A novel iron-carbon micro-electrolysis reaction system and application thereof

Abstract

The application discloses a novel iron-carbon micro-electrolysis reaction system and application thereof, and belongs to the technical field of wastewater treatment. The system comprises a centrifugal pump, a jet device, a diffusion nozzle, a reactor internally filled with vertical hollow tubular iron-carbon filler, a porous mesh plate internally serving as support and being distributed in a penetrating mode, acid supplementing in a middle section and the like. The jet device inhales air to replace the traditional perforated pipe or aeration head through a fan for aeration, simplifies the water distribution and air distribution pipeline structure at the bottom of the reactor, saves the energy consumption of the fan aeration, and improves the operation efficiency of the system. The vertical hollow tubular iron-carbon filler column is different from the traditional fixed-bed disordered stacking iron-carbon particle filler, is penetrated between the porous mesh plates, and is not in contact with each other, so that there is no risk of hardening. The backflow water is driven by the centrifugal pump to increase the upward flow rate of the water body in the reactor, strengthens the scouring of the water flow and the air flow on the filler, and greatly reduces the risk of passivation on the surface of the filler.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wastewater treatment, and particularly relates to a novel iron-carbon micro-electrolysis reaction system and application thereof. BACKGROUND

[0002] Iron-carbon micro-electrolysis technology is to form a primary cell with iron and carbon as electrodes to decompose the refractory organic pollutants in wastewater into small-molecule organic matter which is easy to be biodegraded, so as to not only remove the pollutants but also improve the biodegradability of wastewater. The micro-electrolysis reaction process mainly includes primary cell reaction (formation of potential difference between iron and carbon, electrochemical degradation of organic matter in water), oxidation-reduction reaction (generation of new Fe 2+ and [H] in the system, which is easy to react with oxidizing substances in water to change the structure of some organic polymers), adsorption and precipitation (iron hydroxide complex generated by hydrolysis of Fe 2+ and Fe 3+ has a network adsorption effect, which assists the removal of part of the pollutants by co-precipitation).

[0003] At present, the iron-carbon micro-electrolysis systems on the market basically adopt fixed bed type reaction tank or reaction tower form, that is, water inlet and air inlet pipelines are arranged at the bottom of the reactor, a porous glass steel or stainless steel support plate is arranged at the upper part, and various shapes of regular iron-carbon fillers (flat round, round or columnar, etc.) are poured on the upper part of the support plate, usually with a filling height of several meters or stacked in multiple layers. The regular iron-carbon fillers are fixed bed stacked in the reactor, and there are large and small gaps between the particles. The water flow and gas flow are adjusted to be acidic and flow upward from the bottom of the filler bed, and the three-phase contact reaction is carried out through the filler area. While the pollutants are degraded, the iron-carbon fillers dissolve the ferrous ions, and then the pH is adjusted to form iron mud precipitation separation to achieve the effluent.

[0004] During the operation of the iron-carbon micro-electrolysis system, under the aeration environment, part of the ferrous iron dissolved from the iron-carbon hydrolyzes to form ferrous hydroxide and ferric hydroxide, which is easy to be adsorbed in the gaps of the iron-carbon fillers or in the dead angle area where the water flow and gas flow cannot fully contact, and gradually forms a passivation film, which hinders or even blocks the electrochemical action between iron and carbon, reduces the reaction efficiency, and with the long-time operation of the system, the passivation film gradually grows and adheres to cause the iron-carbon particles to be hardened. Therefore, the iron-carbon micro-electrolysis reaction system needs to be provided with gas-water backwashing to regularly flush the iron-carbon filler bed and reduce the accumulation of iron complex on the surface of the filler and the gaps.

