An electrochemical sewage pipe network sulfide control device and method

Abstract

The present invention discloses an electrochemical sewage pipe network sulfide control device and method, which relates to the field of water treatment technology and includes an electrochemical module, a cathode electrode, an anode electrode, an anion exchange membrane and a cation exchange membrane. The electrochemical sewage pipe network sulfide control device utilizes the reaction occurring on the anode and cathode to generate reagents in situ for a long time, eliminating the safety hazards of transporting and storing reagents from the source, and can effectively control sulfides in the sewage pipe network, eliminate the generation of hydrogen sulfide gas, and prevent the occurrence of pipe network odor and corrosion. The device can be lowered and lifted using a fixed rod to control the position of the device in the pipe network. Different products can also be regulated according to the characteristics of the sewage, so that workers do not need to go down the well. The present invention is highly efficient and can greatly reduce the cost of removing sulfides in the sewage pipe network.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and more particularly to an electrochemical sewage pipe network sulfide control device. Background Art

[0002] Urban underground sewage pipe networks are a vital component of urban infrastructure, and their sustained and stable operation plays a positive role in the normal functioning of cities and the well-being of citizens. However, over the years, issues related to these pipe networks have become increasingly prominent, with the impact of harmful gases generated within these pipes being a major concern. Because sewage pipes maintain an anaerobic state for a long time, and because underground pipes currently extend for several kilometers or even more than ten kilometers, resulting in long hydraulic retention times, anaerobic microorganisms in sediment and biofilms on pipe walls generate large quantities of toxic and harmful gases within the pipes.

[0003] The sulfate content in urban sewage networks ranges from 40 to 200 mg / L. Sulfate-reducing bacteria readily reduce this sulfate to sulfide within the pipe network. This sulfide can then escape into the gas phase, forming hydrogen sulfide, a major source of toxic and hazardous gases within the pipe network. Currently, sulfide poses two major hazards within pipe networks. First, it can escape from the pipe network, causing foul odors in urban areas and potentially poisoning workers if inhaled. Second, it can corrode drainage pipes, resulting in significant costs for repairing or replacing corroded pipes. Therefore, measures are needed to reduce the generation and emission of hydrogen sulfide.

[0004] Regarding sulfide control technologies in sewage pipe networks, research both domestically and internationally has shown that increasing the redox potential of wastewater within the pipe network not only oxidizes sulfide but also effectively inhibits the activity of sulfate-reducing bacteria. Raising the pH of wastewater within the pipe network prevents the escape of generated sulfide and inhibits the activity of sulfate-reducing bacteria. Adding metal salts, such as iron salts, removes the sulfur element from the wastewater system, achieving sulfide control. While these measures are very effective in controlling hydrogen sulfide, the production, transportation, and storage of these chemicals involve numerous challenges, which can increase labor costs. Furthermore, the use of chemicals cannot be quantified and accurately, resulting in low chemical efficiency. The presence of calcium and magnesium ions in pipe network wastewater can cause scaling on the ion exchange membranes of electrochemical devices after long-term operation, leading to increased resistance and significant power consumption.

[0005] Therefore, it is an urgent problem for those skilled in the art to propose an electrochemical sewage pipe network sulfide control device and method to eliminate the cost of transportation and storage of chemicals and achieve the goal of eliminating the need for frequent manual addition of chemicals. Summary of the Invention

[0006] In light of this, the present invention provides an electrochemical sulfide control device and method for sewage pipe networks to address issues such as reagent transportation and storage, as well as high labor costs associated with existing dosing technologies. This device avoids environmental pollution caused by generated products, mitigates the impact on subsequent sewage treatment, and eliminates membrane scaling issues often encountered in electrochemical processes.

[0007] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: an electrochemical sewage pipe network sulfide control device, comprising: an electrochemical module, a cathode electrode, a cation exchange membrane, an anion exchange membrane and an anode electrode;

[0008] The electrochemical module includes a first pressing plate, a gas chamber, a cathode chamber, an anti-scaling chamber, a secondary anode chamber, a main anode chamber and a second pressing plate connected in sequence; branch pipes are staggered on both sides of the chamber;

[0009] The cathode electrode is arranged between the gas chamber and the cathode chamber, the cation exchange membrane is arranged between the cathode chamber and the anti-scaling chamber, the anion exchange membrane is arranged between the anti-scaling chamber and the auxiliary anode chamber, and the anode electrode is arranged between the auxiliary anode chamber and the main anode chamber.

