current efficiency of wastewater; Delamination of insulating particles and conductive particles during the reaction.

The function of the aeration device 6: on the one hand, the concentration of O ₂ in the wastewater system is increased; on the other hand, under the action of aeration, the particle electrodes in the three-dimensional electrode reactor are in a suspended state, and the contact area between the particle electrodes and the wastewater system is large. Enhanced mass transfer is beneficial to improve current efficiency.

Example 2:

The three-dimensional electrode wastewater treatment reactor shown in FIG. 1 is used to treat the printing and dyeing wastewater of a certain factory. The operating conditions are as follows: the printing and dyeing wastewater to be treated enters the electrolytic cell 1 through the liquid inlet 10, and the treated printing and dyeing wastewater is discharged from the liquid outlet 11. Aeration in electrolyzer 1 by aerator 6, aeration volume is 70L/h; Anode 2 adopts ruthenium-iridium coating titanium electrode, links with the positive pole of DC power supply 5; Negative electrode 3 adopts graphite electrode, with DC power supply 5 The anode 2 and cathode 3 are connected to each other, and the distance between anode 2 and cathode 3 is 5 cm; the activated carbon and insulating particle glass beads that are saturated with adsorption are filled between anode 2 and cathode 3 according to the mass ratio of 1:1, and the bulk density of activated carbon and glass beads are both 0.47 g/cm ³ . The porosity of the fixed plate 9 is 70% and the pore diameter is 3 mm; the operating current density of the three-dimensional electrode wastewater treatment reactor is 50 mA/cm ² , the reaction time is 120 min, and the pH of the solution is 5. The COD of the influent printing and dyeing wastewater was 4725mg/L. After the three-dimensional electrode reactor treatment, the effluent COD of the printing and dyeing wastewater was reduced to 853mg/L, the COD removal rate was 81.9%, and the energy consumption was 77kWh/kgCOD.

Example 3:

The three-dimensional electrode wastewater treatment reactor shown in FIG. 1 is used to treat the printing and dyeing wastewater of a certain factory. The operating conditions are as follows: the printing and dyeing wastewater to be treated enters the electrolytic cell 1 through the liquid inlet 10, and the treated printing and dyeing wastewater is discharged from the liquid outlet 11. Aeration in electrolyzer 1 by aerator 6, aeration volume is 90L/h; Anode 2 adopts ruthenium-iridium coating titanium electrode, is connected with the positive pole of DC power supply 5; Negative electrode 3 adopts activated carbon fiber electrode, and DC power supply The negative electrodes of 5 are connected, and the distance between the anode 2 and the cathode 3 is 5 cm; the activated carbon and insulating particle glass beads that are saturated with adsorption are filled between the anode 2 and the cathode 3 according to the mass ratio of 2:1, and the bulk density of the activated carbon and the glass beads are both. 0.47 g/cm ³ ; the porosity of the fixed plate 9 is 70%, the pore diameter is 3 mm; the operating current density of the three-dimensional electrode wastewater treatment reactor is 40 mA/cm ² , the reaction time is 120 min, and the pH of the solution is 5. The influent COD of printing and dyeing wastewater was 4970mg/L. After the three-dimensional electrode reactor treatment, the effluent COD of printing and dyeing wastewater was reduced to 595mg/L, the COD removal rate was 88.0%, and the energy consumption was 55kWh/kgCOD.

Example 4:

The three-dimensional electrode wastewater treatment reactor shown in FIG. 1 is used to treat citric acid wastewater in a certain factory. The operating conditions are: the citric acid wastewater to be treated enters the electrolytic cell 1 through the liquid inlet 10, and the treated citric acid wastewater is discharged from the liquid outlet. The mouth 11 is discharged; Aeration is carried out in the electrolytic cell 1 by the aerator 6, and the amount of aeration is 80L/h; The negative electrode of the DC power supply 5 is connected, and the distance between the anode 2 and the cathode 3 is 7 cm; the adsorbed activated carbon and the insulating particle ceramsite are filled between the anode 2 and the cathode 3 according to the mass ratio of 2:1, and the bulk density of the activated carbon and the ceramsite is Both are 0.51 g/cm ³ ; the porosity of the fixed plate 9 is 70%, and the pore diameter is 3 mm; the operating current density of the three-dimensional electrode wastewater treatment reactor is 50 mA/cm ² , the reaction time is 120 min, and the pH of the solution is 6. The COD of citric acid wastewater influent was 4332mg/L. After three-dimensional electrode reactor treatment, the COD of citric acid wastewater effluent was reduced to 745mg/L, the COD removal rate was 82.8%, and the energy consumption was 84kWh/kgCOD.