[0005] In the related art, such as the Chinese invention patent with publication number CN103508519A, a replaceable iron-carbon micro-electrolytic water treatment device is disclosed, and specifically discloses a replaceable iron-carbon micro-electrolytic water treatment device, which comprises a reaction tower, a Venturi jet, an inlet pipe, a backwashing pipe which also serves as an outlet pipe, an air pipe, a supporting layer, and a filler layer. The outlet of the Venturi jet is in communication with the inlet of the inlet pipe. The inlet pipe, the backwashing pipe, and the air pipe are distributed at the bottom of the reaction tower, and the inlet pipe and the backwashing pipe are provided with water distribution ports, and the air pipe is provided with an air distribution port. The supporting layer is arranged inside the reaction tower and above the inlet pipe, the backwashing pipe, and the air pipe. The filler layer is placed on the supporting layer. The top of the reaction tower is provided with an exhaust pipe connected with an exhaust gas absorption device, and a backwashing drain pipe is arranged on the sidewall above the filler layer. The air inlet of the air pipe is in communication with the air outlet of a blower. The inlet pipe and the backwashing pipe are in communication with a water pipe. The part of the backwashing pipe outside the reaction tower is divided into a backwashing branch provided with a gate valve and a drain branch provided with a drain valve through a tee joint. The filler layer is composed of a cylindrical barrel and a cross-shaped filler placed in the barrel. The filler is made of iron powder, carbon powder, and RuO2, and is mixed, formed, sintered into a long rectangle with a length of 40 cm and a width of 20 cm, and is arranged into a cross. The mass fraction of Ru is 0.5%. The inlet of the inlet pipe and the air inlet of the air pipe are both provided with a check valve. A set of efficiency nozzles is arranged on the inlet pipe and located directly below the filler layer. The material of the cylindrical barrel is PVC. The inlet pipe, the backwashing pipe, and the air pipe inside the reaction tower are all in a mesh structure composed of a main pipe and a plurality of radial branch pipes. The inlet pipe, the backwashing pipe, and the air pipe are distributed above the air pipe, and the branch pipes of the air pipe are connected with large-hole aeration heads. The diameter of the exhaust pipe is 4 times the diameter of the inlet pipe and the diameter of the air pipe. The backwashing drain pipe is arranged 0.5 m above the normal operating liquid level of the reaction tower, and the diameter of the backwashing drain pipe is twice the diameter of the backwashing pipe inside the reaction tower. The iron-carbon filler of the invention is in the shape of a cross, and is packed in a PVC cylindrical barrel. When the gas in the barrel flows upward, it can drive the water to flow out of the barrel to form an internal and external circulation to increase the reaction efficiency. However, no matter what shape the iron-carbon filler is, it will be consumed. In the fixed bed filling mode, the fillers will interfere with each other, that is, there is a certain risk of hardening. The arrangement of the backwashing system can strengthen the flushing of the filler surface and reduce the hardening and passivation phenomenon, but the arrangement of the air and water backwashing system increases the complexity of the reaction device. SUMMARY

[0006] 1. PROBLEMS TO BE SOLVED

[0007] The purpose of the present application is to overcome the technical problems of high risk of passivation compaction, large loading capacity, and complex reaction system caused by the existing iron-carbon filler fixed bed disordered accumulation, and to provide a new type of iron-carbon micro-electrolysis reaction system and its application. The iron-carbon micro-electrolysis reaction system adopts hollow tubular iron-carbon filler, which is distributed in the reactor or pool, and the fillers are separated from each other, avoiding the risk of compaction and passivation. During operation, the gas and water can fully wash the surface of the filler, and there is no need to additionally set up a backwashing unit, which greatly simplifies the system configuration and improves the operation efficiency.

[0008] 2. Technical solution

[0009] In order to solve the above problems, the technical scheme adopted by the present application is as follows:

[0010] The present application provides a new type of iron-carbon micro-electrolysis reaction system, which comprises:

[0011] The reactor is provided with a water outlet at the upper part, a emptying port at the lower part, a tread plate at the top, and a conical slope at the bottom. A water inlet pipeline with a diffusion nozzle is arranged above the conical slope. A support layer and a filler layer are arranged above the water inlet pipeline.

[0012] The other end of the water inlet pipeline is connected with the outlet of the jet device. The jet device is respectively connected with the outlet of the air buffer tank and the centrifugal pump.

[0013] The inlet of the centrifugal pump is connected with the outlet of the adjusting tank. The inlet of the adjusting tank is connected with the outlet of the raw water.

[0014] Further, the support layer comprises a porous support plate and a porous plate, both of which are porous mesh plates, and the middle single hole is square. The lower part of the porous support plate and the porous plate is provided with a steel structure support transverse strip laid along the mesh plate framework.

[0015] The filler layer is a hollow tubular iron-carbon filler column, which vertically penetrates the middle single hole of the porous plate and falls on the porous support plate.

[0016] The length of the hollow tubular iron-carbon filler column is greater than the distance between the porous support plate and the porous plate. The outer diameter of the hollow tubular iron-carbon filler column is greater than the side length of the middle single hole of the porous support plate and less than the side length of the middle single hole of the porous plate.

[0017] Further, the support layer further comprises a porous flexible support net, which is laid close to the upper part of the porous support plate.

[0018] Further, the above-mentioned porous support plate is made of acid-resistant glass steel material, the length of the single hole in the middle is 20 mm, the skeleton wall thickness is 5 mm, and the plate thickness is 40 mm, which is laid at a distance of 0.5 m from the bottom of the reactor; the above-mentioned porous plate is made of acid-resistant glass steel material, the length of the single hole in the middle is 45 mm, the skeleton wall thickness is 5 mm, and the plate thickness is 25 mm, which is laid and fixed at a distance of 1.5 m from the bottom of the reactor; the porous flexible support net is made of acid-resistant PP material and has a mesh structure, and the length of the single hole in the middle is 10 mm.

[0019] Further, the length of the above-mentioned hollow tubular iron-carbon filler column is 1.5 m, the outer diameter is 40 mm, and the inner diameter is 30 mm, which is vertically inserted into the single hole in the middle of the porous plate and falls on the porous support plate.

[0020] Further, the above-mentioned hollow tubular iron-carbon filler column has a symmetric semicircular tab on the pipe wall, which is formed by a drill bit punch and bends inward into the pipe. Further, the tab has a diameter of 1.5 cm and bends inward by 30°.