[0010] Optionally, the interiors of the gas chamber, cathode chamber, anti-scaling chamber, auxiliary anode chamber and main anode chamber are all hollow structures.

[0011] Optionally, the cathode electrode is carbon paper, carbon cloth, carbon felt or stainless steel mesh coated with a carbon-containing catalyst, and a cathode electrode gasket is placed between the gas chamber and the cathode electrode;

[0012] The anode electrode is a thin sheet oxygen evolution electrode or low carbon steel, and an anode electrode gasket is placed between the anode electrode and the main anode chamber.

[0013] Optionally, a first gasket, a cation exchange membrane and a second gasket are placed in sequence between the cathode chamber and the anti-scaling chamber, and a third gasket, an anion exchange membrane and a fourth gasket are placed in sequence between the anti-scaling chamber and the sub-anode chamber.

[0014] Optionally, branch pipes are installed on both sides of the gas chamber, cathode chamber, anti-scaling chamber, auxiliary anode chamber and main anode chamber, and the branch pipes are staggered on both sides of the chamber.

[0015] Optionally, at least two branch pipes are alternately arranged on both sides of the auxiliary anode chamber and the main anode chamber.

[0016] Optionally, the gas chamber, cathode chamber, anti-scaling chamber, auxiliary anode chamber, and main anode chamber are each provided with mounting holes, and at least four sets of fixing rods are installed to fit into the mounting holes and sequentially penetrate the mounting holes of the gas chamber, cathode chamber, anti-scaling chamber, auxiliary anode chamber, and main anode chamber.

[0017] Optionally, an electrochemical sewage pipe network sulfide control method includes:

[0018] The auxiliary anode chamber and the main anode chamber use oxygen evolution anode to generate oxygen in situ to oxidize the sulfide in the sewage, and convert the sulfide in the water into elemental sulfur or sulfur oxide;

[0019] When the main anode chamber uses low-carbon steel as the anode, a magnetite nanoparticle solution is generated, and the magnetite nanoparticle solution reacts with sulfide in water to form ferrous sulfide precipitate that is insoluble in water;

[0020] The anti-scaling chamber prevents calcium and magnesium ions in the pipe network sewage from migrating into the cathode chamber solution.

[0021] Optionally, while the sulfide removal reaction occurs at the anode, a stainless steel mesh or a carbon electrode is used as a cathode to simultaneously generate an alkali or alkali / hydrogen peroxide solution in situ in the cathode chamber;

[0022] The alkali or alkali / hydrogen peroxide solution is pumped into the auxiliary anode chamber and the main anode chamber through the branch pipe during the energization interval.

[0023] Optionally, when the pipe network is impacted by high-concentration sulfide wastewater, the alkali or alkali / hydrogen peroxide solution generated in the cathode chamber is pumped into the pipe network through a branch pipe, and the sulfide in the wastewater is removed by synergistic treatment between the products.

[0024] It can be seen from the above technical solutions that, compared with the prior art, the present invention provides an electrochemical sewage pipe network sulfide control device and method, which has the following beneficial effects:

[0025] Compared with directly adding iron salts, alkali, oxygen and hydrogen peroxide, the device of the present invention has low cost, avoids the disadvantages of needing to transport, store and add reagents, and innovatively combines multiple electrodes to achieve in-situ changes in product generation, and can adapt to pipe network sewage with different sulfide levels.

[0026] Compared with traditional dosing methods, the device of the present invention can regulate the current through a DC motor to accurately control the dosage of product generation, adapt to the sulfide concentration in sewage, and thus control sulfide at a low cost.

[0027] The oxygen bubbles generated in situ by the device of the present invention have small particle sizes, and can achieve efficient mass transfer of oxygen.

[0028] The device of the present invention realizes long-term use of the electrochemical device through the anti-scaling chamber, and does not cause scaling of calcium and magnesium ions on the membrane due to alkali production or alkali / hydrogen peroxide production in the cathode chamber.

[0029] The device of the present invention has a simple structure and is easy to assemble. The electrodes can be replaced at any time, which greatly reduces the maintenance and use costs of drainage network equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0031] Figure 1 This is a structural schematic diagram of an electrochemical sewage pipe network sulfide control device provided by the present invention.

[0032] Figure 2 This is a schematic diagram of the oxygen production effect provided by the present invention.

