CN116332428B

CN116332428B - Chromium-containing industrial wastewater treatment process

Info

Publication number: CN116332428B
Application number: CN202310456623.9A
Authority: CN
Inventors: 姜娜
Original assignee: Qingdao Guobiao Environmental Protection Engineering Co ltd
Current assignee: Qingdao Guobiao Environmental Protection Engineering Co ltd
Priority date: 2023-04-25
Filing date: 2023-04-25
Publication date: 2023-12-15
Anticipated expiration: 2043-04-25
Also published as: CN116332428A

Abstract

The application relates to a chromium-containing industrial wastewater treatment process, which belongs to the field of wastewater treatment technologies of surface treatment workshops and comprises precipitation and diversion: the wastewater is deposited in a inclined tube deposition tank, and the supernatant is continuously subjected to subsequent treatment; the inclined tube sedimentation tank comprises a sedimentation tank body, a plurality of mud hoppers are arranged at the bottom of the sedimentation tank body, and a scraper is arranged on the inner side wall of each mud hopper; a high-pressure water pipe is arranged at the position corresponding to the scraper, and a scraper cleaning nozzle and an end wall cleaning nozzle are arranged on the high-pressure water pipe; a sludge guiding mechanism is arranged at the position corresponding to the scraper and is used for guiding sludge scraped by the scraper; the mud bucket is provided with a synchronous driving mechanism which is used for synchronously driving the two scrapers to move along the inner wall of the mud bucket. The application has the effects of facilitating the falling of the sludge adhered to the bottom of the sedimentation tank, improving the sludge discharge effect, improving the sedimentation efficiency of the sedimentation tank and further improving the wastewater treatment effect.

Description

Chromium-containing industrial wastewater treatment process

Technical Field

The application relates to the field of wastewater treatment technologies of surface treatment workshops, in particular to a chromium-containing industrial wastewater treatment process.

Background

The industrial wastewater generated in the surface treatment workshop mainly comprises chromium-containing wastewater, nickel-containing wastewater, lead-containing wastewater, copper-containing wastewater, cyanide-containing wastewater, silver-containing wastewater and comprehensive wastewater, and the wastewater mainly comprises heavy metal ions as pollution factors and also contains partial organic matters and ammonia nitrogen. Wherein the chromium-containing wastewater mainly originates from the water washing tank and the production water of the spraying tank after the chromium-containing main tank of the surface treatment production line.

In order to facilitate the treatment of industrial wastewater, generally, when the industrial wastewater generated in a surface workshop is treated, wastewater containing different heavy metals is firstly collected and pretreated respectively, and the pretreated wastewater is collected and subjected to advanced treatment uniformly. When the chromium-containing wastewater is pretreated, a chemical reduction treatment process is generally adopted to treat the wastewater, the reacted wastewater undergoes flocculation reaction and is finally precipitated by a precipitation tank, and supernatant fluid is mixed with supernatant fluid obtained by pretreatment of wastewater containing other heavy metal ions, so that the supernatant fluid is subjected to advanced treatment uniformly.

Aiming at the related technology, when the chromium-containing wastewater is precipitated in the precipitation tank, the sludge in the chromium-containing wastewater has certain viscosity and is easy to adhere to the bottom of the precipitation tank and not easy to fall off, so that the sludge discharge effect is poor, and the precipitation efficiency of the precipitation tank is further influenced.

Disclosure of Invention

In order to facilitate the falling of the sludge adhered to the bottom of the sedimentation tank, improve the sludge discharge effect, so as to improve the sedimentation efficiency of the sedimentation tank and further improve the wastewater treatment effect, the application provides a chromium-containing industrial wastewater treatment process.

The application provides a chromium-containing industrial wastewater treatment process which adopts the following technical scheme:

