Sewage treatment system and process

Abstract

The invention provides a sewage treatment system which comprises a ferrous tank, a hydrogen peroxide tank, an alkali tank, a degassing tank, a flocculation tank and a first sedimentation tank which are communicated in sequence, the ferrous tank is used for adding an agent containing ferrous ions, the hydrogen peroxide tank is used for adding hydrogen peroxide and a catalyst, the alkali tank is used for adding an alkaline agent, and the degassing tank is used for adding a flocculating agent. A porous aeration pipe is arranged in the degassing tank and used for injecting bubbles into the degassing tank, the flocculation tank is used for adding a flocculating agent, the first sedimentation tank is used for mud-water separation, and the bottom of the first sedimentation tank is communicated with a first blow-off pipe.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment and relates to a sewage treatment system and process. Background Art

[0002] The Fenton reaction is an inorganic chemical reaction in which hydrogen peroxide (H2O2) reacts with divalent iron ions Fe 2+ The mixed solution can oxidize many known organic compounds such as carboxylic acids, alcohols, and esters into inorganic states. The reaction has a high ability to remove refractory organic pollutants and is widely used in the treatment of printing and dyeing wastewater, oily wastewater, phenolic wastewater, coking wastewater, nitrobenzene-containing wastewater, diphenylamine wastewater, and other wastewater.

[0003] During the reaction, 1 mol of H2O2 and 1 mol of Fe 2+ After the reaction, 1 mol of Fe is generated. 3+ , and at the same time, 1 mol of OH- plus 1 mol of hydroxyl radicals are generated. It is the presence of hydroxyl radicals that makes Fenton's reagent have strong oxidizing ability. It is calculated that in a solution with pH = 4, the oxidation potential of OH· radicals is as high as 2.73V. In nature, its oxidizing ability in the solution is second only to fluorine. Therefore, persistent organic matter, especially aromatic compounds and some heterocyclic compounds that are difficult to oxidize with conventional reagents, are all degraded by non-selective oxidation in front of Fenton's reagent. Summary of the invention

[0004] The purpose of the present invention is to provide a sewage treatment system and process, aiming to provide a new sewage treatment system.

[0005] In order to achieve the above technical effects, the present invention provides a sewage treatment system, comprising a ferrous tank, a hydrogen peroxide tank, an alkali tank, a degassing tank, a flocculation tank and a first sedimentation tank connected in sequence, the ferrous tank is used for adding a ferrous ion-containing agent, the hydrogen peroxide tank is used for adding hydrogen peroxide and a catalyst, the alkali tank is used for adding an alkaline agent, the degassing tank is provided with a porous aeration pipe for injecting bubbles into the degassing tank, the flocculation tank is used for adding a flocculant, the first sedimentation tank is used for mud-water separation, and the bottom of the first sedimentation tank is connected with a first sewage pipe.

[0006] The present invention is further configured such that the aeration pipes are arranged at the bottom of the ferrous tank, the hydrogen peroxide tank, the alkaline tank and the flocculation tank.

[0007] The present invention is further configured to include a second sedimentation tank, the bottom of which is connected to a second sewage pipe, the second sedimentation tank is communicated with the upstream end of the ferrous tank, the second sedimentation tank and the ferrous tank, the ferrous tank and the hydrogen peroxide tank, the hydrogen peroxide tank and the alkali tank, the alkali tank and the degassing tank, the degassing tank and the flocculation tank, and the flocculation tank and the first sedimentation tank are all connected through flow holes, and the flow holes between the ferrous tank and the hydrogen peroxide tank, the flow holes between the hydrogen peroxide tank and the alkali tank, and the flow holes between the alkali tank and the degassing tank are all at a distance from the bottom of the corresponding pool wall that is shorter than the distance from the top, and the distance between the flow holes between the degassing tank and the flocculation tank and the top of the corresponding pool wall is shorter than the distance from the bottom.

[0008] The present invention is further configured such that the flow hole of the second sedimentation tank flowing to the ferrous pool is used for adding sulfuric acid, the reagent added in the ferrous pool includes ferrous sulfate heptahydrate, the catalyst includes clinoptilolite, and the flocculant includes polyacrylamide.

[0009] The present invention is further configured to include a pre-aeration tank, the pre-aeration tank is connected to the second sedimentation tank through a pipeline, the pipeline is used to input the liquid in the pre-aeration tank into the second sedimentation tank, a microbubble tube is arranged at the bottom of the pre-aeration tank, and a plurality of microbubble disks are connected to the microbubble tube.