[0033] Figure 3 This is a schematic diagram of the sulfide control effect provided by the present invention.

[0034] Figure 4 This is a schematic diagram of the alkali production effect of the cathode chamber provided by the present invention.

[0035] Figure 5 This is a schematic diagram of the effect of the cathode chamber alkaline solution on the pH of sewage provided by the present invention.

[0036] Figure 6 This is a schematic diagram of the hydrogen peroxide and alkali production effects provided by the present invention.

[0037] Figure 7 This is a schematic diagram of the long-term operation results of hydrogen peroxide provided by the present invention.

[0038] Figure 8 This is a schematic diagram of the long-term sulfide control results of the anode provided by the present invention.

[0039] FIG9( a ) is a front view of the cathode chamber provided by the present invention.

[0040] FIG9( b ) is a left side view of the cathode chamber provided by the present invention.

[0041] FIG9( c ) is a top view of the cathode chamber provided by the present invention.

[0042] Figure 10 This is a front view of the anti-scaling chamber provided by the present invention.

[0043] Figure 11 This is a front view of the anode sub-chamber provided by the present invention.

[0044] FIG12( a ) is a left side view of the anode sub-chamber provided by the present invention.

[0045] FIG12( b ) is a left side view of the main anode chamber provided by the present invention.

[0046] Figure 13 A front view of the gas chamber provided by the present invention.

[0047] Wherein: 1-first pressure plate, 2-gas chamber, 3-cathode electrode gasket, 4-cathode chamber, 5a-first gasket, 5b-second gasket, 5c-third gasket, 5d-fourth gasket, 6-anti-scaling chamber, 7-anode sub-chamber, 8-anode electrode gasket, 9-main anode chamber, 10-cathode electrode, 11-cation exchange membrane, 12-anion exchange membrane, 13-anode electrode, 14-fixed rod, 15-branch pipe, 16-second pressure plate. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0049] The embodiment of the present invention discloses an electrochemical sewage pipe network sulfide control device, comprising: an electrochemical module, a cathode electrode 10, a cation exchange membrane 11, an anion exchange membrane 12 and an anode electrode 13;

[0050] The electrochemical module comprises a first pressing plate 1, a gas chamber 2, a cathode chamber 4, an anti-scaling chamber 6, a secondary anode chamber 7, a main anode chamber 9 and a second pressing plate 16 connected in sequence; branch pipes 15 are staggered on both sides of the chamber;

[0051] The cathode electrode 10 is arranged between the gas chamber 2 and the cathode chamber 4, the cation exchange membrane 11 is arranged between the cathode chamber 4 and the anti-scaling chamber 6, the anion exchange membrane 12 is arranged between the anti-scaling chamber 6 and the auxiliary anode chamber 7, and the anode electrode 13 is arranged between the auxiliary anode chamber 7 and the main anode chamber 9.

[0052] Furthermore, the pressure plate 1 and chamber are both made of acrylic. The electrochemical sewage network sulfide control device is placed within the water in the sewage network inspection well, with the remaining components connected to the branch pump via branch pipes. The pressure plate 1 is a plate with no internal holes, and there are at least two of them.

[0053] Furthermore, the interiors of the gas chamber 2 , the cathode chamber 4 , the anti-scaling chamber 6 , the auxiliary anode chamber 7 and the main anode chamber 9 are all hollow structures.

[0054] Furthermore, the cathode electrode 10 is made of carbon paper, carbon cloth, carbon felt, or stainless steel mesh coated with a carbon-containing catalyst, and a cathode electrode gasket 3 is placed between the gas chamber 2 and the cathode electrode 10. The anode electrode 13 is a thin sheet of oxygen evolution electrode or low-carbon steel, and an anode electrode gasket 8 is placed between the anode electrode 13 and the main anode chamber 9. The cathode electrode 10 is connected to a DC power supply via a wire. The anode electrode 13 is also connected to a DC power supply via a wire.

[0055] Furthermore, a first gasket 5, a cation exchange membrane 11, and a second gasket 5 are sequentially placed between the cathode chamber 4 and the anti-scaling chamber 6. A third gasket 5, an anion exchange membrane 12, and a fourth gasket 5 are sequentially placed between the anti-scaling chamber 6 and the secondary anode chamber 7. The anti-scaling chamber 6 has the same structure as the gas chamber 2. The size of the cation exchange membrane 11 is larger than the hollowed area. The size of the anion exchange membrane 12 is larger than the hollowed area.

