Compact industrial wastewater in-situ oxidation adsorption treatment method and device

Abstract

The invention discloses a compact industrial wastewater in-situ oxidation adsorption treatment method and device, and belongs to the technical field of wastewater treatment.The treatment device comprises primary separation equipment, the primary separation equipment comprises a shell, a cylinder assembly is arranged in the center of the shell, a stirring piece is rotationally connected to the upper portion of the cylinder assembly, and the shell is provided with an inflow pipe and an outflow pipe; the barrel assembly comprises an inner barrel, first holes are evenly distributed in the top of the inner barrel in the circumferential direction, the stirring piece comprises a frustum-shaped body, stirring blades are evenly distributed on the inclined face of the body, the periphery of the body is connected with a partition plate, and the partition plate is arranged on the top of the inner side of the inner barrel. Second holes are evenly distributed in the partition plate in the circumferential direction. The treatment method comprises the step of carrying out in-situ oxidation adsorption treatment of two-step pH regulation coupled with two-step solid-liquid separation on the industrial wastewater by adopting the device. The device disclosed by the invention can realize efficient removal of organic matters, and is compact in structure, small in occupied area and low in use cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and particularly relates to a compact in-situ oxidation adsorption treatment method and device for industrial wastewater. Background Art

[0002] With the rapid development of industrialization, the discharge of industrial wastewater has been increasing year by year, and the refractory organic pollutants therein have brought great pressure to the water environment. These pollutants usually have characteristics such as stable structure and strong biological toxicity, making it difficult for traditional biological treatment technologies to achieve ideal degradation effects. To solve this problem, the oxidation-adsorption combined process that combines chemistry and physics has gradually become the research focus. This process destroys the molecular structure of organic substances through oxidants and then enriches the degradation products through adsorbents, showing excellent treatment capabilities. However, the existing oxidation-adsorption combined processes require separate setting of oxidation units and adsorption units, with disadvantages such as complex process flows, long treatment cycles, and large floor areas. At the same time, they generally face technical bottlenecks such as large consumption of oxidants, strong dependence on catalysts, and difficult regeneration of adsorbents. In contrast, the in-situ oxidation adsorption technology has unique advantages. This technology integrates the oxidation and adsorption processes in the same reaction unit, and realizes the synchronous oxidation degradation and adsorption removal of pollutants by optimizing the reaction conditions, which not only simplifies the process flow but also significantly improves the treatment efficiency. For the in-situ oxidation adsorption technology, the efficient solid-liquid separation of the adsorbent is a key link to ensure the treatment effect, directly affecting the effluent quality and the stability of the process operation.

[0003] The Korean invention patent with the application number KR101587264B1 discloses a water treatment tank with floating and sedimentation functions, which includes a cylindrical main body, the lower part of which includes a gradually narrowing conical part; an inflow pipe for enabling the water to be treated to flow into the interior of the main body; a first tank installed inside the main body, enabling the water to be treated discharged from the treated water inflow pipe to flow in from the lower part and form an upward flow; a second tank installed at an interval from the main body and the first tank, the top and bottom of which are respectively higher than the top and bottom of the first tank, enabling the water to be treated overflowing from the top of the first tank to flow in and form a downward flow; a treated water overflow inflow part installed on the inner side surface of the main body to form a treated water inflow space, enabling the treated water from which pollutants have been removed after passing through the second tank to float and flow in; and a treated water discharge pipe installed on the main body and connected to the treated water inflow space for discharging the treated water to the outside. This invention utilizes the water flow characteristics to achieve efficient solid-liquid separation during the water treatment process.

[0004] However, the existing inventions only focus on the removal of suspended substances and fail to solve the problem of chemical regulation during the oxidation process. In addition, most in-situ oxidation adsorption technologies still rely on catalysts, suffering from problems such as catalyst deactivation and difficult regeneration. In particular, for reversible adsorption-type pollutants, there is a risk of secondary release of pollutants after adsorption in the existing technologies. Therefore, developing an in-situ oxidation adsorption technology that does not rely on catalysts, is highly efficient and stable, and can prevent the secondary release of pollutants is of great significance for promoting the progress of industrial wastewater treatment technology. Summary of the Invention

[0005] The object of the present invention is to provide a compact in-situ oxidation adsorption treatment method and device for industrial wastewater that does not rely on catalysts, is highly efficient and stable, and can prevent the secondary release of pollutants.