[0010] The present invention is further configured such that a baffle is vertically arranged on the top inner wall of the first sedimentation tank, both ends of the baffle are connected to the inner wall of the first sedimentation tank, an external discharge port is opened on the side wall of the first sedimentation tank, the baffle is located upstream of the external discharge port, and the external discharge port is higher than the bottom of the baffle.

[0011] The present invention is further configured to include a molecular sieve chamber communicated with the external discharge port, wherein a porous support body and a filter element located on the support body are arranged in the molecular sieve chamber, and the liquid in the external discharge port flows downstream after passing through the support body and the filter element.

[0012] The present invention is further configured such that a plurality of molecular sieve chambers are provided, and adjacent molecular sieve chambers are connected through flow transfer holes, and the two flow transfer holes located on both sides of the support body and the filter element are located below the support body and above the filter element respectively;

[0013] A gas supply pipe is provided at the bottom of each molecular sieve chamber, and a gas supply plate is connected to the gas supply pipe. The gas supply pipe and the gas supply plate are used to inject gas into the molecular sieve chamber. The gas supply pipe is provided with a first control valve and a second control valve for controlling the opening and closing of the gas supply pipe, and all the gas supply plates are located between the first control valve and the second control valve;

[0014] Also included are:

[0015] An anaerobic tank, wherein one side of the anaerobic tank is provided with a flow connection hole communicating with the external discharge port, and the other side is communicated with the molecular sieve chamber at the upstream end through a flow transmission hole, the flow transmission hole communicating with the anaerobic tank is located at the bottom of the anaerobic tank, and the flow connection hole is located at the top of the anaerobic tank;

[0016] A third sedimentation tank, wherein the water inlet of the third sedimentation tank is communicated with the flow transfer hole located at the downstream end, and a third sewage pipe is arranged at the bottom of the third sedimentation tank.

[0017] The present invention is further configured such that the filter element comprises mordenite.

[0018] The present invention also discloses a process based on a sewage treatment system as described in any one of the above items, comprising the following steps:

[0019] S1, introducing sewage with a pH of 3-3.5 into a ferrous pool, and adding ferrous sulfate heptahydrate into the ferrous pool;

[0020] S2, adding hydrogen peroxide into the sewage at the outlet of the ferrous pool, so that the sewage mixed with hydrogen peroxide flows into the hydrogen peroxide pool for reaction;

[0021] S3, after the sewage reacts in the hydrogen peroxide tank, it is poured into the alkaline tank to adjust the pH value of the sewage to 7-8;

[0022] S4, introducing the sewage into the degassing tank, while releasing bubbles from the aeration pipe at the bottom to degas the sewage;

[0023] S5, introducing the sewage into the flocculation tank and adding flocculant;

[0024] S6, sewage enters the first sedimentation tank for sedimentation, sludge is discharged from the first sewage pipe at the bottom, and sewage is discharged from the external discharge port at the top.

[0025] Compared with the prior art, the present invention provides a sewage treatment system. When treating sewage, sewage with a pH value of 3-3.5 is first introduced into a ferrous pool, and ferrous sulfate heptahydrate is added into the ferrous pool; then hydrogen peroxide is added into the sewage at the outlet of the ferrous pool, so that the sewage mixed with hydrogen peroxide flows into the hydrogen peroxide pool for reaction; after the sewage reacts in the hydrogen peroxide pool, it is poured into an alkaline pool, and the pH value of the sewage is adjusted to 7-8; then the sewage is introduced into a degassing pool, and bubbles are released from an aeration pipe at the bottom to degas the sewage; then the sewage is introduced into a flocculation pool and a flocculant is added; finally, the sewage enters a first sedimentation pool for sedimentation, sludge is discharged from a first sewage pipe at the bottom, and sewage is discharged from an external discharge port at the top.

[0026] From the time hydrogen peroxide is added, tiny bubbles are continuously generated in the water during the entire reaction process. These bubbles include carbon dioxide (formed by oxidation of pollutants), a small amount of oxygen (formed by decomposition of hydrogen peroxide), and scum formed by oxidation reaction of relatively light organic matter, etc. Most of these tiny bubbles or scum will be adsorbed on the sludge. If they are not separated, the sludge in the subsequent first sedimentation tank will float on the water surface and will not be easy to settle. Therefore, during degassing, large (relative to tiny bubbles and scum) bubbles are injected to stir the sewage. Since the bubbles injected from the aeration pipe are too large, they are almost insoluble in water. However, the bubbles can separate small bubbles, scum, etc. from the sludge during the upward process, which is convenient for subsequent flocculation and sedimentation treatment, thereby making the sewage treatment effect better. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is an overall schematic diagram of the present invention;

[0028] Figure 2 Yes, the ferrous pool is shown in the figure Figure 1 ;

[0029] Figure 3 This is a partial schematic diagram of the molecular sieve chamber;

[0030] Figure 4 Yes, the ferrous pool is shown in the figure Figure 2 ;

[0031] Figure 5 Yes, the ferrous pool is shown in the figure Figure 3 ;

[0032] Figure 6 Yes, the ferrous pool is shown in the figure Figure 4 .