[0021] Further, the above-mentioned support layer can be arranged according to the shape of the reactor and can be square, rectangular or circular.

[0022] Further, the above-mentioned new type of iron-carbon micro-electrolysis reaction system comprises:

[0023] The upper part of the reactor is also provided with a reflux port, which is connected with the inlet pipeline of the centrifugal pump.

[0024] Further, the above-mentioned reflux port is sequentially connected with an electromagnetic valve and a flow meter between the centrifugal pump.

[0025] Further, the above-mentioned new type of iron-carbon micro-electrolysis reaction system comprises:

[0026] The iron-carbon micro-electrolysis reaction zone, i.e. the middle part of the reactor, is provided with an acid supplement port between the porous support plate and the porous plate, which is used to adjust the pH of the iron-carbon micro-electrolysis reaction zone.

[0027] Further, the above-mentioned new type of iron-carbon micro-electrolysis reaction system comprises:

[0028] The acid storage tank is connected with the adjusting tank and the acid supplement port respectively, which is used to adjust the pH.

[0029] Further, the above-mentioned acid storage tank is sequentially connected with a metering pump, a flow meter and an electromagnetic valve between the adjusting tank, which is used to control the amount of acid added.

[0030] Further, the above-mentioned acid storage tank is sequentially connected with a metering pump, a flow meter and an electromagnetic valve between the acid supplement port, which is used to supplement acid and control the amount of acid added.

[0031] Further, the above-mentioned adjusting tank is also provided with a pH online instrument, which can monitor the pH of the wastewater in the adjusting tank in real time.

[0032] Further, the air is sequentially connected with the flow meter, the electromagnetic valve and the check valve between the buffer tank and the jet device, for controlling the air flow.

[0033] The application also provides the application of any of the novel iron-carbon micro-electrolysis reaction systems in wastewater treatment.

[0034] Further, the application comprises:

[0035] The raw water is mixed with the reflux water after being pre-adjusted in pH in the adjusting pool and is delivered to the jet device by the centrifugal pump;

[0036] Meanwhile, the air is sucked into the jet device through the pipeline in the buffer tank;

[0037] The air and the mixed water (the raw water and the reflux water) are fully mixed in the jet device, are delivered to the diffusion nozzle through the water inlet pipeline, and are sprayed and impacted on the conical slope surface to form large-area diffusion, so that the air and water are uniformly formed into upward flow, the gas-liquid-solid three-phase contact occurs in the micro-electrolysis reaction in the region of the vertically arranged hollow tubular iron-carbon filler column, and the water flow after the reaction continues to flow upward to the water outlet.

[0038] Further, the application also comprises interval acid supplement through the acid supplement port.

[0039] Further, the water quantity of the raw water after the pH adjustment and the water quantity of the reflux water are in the proportion of 1:2, and the water quantity of the raw water and the air quantity are in the proportion of 1:1, that is, the water quantity of the raw water: the air quantity: the jet pump flow = 1:1:3.

[0040] 3. Beneficial effects

[0041] Compared with the prior art, the application has the beneficial effects that:

[0042] (1) The novel iron-carbon micro-electrolysis reaction system and the application thereof provided by the application mainly comprise the centrifugal pump, the jet device, the diffusion nozzle, the reactor internally filled with the vertical hollow tubular iron-carbon filler, the porous mesh plate internally serving as the support and the distribution, the middle-section acid supplement, etc., the air is sucked by the jet device instead of being aerated by the fan through the traditional perforated pipe or the aeration head, the structure of the water distribution and air distribution pipeline at the bottom of the reactor is simplified, the energy consumption of the fan aeration is saved, and the system operation efficiency is improved.

[0043] (2) The application provides a novel iron-carbon micro-electrolysis reaction system and its application. The centrifugal pump is used to simultaneously suck the raw water and part of the reflux water to mix the air into the reactor. On the one hand, the degraded sewage in the upper part of the reactor is used to dilute the raw water, which can improve the overall efficiency of the reaction system. On the other hand, it provides a guarantee for the jet device to bring in a sufficient amount of air. At present, the gas-water ratio efficiency of the jet device is basically 1:2-1:3, that is, two to three volumes of water bring in one volume of gas. In this system, one volume of raw water and two volumes of reflux water can bring in one volume of air, so that the system operation power consumption and efficiency are in the best state.