[0006] To achieve the above object, the first aspect of the present invention provides a compact in-situ oxidation adsorption treatment device for industrial wastewater, comprising: a primary separation device, the primary separation device comprising: a housing, a cylinder assembly is provided at the center of the housing, a stirring member is rotatably connected above the cylinder assembly, the housing is provided with an inflow pipe and an outflow pipe, the inflow pipe allows the water to be treated to flow in from below the center of the cylinder assembly and rise, and the outflow pipe discharges the treated water body. The wastewater containing sludge is output through the inflow pipe to below the center of the cylinder assembly and rises. The stirring member stirs the water body to form a swirling flow. The sludge and particulate matter in the wastewater diffuse outward away from the rotation center under the action of centrifugal force, realizing the separation of the wastewater to form supernatant and sludge. The sludge and particulate matter sink along the inner wall of the housing under the action of gravity, waiting for subsequent centralized discharge. The supernatant is discharged through the outflow pipe and undergoes the next treatment process. Among them, the swirling flow of the water body formed by the stirring member above the cylinder assembly has a low-pressure area at the center of the cylinder assembly in the swirling flow center, which helps the water body discharged from the outflow pipe to form an upward guidance and a central convergence. Without an additional driving device to increase the output power of the inflow pipe, the upward discharge efficiency of the liquid waste with solid-liquid mixture is improved. While reducing energy consumption, it avoids the blockage of sludge in the inflow pipe due to insufficient water body output power, improving the stability and efficiency of the wastewater treatment process.

[0007] Preferably, the cylinder assembly includes an inner cylinder, and the top of the inner cylinder is circumferentially provided with first holes evenly.

[0008] Preferably, the stirring member includes a frustum-shaped body. Stirring blades are evenly distributed on the inclined surfaces of the body. A partition is connected to the periphery of the body. The partition is at the inner top of the inner cylinder, and second holes are evenly distributed along the circumference of the partition. The wastewater released from the inflow pipe forms an upward water flow in the inner cylinder and contacts the stirring member. The stirring member drives the rotation of the stirring blades through the body to form a swirling flow of the upward water flow. The swirling flow causes the sludge and particulate matter to move downward and outward under the action of centrifugal force. At this time, the water body is separated into supernatant containing suspended matter, sedimented sludge and particulate matter. The supernatant rising in a swirling posture is guided and diffused outward by the conical body and successively passes through the second holes and the first holes and finally reaches the outside of the inner cylinder. While the main body drives the partition to keep rotating, the second holes on the partition constantly change positions relative to the first holes on the inner cylinder, that is, the flow-through channels formed by the second holes and the first holes constantly change, increasing the complexity of the movement of suspended substances in the upper-layer supernatant. The dispersion of the suspended substances is realized by the cutting of the fluid passing through the hole body, improving the distribution balance degree of the suspended substances in the supernatant, making the supernatant output by the outflow pipe have a stable concentration and viscosity. The stable supernatant concentration can reduce the frequent adjustment of pH value adjustment and flocculant dosing, reduce the operation difficulty, and the stable supernatant concentration can reduce the water quality fluctuation, making the pH value adjustment of the wastewater easier to control, avoiding excessive acid or alkali addition caused by concentration fluctuation, and realizing the saving of the dosage of acid-base solution and flocculant; The supernatant with a stable concentration is formed through the above scheme, which is beneficial to the full play of the flocculant, forming larger and denser flocs and improving the solid-liquid separation efficiency.

[0009] Preferably, there is an annular gap between the partition and the inner cylinder. Blades are evenly distributed along the circumference on the outside of the partition. Annular extension plates are provided on the upper and lower edges on the outside of the partition. The extension plates and the blades are both matched with the inner wall of the inner cylinder. The extension pieces form a relatively closed structure with openings at the upper and lower sides for the annular gap between the partition and the inner cylinder. During the rotation of the main body driving the partition and the stirring blades, the upward supernatant in the inner cylinder cannot directly enter the annular gap, but reaches the annular space through the second holes of the partition under the guiding action of the main body, ensuring that the water body and suspended substances can be effectively cut and evenly dispersed. The extension plates and the blades divide the annular space between the inner cylinder and the partition into multiple water body flow-through spaces, and the channels constantly change positions along with the rotation of the blades. When the first hole and the second hole are misaligned, each water body flow-through space is relatively airtight to form a negative pressure. At this time, along with the rotation of the partition, the first hole and the second hole are connected, and the water body in the water body flow-through space can be quickly released to the outside of the inner cylinder under the pressure change, improving the flow rate of water body release and dispersion without increasing the rotation speed of the stirring member, realizing the energy saving of the stirring member; The blades keep rotating to continuously contact the inner wall surface of the inner cylinder, and can scrape off the suspended substances or floating objects blocking or adhering to the opening of the first hole on the inner wall of the inner cylinder, realizing self-cleaning during the solid-liquid separation process, ensuring the water body circulation rate and avoiding blockage.

