CN107522267A - A kind of multistage out-phase three-dimensional electrochemical reaction unit for waste water treatment - Google Patents

Abstract

The invention discloses a kind of multistage out-phase three-dimensional electrochemical reaction unit for waste water treatment, the device is multi-stage series system, every section of at least two reative cells for including being separated by central dividing plate and a gas distribution deslagging chamber, the battery lead plate of vertical parallel arrangement is provided with reative cell, battery lead plate is alternately positive pole and negative pole, is connected in parallel on external power supply.The granule electrode of supported catalyst is filled between battery lead plate.Aeration board, pipe or disk are set in gas distribution deslagging chamber, external gas generator is connected by gas pipeline, oxidizing gas is provided into reactor.Gas distribution deslagging chamber lower end is provided with evacuation port, periodically carries out body refuse cleaning and the emptying of sewage.The connection of aqueous phase is realized by the gas distribution deslagging chamber of lower end between each reative cell, realizes the UNICOM of aqueous phase between each section of reactor by overfall.Structural reduction of the present invention and integration, easy to operation, maintenance and Automated condtrol, sewage treating efficiency is high, it is few to add chemical agent, sludge output.

Description

A multi-stage heterogeneous three-dimensional electrochemical reaction device for wastewater treatment

technical field

The invention belongs to the technical field of sewage treatment and relates to a multi-stage heterogeneous three-dimensional electrochemical reaction device.

Background technique

At present, the treatment of a large number of high-concentration and refractory industrial wastewater in China has become a major issue that needs to be solved urgently in the environmental field. These industrial wastewater have high concentrations of organic matter, poor biodegradability, complex components, and biological toxic substances. Traditional physicochemical and biochemical treatment methods have Greater limitations.

Three-dimensional electrochemical technology is a new type of advanced oxidation technology. It is composed of particle electrodes filled in traditional two-dimensional electrochemical reactors. It has high treatment efficiency, short hydraulic retention time, small footprint, less waste residue, and broad spectrum adaptability It has broad application prospects and has become one of the research hotspots in the field of pollution control at home and abroad. The action mechanism of three-dimensional electrochemistry includes direct action and indirect action. The direct effect is the electrochemical oxidation and reduction reaction carried out on the electrode surface, which includes both the surface of the main electrode of the yin and yang, and the surface of all particle electrodes. Numerous particle electrodes greatly increase the contact area between the solution and the electrode, shorten the mass transfer distance, and improve the current efficiency and pollutant degradation effect.

The indirect effect refers to the chain reaction of free radicals induced in the electric field. After aeration, the dissolved oxygen, the oxygen generated at the anode and the anode of the particle electrode, are reduced at the cathode and the cathode of the particle electrode to generate highly oxidizing hydrogen peroxide and hydroxyl radicals. , and at the same time, under the action of the electromagnetic field and redox electrons in the system on the catalyst, a large number of highly oxidizing free radicals, such as HO ₂ ^- ·, O·, H·, O ₂ ^- ·, O ₃ ^- ·, etc. are generated. These free radicals react with organic matter in wastewater to generate unstable organic free radicals R·, etc., which trigger a large number of free radical chain reactions, thereby gradually and completely oxidizing and decomposing organic pollutants into CO ₂ and H ₂ O.

At present, the actual engineering application of three-dimensional electrochemical technology is still very little, the equipment investment is high, the operation cost is high, and there is no mature equipment and process. The large-scale application of three-dimensional electrochemical technology also requires a lot of basic research work and engineering practice in terms of the structure of the reaction device, the properties of the particle electrode material, the nature of the catalyst type, and the operating process conditions.

Contents of the invention

The purpose of the present invention is to provide a simple structure, simple operation, easy maintenance and automatic control, high processing efficiency, no need to add any chemical agents, low sludge production and high efficiency multi-stage out-of-phase Three-dimensional electrochemical reaction device.

