A system and method for treating polyether-containing wastewater

Abstract

This invention discloses a method for treating polyether-containing wastewater. The method involves pre-treating the polyether wastewater to reduce its COD and increase the B / C ratio, adding ferrous sulfate for flocculation, and then further treating it using a high-efficiency shallow air flotation device. This solves the problems of easy foaming and poor biochemical treatment in subsequent biological processes. It significantly reduces the foaming performance of the wastewater while improving its biochemical properties and reducing its COD. The COD removal rate of this invention is above 80%, and the B / C ratio is above 0.45, achieving compliant discharge. The treatment system includes a CNP feeding device installed on the aeration tank. A motor drives rotating shafts connected by chains, causing all shafts to rotate, which in turn drives the first and second stirring paddles and the metering chamber to rotate, thus performing metering, feeding, and stirring / dissolving. The feeding process is automated.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a treatment system and method for polyether-containing wastewater. Background Technology

[0002] Polyether production wastewater is one of the more challenging types of recalcitrant organic chemical wastewaters. It contains a large amount of macromolecular polymers, has a high COD value, a low B / C ratio, and poor biodegradability. This wastewater must be treated to prevent environmental pollution. Alkylphenol polyoxyethylene ethers are prone to foaming; direct entry of polyether-containing wastewater into a biological aerobic system will generate excessive foam, affecting the normal operation of the wastewater biological treatment plant. Current methods for treating similar organic chemical wastewater include conventional biological methods, advanced oxidation methods, combined biological methods, and iron-carbon micro-electrolysis-aerated biological filter methods. After treatment, the wastewater generally only meets standards. These processes are lengthy, with complex equipment and structures, making them difficult to operate and manage. Summary of the Invention

[0003] To address the aforementioned problems, this invention discloses a treatment system and method for polyether-containing wastewater.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] This invention provides a method for treating polyether-containing wastewater, comprising the following steps:

[0006] (1) Add ether-containing wastewater to a pretreatment tank, arrange ceramic material electrodes, add activated carbon-supported metal catalyst between the electrode plates, keep the wastewater temperature at 25-40℃, react for 3-4 hours, and obtain pretreated water;

[0007] (2) Transfer the pretreated water to the equalization tank, add ferrous sulfate, stir and react for 10-30 minutes, and then run the high-efficiency shallow air flotation device for 3-5 minutes to obtain the supernatant.

[0008] (3) Transfer the supernatant to the aeration tank, add flour, urea and calcium phosphate every 2 hours, adjust the pH to 10-11 with sodium hydroxide, aerate at 50-60℃ for 12-18 hours to obtain oxidized water;

[0009] (4) Adjust the pH of the oxidation water to 7-10, transfer it to the activated sludge tank, set the biochemical aeration pressure to 0.04-0.045 MPa, the dissolved oxygen to 1.5-1.8 mg / L, and after hydraulic retention for 12-24 hours, transfer it to the sedimentation tank for sedimentation. After solid-liquid separation, discharge the supernatant and return the sludge to the activated sludge tank.

[0010] Furthermore, in step (1), the metals of the activated carbon-supported metal catalyst are Pb and Fe, or Pb and Cu, or Cu and Fe.

[0011] Furthermore, the preparation method of activated carbon supported metal catalyst includes the following steps: adding a first metal source and activated carbon at a mass ratio of 0.8-1.5:1, stirring at 30-50℃ for 1-2 hours, adding a second metal source, stirring for 1-2 hours, letting stand for 4-5 hours, pouring out the solution, and drying to obtain activated carbon supported metal catalyst, wherein the mass ratio of the second metal source to activated carbon is 0.8-1.5:1.

[0012] Furthermore, the first metal source is one of iron oxide and copper oxide, and the second metal source is one of copper oxide and Pb.

[0013] Furthermore, in step (2), the mass ratio of ferrous sulfate to pretreated water is 0.2-0.6:1000.

[0014] Furthermore, in step (3), flour, urea and calcium phosphate are added at a ratio of C:N:P of 150:6:1 to maintain a total phosphorus concentration of 10-12 mg / L.

[0015] Furthermore, in step (4), the concentration of activated sludge is 1.5-2 g / L.

[0016] The present invention also provides a treatment system for polyether-containing wastewater using the treatment method described above, comprising a pretreatment tank, an equalization tank, a high-efficiency shallow air flotation device, an aeration tank, an activated sludge tank, and a sedimentation tank connected in sequence; the pretreatment tank is also connected to a first filter, the high-efficiency shallow air flotation device is also connected to a second filter between the aeration tank, and a CNP feeding device is also provided in the aeration tank.