[0010] Preferably, the cylinder assembly further includes an outer cylinder, and the outer cylinder forms an annular channel with a lower opening outside the inner cylinder. The water body flowing out from the first hole enters the annular channel and can descend. After passing through the first hole of the inner cylinder, the water body reaches the top of the annular channel and descends. The descending water body has a lower flow rate. On the one hand, it can gently guide the separated sludge to accelerate sedimentation, and at the same time inhibit the resuspension of the sludge, improve the efficiency of solid-liquid separation in industrial wastewater treatment, shorten the time required for the overall process flow of wastewater treatment, and reduce the energy consumption of standby equipment in the wastewater treatment process; The above solution enables the water body to rise in the inner cylinder, reach the annular channel and descend, and realizes solid-liquid separation by utilizing the gravity and flow characteristics of the wastewater itself, reduces the dependence on the pump body for transporting the waste liquid, and reduces the energy consumption of pumping the wastewater.

[0011] Preferably, a collection tank is provided outside the inner cylinder, and a discharge pipe is connected to the collection tank. The collection tank collects the floating impurities passing through the first hole. After the solid sludge in the wastewater is separated, there are still floating substances in the supernatant. After the water body is released from the first hole to the outside of the inner cylinder, under the action of the gravity of the fluid itself, the water body falls, and the floating substances remain floating. When the water body is released from the first hole, it is a swirling flow, and the floating substances are continuously collected by the collection tank under the guiding action of the swirling flow, realizing the collection and removal of the floating substances in the wastewater, reducing or avoiding their interference with the functions of chemical agents such as flocculants and oxidants, improving the use efficiency of subsequent agents, and reducing the treatment cost.

[0012] Preferably, the stirring member further includes a motor, and the motor is installed outside the housing and connected to the main body. The motor is used to provide the rotational driving force for the main body.

[0013] Preferably, a filter screen is provided at the middle height position inside the inner cylinder. The filter screen performs preliminary filtration on the wastewater released upward by the inflow pipe and blocks part of the sludge rising with the waste liquid to avoid blockage.

[0014] Preferably, the bottom of the housing has a conical portion that converges downward to the center, and the conical portion has a sludge discharge port. The conical portion guides the sludge diffusing downward and outward, enabling the sludge to reach the sludge discharge port and be released, which helps to improve the sludge discharge efficiency.

[0015] The second aspect of the present invention provides a compact in-situ oxidation and adsorption treatment method for industrial wastewater, which uses the above device to treat the biochemical effluent of industrial wastewater. The principle of the method of the present invention is to degrade organic matter through the strongly oxidizing hydroxyl radicals generated by the reaction of ferrous ions and hydrogen peroxide, and at the same time, ferric ions are rapidly hydrolyzed to further adsorb and remove organic matter in-situ. The method includes the following steps: Step (1): Adjust the pH of the biochemical effluent of industrial wastewater to 4-6 with an acid solution; Step (2): Add soluble metal mixed salts and a mixed oxidant to the wastewater treated in step (1); Step (3): Add a composite flocculant according to the suspended solid concentration in the wastewater treated in step (2). Step (4): Feed the wastewater treated in step (3) into the primary separation device for primary separation to form supernatant and sludge. The supernatant after primary separation is subjected to the next step, and the sludge from primary separation is fed into the thickening tank. Step (5): Adjust the pH of the supernatant treated in step (4) to 7 with an alkali solution, and add a composite flocculant thereto according to the suspended solid concentration in the supernatant at this time. Step (6): Perform secondary separation on the supernatant treated in step (5) to form supernatant and sludge. The supernatant generated from secondary separation is discharged, and the sludge generated from secondary separation is fed into the thickening tank. Step (7): Discharge the sludge in the thickening tank, and feed the supernatant in the thickening tank into step (1) to be treated together with the biochemical effluent of the industrial wastewater in accordance with the step sequence.

[0016] Preferably, in step (2), the soluble metal mixed salt is composed of one or more of soluble iron (Fe²⁺ / Fe³⁺), copper (Cu⁺ / Cu²⁺), manganese (Mn²⁺ / Mn³⁺), cobalt (Co²⁺ / Co³⁺), calcium (Ca²⁺) and magnesium (Mg2+) salts. The mixed oxidant is composed of one or more of hydrogen peroxide (H2O2), persulfate (S2O82-) and hypochlorite (ClO-).