[0033] Among them, 1. ferrous tank; 2. hydrogen peroxide tank; 3. alkaline tank; 4. degassing tank; 5. flocculation tank; 6. first sedimentation tank; 7. aeration pipe; 8. first sewage pipe; 9. second sedimentation tank; 10. second sewage pipe; 11. pre-aeration tank; 12. micro bubble tube; 13. micro bubble disk; 14. baffle; 15. external discharge port; 16. molecular sieve chamber; 17. support body; 18. filter element; 19. flow transfer hole; 20. air supply disk; 21. anaerobic tank; 22. flow connection hole; 23. third sedimentation tank; 24. third sewage pipe. DETAILED DESCRIPTION

[0034] The following is a further detailed description of a sewage treatment system and process proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will become clearer. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. The same or similar reference numerals in the accompanying drawings represent the same or similar components.

[0035] A sewage treatment system, such as Figures 1 to 6 As shown (where y in the figure is a water distributor and k is a flow hole), it includes a ferrous pool 1, a hydrogen peroxide pool 2, an alkaline pool 3, a degassing pool 4, a flocculation pool 5 and a first sedimentation pool 6 which are connected in sequence (wherein the size of each pool body is only for illustration and does not represent the actual proportion or size), the ferrous pool 1 is used for adding a ferrous ion-containing agent, the hydrogen peroxide pool 2 is used for adding hydrogen peroxide and a catalyst, the alkaline pool 3 is used for adding an alkaline agent, the degassing pool 4 is provided with a porous aeration pipe 7 for injecting bubbles into the degassing pool 4, the flocculation pool 5 is used for adding a flocculant, the first sedimentation pool 6 is used for mud-water separation, and the bottom of the first sedimentation pool 6 is connected with a first sewage pipe 8 (each sewage pipe has a sewage pump).

[0036] The bottoms of the ferrous tank 1 , the hydrogen peroxide tank 2 , the alkaline tank 3 and the flocculation tank 5 are all provided with the aeration pipe 7 .

[0037] It also includes a second sedimentation tank 9, the bottom of which is connected to a second sewage pipe 10, the second sedimentation tank 9 is communicated with the upstream end of the ferrous tank 1, the second sedimentation tank 9 and the ferrous tank 1, the ferrous tank 1 and the hydrogen peroxide tank 2, the hydrogen peroxide tank 2 and the alkali tank 3, the alkali tank 3 and the degassing tank 4, the degassing tank 4 and the flocculation tank 5, and the flocculation tank 5 and the first sedimentation tank 6 are all connected through flow holes, and the flow holes between the ferrous tank 1 and the hydrogen peroxide tank 2, the flow holes between the hydrogen peroxide tank 2 and the alkali tank 3, and the flow holes between the alkali tank 3 and the degassing tank 4 are all at a distance from the bottom of the corresponding tank wall that is shorter than the distance from the top, and the distance between the flow holes between the degassing tank 4 and the flocculation tank 5 and the top of the corresponding tank wall is shorter than the distance from the bottom.

[0038] The flow hole of the second sedimentation tank 9 flowing to the ferrous pool 1 is used for adding sulfuric acid. The reagent added in the ferrous pool 1 includes ferrous sulfate heptahydrate, the catalyst includes clinoptilolite, and the flocculant includes polyacrylamide.

[0039] The invention also includes a pre-aeration tank 11, which is connected to the second sedimentation tank 9 through a pipeline. The pipeline is used to input the liquid in the pre-aeration tank 11 into the second sedimentation tank 9. A microbubble tube 12 is arranged at the bottom of the pre-aeration tank 11, and a plurality of microbubble disks 13 are connected to the microbubble tube 12.

[0040] A baffle plate 14 is vertically arranged on the top inner wall of the first sedimentation tank 6, and both ends of the baffle plate 14 are connected to the inner wall of the first sedimentation tank 6. An external discharge port 15 is opened on the side wall of the first sedimentation tank 6, and the baffle plate 14 is located upstream of the external discharge port 15, and the external discharge port 15 is higher than the bottom of the baffle plate 14.