[0017] Furthermore, the aeration tank includes a tank body and a tank cover. A ladder is provided on the outer wall of the tank body. The tank cover has a grid-shaped hollow structure and includes an edge plate, a horizontal plate, and a vertical plate. The edge plate is U-shaped. The horizontal plates are evenly arranged along the front-back direction of the edge plate, and the vertical plates are evenly arranged along the left-right direction of the edge plate. A CNP feeding device is provided at the overlapping part of the horizontal and vertical plates. The CNP feeding device includes an upper box and a lower box. A partition is provided between the upper and lower boxes. A box cover is provided on the upper box. The box cover is provided with a push-pull rotating cover. A rotating shaft is provided through the box cover. The bottom of the rotating shaft passes through the partition. A first stirring paddle is provided on the rotating shaft above the partition. A gearbox is provided below the partition. The gears are connected by a chain. The gearbox has a first through hole for the chain to run. A second through hole corresponding to the first through hole is provided in the lower box. The first through hole and the second through hole are connected by a pipe. A metering box is provided below the gearbox. A second stirring paddle is provided on the rotating shaft at the bottom of the metering box. A motor is provided on one of the CNP feeding devices.

[0018] Furthermore, the partition plate has one or two first discharge ports, the metering box is uniformly provided with multiple metering cavities, the metering box is provided with a first inlet corresponding to the first discharge port at the top, the metering box is provided with a second discharge port spaced apart from the first inlet port at the bottom, and the bottom of the lower box and the second stirring paddle are placed in the liquid.

[0019] The beneficial effects of this invention are as follows:

[0020] This invention discloses a method for treating polyether-containing wastewater. The method involves pre-treating the polyether wastewater to reduce its COD, increase the B / C ratio, and decrease its toxicity, thus aiding subsequent treatment. Ferrous sulfate is added for flocculation, followed by treatment with a high-efficiency shallow air flotation device. This solves the problems of easy foaming and poor biochemical treatment in subsequent biological processes. It significantly reduces the foaming performance of the wastewater, improves its biodegradability, and lowers its chemical oxygen demand (COD). This invention achieves a COD removal rate of over 80% and a B / C ratio of over 0.45, meeting discharge standards.

[0021] This invention discloses a treatment system for polyether-containing wastewater. It incorporates a high-efficiency shallow air flotation device to efficiently remove solids from the wastewater, solving the problems of easy foaming and poor biochemical treatment in subsequent processes. This significantly reduces the foaming performance of the wastewater while improving its biodegradability and lowering its chemical oxygen demand (COD). A CNP feeding device is installed on the aeration tank. A motor drives rotating shafts connected by chains, causing all shafts to rotate. This, in turn, rotates the first and second stirring paddles and the metering chamber, enabling quantitative feeding, stirring, and dissolution. The feeding process is automated. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the external structure of the aeration tank of the present invention;

[0023] Figure 2 A schematic diagram of the internal structure of the CNP feeding device;

[0024] List of identifiers in attached diagrams:

[0025] 1. Aeration tank; 2. CNP feeding device; 3. Edge plate; 4. Horizontal plate; 5. Vertical plate; 6. Motor; 7. Upper box; 8. Chain; 9. Box cover; 10. Lower box; 11. Rotating shaft; 12. Gearbox; 13. Metering box; 14. Second stirring paddle; 15. First stirring paddle. Detailed Implementation

[0026] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Example 1

[0027] The COD of the polyether production wastewater from a certain company is 3340 mg / L.

[0028] A method for treating polyether-containing wastewater includes the following steps:

[0029] (1) Add ether-containing wastewater to a pretreatment tank, arrange ceramic material electrodes, add activated carbon-supported metal catalyst between the electrode plates, keep the wastewater temperature at 25-35℃, react for 4 hours, and obtain pretreated water;

[0030] (2) Transfer the pretreated water to the equalization tank, add ferrous sulfate, stir and react for 15 minutes, and then run the high-efficiency shallow air flotation device for 3-5 minutes to obtain supernatant water; the mass ratio of ferrous sulfate to pretreated water is 0.6:1000.

[0031] (3) Transfer the supernatant to the aeration tank. Every 2 hours, add flour, urea and calcium phosphate in sequence. Adjust the pH to 10-11 with sodium hydroxide. Aerate at 50-60℃ for 12 hours to obtain oxidized water. Add flour, urea and calcium phosphate at a ratio of C:N:P of 150:6:1 to maintain the total phosphorus concentration at 10-12 mg / L.

[0032] (4) Adjust the pH of the oxidation water to 8-9, transfer it to the activated sludge tank, set the biochemical aeration pressure to 0.04-0.045 MPa, and the dissolved oxygen to 1.5-1.8 mg / L. After hydraulic retention for 24 hours, transfer it to the sedimentation tank for sedimentation. After solid-liquid separation, discharge the supernatant and return the sludge to the activated sludge tank. The concentration of activated sludge is 2 g / L.