[0017] The device of the present invention has the following beneficial effects compared with the prior art: The stirring member rotates above the cylinder assembly to provide the upward driving force of the waste liquid and the centrifugal force for sludge separation, realizing solid-liquid separation while reducing the possibility of sludge suspension; The partition plate rotates relative to the first hole through the second hole to evenly cut the suspended matter, making the supernatant have a stable concentration and viscosity, reducing the operation difficulty and the dosage of chemical agents, and reducing the cost; The cutting through the hole body improves the balance degree of the suspended matter distribution in the supernatant, which is beneficial to the full play of the flocculant and improves the solid-liquid separation efficiency; The blades and the extension plates form an annular interval, and the negative pressure is utilized during the rotation process to increase the speed of the released water body, realizing energy conservation; The stirring blades scrape the opening of the first hole to achieve self-cleaning, ensuring the water flow rate and avoiding blockage; The annular channel formed by the inner cylinder and the outer cylinder enables the upward water body to descend by using the self-weight of the fluid, realizing the inhibition of sludge suspension while improving the efficiency of solid-liquid separation in industrial wastewater treatment and reducing the energy consumption of standby equipment; The collection tank collects the floating impurities in the upward water body under the action of the stirring member, realizing the collection and removal of the floating substances, reducing their interference with the chemical agents, improving the agent efficiency and thus reducing the treatment cost. The method of the present invention has the following advantages: The free radicals generated by the spontaneous reaction of the soluble metal mixed salt and the mixed oxidant are used to rapidly degrade the organic matter, and no additional catalyst needs to be added; The soluble metal mixed salt is rapidly hydrolyzed after being oxidized by the oxidant, and the generated hydrolyzate has an adsorption effect, realizing the simultaneous completion of oxidation and adsorption in one unit; The two-step pH adjustment is coupled with the two-step solid-liquid separation to avoid the release of the adsorbed organic matter through the proton exchange effect during the pH adjustment process, further improving the removal rate of the refractory organic matter. Therefore, the present invention is a compact in-situ oxidation and adsorption treatment method and device for industrial wastewater that does not rely on a catalyst, is highly efficient and stable, and can prevent secondary release of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional view of a compact in-situ oxidation and adsorption treatment device for industrial wastewater; Figure 2 It is a schematic structural view of the inner cylinder; Figure 3 It is a schematic structural view of the stirring member; Figure 4 It is a schematic view of the positional relationship between the stirring member and the inner cylinder; Figure 5 It is a schematic flow chart of a compact in-situ oxidation and adsorption treatment method for industrial wastewater; Figure 6 It is a schematic structural view of the diffusion part in the second embodiment of the present invention.

[0019] Reference numerals: housing 1; conical part 11; cylinder assembly 2; inner cylinder 21; first hole 210; diffusion part 211; outer cylinder 22; stirring member 3; body 31; stirring blades 32; partition plate 33; second hole 330; blades 34; extension plate 35; motor 36; liquid inlet pipe 4; liquid outlet pipe 5; filter screen 6; collection tank 7; discharge pipe 71. Detailed implementation manners

[0020] The technical solutions of the present invention will be further described in detail below in conjunction with the specific implementation manners and the drawings: Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0021] Embodiment 1: Refer to the attached Figure 1 , a compact in-situ oxidation adsorption treatment device for industrial wastewater, comprising: a primary separation device, the primary separation device comprising: a housing 1, a cylinder assembly 2 is provided at the center of the housing 1, a stirring member 3 is rotatably connected above the cylinder assembly 2, an inflow pipe 4 and an outflow pipe 5 are provided on the housing 1, and the inflow pipe 4 allows the water to be treated to flow in from below the center of the cylinder assembly 2 and rise, and the outflow pipe 5 discharges the treated water body.

[0022] The wastewater containing sludge is output through the inflow pipe 4 to below the center of the cylinder assembly 2 and rises. The stirring member 3 stirs the water body to form a swirling flow. The sludge and particulate matter in the wastewater diffuse outward away from the center of rotation under the action of centrifugal force, realizing the separation of the wastewater into supernatant and sludge. The sludge and particulate matter sink along the inner wall of the housing 1 under the action of gravity and wait for subsequent centralized discharge. The supernatant is discharged through the outflow pipe 5 and undergoes the next treatment process.

[0023] Among them, the swirling flow of the water body formed by the stirring member 3 above the cylinder assembly 2 has a low-pressure area at the center inside the cylinder assembly 2 at the center of the swirling flow. This helps to form an upward guidance and a central gathering for the water body released from the outflow pipe 5. Without an additional driving device to increase the output power of the inflow pipe 4, the upward discharge efficiency of the solid-liquid mixed waste liquid is improved. While reducing energy consumption, it also avoids the blockage of sludge in the inflow pipe 4 due to insufficient water body output power, improving the stability and efficiency of the wastewater treatment process.