To achieve the above object, the present invention adopts the following technical solutions:

A multi-stage heterogeneous three-dimensional electrochemical reaction device for wastewater treatment, characterized in that the device includes: a body, an external power supply and an external gas generator, the front end of the body is provided with a water inlet, and the end is provided with a water outlet, and at least Two-stage reactors are set up, and the reactors of each stage are connected in series and the water phase communication between the adjacent reactors is realized through the overflow port, wherein:

Each section of the reactor is divided into at least two reaction chambers by the middle partition, and the water phase communication between the reaction chambers is realized through the gas distribution and slag discharge chamber at the lower end; each reaction chamber is equipped with at least two vertically parallel electrode plates, each The positive and negative poles of the electrode plates in the reaction chamber are arranged alternately, and are connected in parallel to an external power supply; particle electrodes are filled between the electrode plates, and the particle electrodes are placed in a basket with sieve holes or stacked on the orifice plate at the bottom of the reaction chamber; The slag chamber is equipped with an aeration plate, tube or plate, and is connected to an external gas generator through a gas pipeline, and the lower end of each section of the reactor is provided with an emptying port.

The electrode plate is one of a boron-doped diamond film plate (BDD), a titanium-based transition metal oxide coating electrode (DSA), a stainless steel plate, a graphite plate or an alloy plate. Preferably, the anode is one of boron-doped diamond film electrode (BDD) and titanium-based transition metal oxide coating electrode (DSA); the cathode is one of stainless steel electrode and graphite electrode.

The particle electrode is based on particles, on which are loaded catalysts for the degradation and removal of pollutants in heterogeneous catalysis; the substrate is granular activated carbon, aluminum oxide particles or zeolite particles, used alone or in combination of two or more Use; The catalyst is one or more mixtures of titanium dioxide, metal or transition metal oxides. Preferably, the particle electrode uses activated carbon particles or activated carbon particles doped with aluminum oxide particles as the matrix, and the matrix supports nano-titanium dioxide, manganese oxide, copper oxide, iron oxide, ruthenium oxide, palladium oxide, cobalt oxide, One or more of silver oxide, cerium oxide, titanium oxide, zinc oxide, etc. are particle electrodes.

The stuffing baskets are connected in series horizontally or vertically.

The external power supply is set to one or several sets, and each section of reactor is provided with one or several sections of reactors share one.

The air distribution and slagging chamber is an inverted cone or rectangular structure. Preferably, it is designed as a cuboid structure. The bottom of the air distribution and slagging chamber is provided with a certain inclination angle, which is conducive to the discharge of sludge and sewage. The air distribution and slag discharge chamber is equipped with an aeration plate, tube or plate; the aeration plate, tube or plate is connected to an external gas generator through a gas pipeline;

The external gas generator is an air compressor or an ozone generator. Preferably, an external air compressor or an ozone generator is connected through a gas pipeline to provide compressed air or ozone into the reactor.

The emptying port is used for cleaning mud and slag and emptying sewage.

The present invention is used for the degradation of refractory organic waste water with B/C less than 0.3. The waste water needs to be pretreated before entering the device of the present invention. Coagulation sedimentation technology is generally used for pretreatment to remove suspended solids, colloidal impurities and calcium and magnesium in the waste water. , phosphorus, metal ions, etc., to reduce the poisonous effect of these interfering factors on the catalyst.

The multi-stage heterogeneous three-dimensional electrochemical treatment of the present invention is to load the catalyst that catalyzes the degradation of pollutants on the particle electrode, and under the promotion of electric field energy, the pollutants in the water phase are degraded by heterogeneous catalysis, and the direct and indirect redox effects are used to Organic molecules with complex structures in sewage are non-selectively oxidatively decomposed or reductively modified to open rings and break bonds, improve B/C, and at the same time greatly remove COD and degrade organic amines and ammonia nitrogen.

Beneficial effects of the present invention

1) The present invention is used to treat refractory organic wastewater and has the following advantages:

a Strong impact load resistance, stable treatment effect, excellent water quality;

b Convenient management, modular reaction device, complete set of technology, and precise control, so as to ensure the stable operation of the treatment process;

c Compact structure, low operating costs.