a chromium-containing industrial wastewater treatment process comprises the following steps of S1, collecting chromium-containing wastewater: collecting wastewater generated in a production workshop into a chromium-containing wastewater regulating tank, regulating the homogenizing average amount of the wastewater by using an air stirring device, and then lifting the wastewater into a chromium-containing wastewater reaction tank; s2, chemical reduction treatment: the pH value of the wastewater is regulated to 2-3 by automatically controlling the adding amount of acid through a pH automatic control system, and meanwhile, the adding amount of a reducing agent is controlled through an ORP automatic control system, so that the ORP value of the wastewater is between 230 and 320mv, and the reaction time is about 15-25min; s3, flocculation reaction: automatically controlling the addition amount of alkali by a PH automatic control system, adjusting the PH value of the wastewater to 7.5-8.5, simultaneously controlling a dosing pump by a PLC, quantitatively adding PAC and PAM into a chromium-containing wastewater reaction tank by the dosing pump, and performing flocculation reaction; s4, precipitation and split flow: conveying the wastewater subjected to flocculation reaction from the chromium-containing wastewater reaction tank to a pipe chute sedimentation tank for sedimentation, continuously carrying out subsequent treatment on supernatant fluid, and discharging sludge into a chromium sludge tank for treatment according to dangerous waste; s5, pulse electric flocculation treatment: oxidizing organic matters in the wastewater, degrading ammonia nitrogen and coagulating a part of heavy metals through the action of current between polar plates; s6, air floatation integrated treatment: the electrolyzed wastewater enters an air floatation integrated tank, and under the dual actions of precipitation and dissolved air floatation, clarified liquid is discharged into a circulating oxidation tank, and sludge is discharged into a sludge tank; s7, cyclic oxidation treatment: sodium hypochlorite and ozone are quantitatively added into the circulating oxidation tank, and circulating treatment is carried out for 30-40min through a circulating water pump, so that ammonia nitrogen and organic matters in the wastewater are further reduced; s8, purifying quartz sand and activated carbon: the wastewater after cyclic oxidation passes through a quartz sand filter and an activated carbon filter, so that the wastewater is filtered by quartz sand and adsorbed by activated carbon and then is discharged into a buffer pool to enter a state to be discharged;

the inclined tube sedimentation tank used in the step S4 comprises a sedimentation tank body, wherein a plurality of mud hoppers are arranged at the bottom of the sedimentation tank body, and scrapers are arranged on the inner side walls of each mud hopper; a high-pressure water pipe is arranged at the position corresponding to the scraper, and a scraper cleaning spray head is arranged on the high-pressure water pipe and used for flushing the scraper; the high-pressure water pipe is provided with an end wall cleaning spray head which is used for cleaning the end wall of the mud bucket; a sludge guiding mechanism is arranged at the position corresponding to the scraper and is used for guiding sludge scraped by the scraper; the mud bucket is provided with a synchronous driving mechanism which is used for synchronously driving the two scrapers to move along the inner wall of the mud bucket.

Through adopting above-mentioned technical scheme, synchronous actuating mechanism provides power for the scraper, makes the scraper follow two lateral walls up-and-down motion that the mud fill was inclined in mud sediment process, and the scraper tip is in the motion process, scrapes down the silt on the mud fill inner wall, makes the silt that adheres to the precipitation tank bottom drop.

When mud is scraped downwards along the inner wall of the mud bucket, high-pressure water is sprayed out of the scraper cleaning spray head along the high-pressure water pipe, and sprayed water is impacted onto the side wall of the scraper so as to wash up the mud on the scraper, thereby realizing the effects of scraping mud and cleaning the scraper. The sludge on the scraper is convenient to clean, so that the working efficiency and the sludge scraping effect of the scraper are improved.

The sludge guiding mechanism guides sludge scraped by the scraper, drives sludge rushed from the surface of the scraper to the bottom of the sludge bucket, facilitates sludge collection to the bottom of the sludge bucket, and improves the treatment efficiency of the sludge.

High-pressure water is sprayed out from the end wall cleaning spray heads along the high-pressure water pipe, and the sprayed water is impacted to the two vertical end walls of the mud bucket, so that mud falls off from the end walls, the end walls of the mud bucket can be cleaned, and the treatment efficiency of the mud can be improved.

In conclusion, when the chromium-containing wastewater is precipitated in the precipitation tank, the sludge adhered to the bottom of the precipitation tank can be conveniently fallen off, and the sludge discharge effect is improved, so that the precipitation efficiency of the precipitation tank is improved. Thereby improving the overall treatment effect of the industrial wastewater.

Optionally, the sludge guiding mechanism comprises a water wheel; the water wheel is used for driving the rotating blades to rotate; and the water supply pipeline is communicated with the high-pressure water pipe and is used for providing power for the water wheels.

Through adopting above-mentioned technical scheme, high-pressure water gets into water supply pipe along the high-pressure water pipe to drive water wheels rotates, and the water wheels drive rotating vane and rotate around the pivot, and rotating vane rotates downwards, drives the silt of dashing to the mud bucket bottom, is convenient for collect the silt to mud bucket bottom, improves the treatment effeciency of silt. The high-pressure water is discharged from the water discharge pipeline through the water wheel.

Optionally, the synchronous driving mechanism comprises two screws, the axis of each screw is parallel to the side wall of the mud bucket, the screws are in rotary connection with the mud bucket, the screws are in threaded fit with the scraper, and driven gears are fixedly arranged on the screws; the driving gear is rotationally connected with the mud bucket and is meshed with the two driven gears; the driving motor is fixedly connected with the mud bucket, and an output shaft of the driving motor is fixedly connected with the driving gear.

Through adopting above-mentioned technical scheme, driving motor's output shaft rotates, drives driving gear and rotates, and driving gear drives two driven gear synchronous rotations to make two screw rods synchronous rotation, drive scraper on the screw rod along mud bucket inner wall up-and-down motion. And one power source drives the two scrapers to synchronously move, so that power input is saved.