[0024] Refer to the attached Figure 2 , the cylinder assembly 2 includes an inner cylinder 21, and a plurality of first holes 210 are evenly distributed along the circumference at the top of the inner cylinder 21.

[0025] Refer to the attached Figure 3, the stirring member 3 includes a frustum-shaped body 31, stirring blades 32 are evenly distributed on the inclined surfaces of the body 31, a partition plate 33 is connected to the periphery of the body 31, the partition plate 33 is at the inner top of the inner cylinder 21, and second holes 330 are evenly distributed along the circumferential direction of the partition plate 33.

[0026] The wastewater released by the inflow pipe 4 forms an upward water flow in the inner cylinder 21 and contacts the stirring member 3. The stirring member 3 forms a swirling flow with the upward water flow through the rotation of the body 31 carrying the stirring blades 32. The swirling flow causes the sludge and particulate matter to move downward and outward under the action of centrifugal force. At this time, the water body is separated into supernatant containing suspended matter, sedimented sludge and particulate matter. The supernatant rising in a swirling posture is guided and diffused outward by the conical body 31, and successively passes through the second holes 330 and the first holes 210 and finally reaches the outside of the inner cylinder 21. While the main body carries the partition plate 33 and keeps rotating, the second holes 330 on the partition plate 33 continuously change positions relative to the first holes 210 on the inner cylinder 21, that is, the flow-through channels formed by the second holes 330 and the first holes 210 continuously change, increasing the complexity of the movement of suspended substances in the upper-layer supernatant. The dispersion of suspended substances is realized by the cutting of the fluid passing through the hole body, improving the distribution balance degree of suspended substances in the supernatant, and enabling the supernatant output by the outflow pipe 5 to have a stable concentration and viscosity. The stable supernatant concentration can reduce the frequent adjustment of pH value adjustment and flocculant dosing, and reduce the operation difficulty.

[0027] The stable supernatant concentration can reduce the water quality fluctuation, making the pH value adjustment of the wastewater easier to control, avoiding excessive acid or alkali addition caused by concentration fluctuation, and realizing the saving of the dosage of acid-base solution and flocculant; By the above scheme, a supernatant with a stable concentration is formed, which is beneficial to the full play of the flocculant, forming larger and denser flocs and improving the solid-liquid separation efficiency.

[0028] There is an annular interval between the partition plate 33 and the inner cylinder 21. Blades 34 are evenly distributed along the circumferential direction on the outside of the partition plate 33. Annular extension plates 35 are provided along the upper and lower edges on the outside of the partition plate 33. Both the extension plates 35 and the blades 34 are matched with the inner wall of the inner cylinder 21.

[0029] The extension pieces form a relatively closed upper and lower opening for the annular interval between the partition plate 33 and the inner cylinder 21. During the rotation of the main body carrying the partition plate 33 and the stirring blades 32, the upward supernatant in the inner cylinder 21 cannot directly enter the annular interval, but reaches the annular space through the second holes 330 of the partition plate 33 under the guiding action of the main body, ensuring that the water body and suspended substances can be effectively cut and evenly dispersed.

[0030] The extension plate 35 and the blade 34 divide the annular space between the inner cylinder 21 and the partition plate 33 to form a plurality of water body flow-through spaces, and the channels continuously change positions along with the rotation of the blade 34. When the first hole 210 and the second hole 330 are misaligned, each water body flow-through space is relatively sealed to form a negative pressure. At this time, along with the rotation of the partition plate 33, the first hole 210 and the second hole 330 are connected, and the water body in the water body flow-through space can be quickly released outside the inner cylinder 21 under the change of pressure, improving the flow rate of water body release and dispersion without increasing the rotation speed of the stirring member 3, and realizing the energy saving of the stirring member 3; The blade 34 continuously rotates to achieve continuous contact with the inner wall surface of the inner cylinder 21, and can scrape off the suspended substances or floating objects blocked or attached to the opening of the first hole 210 on the inner wall of the inner cylinder 21, realizing self-cleaning in the solid-liquid separation process, ensuring the water body circulation rate, and avoiding blockage.

[0031] See the appendix Figure 1 The cylinder assembly 2 further includes an outer cylinder 22. The outer cylinder 22 forms an annular channel with an opening at the bottom outside the inner cylinder 21. The water body flowing out of the first hole 210 enters the annular channel and can descend.