[0044] (3) The application provides a novel iron-carbon micro-electrolysis reaction system and its application. The hollow tubular iron-carbon filler column vertically placed in the reactor is different from the traditional fixed bed disordered accumulation of iron-carbon particle filler. It is inserted between the porous mesh plates, and the fillers do not contact each other, so there is no risk of hardening. When the mixed gas and water rise from the bottom and pass through the hollow tubular filler, due to the semicircular tabs protruding from the inner wall of the filler column, the gas and water collide with each other to form sufficient turbulence, which drives the turbulent mixing of the fillers inside and outside the pipe, greatly improving the reaction efficiency. At the same time, the reflux water driven by the centrifugal pump increases the upward flow rate of the water body in the reactor, which strengthens the scouring of the water flow and the gas flow on the filler, greatly reducing the risk of passivation on the surface of the filler. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a schematic diagram of a micro-electrolysis reaction system, wherein: 1 - adjustment tank; 2 - centrifugal pump; 3 - jet device; 4 - buffer tank; 5, 16, 20, 25 - flow meter; 6, 17, 19, 24 - electromagnetic valve; 7 - one-way valve; 8 - diffusion nozzle; 9 - cylindrical slope; 10 - porous support plate; 11 - porous flexible support net; 12 - porous plate; 13 - hollow tubular iron-carbon filler column; 14 - pH online instrument; 15 - pedal; 18 - reactor; 21 - acid storage tank; 22, 23 - metering pump; 26 - emptying port; 27 - reflux port; 28 - water outlet.

[0046] Figure 2 is a top view of the structure of the porous mesh plate, wherein: D is the side length of the square hole of the mesh plate.

[0047] Figure 3 is an outline drawing of the hollow iron-carbon filler column 13, wherein: R1: outer diameter; R2: inner diameter; R3: tab diameter; L: length; θ: inward bending angle. DETAILED DESCRIPTION

[0048] The application will be further described below in combination with specific embodiments.

[0049] It is to be noted that the terms such as "upper", "lower", "left", "right", "intermediate" and the like as cited in the present specification are merely intended to facilitate the description of the present application and are not used to limit the scope of the application, and any change in the relative relationship or adjustment thereof without substantial change in the technical content is also deemed to be within the scope of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] Unless otherwise indicated, conventional conditions or manufacturer's recommended conditions are employed in the examples. Unless otherwise indicated, all reagents or apparatuses are commercially available and are conventional in the art.

[0052] As used herein, the term "about" is used to provide flexibility to a given term, measurement, or value. The degree of flexibility of a particular variable will be readily determined by one of skill in the art.

[0053] As used herein, the term "at least one of" is intended to mean one or more of the listed items. For example, "at least one of A, B, and C" is intended to mean: A alone; B alone; C alone; A and B together; A and C together; B and C together; or A, B, and C together.

[0054] Concentrations, amounts, and other numerical data can be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be construed as having been followed to following the principle of including and disclosing every single numerical value falling within the range even though the exact values are not explicitly listed. For instance, a numerical range of about 1 to about 4.5 should be interpreted to include not only the explicitly recited values of about 1 to about 4.5, but also include an implicit range of values from about 1 to about 4.5, such as, for example, values like 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, and 4.5, etc. Similarly, a range of "less than about 4.5" is to be interpreted to include not only the explicitly recited value of less than about 4.5, but also include an implicit range of values from about 1 to about 4.5, such as, for example, values like 4, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, and 1, etc. This same principle applies to ranges reciting only one numerical value, such as "less than about 4.5", which should be interpreted to include all of the above-mentioned values and ranges.

[0055] Example 1

[0056] The present embodiment provides a novel iron-carbon micro-electrolysis reaction system, which refers to Figure 1 The system comprises:

[0057] The reactor 18 is provided with a water outlet 28 at the upper part, a discharge port 26 at the lower part, a footboard 15 at the top, and a conical slope 9 at the bottom. A water inlet pipeline with a diffusion nozzle 8 is arranged above the conical slope 9. A support layer and a filler layer are arranged above the water inlet pipeline.

[0058] The other end of the water inlet pipeline is connected with the outlet of the jet device 3. The jet device 3 is respectively connected with the air buffer tank 4 and the outlet of the centrifugal pump 2.

[0059] The inlet of the centrifugal pump 2 is connected with the outlet of the adjusting pool 1. The inlet of the adjusting pool 1 is connected with the raw water outlet.

[0060] In the operation process, the raw water is pre-adjusted in pH by the adjusting pool 1 and then is delivered to the jet device 3 by the centrifugal pump 2. At the same time, the air is sucked into the jet device 3 through the pipeline in the air buffer tank 4. The air and the raw water pre-adjusted in pH are fully mixed in the jet device 3, are delivered to the diffusion nozzle 8 through the water inlet pipeline, and are sprayed and impacted on the conical slope 9 arranged at the bottom of the reactor 18 to form a large-area diffusion. The air and water are uniformly formed into an upward flow, pass through the filler layer area, and the micro-electrolysis reaction occurs in the three-phase contact of air, liquid and solid. The reacted water flow continues to flow upward to the water outlet 28 of the reactor 18 and is discharged. The jet suction air replaces the traditional perforated pipe or air exposure head through the air blower, simplifies the water distribution and air distribution pipeline structure arranged at the bottom of the reactor, saves the energy consumption of the air blower, and improves the system operation efficiency.