[0056] Furthermore, pressurized air flows through the gas chamber 2. A low-concentration sodium chloride solution flows through the cathode chamber 4. A high-concentration sodium chloride solution flows through the anti-scaling chamber 6. Actual sewage flows through the auxiliary anode chamber 7 and the main anode chamber 9.

[0057] Furthermore, branch pipes 15 are installed on both sides of the gas chamber 2, cathode chamber 4, anti-scaling chamber 6, auxiliary anode chamber 7 and main anode chamber 9, and the branch pipes 15 are staggered on both sides of the chamber.

[0058] Furthermore, at least two branch pipes 15 are staggeredly arranged on both sides of the auxiliary anode chamber 7 and the main anode chamber 9. The branch pipes 15 pass through the acrylic plate and are connected to the interior of the chamber.

[0059] Furthermore, the cathode chamber is also fixed with two branch pipes and a horizontal flow channel, and the branch pipes are the same as the branch pipes in the gas chamber. The purpose of staggered arrangement of at least two branch pipes on both sides is to facilitate circulation, and the top branch pipe is arranged to facilitate sampling and measurement of the product during on-site processing or measurement of electrode potential using a reference electrode. For easy understanding, the top branch pipe can be deleted and a sampling hole can be arranged between the pump pipes. The purpose of the flow channel is to optimize the yield of the product. Figure 9a It can also be clearly observed that there is a flow channel inside the chamber.

[0060] Furthermore, mounting holes are provided on the gas chamber 2, cathode chamber 4, anti-scaling chamber 6, auxiliary anode chamber 7 and main anode chamber 9, and at least four sets of fixing rods 14 are installed to adapt to the mounting holes and pass through the mounting holes on the gas chamber 2, cathode chamber 4, anti-scaling chamber 6, auxiliary anode chamber 7 and main anode chamber 9 in sequence.

[0061] Furthermore, an electrochemical sewage pipe network sulfide control method includes:

[0062] The auxiliary anode chamber 7 and the main anode chamber 9 use oxygen evolution anode to generate oxygen in situ to oxidize the sulfide in the sewage, converting the sulfide in the water into elemental sulfur or sulfur oxide;

[0063] When the main anode chamber 9 uses low-carbon steel as the anode, a magnetite nanoparticle solution is generated, and the magnetite nanoparticle solution reacts with the sulfide in the water to form a ferrous sulfide precipitate that is hardly soluble in water;

[0064] The anti-scaling chamber 6 prevents calcium and magnesium ions in the pipe network sewage from migrating into the cathode chamber solution, thereby avoiding scaling of the cation exchange membrane 11 or the cathode electrode 10 .

[0065] Furthermore, while the anode reacts to remove sulfides, a stainless steel mesh or a carbon electrode is used as a cathode to simultaneously generate an alkali or alkali / hydrogen peroxide solution in situ in the cathode chamber 4;

[0066] The alkali or alkali / hydrogen peroxide solution is pumped into the auxiliary anode chamber 7 and the main anode chamber 9 through the branch pipe during the power-on interval.

[0067] Furthermore, when the pipe network is impacted by high-concentration sulfide wastewater, the alkali or alkali / hydrogen peroxide solution generated in the cathode chamber 4 is pumped into the pipe network through the branch pipe, and the sulfide in the wastewater is removed by the coordinated treatment between the products.

[0068] The present invention uses electrochemical in-situ generation of oxygen, which has the advantage of fine dispersed bubbles (about 1-30 mm), improves mass transfer efficiency and accelerates the oxidation effect; in addition, when low-carbon steel is used as the anode electrode, a high-strength magnetite nanoparticle solution (particle size between 120-160 nm) is produced in situ, which does not cause sewage acidification and sulfide escape like the traditional addition of iron salts. It can also eliminate the potential adverse effects of heavy metals (such as Cr, Zn, Ni, Sn) contained in ordinary iron salts on the quality of sewage and sludge. In addition, the in-situ generated hydrogen peroxide avoids its easy-to-explode properties, and can be used safely and conveniently. The electrochemical device can realize the in-situ generation of hydrogen peroxide, oxygen, alkali, and magnetite nanoparticles, perfectly eliminating the cost of the reagents during transportation and storage. An anti-scaling chamber is added to the electrochemical device, and the anion and cation exchange membrane therein is passed through a sodium chloride solution to prevent calcium and magnesium ions from entering the cathode chamber, thereby preventing the occurrence of scaling and enabling the long-term stable operation of the electrochemical device.