[0032] After the water body passes through the first hole 210 of the inner cylinder 21, it reaches the top of the annular channel and descends. The descending water body has a lower flow rate. On the one hand, it can gently guide the separated sludge to accelerate sedimentation, and at the same time realize the inhibition of sludge resuspension, improve the efficiency of solid-liquid separation in industrial wastewater treatment, shorten the overall process time required for wastewater treatment, and reduce the energy consumption of standby equipment in the wastewater treatment process; The above scheme enables the water body to rise in the inner cylinder 21 and then reach the annular channel and descend, realizing solid-liquid separation by using the gravity and flow characteristics of the wastewater itself, reducing the dependence on the pump body for transporting the waste liquid, and reducing the energy consumption of pumping the wastewater.

[0033] A collection tank 7 is provided outside the inner cylinder 21. The collection tank 7 is connected with a discharge pipe 71. The collection tank 7 collects the floating impurities passing through the first hole 210.

[0034] After the solid sludge in the wastewater is separated, there are still floating substances in the supernatant. After the water body is released from the first hole 210 to the outside of the inner cylinder 21, under the action of the gravity of the fluid itself, the water body falls, and the floating objects remain floating. When the water body is released from the first hole 210, it is a swirling flow. The floating objects are continuously collected by the collection tank 7 under the guiding action of the swirling flow, realizing the collection and removal of oil in the wastewater, reducing or avoiding the interference of oil on chemical agents such as flocculants and oxidants, improving the use efficiency of subsequent agents, and reducing the treatment cost.

[0035] See the appendix Figure 4 The stirring member 3 further includes a motor 36. The motor 36 is installed outside the housing 1 and is connected to the main body 31. The motor 36 is used to provide the rotational driving force for the main body.

[0036] A filter screen 6 is provided at the height position in the middle of the inner side of the inner cylinder 21. The filter screen 6 performs primary filtration on the wastewater released upward by the inflow pipe 4 and blocks part of the sludge rising along with the waste liquid to prevent blockage.

[0037] The bottom of the housing 1 has a conical part 11 that converges downward to the center, and the conical part 11 has a sludge discharge port. The sludge can reach the sludge discharge port and be discharged, which helps to improve the sludge discharge efficiency.

[0038] See the appendix Figure 5 , a compact in-situ oxidation and adsorption treatment method for industrial wastewater, comprising the following steps: Step (1): Adjust the pH of the biochemical effluent of industrial wastewater to 4 - 6 with an acid solution; Step (2): Add soluble metal mixed salts and a mixed oxidant to the wastewater treated in step (1); Step (3): Add a composite flocculant according to the suspended solid concentration in the wastewater treated in step (2); Step (4): Feed the wastewater treated in step (3) into a primary separation device for primary separation to form supernatant and bottom sludge. The supernatant after primary separation undergoes the next step, and the bottom sludge after primary separation is fed into a thickening tank; Step (5): Adjust the pH of the supernatant treated in step (4) to 7 with an alkali solution, and add a composite flocculant according to the suspended solid concentration in the supernatant at this time; Step (6): Perform secondary separation on the supernatant treated in step (5) to form supernatant and bottom sludge. The supernatant generated from secondary separation is discharged, and the bottom sludge generated from secondary separation is fed into a thickening tank; Step (7): Discharge the bottom sludge in the thickening tank, and feed the supernatant in the thickening tank into step (1) to be treated together with the biochemical effluent of industrial wastewater in accordance with the step sequence.

[0039] In step (1), the industrial wastewater includes industrial wastewaters from industries such as coking wastewater, pesticide wastewater, chemical industrial park wastewater, fine chemical wastewater, coal gasification wastewater, leather-making wastewater, antibiotic fermentation production wastewater, etc.; the biochemical effluent of industrial wastewater is the effluent from the secondary sedimentation tank after the wastewater has undergone biological treatment.

[0040] In step (1), the acid solution includes any one or a combination of two of hydrochloric acid and sulfuric acid.

[0041] In step (2), the soluble metal mixed salts consist of soluble iron (Fe 2+ and / or Fe 3+ ), copper (Cu + and / or Cu 2+ ), manganese (Mn 2+ and / or Mn 3+ ), cobalt (Co 2+ and / or Co3+ ), calcium (Ca 2+ ), and magnesium (Mg 2+ ), or any combination thereof, in the salt.

[0042] In step (2), the mixed oxidant is composed of hydrogen peroxide (H 2 O 2 ), persulfate (S 2 O8 8 - ), and hypochlorite (ClO - ), or any combination thereof.