[0061] Example 2

[0062] The embodiment provides a novel iron-carbon micro-electrolysis reaction system, and the system comprises a reactor 18, an adjusting pool 1, a centrifugal pump 2, a jet device 3, an air buffer tank 4, and a water inlet pipeline with a diffusion nozzle 8. Figure 1 The system comprises:

[0063] The reactor 18 is provided with a water outlet 28 at the upper part, a discharge port 26 at the lower part, a footboard 15 at the top, and a conical slope 9 at the bottom. A water inlet pipeline with a diffusion nozzle 8 is arranged above the conical slope 9. A support layer and a filler layer are arranged above the water inlet pipeline.

[0064] The support layer comprises a porous support plate 10 and a porous plate 12. Both the porous support plate 10 and the porous plate 12 are porous mesh plates, such as Figure 2As shown, the shape of the reactor 18 can be set to be square (a), rectangular or circular (b), and the middle single hole is square; the lower part of the multi-hole support plate 10 and the multi-hole plate 12 are provided with steel support horizontal strips laid along the net plate framework; the multi-hole support plate 10 is made of acid-resistant glass steel material, the length of the middle single hole is 20 mm, the skeleton wall thickness is 5 mm, and the plate thickness is 40 mm, which is laid at a distance of 0.5 m from the bottom of the reactor 18; the multi-hole plate 12 is made of acid-resistant glass steel material, the length of the middle single hole is 45 mm, the skeleton wall thickness is 5 mm, and the plate thickness is 25 mm, which is fixed at a distance of 1.5 m from the bottom of the reactor 18;

[0065] The filler layer is a hollow tubular iron-carbon filler column 13, the length of the hollow tubular iron-carbon filler column 13 is 1.5 m, the outer diameter is 40 mm, and the inner diameter is 30 mm, which is vertically inserted into the middle single hole of the multi-hole plate 12 and falls on the multi-hole support plate 10;

[0066] The other end of the water inlet pipeline is connected with the outlet of the jet device 3; the jet device 3 is respectively connected with the air buffer tank 4 and the outlet of the centrifugal pump 2;

[0067] The inlet of the centrifugal pump 2 is connected with the outlet of the adjusting pool 1; the inlet of the adjusting pool 1 is connected with the raw water outlet.

[0068] In the running process, the raw water is pre-adjusted in pH by the adjusting pool 1 and then delivered to the jet device 3 by the centrifugal pump 2; at the same time, the air is sucked into the jet device 3 through the pipeline in the air buffer tank 4; the air and the raw water pre-adjusted in pH are fully mixed in the jet device 3, delivered to the diffusion nozzle 8 through the water inlet pipeline, and sprayed and impacted on the conical slope 9 arranged at the bottom of the reactor 18 to form a large-area diffusion, so that the gas and water are uniformly formed into an upward flow, which passes through the area of the vertically arranged hollow tubular iron-carbon filler column 13, and the micro-electrolysis reaction occurs in the gas-liquid-solid three-phase contact, and the reacted water flow continues to flow upward to the water outlet 28 of the reactor 18 to discharge water. The multi-hole support plate 10 is used to support the hollow tubular iron-carbon filler column 13, the length of the mesh (middle single hole) of the multi-hole plate 12 is significantly smaller than the diameter of the hollow tubular iron-carbon filler column 13, and the thickness of 40 mm provides sufficient bearing strength to ensure that the filler does not fall off; the length of the mesh (middle single hole) of the multi-hole plate 12 is slightly larger than the outer diameter of the hollow tubular iron-carbon filler column 13, which is convenient for filling and leaves a gap between the mesh and the iron-carbon to make the gas and water pass through the contact reaction and flow scouring, so as to strengthen the reaction and reduce the risk of iron complex accumulation; more importantly, the hollow tubular iron-carbon filler column 13 is slightly inclined and loose when inserted into the mesh of the multi-hole plate 12, when the inner wall of the hollow tubular iron-carbon filler column 13 is impacted by the gas and water, on the one hand, the contact occurs, and on the other hand, the strong gas flow has the effect of air stripping, which can make the hollow tubular iron-carbon filler column 13 slightly shake in the relatively fixed square hole net plate, realize "self-cleaning", and further avoid the growth of passivation film.

[0069] In the embodiment, the support layer further comprises a porous flexible support net 11, which is laid on the porous support plate 10. In the embodiment, the porous flexible support net 11 is made of acid-resistant PP material and has a mesh structure with a single hole of 10 mm in length. The porous flexible support net 11 is laid on the upper side of the porous support plate 10. When the hollow tubular iron-carbon filler column 13 is used for a long time, the wall of the column becomes thin and the overall strength becomes poor, and local disconnection may occur. However, even if the hollow tubular iron-carbon filler column 13 is disconnected into multiple sections, the column can still lie on the porous flexible support net 11 without falling to the bottom of the reactor to cause a dead zone.