[0069] In a specific embodiment, an electrochemical sewage network sulfide control device includes: an electrochemical module, a cathode electrode 10, a cation exchange membrane 11, an anion exchange membrane 12 and an anode electrode 13;

[0070] The electrochemical module comprises a first pressing plate 1, a gas chamber 2, a cathode chamber 4, an anti-scaling chamber 6, a secondary anode chamber 7, a main anode chamber 9 and a second pressing plate 16 connected in sequence; branch pipes 15 are staggered on both sides of the chamber;

[0071] The cathode electrode 10 is arranged between the gas chamber 2 and the cathode chamber 4, the cation exchange membrane 11 is arranged between the cathode chamber 4 and the anti-scaling chamber 6, the anion exchange membrane 12 is arranged between the anti-scaling chamber 6 and the auxiliary anode chamber 7, and the anode electrode 13 is arranged between the auxiliary anode chamber 7 and the main anode chamber 9.

[0072] Furthermore, the present invention relates to the following reaction:

[0073] Anode produces dissolved magnetite nanoparticles:

[0074] Anode oxygen production:

[0075] Cathode alkali production:

[0076] Cathodic alkali production / hydrogen peroxide:

[0077] The process steps of an electrochemical sewage pipe network sulfide control device are as follows:

[0078] S1: Designing a sulfide control device that is enlarged or reduced to a suitable size according to the water volume of the drainage network, and assembling the electrochemical sewage network sulfide control device.

[0079] S2: Place the electrochemical sewage pipe network sulfide control device into the sewage pipe network inspection well through the fixing rod 14, and adjust the direction angle of the device so that the branch pipe is parallel to the sewage flow direction.

[0080] S2.1: If Figure 11 As shown, the sewage flows into the main and auxiliary anode chambers of the electrochemical device through the branch pipe 15f, and flows out from the branch pipe 15g after being treated by the electrochemical products.

[0081] As shown in Figure 9(a), Figure 9(b), Figure (9c) and Figure 10 As shown, the electrolyte enters the cathode chamber 4 and the anti-scaling chamber 6 through the branch pipes 15a and 15c respectively, and is connected to a direct current for electrochemical treatment. After the treatment, the sulfide concentration of the effluent is measured.

[0082] S3: When impacted by high-concentration sulfide wastewater or during shutdown and maintenance, the alkali or alkali / hydrogen peroxide retained in the cathode can flow into the main and auxiliary anode chambers through the branch pipe 15b to suppress sulfide.

[0083] S4: As Figure 13As shown, when the product of the cathode chamber 4 is alkali / hydrogen peroxide, it should be properly ventilated, and air can flow in from the branch pipe 15i and out from 15j.

[0084] Furthermore, as shown in Figures 12(a) and 12(b), the anode sub-chamber 7 and the main anode chamber 9 are identical except for the difference in thickness. The purpose of setting up the two chambers is to improve the utilization efficiency of oxygen generated on the front and back sides of the electrode. Four branch pipes 15 are fixed outside the chamber body of the sub-anode chamber 7. The branch pipes 15 are respectively located on both sides of the chamber and are distributed at different heights. The upper and lower branch pipes 15e and 15h on both sides are sewage circulation flows, and the branch pipes 15f and 15g are sewage continuous flow pipelines. The circulating flow and continuous flow are both inlet and outlet. Two branch pipes are used for sewage circulation, and the other two branch pipes promote oxygen mass transfer for sewage circulation.

[0085] Specifically, the difference between the main anode chamber 9 and the anode sub-chamber 7 lies in the thickness of the acrylic plate, and the thickness determines the volume of the circulating sewage.

[0086] Long-term control of sulfide levels in piped wastewater requires regular maintenance of the entire device and cleaning of any remaining dirt. Electrodes should also be replaced based on water quality to continuously remove hydrogen sulfide from the wastewater pipe network and suppress sulfide activity to a low level, thereby inhibiting the generation of malodorous gases and mitigating corrosion in the pipe network. The electrochemical sewage pipe network sulfide control device and method described in the present invention boasts a simple structure and a feasible solution. Sulfide levels in piped wastewater are controlled by producing oxygen through an anodic oxygen evolution electrode or by refining low-carbon steel to produce soluble magnetite nanoparticles.