[0033] The preparation method of activated carbon supported metal catalyst includes the following steps: adding copper oxide and activated carbon at a mass ratio of 1.5:1, stirring at 35°C for 2 hours, adding Pb, stirring for 2 hours, letting stand for 4-5 hours, pouring out the solution, and drying to obtain activated carbon supported metal catalyst, wherein the mass ratio of Pb to activated carbon is 1.5:1.

[0034] After the above treatment, the COD of the wastewater decreased from 3340 mg / L to below 340 mg / L, and the B / C ratio was 0.46. Example 2

[0035] The COD of the polyether production wastewater from a certain company is 3340 mg / L.

[0036] A method for treating polyether-containing wastewater includes the following steps:

[0037] (1) Add ether-containing wastewater to a pretreatment tank, arrange ceramic material electrodes, add activated carbon-supported metal catalyst between the electrode plates, keep the wastewater temperature at 25-35℃, react for 4 hours, and obtain pretreated water;

[0038] (2) Transfer the pretreated water to the equalization tank, add ferrous sulfate, stir and react for 15 minutes, and then run the high-efficiency shallow air flotation device for 3-5 minutes to obtain supernatant water; the mass ratio of ferrous sulfate to pretreated water is 0.4:1000.

[0039] (3) Transfer the supernatant to the aeration tank. Every 2 hours, add flour, urea and calcium phosphate in sequence. Adjust the pH to 10-11 with sodium hydroxide. Aerate at 50-60℃ for 12 hours to obtain oxidized water. Add flour, urea and calcium phosphate at a ratio of C:N:P of 150:6:1 to maintain the total phosphorus concentration at 10-12 mg / L.

[0040] (4) Adjust the pH of the oxidation water to 7-8, transfer it to the activated sludge tank, set the biochemical aeration pressure to 0.04-0.045 MPa, and the dissolved oxygen to 1.5-1.8 mg / L. After hydraulic retention for 24 hours, transfer it to the sedimentation tank for sedimentation. After solid-liquid separation, discharge the supernatant and return the sludge to the activated sludge tank. The concentration of activated sludge is 2 g / L.

[0041] The preparation method of activated carbon supported metal catalyst includes the following steps: adding iron oxide and activated carbon at a mass ratio of 1.5:1, stirring at 35°C for 2 hours, adding copper oxide, stirring for 2 hours, letting stand for 4-5 hours, pouring out the solution, and drying to obtain activated carbon supported metal catalyst, wherein the mass ratio of copper oxide to activated carbon is 1.5:1.

[0042] After the above treatment, the COD of the wastewater decreased from 3340 mg / L to below 380 mg / L, and the B / C ratio was 0.40. Example 3

[0043] The treatment system for polyether-containing wastewater includes a pretreatment tank, an equalization tank, a high-efficiency shallow air flotation device, an aeration tank 1, an activated sludge tank, and a sedimentation tank connected in sequence. The pretreatment tank is also connected to a first filter, and a second filter is connected between the high-efficiency shallow air flotation device and the aeration tank 1. A CNP feeding device 2 is also installed in the aeration tank 1.

[0044] The aeration tank 1 includes a tank body and a tank cover. A ladder is installed on the outer wall of the tank body. The tank cover has a grid-shaped perforated structure and includes an edge plate 3, horizontal plates 4, and vertical plates 5. The edge plate 3 is U-shaped. The horizontal plates 4 are evenly distributed along the front-to-back direction of the edge plate 3, and the vertical plates 5 are evenly distributed along the left-to-right direction of the edge plate 3. A CNP feeding device 2 is installed at the overlapping portion of the horizontal plates 4 and vertical plates 5. The CNP feeding device 2 includes an upper box 7 and a lower box 10, with a partition between the upper box 7 and the lower box 10. A box cover 9 is installed on the upper box 7, and the box cover 9 is a push-pull rotating cover. A rotating shaft 11 is installed through the cover 9, and a partition is installed through the bottom of the rotating shaft 11. A first stirring paddle 15 is installed on the rotating shaft 11 above the partition, and a gearbox 12 is installed below the partition. The gears are connected by a chain 8. The gearbox 12 has a first through hole for the chain 8 to operate. The lower box 10 has a second through hole corresponding to the first through hole. The first through hole and the second through hole are connected by a pipe. A metering box 13 is installed below the gearbox 12. A second stirring paddle 14 is installed on the rotating shaft 11 at the bottom of the metering box 13. A motor 6 is installed on one of the CNP feeding devices 2.

[0045] The partition has one or two first discharge ports, and the metering box 13 is uniformly provided with multiple metering chambers. The metering box 13 is provided with a first inlet corresponding to the first discharge port at the top, and a second discharge port spaced apart from the first inlet port at the bottom. The bottom of the lower box 10 and the second stirring paddle 14 are placed in the liquid.