3) The device of the present invention can realize efficient treatment of refractory organic wastewater, protect the ecological environment, and solve key technical problems for the treatment of refractory organic wastewater.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of embodiment 2 of the present invention;

Fig. 3 is a schematic structural diagram of Embodiment 3 of the present invention;

Fig. 4 is a schematic structural diagram of Embodiment 4 of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

Referring to Figure 1, the present invention includes a body 1 composed of multiple (≥ 2) reactors connected in series, an overflow port 2 that realizes water phase communication between adjacent reactors, and an intermediate partition 3 that separates the reactors. Plate-separated reaction chamber 4, gas distribution and slag discharge chamber 5 at the lower end of the reactor, two or more electrode plates 6 arranged vertically and parallelly in the reaction chamber, external power supply 7, and particle electrodes 8 filled between the electrode plates , the bottom orifice plate 10 for stacking particle electrodes, the aeration plate, tube or disc 11 arranged in the air distribution and slagging chamber, the gas pipeline 12 and the gas generator 13, the emptying port 14 at the lower end of the reactor, and the Water inlet 15, water outlet 16.

Example 1

Referring to FIG. 1 , in this embodiment, four stages of reactors are connected in series in sequence, and the flow of water between each stage of reactors is realized through an overflow port 2 . The middle partition 3 divides each section of the reactor into two reaction chambers 4 of equal volume. The reaction chambers 4 are connected through the air distribution and slagging chamber 5 at the lower end of the reaction chamber 4. The air distribution and slagging chamber 5 is designed as an inverted cone structure. Each reaction chamber is provided with two vertical and parallel electrode plates 6, and the electrode plates 6 are connected to an external power supply 7 in parallel. The anode electrode plate uses a titanium-based ruthenium-iridium electrode, and the cathode uses a pure titanium-based electrode. The particle electrode 8 filled between the electrode plates adopts granular activated carbon matrix to support nano-scale titanium dioxide, and the particle electrode 8 is placed on the porous sieve plate 10 provided at the bottom of the reaction chamber 4 . An aeration plate 11 is installed in the air distribution and slag discharge chamber 5, and an external air compressor 13 is connected through a gas pipeline 12 to provide compressed air to the reactor. The lower end of the reactor is provided with an emptying port 14 for cleaning sludge and emptying sewage. A water inlet 15 is arranged at the front end of the reaction device, and a water outlet 16 is arranged at the rear end.

This example works like this:

The multi-stage heterogeneous three-dimensional electrochemical reaction device is used to treat high-concentration refractory (B/C less than 0.3) organic wastewater, heterogeneously catalyze broad-spectrum degradation of organic pollutants, oxidative decomposition or reduction modification, ring-opening and bond breaking, and increase B/C C. At the same time, COD is greatly removed, and organic amines and ammonia nitrogen are degraded. Before the sewage enters the multi-stage heterogeneous three-dimensional electrochemical reaction device, pretreatment is required, two-dimensional electrochemical coagulation or traditional chemical coagulation, to remove suspended solids, colloidal impurities, calcium, magnesium, phosphorus, metal ions, etc. in the wastewater, and at the same time Remove certain COD. The reaction device first installs the electrode plate, connects the wires, connects the power supply, installs the particle electrode in the reactor, connects the power supply, and passes the pre-treated wastewater into the multi-stage heterogeneous three-dimensional electrochemical reaction device through the water inlet 15, and the wastewater enters the first reaction chamber, enters the second reaction chamber through the lower perforated sieve plate 10 and the air distribution and slag discharge chamber 5, and then enters the third reaction chamber through the overflow port at the upper end of the second reaction chamber and the third reaction chamber, and so on, the waste water flows through In each reaction chamber, some pollutants are adsorbed on the surface of the main electrode and the surface of the particle electrode. Driven by the energy of the electric field, these pollutants undergo direct oxidation and reduction on the surface of the cathode and anode electrodes and the surfaces of many particle electrodes. At the same time, the oxygen dissolved by aeration, the anode and the oxygen produced at the anode of the particle electrode are reduced at the cathode and the cathode of the particle electrode to generate highly oxidizing hydrogen peroxide and hydroxyl radicals. At the same time, the electromagnetic field and redox electron pairs in the system Under the action of catalysis, a large number of highly oxidizing free radicals are produced, such as HO ₂ ^- ·, O·, H·, O ₂ ^- ·, O ₃ ^- ·, etc. These free radicals react with organic matter in wastewater to generate unstable organic free radicals R·, etc., thereby triggering a large number of free radical chain reactions. When the wastewater flows through each reaction chamber, under the direct action of the electrode surface and the indirect action of the free radical chain reaction, the refractory organic matter in it is gradually degraded, and the macromolecular organic matter is gradually broken and ring-opened to degrade into small molecular organic matter. Organic matter is completely oxidized and decomposed into CO ₂ and H ₂ O. Finally, the effluent enters the subsequent treatment or enters the effluent pool from the water outlet 16 .