[0087] In Example 1, the size of the electrochemical sewage network sulfide control device is 70×70×112mm, the total volume of the main anode chamber 9 and the anode sub-chamber is 64mL, the anode plate is foam titanium-based IrO2, the cathode plate is a stainless steel plate, and the distance between adjacent anode plates and cathode plates is 2.5cm. In order to promote the flow of liquid in the cathode chamber and the anti-scaling chamber, peristaltic pumps can be respectively provided for circulation. In this embodiment, the actual sewage sulfide concentration in the pipeline network is 10mg-S / L, the conductivity is 900μS / cm, and the pH value is 7.58. The device is used to measure the dissolved oxygen level of the sewage, and the total water inlet flow rates of the main and sub-anode chambers are maintained at 1.92, 2.88, 4.32, 5.76, and 7.68Lh, respectively. -1 The current densities were 6.4, 8.2, and 10 mA cm -2 After the reaction lasted for 3.5 hours, the dissolved oxygen level was Figure 2 As shown. The flow rate is 2.88L h -1 , with current densities of 6.4 and 10 mA cm, respectively. -2 When the instantaneous control effect of sulfide is Figure 3 As shown, the effluent sulfide concentration is 1.15 mg-S / L. For domestic sewage, a dissolved oxygen level above 2 mg / L is sufficient to remove hydrogen sulfide. When the anode of the present invention is an oxygen evolution electrode, varying the current density at different flow rates allows for regulation of anode oxygen production.

[0088] When encountering high-concentration sulfide wastewater or during shutdown and maintenance intervals, the alkaline solution generated in situ at the cathode can be pumped into the wastewater to prevent sulfide from escaping. Figure 4 As shown in Figure 2, the alkali concentration in the cathode chamber can continue to accumulate during the process of anode oxygen production. Figure 5 As shown in the figure, a volume of 0.4 ml of alkali solution can raise the pH of the sewage to 9.0, which can completely inhibit the escape of sulfide.

[0089] In Example 1, the oxygen evolution electrode is titanium foam-based IrO2, the anti-scaling chamber 6 uses 20 g / L sodium chloride as the electrolyte, and the cathode chamber uses 6 g / L sodium chloride as the electrolyte.

[0090] In Example 2, the dimensions of the electrochemical sewage network sulfide control device were 100 × 100 × 112 mm, the total volume of the main anode chamber and the auxiliary anode chamber was 196 mL, the anode plate was a titanium foam-based IrO2, the cathode plate was a carbon electrode, and the spacing between adjacent anode and cathode plates was 2.5 cm. The actual sewage sulfide concentration in the network was 15 mg-S / L, the conductivity was 1050 μS / cm, and the pH was 7.78. The alkali / hydrogen peroxide production within 240 minutes was as follows: Figure 6 As shown in the figure, for domestic sewage, hydrogen peroxide above 60 mg / L can oxidize sulfide and inhibit the activity of sulfur-reducing bacteria. At the same time, the generated alkali can further prevent the escape of sulfide. After treatment with 60 mg / L alkali / hydrogen peroxide solution, the sulfide content of the sewage is 0.3 μg-S / L, which meets the sewage discharge standard. The long-term operation results of the cathode solution are shown in the figure. Figure 7 shown.

[0091] In Example 3, the size of the electrochemical sewage network sulfide control device is 90×90×112mm, the total volume of the main anode chamber and the auxiliary anode chamber is 144mL, the anode plate is refined low-carbon steel, the product is soluble magnetite nanoparticles, the cathode plate is a carbon electrode, and the product is alkali / hydrogen peroxide. The distance between adjacent anode plates and cathode plates is 2.5cm. The actual sewage sulfide concentration in the pipeline network is: 5mg-S / L, the conductivity is 1150μS / cm, and the pH value is 7.80. The long-term sulfide control effect is as follows Figure 8 shown.

[0092] From the above experimental results, it can be seen that the electrochemical sewage pipe network sulfide control device and method described in the present invention can effectively remove sulfides in the pipe network sewage. Under the action of electric current, oxygen, soluble magnetite nanoparticles, alkali, and alkali / hydrogen peroxide are effectively generated in situ. At the same time, at this current density of 10mA / cm 2 The electricity can be fully provided by solar energy and clean energy, thereby further improving the cost-effectiveness in actual use.