[0070] In the embodiment, the wall of the hollow tubular iron-carbon filler column 13 is punched by a drill bit to form symmetric semicircular tabs that are bent inward into the tube, as shown in FIG. 4. Figure 3 In the embodiment, the diameter of the tab is 1.5 cm and the tab is bent inward by 30°. When the mixed gas and water rise from the bottom and pass through the hollow tubular iron-carbon filler column 13, the semicircular tabs on the inner wall cause the gas and water to impact each other to form sufficient turbulence, which drives the turbulent mixing of the inside and outside of the hollow tubular iron-carbon filler column 13, greatly improving the reaction efficiency.

[0071] Embodiment 3

[0072] The embodiment provides a novel iron-carbon micro-electrolysis reaction system. Referring to Embodiment 2 and Figure 1 The system further comprises:

[0073] The reactor 18 is further provided with a backflow port 27, which is connected to the inlet pipeline of the centrifugal pump 2. In the embodiment, the backflow port 27 is sequentially connected to the electromagnetic valve 17 and the flow meter 16 between the backflow port 27 and the centrifugal pump 2. The centrifugal pump 2 is used to simultaneously suck the raw water and part of the backflow water to mix air and enter the reactor 18. On the one hand, the raw water is diluted by the degraded wastewater in the upper part of the reactor 18 to improve the overall efficiency of the reaction system. On the other hand, it provides a guarantee for the jet device to bring in a sufficient amount of air.

[0074] Embodiment 4

[0075] The embodiment provides a novel iron-carbon micro-electrolysis reaction system. Referring to Embodiment 3 and Figure 1 The system further comprises:

[0076] The iron-carbon micro-electrolysis reaction zone, i.e., the middle part of the reactor 18, is provided with an acid supplement port between the porous support plate 10 and the porous plate 12.

[0077] Generally, iron-carbon micro-electrolysis reaction requires an acidic environment, i.e., the pH of the inlet water is controlled between 3 and 3.5, and the water sample contacts the reaction in the filler area to consume H +, resulting in the pH of the reaction water increasing. In the reactor, the water is usually fed from the bottom and discharged from the top, and the acidic wastewater is pre-adjusted and gradually rises to contact the iron-carbon filler, H + is continuously consumed, resulting in the pH in the iron-carbon reaction zone gradually increasing from bottom to top. When the degradation of the wastewater is intense, a large amount of H + The pH increases too rapidly (pH > 5.5), which reduces the efficiency of the micro-electrolysis reaction. The acid supplement port in the iron-carbon filler contact reaction zone can compensate for the efficiency reduction caused by the pH increasing too rapidly in the reaction system. In addition, it is not appropriate to control the pH too low in the adjustment tank to compensate for the problem of the pH increasing too rapidly in the reaction system, because when the pH < 3, the reaction process of the iron-carbon micro-electrolysis will be accompanied by more elemental iron acid dissolution, rather than the electrochemical corrosion reaction required by the micro-electrolysis process, which will instead reduce the efficiency of the electrochemical reaction.

[0078] Example 5

[0079] This embodiment provides a novel iron-carbon micro-electrolysis reaction system, which refers to the iron-carbon micro-electrolysis reaction system in any one of Examples 1 to 4 and Figure 1 The system further comprises:

[0080] The adjustment tank 1 is also provided with a pH on-line instrument 14, which can monitor the pH of the wastewater in the adjustment tank in real time;

[0081] The acid storage tank 21 is connected with the adjustment tank 1 and is used for adjusting the pH of the raw water. The acid storage tank 21 is connected with the adjustment tank 1 in sequence with a metering pump 22, a flow meter 25 and an electromagnetic valve 24, which are used for controlling the amount of acid added;

[0082] The acid storage tank 21 is connected with the acid supplement port and is used for adjusting the pH of the iron-carbon micro-electrolysis reaction zone. The acid storage tank 21 is connected with the acid supplement port in sequence with a metering pump 23, a flow meter 20 and an electromagnetic valve 19, which are used for supplementing acid and controlling the amount of acid added;

[0083] The air is connected with the jetifier 3 through the buffer tank 4 in sequence with a flow meter 5, an electromagnetic valve 6 and a check valve 7, which are used for controlling the air flow.

[0084] Example 6

[0085] This embodiment provides the application of the novel iron-carbon micro-electrolysis reaction system described in any one of Examples 3 to 5, which comprises:

[0086] The raw water is pre-adjusted in the adjustment tank and then transported to the jetifier 3 with the backflow water through the centrifugal pump 2;

[0087] At the same time, the air is sucked into the jetifier 3 through the pipeline in the buffer tank 4;

[0088] The air and mixed water (mixing of raw water and backflow water) are fully mixed in the jet device 3, delivered to the diffusion nozzle 8 through the water inlet pipeline, and sprayed to the conical slope 9 arranged at the bottom of the reactor 18 to form a large-area diffusion. The air and water are uniformly formed into upward flow, pass through the vertically arranged hollow tubular iron-carbon filler column 13, and the air, water and solid three-phase contact occurs micro-electrolysis reaction. The reacted water continues to flow upward to the water outlet 28 of the reactor 18 and is discharged.

[0089] In the embodiment, if necessary, the interval acid supplementing through the acid supplementing port is also included.