Take the treatment of pyridine insecticide production wastewater in a chemical holding company as an example. The wastewater is organic wastewater with high organic content, high salt, and refractory degradation. The water quality index after coagulation treatment is: CODcr 19110 mg/L, BOD1146 mg/L, NH ₃ -N 38.5 mg/L, Cl ^- 8879 mg/L. After the coagulation treatment, the pyridine insecticide production wastewater enters the multi-stage heterogeneous three-dimensional electrochemical reaction device of the embodiment 1 through the water inlet 15 , and the effluent flows out of the reaction device through the water outlet 16 . Continuous water inflow and outflow, hydraulic retention time 160min, voltage intensity 0.5V/cm, after 10 days of continuous operation, the effluent indicators are: CODcr3862 mg/L, BOD 686 mg/L, NH ₃ -N 15 mg/L, Cl ^- 1624 mg/L L. BOD ₅ /COD increased from 0.06 to 0.18, and the biodegradability was obviously improved. Active microorganisms and protozoa (mainly ciliates) were observed under the microscope after being left in the water for 14 days. The effluent can adjust the load to enter the subsequent biological treatment unit and the subsequent desalination unit.

Example 2

Referring to FIG. 2 , in this embodiment, four stages of reactors are set in series in series, and the flow of water between each stage of reactors is realized through the overflow port 2 . The middle partition 3 divides each section of the reactor into two reaction chambers 4 of equal volume. The reaction chambers 4 are connected through the air distribution and slagging chamber 5 at the lower end of the reaction chamber 4. The air distribution and slagging chamber 5 is designed as an inverted cone structure. Each reaction chamber is provided with two vertical and parallel electrode plates 6, and the electrode plates 6 are connected to an external power supply 7 in parallel. The anode electrode plate of the reactor is made of boron-doped diamond film plate (BDD), and the cathode is made of stainless steel electrode. The particle electrode 8 adopts the granular activated carbon matrix to support manganese oxide, copper oxide and iron oxide. The particle electrode 8 is filled in the packing basket 9 with sieve holes, and multiple packing baskets 9 in the reaction chamber 4 are connected in series horizontally or vertically. An aeration plate 11 is installed in the air distribution and slag discharge chamber 5, and an external air compressor 13 is connected through a gas pipeline 12 to provide compressed air to the reactor. The lower end of the reactor is provided with an emptying port 14 for cleaning sludge and emptying sewage. A water inlet 15 is arranged at the front end of the reaction device, and a water outlet 16 is arranged at the rear end. The working process of this embodiment is the same as that of Embodiment 1.