[0046] Working principle: C source, N source and P source are added to CNP feeding device 2 respectively, or mixed in proportion and then added to CNP feeding device 2 respectively, preferably the latter. Motor 6 is turned on, and the electric shaft 11 of motor 6 rotates. The first stirring paddle 15 adds the material to the metering chamber in metering tank 13 through the first discharge port and the first feed port. The metering chamber rotates and adds the material to the wastewater solution through the second discharge port. The second stirring paddle 14 stirs the material to dissolve it in time. Motor 6 is set to add material once every two hours through the control panel. The number of revolutions of the shaft 11 each time limits the running time of motor 6.

[0047] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A method for treating polyether-containing wastewater, characterized in that, Includes the following steps: (1) Add polyether-containing wastewater to a pretreatment tank, arrange ceramic material electrodes in the pretreatment tank, add activated carbon-supported metal catalyst between the electrode plates, keep the temperature of the ether-containing wastewater at 25-40℃, react for 3-4 hours, and obtain pretreated water. (2) Transfer the pretreated water to the equalization tank, add ferrous sulfate, stir and react for 10-30 minutes, and then run the high-efficiency shallow air flotation device for 3-5 minutes to obtain the supernatant. (3) Transfer the supernatant to the aeration tank, add flour, urea and calcium phosphate every 2 hours, adjust the pH to 10-11 with sodium hydroxide, aerate at 50-60℃ for 12-18 hours to obtain oxidized water; (4) Adjust the pH of the oxidation water to 7-10, transfer it to the activated sludge tank, the biochemical aeration pressure is 0.04-0.045 MPa, the dissolved oxygen is 1.5-1.8 mg / L, after hydraulic retention for 12-24 hours, it is transferred to the sedimentation tank for sedimentation, after solid-liquid separation, the supernatant is discharged, and the sludge is returned to the activated sludge tank. In step (1), the metals of the activated carbon-supported metal catalyst are Pb and Fe, or Pb and Cu, or Cu and Fe; A method for preparing an activated carbon-supported metal catalyst includes the following steps: adding a first metal source and activated carbon at a mass ratio of 0.8-1.5:1, stirring at 30-50℃ for 1-2 hours, adding a second metal source, stirring for 1-2 hours, allowing to stand for 4-5 hours, pouring out the solution, and drying to obtain the activated carbon-supported metal catalyst, wherein the mass ratio of the second metal source to activated carbon is 0.8-1.5:

1. The first metal source is one of iron oxide and copper oxide, and the second metal source is one of copper oxide and Pb. In step (2), the mass ratio of ferrous sulfate to pretreated water is 0.2-0.6:1000; In step (3), flour, urea and calcium phosphate are added at a ratio of C:N:P of 150:6:1 to maintain a total phosphorus concentration of 10-12 mg / L; In step (4), the concentration of activated sludge is 1.5-2 g / L.

2. A treatment system for polyether-containing wastewater used in the treatment method as described in claim 1, characterized in that, It includes a pretreatment tank, an equalization tank, a high-efficiency shallow air flotation device, an aeration tank, an activated sludge tank, and a sedimentation tank connected in sequence; the pretreatment tank is also connected to a first filter, the high-efficiency shallow air flotation device is also connected to a second filter between the aeration tank, and a CNP feeding device is also installed in the aeration tank. The aeration tank includes a tank body and a tank cover. A ladder is installed on the outer wall of the tank body. The tank cover has a grid-shaped hollow structure and includes an edge plate, a horizontal plate, and a vertical plate. The edge plate is U-shaped. The horizontal plates are evenly arranged along the front-back direction of the edge plate, and the vertical plates are evenly arranged along the left-right direction of the edge plate. A CNP feeding device is installed at the overlapping part of the horizontal and vertical plates. The CNP feeding device includes an upper box and a lower box. A partition is installed between the upper box and the lower box. A box cover is installed on the upper box. The box cover has a push-pull rotating cover. A rotating shaft is installed through the box cover. The bottom of the rotating shaft passes through the partition. A first stirring paddle is installed on the rotating shaft above the partition. A gearbox is installed below the partition. The gears are connected by a chain. The gearbox has a first through hole for the chain to run. A second through hole is installed in the lower box corresponding to the first through hole. The first through hole and the second through hole are connected by a pipe. A metering box is installed below the gearbox. A second stirring paddle is installed on the rotating shaft at the bottom of the metering box. A motor is installed on one of the CNP feeding devices. The partition plate has one or two first discharge ports, the metering box is uniformly provided with multiple metering chambers, the metering box is provided with a first inlet corresponding to the first discharge port at the top, the metering box is provided with a second discharge port spaced apart from the first inlet port at the bottom, and the bottom of the lower box and the second stirring paddle are placed in the liquid.

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