[0090] In the embodiment, the ratio of the raw water volume to the backflow water volume is 1:2, and the ratio of the raw water volume to the air volume is 1:1, that is, the raw water volume:air volume:jet device flow rate = 1:1:3. The system operates according to the parameters that the ratio of the raw water volume to the backflow water volume is 1:2, and the ratio of the raw water volume to the air volume is 1:1, that is, the raw water volume:air volume:jet pump flow rate = 1:1:3. The raw water volume is usually fluctuant, so the adjusting pool needs to be set to keep the water volume entering the reactor relatively stable, on the one hand to facilitate the adjustment of pH, and on the other hand to control the flow rate of the centrifugal pump, that is, the backflow water volume is relatively stable, so as to control the pH fluctuation in the reactor as small as possible and make the system operate stably. Generally, the conventional iron-carbon reactor requires that the aeration volume is 3-5 times of the water volume, one is to provide sufficient dissolved oxygen for the iron-carbon micro-electrolysis reaction, and the other is that a large amount of residual gas can continuously flush the surface of the iron-carbon filler to reduce the risk of caking, but too much residual gas will cause the hydrolysis and oxidation of the dissolved divalent iron ions to generate ferrous hydroxide and ferric hydroxide hydrate complexes, which have strong adsorption and are easy to form passivation film. The system operates with the ratio of the raw water volume to the air volume being 1, because the distributed filling of the iron-carbon filler pipe has no caking risk, and there is no need for large amount of air flushing, and there is no dead zone in the filler reaction area, so the contact reaction efficiency is higher, and the air consumption can be significantly reduced. The operation process of the micro-electrolysis reaction system does not need to additionally set a gas-water backwashing unit, and the system operation is simple.

[0091] Example 7

[0092] The embodiment provides the application of the new type iron-carbon micro-electrolysis reaction system in treating specific wastewater.

[0093] The nitrobenzene water is used as the raw water of the wastewater, the flow rate is controlled to be 0.5 m 3 / h, the pH is adjusted to be 3 in advance in the adjusting pool 1 by using 98% concentrated sulfuric acid, then the wastewater is delivered to the jet device 3 by the centrifugal pump 2, the backflow water volume is controlled to be 1 m 3 / h (the reactor is filled with the nitrobenzene water in advance); at the same time, the air is inhaled into the jet device 3 through the pipeline by the buffer tank 4, the flow meter 5, the electromagnetic valve 6 and the check valve 7, and the air flow rate is controlled to be 0.5 m 3 / h; the air and the pre-adjusted pH raw water and backflow water are mixed fully in the jet device 3, are transported to the diffusion nozzle 8 at the bottom of the reactor 18 through the pipeline, the mixed gas and water are sprayed and impact on the conical slope 9 arranged at the bottom to form diffusion, the gas and water are uniformly formed to rise, pass through the area of the vertical arranged iron-carbon filler column 13, the micro-electrolysis reaction occurs through the gas-liquid-solid three-phase contact, the water flow after the reaction continues to flow upwards to the water outlet 28 at the top of the reactor to discharge water, and the hydraulic retention time is controlled to be 30 min.

[0094] Example 8

[0095] The embodiment provides application of the novel iron-carbon micro-electrolysis reaction system in treating specific wastewater.

[0096] The aniline water is used as the raw water of the wastewater, the flow rate is controlled to be 0.5 m 3 / h, the pH is adjusted to be 3 in advance in the adjusting pool 1 by using 98% concentrated sulfuric acid, then the wastewater is transported to the jet device 3 through the centrifugal pump 2, the backflow water amount is controlled to be 1 m 3 / h (the reactor is filled with the aniline water in advance); meanwhile, the air is sucked into the jet device 3 through the pipeline by the buffer tank 4, the flow meter 5, the electromagnetic valve 6 and the check valve 7, and the air flow rate is controlled to be 0.5 m 3 / h; the air and the pre-adjusted pH raw water and backflow water are mixed fully in the jet device 3, are transported to the diffusion nozzle 8 at the bottom of the reactor 18 through the pipeline, the mixed gas and water are sprayed and impact on the conical slope 9 arranged at the bottom to form diffusion, the gas and water are uniformly formed to rise, pass through the area of the vertical arranged iron-carbon filler column 13, the micro-electrolysis reaction occurs through the gas-liquid-solid three-phase contact, the water flow after the reaction continues to flow upwards to the water outlet 28 at the top of the reactor to discharge water, and the hydraulic retention time is controlled to be 30 min.

[0097] Example 9

[0098] The embodiment provides application of the novel iron-carbon micro-electrolysis reaction system in treating specific wastewater.