[0041] It also includes a molecular sieve chamber 16 communicated with the external discharge port 15, wherein a porous support 17 and a filter element 18 located on the support 17 are disposed in the molecular sieve chamber 16, and the liquid in the external discharge port 15 flows downstream after passing through the support 17 and the filter element 18.

[0042] There are a plurality of molecular sieve chambers 16, and adjacent molecular sieve chambers 16 are connected through flow holes 19. The two flow holes 19 located on both sides of the support 17 and the filter element 18 are located below the support 17 and above the filter element 18, respectively.

[0043] A gas supply pipe is provided at the bottom of each molecular sieve chamber 16, and a gas supply disk 20 is provided on the gas supply pipe in communication, and the gas supply pipe and the gas supply disk 20 are used to inject gas into the molecular sieve chamber 16, and a first control valve and a second control valve for controlling the opening and closing of the gas supply pipe are provided on the gas supply pipe, and all the gas supply disks 20 are located between the first control valve and the second control valve;

[0044] Also included are:

[0045] An anaerobic tank 21, wherein a flow connection hole 22 is provided on one side of the anaerobic tank 21 and is communicated with the external discharge port 15 (via a pipeline or directly), and the other side is communicated with the molecular sieve chamber 16 at the upstream end via a flow transfer hole 19, wherein the flow transfer hole 19 communicated with the anaerobic tank 21 is located at the bottom of the anaerobic tank 21, and the flow connection hole 22 is located at the top of the anaerobic tank 21;

[0046] The third sedimentation tank 23 has a water inlet that communicates with the flow hole 19 at the downstream end, and a third sewage pipe 24 is disposed at the bottom of the third sedimentation tank 23 .

[0047] The filter element 18 includes mordenite.

[0048] In the present application, it is preferred to first lift the sewage to a higher height, and then the sewage flows in each reaction chamber by relying on the gravity of the sewage, so that the sewage only needs to be lifted once; or pipes and pumps can be set between each reaction chamber for transportation.

[0049] The present invention also discloses a process based on a sewage treatment system as described in any one of the above items, comprising the following steps:

[0050] S1, introducing sewage with a pH of 3-3.5 into the ferrous pool 1, and adding ferrous sulfate heptahydrate into the ferrous pool 1;

[0051] S2, adding hydrogen peroxide into the sewage at the outlet of the ferrous pool 1, so that the sewage mixed with hydrogen peroxide flows into the hydrogen peroxide pool 2 for reaction;

[0052] S3, after the sewage is reacted in the hydrogen peroxide tank 2, it is poured into the alkaline tank 3 to adjust the pH value of the sewage to 7-8;

[0053] S4, the sewage is introduced into the degassing tank 4, and bubbles are released from the aeration pipe 7 at the bottom to degas the sewage;

[0054] S5, introducing the sewage into the flocculation tank 5 and adding flocculant;

[0055] S6, the sewage enters the first sedimentation tank 6 for sedimentation, the sludge is discharged from the first sewage pipe 8 at the bottom, and the sewage is discharged from the external discharge port 15 at the top.

[0056] The present invention provides a sewage treatment system. When treating sewage, sewage with a pH value of 3-3.5 is first introduced into a ferrous pool 1, and ferrous sulfate heptahydrate is added into the ferrous pool 1; then hydrogen peroxide is added into the sewage at the outlet of the ferrous pool 1, so that the sewage mixed with hydrogen peroxide flows into a hydrogen peroxide pool 2 for reaction; after the sewage reacts in the hydrogen peroxide pool 2, it is poured into an alkaline pool 3, and the pH value of the sewage is adjusted to 7-8; then the sewage is introduced into a degassing pool 4, and bubbles are released from an aeration pipe 7 at the bottom to degas the sewage; then the sewage is introduced into a flocculation pool 5 and a flocculant is added; finally, the sewage enters a first sedimentation pool 6 for sedimentation, sludge is discharged from a first sewage pipe 8 at the bottom, and sewage is discharged from an external discharge port 15 at the top.

[0057] From the time hydrogen peroxide is added, tiny bubbles are continuously generated in the water during the entire reaction process. These bubbles include carbon dioxide (formed by oxidation of pollutants), a small amount of oxygen (formed by decomposition of hydrogen peroxide), and scum formed by oxidation reaction of relatively light organic matter, etc. Most of these tiny bubbles or scum will be adsorbed on the sludge. If they are not separated, the sludge in the subsequent first sedimentation tank 6 will float on the water surface and will not be easy to settle. Therefore, during degassing, the sewage is stirred by injecting very large (relative to the tiny bubbles and scum) bubbles. Since the bubbles injected into the aeration pipe 7 are too large, they are almost insoluble in water. However, the bubbles can separate small bubbles, scum, etc. from the sludge during the upward process, which is convenient for subsequent flocculation and sedimentation treatment, thereby making the sewage treatment effect better.