Example 5:

The three-dimensional electrode wastewater treatment reactor shown in FIG. 1 is used to treat citric acid wastewater in a certain factory. The operating conditions are: the citric acid wastewater to be treated enters the electrolytic cell 1 through the liquid inlet 10, and the treated citric acid wastewater is discharged from the liquid outlet. The mouth 11 is discharged; Aeration is carried out in the electrolytic cell 1 by the aerator 6, and the amount of aeration is 100L/h; It is connected to the negative electrode of the DC power supply 5, and the distance between the anode 2 and the cathode 3 is 5 cm; the activated carbon and the insulating particle ceramsite that are saturated with adsorption are filled between the anode 2 and the cathode 3 according to the mass ratio of 3:1, and the accumulation of activated carbon and ceramsite The density is 0.51g/cm ³ ; the opening rate of the fixed plate 9 is 65%, and the pore diameter is 3 mm; the operating current density of the three-dimensional electrode wastewater treatment reactor is 40 mA/cm ² , the reaction time is 120 min, and the pH of the solution is 6. The COD of the citric acid wastewater influent was 4261mg/L. After the three-dimensional electrode reactor treatment, the COD of the citric acid wastewater effluent was reduced to 621mg/L, the COD removal rate was 85.4%, and the energy consumption was 66kWh/kgCOD.

The above-mentioned specific embodiments describe in detail the technical solutions and beneficial effects of the present invention. It should be understood that the above-mentioned embodiments are only the most preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, additions and equivalent substitutions made within the scope shall be included within the protection scope of the present invention.

Claims (10)

1. A three-dimensional electrode wastewater treatment reactor is characterized by comprising an electrolytic tank, an anode, a cathode, a particle electrode, a direct current power supply and an aeration device;

the lower part of the electrolytic bath is provided with a liquid inlet, and the upper part of the electrolytic bath is provided with a liquid outlet; two cathodes and an anode are arranged in the electrolytic cell; the anode and the cathode are respectively connected with the anode and the cathode of a direct current power supply; the particle electrode is filled between the anode and the cathode; the aeration device leads air into the electrolytic bath through the microporous aeration pipe.

2. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein the electrolytic cell is a rectangular electrolytic cell, and the inner wall of the electrolytic cell is provided with a clamping groove for fixing the anode and the cathode.

3. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein a fixed plate is disposed inside the electrolytic cell and located at a side close to the bottom of the electrolytic cell to prevent the particle electrode from depositing on the bottom of the electrolytic cell, the fixed plate is perforated with holes having a porosity of 30-80% and a diameter of 1-8 mm.

4. The three-dimensional electrode wastewater treatment reactor of claim 1, wherein the anode is a titanium-based coated electrode.

5. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein the cathode comprises a graphite electrode, a stainless steel electrode, an activated carbon fiber electrode, and a titanium electrode.

6. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein the anode is vertically placed at the center of the electrolytic cell, and a cathode is placed in parallel to each side of the anode.

7. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein the particle electrode is composed of conductive particles and insulating particles, the conductive particles are activated carbon, and the insulating particles are any one of glass beads, ceramsite, quartz sand and artificial zeolite.

8. The three-dimensional electrode wastewater treatment reactor according to claim 7, wherein the conductive particles and the insulating particles have a bulk density similar to each other, and the bulk density is in a range of 0.3-0.8 g/cm ³ 。

9. The three-dimensional electrode wastewater treatment reactor according to claim 7, wherein the mass filling ratio of the conductive particles to the insulating particles is 1: 1-5: 1.

10. The three-dimensional electrode wastewater treatment reactor according to claim 1, wherein the microporous aeration pipe is arranged at the bottom of the electrolytic tank and below the fixing plate, the microporous aeration pipe is connected with the aeration device through a flow meter, the aeration rate is adjusted through the flow meter, and the adjustment range of the flow meter is 0-180L/h.

Images