[0043] In step (2), the mass ratio of the mixed oxidant to the soluble metal mixed salt is less than 5:1, preferably (0.1 - 2):1, and more preferably (0.1 - 0.3):1.

[0044] In steps (3) and (5), the composite flocculant is composed of polyacrylamide and its derivatives, chitosan and its derivatives, cellulose derivatives, polyaluminum chloride, and polyferric sulfate, or any combination thereof, and the composite flocculant is added as needed.

[0045] In step (4), the primary separation device is the hydrocyclone disclosed in the present invention.

[0046] In step (5), the lye includes any one or a combination of two of sodium hydroxide and calcium hydroxide.

[0047] In step (6), the secondary separation device is a sedimentation tank or a membrane device.

[0048] Example Two: Based on Example One of the present invention, See the appendix Figure 6 . The bottom of the inner cylinder 21 has a conical diffusion part 211, the bottom of the housing 1 has a conical part 11 that converges towards the center downward, the conical part 11 has a sludge discharge port, and the outer edge of the diffusion part 211 extends towards the conical part 11.

[0049] The water body descending by its own weight in the annular channel is deflected by the diffusion part 211, promoting the concentrated movement of the sludge towards the conical part 11. The conical part 11 guides the sludge diffusing towards the outer side and downward, enabling the sludge to reach the sludge discharge port in time and be discharged, which helps to improve the sludge discharge efficiency; the water body descending by its own weight in the annular channel is deflected by the diffusion part 211, and it can also reduce the turbulence caused by the contact between the descending water body and the ascending water body released from the input pipe, resulting in sludge suspension.

[0050] Example Three: On the basis of Embodiment 1 of the present invention, the coking wastewater of a certain coking plant in Inner Mongolia was used as the treatment object for implementation. The COD content of the effluent from the secondary sedimentation tank after biochemical treatment of this coking wastewater was 328 mg / L, and the pH value was 7.25. The following steps were taken to treat this wastewater: Step (1): Adjust the pH of the wastewater to 4 with a sulfuric acid solution having a molar concentration of 5 mol / L; Step (2): Add ferrous sulfate in a ratio of the mass concentration of ferric ions to COD of 0.51:1, and then add hydrogen peroxide in a ratio of the molar concentration of ferric ions to hydrogen peroxide of 1:1 to carry out an in-situ oxidation adsorption reaction, with a reaction time of 2 hours; Step (3): Add cationic polyacrylamide to the wastewater at a mass concentration of 0.1 mg / L, and at the same time stir rapidly at a speed of 250 revolutions per minute for 3 minutes, and then stir slowly at a speed of 100 revolutions per minute for 10 minutes; Step (4): Feed the wastewater from Step (3) into the primary separation device at a flow rate of 10 L / h for primary separation. The ratio of the underflow flow rate to the influent flow rate of the primary separation equipment is 0.14, and the ratio of the overflow flow rate to the influent flow rate is 0.86. The underflow enters the gravity thickening tank; In the primary separation device, the inner diameter of the inflow pipe 4 is 70 mm, the axial length of the inflow pipe 4 is 154 mm, the inner diameter of the outflow pipe 5 is 22 mm, the apex angle of the cone part 11 is 60°, the sludge discharge port is a circular pipe orifice with an inner diameter of 27 mm, and the axial extension length of the sludge discharge port is 30 mm.

[0051] Step (5): Adjust the pH of the overflow from Step (4) to 7 with sodium hydroxide having a molar concentration of 5 mol / L, and then add cationic polyacrylamide with a mass concentration of 0.1 mg / L to the wastewater to flocculate the suspended matter.

[0052] Step (6): Feed the wastewater from Step (5) into the sedimentation tank for secondary separation. Take the supernatant effluent from the sedimentation tank and measure the COD. The results are shown in Table 1.

[0053] Control example: In order to highlight the advantages of the present invention, the following discloses a control example of an industrial wastewater in-situ oxidation adsorption treatment method. The control example adopts a traditional oxidation adsorption treatment technology. It includes the following steps: Step (1): Adjust the pH of the wastewater to 4; Step (2): Add ferrous sulfate in a ratio of the mass concentration of ferric ions to COD of 0.51:1, and then add hydrogen peroxide in a ratio of the molar concentration of ferric ions to hydrogen peroxide of 1:1 to carry out an in-situ oxidation adsorption reaction, with a reaction time of 2 hours; Step (3): Adjust the pH of the mixture in step (2) to 7, and then add cationic polyacrylamide to the wastewater to flocculate the suspended solids.

[0054] Step (4): Pass the mixture in step (3) into a sedimentation tank for solid-liquid separation. Take the supernatant water from the sedimentation tank and measure the COD. The results are shown in Table 1.