[0058] When sewage is actually treated, the sewage is first lifted to a higher height, and then flows directly between each reaction chamber. The sewage first flows into the pre-aeration tank 11, and at the same time, the bottom of the pre-aeration tank 11 injects compressed air into the micro-bubble disk 13 through the micro-bubble tube 12 (external air pump, used to transport compressed air), and then the micro-bubble disk 13 divides the compressed air into very small air, which enters the pre-aeration tank 11. In this step, the micro-bubbles can not only balance the water quality, but also oxidize and degrade some organic pollutants, and at the same time prevent the anaerobic deterioration of water quality and reduce the ammonia nitrogen content in the wastewater. At the same time, the aeration effect is conducive to the separation of oil and fat from the wastewater through the "flotation effect".

[0059] After that, the sewage enters the second sedimentation tank 9, where it can be preliminarily precipitated before being treated, and the larger impurities or those with a larger specific gravity in the sewage can be separated out, reducing the difficulty of subsequent treatment. In the present application, each reaction chamber (i.e., the ferrous pool 1, the hydrogen peroxide pool 2, etc.) has an aeration pipe 7 at the bottom (uniform aeration is performed through an aeration disk, wherein the bubble diameter is larger and almost insoluble in water), so that the mixed reaction can be more complete; secondly, a large amount of "gas production" phenomenon in the Fenton reaction process can be solved (i.e., oxidation of organic matter in the Fenton reaction process will produce carbon dioxide, most of which is insoluble in water, so it exists in the form of bubbles, and this part of the gas can be well taken out by aeration, which is convenient for subsequent mud and water separation). This measure can effectively avoid the problem of subsequent sludge sedimentation deterioration due to gas production.

[0060] At the outlet of the second sedimentation tank 9 (i.e., the flow hole, the same below), the first step is to add sulfuric acid to adjust the pH value of the wastewater to between 3 and 3.5. Then, the ferrous sulfate dosing pump is turned on, and after reacting in the ferrous pool 1 for 5 to 10 minutes, hydrogen peroxide reagent is added at the outlet of the ferrous pool 1 and heterogeneous catalyst clinoptilolite is added at the inlet of the hydrogen peroxide pool 2 (i.e., the flow hole, the same below).

[0061] After reacting in the hydrogen peroxide tank 2 for more than 30 minutes, the dosing pump is turned on to add caustic soda flakes into the alkali tank 3 to neutralize the acid and alkali and adjust the pH value to between 7.0 and 8.0; then the sewage enters the degassing tank 4 for degassing; during degassing, the aeration pipe 7 at the bottom is specifically used for aeration and taking out the small bubbles in the sewage. Finally, the sewage enters the flocculation tank 5, and the PAM (i.e. polyacrylamide) dosing pump is turned on. After sedimentation in the subsequent first sedimentation tank 6 coagulation sedimentation tank, the mud and water are separated, and the supernatant enters the subsequent anaerobic tank 21 and molecular sieve chamber 16. The treated effluent enters the temporary storage tank for reuse in production.

[0062] The present application sets a baffle plate 14 at the upstream end of the external discharge port 15 of the first sedimentation tank 6, which can effectively prevent small floating mud (some fibers, oil, foam, etc.) from flowing out with the water; this can reduce the load of the molecular sieve chamber 16 and enable the sewage to be treated normally. After intercepting at the baffle, the workers manually scoop out this part of the floating objects. At the same time, a water distributor can be set at the water inlet of the sedimentation tank (all sedimentation tanks) to disperse the water flow, so that the water inlet flow state and flow rate can be ideally controlled, and a high-angle mud bucket can be used to ensure the efficient mud-water separation effect of the sedimentation tank.

[0063] Moreover, the heterogeneous catalyst clinoptilolite in the present application, which is a zeolite with sodium aluminosilicate crystals, has an interconnected lattice structure, similar to silicon crystals with interconnected pores and channels. This structure allows a wide range of chemical and physical events, which have the following functions:

[0064] 1. Selectively absorb specific gas molecules in sewage (if any);

[0065] 2. Water absorption and water release: It can absorb or release water without any chemical or physical changes in the matrix structure. During the water absorption and water-repellent process, the adsorption and / or exchange effect of clinoptilolite on ions in sewage can be improved, and the absorption performance of organic matter can also be improved.