[0093] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0094] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrochemical sewage pipe network sulfide control device, characterized in that: include: An electrochemical module, a cathode electrode (10), a cation exchange membrane (11), an anion exchange membrane (12) and an anode electrode (13); The electrochemical module comprises a first pressing plate (1), a gas chamber (2), a cathode chamber (4), an anti-scaling chamber (6), a secondary anode chamber (7), a main anode chamber (9) and a second pressing plate (16) which are connected in sequence; branch pipes (15) are staggered on both sides of the chamber; The cathode electrode (10) is arranged between the gas chamber (2) and the cathode chamber (4), the cation exchange membrane (11) is arranged between the cathode chamber (4) and the anti-scaling chamber (6), the anion exchange membrane (12) is arranged between the anti-scaling chamber (6) and the auxiliary anode chamber (7), and the anode electrode (13) is arranged between the auxiliary anode chamber (7) and the main anode chamber (9); The interiors of the gas chamber (2), cathode chamber (4), anti-scaling chamber (6), auxiliary anode chamber (7) and main anode chamber (9) are all hollow structures; A first gasket (5a), a cation exchange membrane (11), and a second gasket (5b) are sequentially placed between the cathode chamber (4) and the anti-scaling chamber (6); and a third gasket (5c), an anion exchange membrane (12), and a fourth gasket (5d) are sequentially placed between the anti-scaling chamber (6) and the auxiliary anode chamber (7); Branch pipes (15) are installed on both sides of the gas chamber (2), the cathode chamber (4), the anti-scaling chamber (6), the auxiliary anode chamber (7) and the main anode chamber (9), and the branch pipes (15) are staggered on both sides of the chamber; At least two branch pipes (15) are staggeredly arranged on both sides of the auxiliary anode chamber (7) and the main anode chamber (9); The gas chamber (2), cathode chamber (4), anti-scaling chamber (6), auxiliary anode chamber (7) and main anode chamber (9) are all provided with mounting holes, and at least four groups of fixing rods (14) are installed to fit the mounting holes and pass through the mounting holes on the gas chamber (2), cathode chamber (4), anti-scaling chamber (6), auxiliary anode chamber (7) and main anode chamber (9) in sequence.

2. The electrochemical sewage pipe network sulfide control device according to claim 1, characterized in that: The cathode electrode (10) is carbon paper, carbon cloth, carbon felt or stainless steel mesh coated with a carbon-containing catalyst, and a cathode electrode gasket (3) is placed between the gas chamber (2) and the cathode electrode (10); the anode electrode (13) is a thin sheet oxygen evolution electrode or low carbon steel, and an anode electrode gasket (8) is placed between the anode electrode (13) and the main anode chamber (9).

3. An electrochemical sewage pipe network sulfide control method, applied to an electrochemical sewage pipe network sulfide control device according to any one of claims 1-2, characterized in that: include: The auxiliary anode chamber (7) and the main anode chamber (9) use oxygen evolution anodes to generate oxygen in situ to oxidize sulfides in the sewage, thereby converting the sulfides in the water into elemental sulfur or sulfur oxides; When the main anode chamber (9) uses low carbon steel as an anode, a magnetite nanoparticle solution is generated, and the magnetite nanoparticle solution reacts with sulfide in water to generate ferrous sulfide precipitate that is hardly soluble in water; The anti-scaling chamber (6) prevents calcium and magnesium ions in the pipe network sewage from migrating into the cathode chamber solution.

4. The electrochemical sewage pipe network sulfide control method according to claim 3 is characterized in that: While the anode reacts to remove sulfides, a stainless steel mesh or a carbon electrode is used as a cathode to simultaneously generate an alkali or alkali / hydrogen peroxide solution in situ in the cathode chamber (4); The alkali or alkali / hydrogen peroxide solution is pumped into the auxiliary anode chamber (7) and the main anode chamber (9) through the branch pipe during the energization interval.

5. The electrochemical sewage pipe network sulfide control method according to claim 4 is characterized in that: When the pipe network is impacted by high-concentration sulfide wastewater, the alkali or alkali / hydrogen peroxide solution generated in the cathode chamber (4) is pumped into the pipe network through a branch pipe, and the sulfide in the wastewater is removed by the coordinated treatment between the products.

Images