Optionally, the scraper is connected with a guide rod in a sliding way, the axis of the guide rod is parallel to the axis of the screw rod, and the guide rod is fixedly connected to the mud bucket.

Through adopting above-mentioned technical scheme, when the scraper moves along the axis direction of screw rod, the both ends of scraper slide along the axis of guide bar for the up-and-down motion process of mounting bracket is more stable.

Optionally, a bachelter tank is fixedly arranged at the top of the sedimentation tank body.

By adopting the technical scheme, the wastewater enters from the water inlet end of the Bashall tank and flows into the precipitation tank body from the water outlet end. The Bashall tank detects the flow of the wastewater flowing to the settling tank body and guides the wastewater to enter the settling tank body.

Optionally, an aeration pipe is arranged at the bottom of the chromium-containing wastewater regulating tank.

By adopting the technical scheme, the regulating tank is aerated regularly, so that the deposition of bottom sludge after a long time is prevented.

Optionally, the chromium-containing wastewater reaction tank is provided with an unqualified reflux valve and an unqualified reflux pipe; the reaction process in the chromium-containing reaction tank is controlled in a closed loop manner by a Programmable Logic Controller (PLC), a PH meter, an ORP meter and an administration pump.

By adopting the technical scheme, monitoring data in any link in the treatment process is unqualified, and after time delay is 30 seconds, the unqualified reflux valve is controlled to be opened, so that wastewater automatically flows back to the chromium wastewater regulating tank through the unqualified reflux pipe. Thereby improving the effect of wastewater treatment.

Optionally, an ethylene-propylene copolymer honeycomb inclined tube is fixedly arranged at the upper part of the precipitation tank body.

Through adopting above-mentioned technical scheme, waste water in the settling tank body passes through ethylene-propylene copolymerization honeycomb chute for supernatant in the waste water moves along the chute upwards, and silt in the waste water moves along the chute downwards, accelerates the sediment.

Drawings

FIG. 1 is a flow chart of a pretreatment process of wastewater containing chromium in an embodiment of the application.

FIG. 2 is a flow chart of a process for deeply treating chromium-containing wastewater in an embodiment of the application.

FIG. 3 is a schematic diagram of the overall structure of the inclined tube settling tank in the embodiment.

Fig. 4 is an enlarged view of a portion a in fig. 3.

FIG. 5 is a schematic illustration of an embodiment for highlighting an automatic mud valve.

Fig. 6 is an enlarged view of a portion B in fig. 5.

Fig. 7 is an enlarged view of a portion C in fig. 5.

Fig. 8 is a sectional view for highlighting the cleaning device.

Fig. 9 is an enlarged view of the portion D in fig. 8.

FIG. 10 is a schematic view of an embodiment for highlighting a screw.

Fig. 11 is an enlarged view of the portion F in fig. 8.

FIG. 12 is a schematic view of an embodiment for highlighting the sludge guide mechanism.

Fig. 13 is an enlarged view of a portion G in fig. 12.

Fig. 14 is an enlarged view of the portion E in fig. 10.

Reference numerals illustrate: 1. a chromium-containing wastewater regulating tank; 11. a chromium-containing wastewater reaction tank; 12. a sludge land; 2. an intermediate pool I; 21. an electric flocculation device; 22. an air floatation integrated tank; 23. a cyclic oxidation tank; 24. a middle water tank II; 25. a quartz sand filter; 26. an activated carbon filter; 27. a buffer pool; 3. a pipe chute precipitation tank; 31. a precipitation tank body; 32. a bashel tank; 321. a water inlet end; 322. a water outlet end; 33. a water inlet weir plate; 331. a water inlet pipe; 332. a baffle; 34. the inclined plate filler installation position; 35. a mud bucket; 351. a mud pipe; 352. an automatic mud valve; 36. a communicating pipe; 361. a connecting pipe; 362. a mud pump installation position; 37. a water outlet weir plate I; 371. a water outlet weir plate II; 372. a water outlet pipe; 38. a base; 39. a reinforcing rod; 4. a mud pumping pipeline; 41. a mud inlet groove; 5. a cleaning device; 51. a mounting frame; 52. a scraper; 6. a high pressure water pipe; 61. the end wall cleaning spray head; 62. the scraper cleans the spray head; 7. a silt guide mechanism; 71. a mounting rod; 72. a water wheel; 73. rotating the blades; 74. a blade mounting plate; 75. a water supply pipe; 76. a drainage pipe; 77. a rotating shaft; 8. a synchronous driving mechanism; 81. a screw; 82. a driven gear; 83. a drive gear; 84. a drive shaft; 85. a motor mounting seat; 86. a driving motor; 87. a guide rod; 9. a maintenance platform; 91. a viewing mirror.