[0066] 3. Ion exchange: the ability to exchange its cations for lead, thallium, cesium or strontium cations;

[0067] 4. Stability: Clinoptilolite powder has high stability and can maintain its crystal structure and adsorption performance at higher temperatures and pH values, while ordinary zeolite powder has relatively low stability.

[0068] The powdered clinoptilolite added in the present application has a crystal size of less than 0.05 mm. The ion exchange and adsorption properties of the clinoptilolite are utilized, and the mutual conversion between divalent iron and trivalent iron ions is catalyzed, thereby enhancing the oxidation capacity and improving the pollutant removal effect.

[0069] The subsequent molecular sieve chamber 16 is composed of multiple grids, and the overall structure is a rectangular rectangle, and the aspect ratio is greater than 1:5, and the width-to-depth ratio is greater than 1:1.5. The third sedimentation tank 23 at the end is preferably a high-efficiency inclined tube sedimentation tank. The molecular sieve chamber 16 is a multi-grid series structure, and the number of grids can be increased according to the required amount of water to be treated. A molecular sieve filler (i.e., filter element 18-mordenite zeolite) is installed in each grid. An air supply pipe and an air supply disk 20 are provided at the bottom of the filler layer of each grid body, and an aeration blower is turned on for aeration during daily operation. The wastewater flows completely through each series-connected molecular sieve chamber 16, and then flows into the high-efficiency inclined tube sedimentation tank by gravity. The inclined tube sedimentation tank adopts a conventional design, using a single-layer honeycomb inclined tube structure, with an inclined tube specification of 1.1m and a honeycomb diameter of 10cm.

[0070] After the wastewater flows out from the external outlet 15 of the first sedimentation tank 6, it flows into the anaerobic tank 21 by gravity, and an anaerobic reaction is carried out inside to remove part of the organic matter; then it is passed to the bottom of the first molecular sieve chamber 16, and under the oxygenation and stirring of the bottom aeration, it passes through the support body 17 and the filter element 18 all the way upward, and then flows out from the flow hole 19 at the top of the first grid into the second molecular sieve chamber 16. At the top of the second grid, the wastewater passes through the filter element 18 and the support body 17 all the way downward and flows to the bottom of the second molecular sieve chamber 16; then it enters the third molecular sieve chamber 16. This process is repeated until the effluent enters the subsequent high-efficiency inclined tube sedimentation tank; the effluent of the third sedimentation tank 23 meets the discharge standards, and part of the precipitated sludge is pumped into the flow hole 19 (sludge return) of the first molecular sieve chamber 16 or the flow hole 22 of the anaerobic tank 21. Therefore, the whole process is also an A / O process for sewage treatment.

[0071] The above structure has the function of removing nitrogen and phosphorus, and also has a good removal effect on organic pollutants. In particular, its multi-grid layout makes it have the advantages of plug flow aeration, delayed aeration, and complete mixing in one. Compared with a large pool without grids, the oxygen utilization efficiency is high, the mixed mass transfer effect is good, and there is no dead zone in the reaction. At the same time, the application adds filter elements 18 of different particle sizes (for example, larger particle sizes upstream and smaller particle sizes downstream) as fillers, and ensures the high permeability of the filter element 18, so that its performance can be further enhanced.

[0072] The filter element 18 (mordenite) has ion exchange and adsorption properties. It has a strong ammonia nitrogen exchange rate. At the same time, the ion exchange property can exchange the residual metal ions in the wastewater. The filter element 18 has a strong adsorption capacity. Most organic matter can be adsorbed and ion exchange can be completed without aeration. At the same time, we have found through research that most fillers are "blocked" after saturation adsorption, such as activated carbon. It is useless when it is fully adsorbed and needs to be replaced and regenerated. However, the mordenite molecular sieve is different. The pH value of the molecular sieve influent can be appropriately adjusted to between 8-9, that is, it can be "cleaned" by increasing the aeration volume under weakly alkaline conditions, and "activation regeneration" can be achieved after 3-5 hours; at the same time, for heavy metals and pigments that cannot be treated by the activated sludge method, this application can also ion exchange heavy metals and decolorize.

[0073] In addition, the mordenite in the present application also has the "oxygenation" capability that other fillers do not have, that is, it can oxygenate the wastewater itself without aeration and oxygenation. Because the interior of the crystal is a three-dimensional polyhedron, such as a cage-shaped channel, a certain amount of oxygen can be stored inside the mordenite (although it is in powder form); at the same time, through experimental research, mordenite has a good decolorization ability, can adsorb the color groups in the wastewater, and reduce the chromaticity of the wastewater.