Taking carbon lipids (dimethyl succinate; diisopropyl succinate; dimethyl succinate, etc.) production wastewater from a chemical group in Hebei as an example, the water quality index after coagulation treatment is: CODcr 63252 mg/L, BOD 0 mg/L, Cl ^- 135 mg/L. After the coagulation treatment, the carbon lipid production wastewater enters the multi-stage heterogeneous three-dimensional electrochemical reaction device of the embodiment 2 through the water inlet 15 , and the effluent flows out of the reaction device through the water outlet 16 . Continuous water inflow and outflow, hydraulic retention time 200min, voltage intensity 1.0V/cm, after 8 days of continuous operation, the effluent indicators are: CODcr 6847 mg/L, BOD 1621 mg/L, Cl ^- 19 mg/L. BOD ₅ /COD increased from 0 to 0.24, and the biodegradability was obviously improved. The effluent can adjust the load to enter the subsequent biological treatment unit and the subsequent desalination unit.

Example 3

Referring to FIG. 3 , in this embodiment, four reactors are connected in series in sequence, and the water flow is connected through the overflow port 2 between each reactor. The middle partition 3 divides each section of the reactor into two reaction chambers 4 of equal volume. The reaction chambers 4 are connected through the air distribution and slagging chamber 5 at the lower end of the reaction chamber 4. The air distribution and slagging chamber 5 is designed as a cuboid structure. Each reaction chamber is provided with two vertical and parallel electrode plates 6, and the electrode plates 6 are connected to an external power supply 7 in parallel. The anode electrode plate of the reactor adopts titanium-based ruthenium iridium electrode, and the cathode adopts graphite electrode. The particle electrode 8 uses a granular activated carbon matrix to load manganese oxide, copper oxide, and iron oxide. The particle electrode 8 is filled in a packing basket 9 with sieve holes, and multiple packing baskets 9 in the reaction chamber 4 are connected in series horizontally or vertically. An aeration plate 11 is installed in the air distribution and slag discharge chamber 5, and an external ozone generator 13 is connected through a gas pipeline 12 to provide compressed ozone into the reactor. The lower end of the reactor is provided with an emptying port 14 for cleaning sludge and emptying sewage. A water inlet 15 is arranged at the front end of the reaction device, and a water outlet 16 is arranged at the rear end. The working process of this embodiment is the same as that of Embodiment 1.

Take triethylamine wastewater treatment as an example. Molecular sieve synthetic crystallization mother liquid wastewater contains various organic amines, the representative of which is triethylamine hydrochloride. This kind of wastewater is typical wastewater with high concentration, high salinity and difficult biodegradation. Due to the lack of effective treatment means, this kind of wastewater is mainly incinerated at high temperature at present, and the treatment cost is high and it is difficult to maintain. In this example, the water quality indicators of triethylamine wastewater after pre-coagulation treatment are: CODcr 46131 mg/L, BOD 545 mg/L, triethylamine concentration 28172 mg/L, Cl ^- 14605 mg/L. The coagulated triethylamine waste water enters the multi-stage heterogeneous three-dimensional electrochemical reaction device of embodiment 3 through the water inlet 15 , and the effluent flows out of the reaction device through the water outlet 16 . Continuous water inflow and outflow, hydraulic retention time 200min, voltage intensity 0.8V/cm, after 15 days of continuous operation, the effluent indicators are: CODcr 8863 mg/L, BOD1265 mg/L, triethylamine 6402 mg/L, Cl ^- 3934mg/L, The removal rate of COD was 81%, the removal rate of triethylamine was 77%, the removal rate of Cl ^- was 73%, and the B/C increased from 0.012 to 0.14. After the load is adjusted, the effluent can enter the subsequent biological treatment unit and the subsequent desalination unit.

Example 4

Referring to FIG. 4 , in this embodiment, four stages of reactors are set in series in series, and the flow of water between each stage of reactors is realized through the overflow port 2 . The middle partition 3 divides each section of the reactor into two reaction chambers 4 of equal volume. The reaction chambers 4 are connected through the air distribution and slagging chamber 5 at the lower end of the reaction chamber 4. The air distribution and slagging chamber 5 is designed as a cuboid structure. Each reaction chamber is provided with two vertical and parallel electrode plates 6, and the electrode plates 6 are connected to an external power supply 7 in parallel. The anode electrode plate of the reactor is made of stainless steel, and the cathode is made of stainless steel electrode. The particle electrode 8 adopts particles h matrix activated carbon particles to load copper oxide and iron oxide, and the particle electrode 8 is placed on the porous sieve plate 10 provided at the bottom of the reaction chamber 4 . An aeration plate 11 is installed in the air distribution and slag discharge chamber 5, and an external ozone generator 13 is connected through a gas pipeline 12 to provide compressed ozone into the reactor. The lower end of the reactor is provided with an emptying port 14 for cleaning sludge and emptying sewage. A water inlet 15 is arranged at the front end of the reaction device, and a water outlet 16 is arranged at the rear end. The working process of this embodiment is the same as that of Embodiment 1.