[0055] Table 1 Number Outlet COD (mg / L) COD Removal Rate (%) Example 3 94 72 Control Example 110 66 The COD removal rates of Example 3 and the control example illustrate that the method and device of the present invention can achieve a higher COD removal rate. Compared with the control example, the method of the present invention effectively avoids the problem of secondary release of organic pollutants and improves the organic matter removal rate through two-step pH adjustment coupled with two-step solid-liquid separation.

[0056] Generally speaking, the method and device of the present invention realize an in-situ oxidation adsorption technology that does not rely on catalysts, is highly efficient and stable, and can prevent secondary release of pollutants. The method process is simple, the device structure is compact, the floor area is small, and the use cost is low.

[0057] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A compact in-situ oxidation adsorption treatment device for industrial wastewater, comprising: The primary separation device is characterized in that: the primary separation device comprises: a shell (1), a barrel assembly (2) is provided at the center of the shell (1), a stirring member (3) is rotatably connected to the top of the barrel assembly (2), the shell (1) is provided with an inlet pipe (4) and an outlet pipe (5), the inlet pipe (4) allows the water to be treated to flow in from the bottom of the center of the barrel assembly (2) and rise, and the outlet pipe (5) discharges the treated water.

2. A compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 1, characterized in that: The cylinder assembly (2) comprises an inner cylinder (21), and the top of the inner cylinder (21) is provided with first holes (210) evenly distributed along the circumferential direction.

3. A compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 2, characterized in that: The stirring member (3) comprises a cone-shaped body (31), the inclined surface of the body (31) being evenly distributed with stirring blades (32), the outer periphery of the body (31) being connected with a partition (33), the partition (33) being at the top of the inner side of the inner cylinder (21), and the partition (33) being evenly distributed with second holes (330) along the circumferential direction.

4. A compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 3, characterized in that: There is an annular gap between the partition plate (33) and the inner cylinder (21); blades (34) are evenly distributed along the circumferential direction on the outer side of the partition plate (33); an annular extension plate (35) is provided on the upper and lower edges of the outer side of the partition plate (33); the extension plate (35) and the blades (34) are both matched with the inner wall of the inner cylinder (21).

5. The compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 2 is characterized by: The cylinder assembly (2) further comprises an outer cylinder (22), wherein the outer cylinder (22) forms an annular channel with an opening at the bottom outside the inner cylinder (21), and water flowing out of the first hole (210) enters the annular channel and can descend.

6. The compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 2 is characterized by: A collecting groove (7) is provided on the outside of the inner cylinder (21), the collecting groove (7) is connected to a discharge pipe (71), and the collecting groove (7) collects floating impurities passing through the first hole (210).

7. The compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 3 is characterized by: The stirring member (3) further comprises a motor (36), wherein the motor (36) is mounted outside the shell (1) and connected to the body (31).

8. The compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 2 is characterized by: A filter screen (6) is provided at a middle height position inside the inner cylinder (21).

9. The compact in-situ oxidation adsorption treatment device for industrial wastewater according to claim 2 is characterized by: The bottom of the shell (1) has a cone (11) that converges toward the center downward, and the cone (11) has a mud discharge port.

10. A compact in-situ oxidation adsorption treatment method for industrial wastewater, using the compact in-situ oxidation adsorption device for industrial wastewater according to claim 1, characterized by the following steps: Step (1): adjusting the pH of the biochemical effluent of industrial wastewater to 4-6 with acid; Step (2): adding a soluble metal mixed salt and a mixed oxidant to the wastewater treated in step (1); Step (3): adding a composite flocculant according to the concentration of suspended matter in the wastewater treated in step (2); Step (4): passing the wastewater treated in step (3) into the primary separation equipment to perform primary separation and form a supernatant and a bottom sludge, the supernatant after the primary separation is subjected to the next step, and the bottom sludge after the primary separation is passed into a concentration tank; Step (5): adjusting the pH of the supernatant after the treatment in step (4) to 7 with an alkali solution, and adding a composite flocculant according to the concentration of suspended matter in the supernatant at this time; Step (6): performing secondary separation on the supernatant treated in step (5) to form a supernatant and a bottom sludge, wherein the supernatant produced by the secondary separation is discharged, and the bottom sludge produced by the secondary separation is passed into the concentration tank; Step (7): The bottom sludge in the concentration tank is discharged, and the supernatant in the concentration tank is sent to the step (1) and treated together with the industrial wastewater biochemical effluent in accordance with the sequence of steps.

Images