[0074] The first control valve and the second control valve in the present application are located on both sides of all the air supply disks 20, so that when treating sewage, the first control valve is opened and the second control valve is closed, and the air flow and properties of the input air are used for aeration; then when regenerating mordenite, the first control valve is closed and the second control valve is opened, and the properties of the input air flow are used for regeneration.

[0075] This application is particularly suitable for the subsequent deep treatment of high-concentration wastewater and the treatment of wastewater from the manufacture and processing of auto parts such as electroplating and phosphating. It has a good purification effect and has been verified by large-scale implementation in enterprises, and can meet the requirements of environmental protection emission standards. Among them, traditional Fenton oxidation mostly adopts step-by-step treatment, that is, one step, one pool or one reaction tank, and after the reaction is completed, it is pumped to the next pool or tank for step-by-step reaction until the whole process is completed. It belongs to intermittent intermittent treatment and cannot achieve continuous water inflow and continuous treatment. However, this application can continuously treat wastewater. Among them, the ferrous pool 1, hydrogen peroxide pool 2, alkali pool 3, etc. in this application are all an integral reaction pool; at the same time, the outlet end of the first sedimentation tank 6 is connected to the anaerobic pool 21, several molecular sieve chambers 16, and the third sedimentation tank 23, etc. in sequence, so that the entire sewage treatment can be carried out continuously and uninterruptedly, ensuring the effect and efficiency of sewage treatment.

[0076] At the same time, the present application does not use a separate tank, but an integrated structure and process integration. All primary lifting and wastewater gravity circulation are achieved, which greatly reduces power consumption and is one-third of the power consumption of traditional independent tanks. In addition, the traditional reaction process uses a mechanical agitator for mixed reaction, which consumes a lot of power. The Fenton reaction part of the present application uses air stirring throughout the reaction process, which greatly shortens the "degassing (i.e., separation of sludge and tiny bubbles)" time. Among them, the traditional Fenton process does not design a degassing process and a degassing tank 4. The present application designs a separate degassing tank 4 and uses air stirring to improve the mud-water mixing mass transfer effect, improves the sludge destabilization, and is more conducive to subsequent sludge separation and sedimentation.

[0077] The following table is a comparison table of the removal rates of the process of this application and the traditional Fenton process (unit: mg / L)

[0078]

[0079] The following table is a comparison table between the traditional Fenton process and the process of this application:

[0080]

[0081] The following table compares the removal capacity of the process of this application with that of the traditional process.

[0082]

[0083] It should also be noted that all "arrangements" and similar descriptive words in this application (especially the specification) express that there is or exists a connection relationship between two structures, but there are no excessive restrictions on the specific means by which the two are connected, and it is usually a conventional connection means, that is, it should be understood that the means are prior art and do not need to be elaborated too much. For example, "n is arranged on m", which only expresses that there is an n structure on the m structure, and the two are specifically connected by welding, riveting, adhesive connection or integral molding, which are all within the protection scope of this application; for another example, "y is rotatably arranged on X", which only expresses that y and x can rotate relative to each other, and whether the two are connected by bearing rotation, or y directly passes through x and is connected to x rotationally, or other feasible methods, are all within the protection scope of this application.

[0084] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A sewage treatment system, characterized in that: The invention comprises a ferrous pool (1), a hydrogen peroxide pool (2), an alkaline pool (3), a degassing pool (4), a flocculation pool (5) and a first sedimentation pool (6) which are connected in sequence. The ferrous pool (1) is used for adding a ferrous ion-containing agent. The hydrogen peroxide pool (2) is used for adding hydrogen peroxide and a catalyst. The alkaline pool (3) is used for adding an alkaline agent. The degassing pool (4) is provided with a porous aeration pipe (7) for injecting bubbles into the degassing pool (4). The flocculation pool (5) is used for adding a flocculant. The first sedimentation pool (6) is used for mud-water separation. The bottom of the first sedimentation pool (6) is connected and provided with a first sewage pipe (8).

2. A sewage treatment system according to claim 1, characterized in that: The bottoms of the ferrous water tank (1), the hydrogen peroxide tank (2), the alkali tank (3) and the flocculation tank (5) are all provided with aeration pipes (7).