Taking a caprolactam production wastewater treatment in Shandong as an example, the water quality indicators after coagulation treatment are: CODcr8560mg/L, BOD 220 mg/L, Cl ^- 7849 mg/L, NH ₃ -N 7957 mg/L. The coagulated waste water enters the multi-stage heterogeneous three-dimensional electrochemical reaction device of Embodiment 4 through the water inlet 15 , and the effluent flows out of the reaction device through the water outlet 16 . Continuous water inflow and outflow, hydraulic retention time 240min, voltage intensity 0.33V/cm, after 10 days of continuous operation, the effluent indicators are: CODcr 1504mg/L, BOD 431 mg/L, Cl ^- 863 mg/L, NH ₃ -N 130 mg/L L. BOD ₅ /COD increased from 0.03 to 0.29, and the biodegradability was obviously improved. The effluent can adjust the load to enter the subsequent biological treatment unit and the subsequent desalination unit.

The above descriptions are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above examples. All technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (9)

1. a kind of multistage out-phase three-dimensional electrochemical reaction unit for waste water treatment, it is characterised in that the device includes：Body （1）, external power supply（7）And external gas generator（13）, the body（1）Front end sets water inlet（15）, end is set out The mouth of a river（16）, at least provided with second stage reactor in it, each section of reactor is in series and passes through overfall（2）Realize adjacent section reactor Between aqueous phase UNICOM, wherein：

Every section of reactor is by central dividing plate（3）It is divided at least two reative cells（4）, and the gas distribution deslagging chamber for passing through lower end（5） Realize the UNICOM of reacting chamber space aqueous phase；Each reative cell（4）At least provided with the battery lead plate of two pieces of vertical parallel arrangements（6）, it is each anti- Answer room（4）Battery lead plate positive pole and negative pole are arranged alternately, and are connected in parallel external power supply（7）；Battery lead plate（6）Between particle filled composite electrode （8）, granule electrode（8）It is placed in the basket with sieve aperture（9）In or be stacked in reative cell（4）The orifice plate of bottom（10）On；Gas distribution is arranged Grit chamber（5）It is interior to be provided with aeration board, pipe or disk（11）, pass through gas pipeline（12）Connect external gas generator（13）, every section anti- Device lower end is answered to be provided with evacuation port（14）.

2. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the gas distribution deslagging chamber （5）For reverse taper or cuboid structure.

3. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the battery lead plate（6） For boron-doped diamond film pole plate（BDD）, titanium-based transition metal oxide coated electrode（DSA）, stainless steel polar plate, graphite electrode plate Or one kind in alloy pole plate.

4. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the external power supply （7）One or several is arranged to, one or several sections reactors of every section of reactor setting share one.

5. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the granule electrode （8）Using particle as matrix, catalyst is loaded with thereon.

6. multistage out-phase three-dimensional electrochemical reaction unit according to claim 5, it is characterised in that the granule electrode （8）Matrix be granular activated carbon, alundum (Al2O3) particle or zeolite granular, be used alone or two kinds or several mixing make With；Catalyst is the one or several kinds of mixing of titanium dioxide, metal or transition metal oxide.

7. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the filler basket（9） Horizontally or vertically concatenated to be several.

8. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the external gas hair Raw device（13）For air compressor or ozone generator.

9. multistage out-phase three-dimensional electrochemical reaction unit according to claim 1, it is characterised in that the evacuation port（14） For the cleaning of body refuse and the emptying of sewage.