[0099] The pesticide wastewater of an industrial wastewater plant in Jiangdu, Yangzhou is used as the raw water of the wastewater, the flow rate is controlled to be 0.25 m 3 / h, the pH is adjusted to be 3 in advance in the adjusting pool 1 by using 98% concentrated sulfuric acid, then the wastewater is transported to the jet device 3 through the centrifugal pump 2, the backflow water amount is controlled to be 0.5 m 3 / h (the reactor is filled with the aniline water in advance); meanwhile, the air is sucked into the jet device 3 through the pipeline by the buffer tank 4, the flow meter 5, the electromagnetic valve 6 and the check valve 7, and the air flow rate is controlled to be 0.5 m 3The air and the pre-adjusted pH raw water and backflow water are mixed fully in the jet device 3, are transported to the diffusion nozzle 8 at the bottom of the reactor 18 through the pipeline, the mixed gas and water are sprayed and impacted on the conical slope 9 arranged at the bottom to form diffusion, the gas and water are uniformly formed to rise, pass through the area of the vertically arranged iron-carbon filler column 13, the micro-electrolysis reaction occurs in the gas-liquid-solid three-phase contact, the water flow after the reaction continues to flow upwards to the water outlet 28 at the top of the reactor to discharge water, the hydraulic retention time is controlled to be 60 min, the 98% sulfuric acid is supplemented once every 12 min through the acid supplementing port at the side wall of the reactor 18, and the acid supplementing amount is 0.2‰ of the raw water.

[0100] The pollutant degradation experiments of the simulated wastewater and the actual wastewater are carried out in examples 7-9, and the reaction results are as follows.

[0101] Table 1 micro-electrolysis reaction experiment data

[0102]

[0103] It can be seen that the micro-electrolysis reaction system of the present application shows certain degradation capacity for the simulated wastewater and the actual pesticide wastewater treatment, the degradation efficiency of the pollutants is closely related to the specific pollutant types of the wastewater, in order to be suitable for different wastewaters, the reaction system of the present application needs to be optimized and designed in parameters so as to perfect and improve the operation effect.

[0104] The present application has been described in detail in the foregoing with specific exemplary embodiments. It should be understood, however, that various modifications and changes can be made without departing from the scope of the present application as defined by the appended claims. The detailed description and the accompanying drawings are therefore to be regarded in an illustrative rather than a restrictive sense, and all such modifications and variations are intended to be within the scope of the present application described herein. Further, the background is intended to provide background information concerning the field of technology to which the present application pertains, and is not admitted to be prior art.

Claims

1. A novel iron-carbon micro-electrolysis reaction system, characterized in that, The system includes: The reactor has an outlet at the top and a conical slope at the bottom; an inlet pipe with a diffuser nozzle is installed above the conical slope; and a support layer and a packing layer are installed above the inlet pipe. The other end of the water inlet pipe is connected to the outlet of the ejector; the ejector is connected to the outlets of the air buffer tank and the centrifugal pump respectively; The inlet of the centrifugal pump is connected to the outlet of the equalization tank; the inlet of the equalization tank is connected to the raw water outlet. The support layer includes a porous support plate and a porous plate, both of which are porous mesh plates with a square hole in the middle. The packing layer consists of hollow tubular iron-carbon packing columns that vertically penetrate the central hole of the perforated plate and rest on the perforated support plate. The length of the hollow tubular iron-carbon packing column is greater than the distance between the porous support plate and the porous plate; the outer diameter of the hollow tubular iron-carbon packing column is greater than the side length of the middle single hole of the porous support plate, but smaller than the side length of the middle single hole of the porous plate. The hollow tubular iron-carbon packing column has symmetrical semi-circular protrusions formed on its tube wall by a drill bit, which bend inwards.

2. The novel iron-carbon micro-electrolysis reaction system according to claim 1, characterized in that, The support layer also includes a porous flexible support mesh, which is laid close to the top of the porous support plate.

3. The novel iron-carbon micro-electrolysis reaction system according to claim 2, characterized in that, The reactor is also equipped with a reflux port at the top, which is connected to the inlet pipe of the centrifugal pump.

4. The novel iron-carbon micro-electrolysis reaction system according to claim 3, characterized in that, An acid replenishment port is provided in the middle of the reactor.

5. The application of the novel iron-carbon micro-electrolysis reaction system according to any one of claims 1-4 in wastewater treatment.

6. The application according to claim 5, characterized in that, The applications include: The raw water is pre-adjusted for pH in the equalization tank and then mixed with the return water before being pumped to the jet injector by a centrifugal pump. Air is drawn into the ejector through a pipeline from the buffer tank. Air and mixed water are fully mixed in the jet injector and transported to the diffuser nozzle through the inlet pipe. The mixed air and water jet impacts the conical slope to form a large-area diffusion. The air and water form an upward flow evenly. After passing through the vertically arranged hollow tubular iron-carbon packing column area, the gas, liquid and solid three phases come into contact and a micro-electrolysis reaction occurs. The water after the reaction continues to flow upward to the outlet.

7. The application according to claim 6, characterized in that, The application also includes intermittent acid replenishment via an acid replenishment port.

8. The application according to claim 6 or 7, characterized in that, The ratio of raw water volume to return water volume after pH adjustment is 1:2, and the ratio of raw water volume to air volume is 1:1.

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