3. A sewage treatment system according to claim 1, characterized in that: The invention also comprises a second sedimentation tank (9), the bottom of which is connected to a second sewage pipe (10), the second sedimentation tank (9) is connected to the upstream end of the ferrous tank (1), and there are two sewage pipes between the second sedimentation tank (9) and the ferrous tank (1), between the ferrous tank (1) and the hydrogen peroxide tank (2), between the hydrogen peroxide tank (2) and the alkaline tank (3), between the alkaline tank (3) and the degassing tank (4), between the degassing tank (4) and the flocculation tank (5), and between the flocculation tank (5). The flocculation tank (5) and the first sedimentation tank (6) are connected via flow holes, and the flow holes between the ferrous tank (1) and the hydrogen peroxide tank (2), the flow holes between the hydrogen peroxide tank (2) and the alkali tank (3), and the flow holes between the alkali tank (3) and the degassing tank (4) are all such that the distance between the flow holes and the bottom of the corresponding tank wall is shorter than the distance between the flow holes and the top of the corresponding tank wall, and the distance between the flow holes between the degassing tank (4) and the flocculation tank (5) and the top of the corresponding tank wall is shorter than the distance between the flow holes and the bottom.

4. A sewage treatment system according to claim 3, characterized in that: The flow hole of the second sedimentation tank (9) flowing to the ferrous tank (1) is used for adding sulfuric acid, and the reagent added in the ferrous tank (1) includes ferrous sulfate heptahydrate, the catalyst includes clinoptilolite, and the flocculant includes polyacrylamide.

5. A sewage treatment system according to claim 3, characterized in that: The invention also comprises a pre-aeration tank (11), wherein the pre-aeration tank (11) is connected to the second sedimentation tank (9) via a pipeline, wherein the pipeline is used to input the liquid in the pre-aeration tank (11) into the second sedimentation tank (9), and a micro-bubble tube (12) is arranged at the bottom of the pre-aeration tank (11), and a plurality of micro-bubble disks (13) are arranged on the micro-bubble tube (12).

6. A sewage treatment system according to claim 1, characterized in that: A baffle plate (14) is vertically arranged on the top inner wall of the first sedimentation tank (6), and both ends of the baffle plate (14) are connected to the inner wall of the first sedimentation tank (6). An external discharge port (15) is opened on the side wall of the first sedimentation tank (6), and the baffle plate (14) is located upstream of the external discharge port (15), and the external discharge port (15) is higher than the bottom of the baffle plate (14).

7. A sewage treatment system according to claim 6, characterized in that: It also includes a molecular sieve chamber (16) communicated with the external discharge port (15), wherein a porous support body (17) and a filter element (18) located on the support body (17) are arranged in the molecular sieve chamber (16), and the liquid in the external discharge port (15) flows downstream after passing through the support body (17) and the filter element (18).

8. A sewage treatment system according to claim 7, characterized in that: A plurality of molecular sieve chambers (16) are provided, and adjacent molecular sieve chambers (16) are connected to each other through flow transfer holes (19), and two flow transfer holes (19) located on both sides of the support body (17) and the filter element (18) are located below the support body (17) and above the filter element (18), respectively; A gas supply pipe is provided at the bottom of each molecular sieve chamber (16), and a gas supply plate (20) is connected to the gas supply pipe. The gas supply pipe and the gas supply plate (20) are used to inject gas into the molecular sieve chamber (16). The gas supply pipe is provided with a first control valve and a second control valve for controlling the opening and closing of the gas supply pipe, and all the gas supply plates (20) are located between the first control valve and the second control valve; Also included are: An anaerobic tank (21), wherein one side of the anaerobic tank (21) is provided with a flow connection hole (22) communicating with the external discharge port (15), and the other side is communicated with the molecular sieve chamber (16) at the upstream end through a flow transmission hole (19), the flow transmission hole (19) communicating with the anaerobic tank (21) is located at the bottom of the anaerobic tank (21), and the flow connection hole (22) is located at the top of the anaerobic tank (21); A third sedimentation tank (23), wherein the water inlet of the third sedimentation tank (23) is communicated with the flow transfer hole (19) located at the downstream end, and a third sewage pipe (24) is provided at the bottom of the third sedimentation tank (23).

9. A sewage treatment system according to claim 7 or 8, characterized in that: The filter element (18) comprises mordenite.

10. A process based on a sewage treatment system according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, introducing sewage with a pH of 3-3.5 into a ferrous pool, and adding ferrous sulfate heptahydrate into the ferrous pool; S2, adding hydrogen peroxide into the sewage at the outlet of the ferrous pool, so that the sewage mixed with hydrogen peroxide flows into the hydrogen peroxide pool for reaction; S3, after the sewage reacts in the hydrogen peroxide tank, it is poured into the alkaline tank to adjust the pH value of the sewage to 7-8; S4, introducing the sewage into the degassing tank, while releasing bubbles from the aeration pipe at the bottom to degas the sewage; S5, introducing the sewage into the flocculation tank and adding flocculant; S6, sewage enters the first sedimentation tank for sedimentation, sludge is discharged from the first sewage pipe at the bottom, and sewage is discharged from the external discharge port at the top.

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