Detailed Description

The application is described in further detail below with reference to fig. 1-14.

The embodiment of the application discloses a chromium-containing industrial wastewater treatment process, which comprises a chromium-containing wastewater pretreatment process and a chromium-containing wastewater advanced treatment process. Referring to fig. 1, the chromium-containing wastewater pretreatment process includes steps S1 to S4.

S1: chromium-containing wastewater collection

The chromium-containing wastewater produced in the production workshop is collected in a chromium-containing wastewater regulating tank 1, and the wastewater is lifted into a chromium-containing wastewater reaction tank 11 after the homogenization average of the wastewater is regulated by using an air stirring device.

The chromium-containing wastewater produced in the production plant is discharged to the chromium-containing wastewater regulating tank 1 in the sewage treatment station through the water discharge pipeline 76, and the treatment capacity is 5m3/h.

An air stirring device is arranged in the waste water regulating tank, and the chromium-containing waste water is stirred in the process of entering the waste water regulating tank so as to regulate the homogenization and uniformity of the chromium-containing waste water.

An electronic liquid level detection device and a sewage lifting pump are arranged in the wastewater regulating tank, and the electronic liquid level detection device monitors the liquid level in the wastewater regulating tank in real time and returns detection data to the control platform. The control platform controls the sewage lifting pump, so that after the water quantity reaches a certain height, the sewage lifting pump lifts the chromium-containing wastewater from the wastewater regulating tank to the chromium-containing wastewater reaction tank 11.

The sewage lifting pump is preferably a plastic pneumatic diaphragm pump, one is provided with common pump parts in normal operation, one is provided with a standby pump, and parts can be directly replaced under abnormal conditions.

An aeration pipe is arranged at the bottom of the chromium-containing wastewater regulating tank 1, and the regulating tank is aerated regularly to prevent sludge deposition at the bottom after a long time.

S2: chemical reduction treatment

The pH value of the wastewater is regulated to 2-3 by automatically controlling the adding amount of acid through a pH automatic control system, and meanwhile, the adding amount of a reducing agent is controlled through an ORP automatic control system, so that the ORP value of the wastewater is between 230 and 320mv, and the reaction time is about 15-25min. Cr6+ is reduced to Cr3+.

Wherein, the reducing agent adopts sodium bisulphite, and the adding amount of the medicine is controlled by a pH meter, an ORP instrument and a PLC to reduce Cr6+ into Cr3+. Hexavalent chromium in electroplating wastewater mainly exists in two forms of Cr2O 72-and CrO42-, and along with the difference of the PH value of the wastewater, transfer balance exists between the two forms:

CrO42-+2H+---Cr2O72-+H2O

Cr2O72-+20H---- CrO42-+ H2O

hexavalent chromium exists mainly in the form of Cr2O 72-under acidic conditions, and in the form of CrO 42-under alkaline conditions. However, the pH of the electroplating chromium-containing wastewater and the rinsing wastewater is generally above 5, and most of the wastewater exists in CrO42-, the reduction is usually optimally controlled between 2 and 3, and the reaction principle is that (the reducing agent is exemplified by Na3SO 3): cr2O72- +3so32- +8h+=2cr3++ 3SO42- +4h2o.

S3: flocculation reaction

The pH value of the wastewater is regulated to 7.5-8.5 by automatically controlling the addition amount of alkali through a pH automatic control system, meanwhile, a dosing pump is controlled by a PLC, PAC and PAM are quantitatively added into the chromium-containing wastewater reaction tank 11 through the dosing pump, and flocculation reaction occurs. The precipitation principle is as follows: cr3++3OH- =cr (OH) 3 ∈.

Wherein, S2, S3 all need put in the medicament to chromium-containing wastewater reaction tank 11, and the medicament can produce chemical reaction in mixing process, and response can produce some volatile gas, consequently adopts mechanical stirring to mix, and mechanical stirrer disposes according to the technology, and the mixer operates steadily, does not appear the noise of friction collision during operation, and the puddler adopts carbon steel lining rubber material.

The chromium-containing wastewater reaction tank 11 adopts a PP tank body or a carbon steel tank body. The inlet of the chromium-containing wastewater reaction tank 11 is provided with a flow detection system, and temporary flow of wastewater is detected in real time and transmitted to a control platform in real time in the running process of the system.

The chromium-containing wastewater reaction tank 11 is subjected to closed treatment, and a ventilation facility is arranged at the top of the chromium-containing wastewater reaction tank to timely pump away generated waste gas; the bottom is provided with a bottom discharge valve and an emptying pipe, and the side face is provided with a disqualified return valve and a disqualified return pipe.

The reaction process in the chromium-containing reaction tank is controlled in a closed loop manner by a Programmable Logic Controller (PLC), a PH meter, an ORP meter and an administration pump. And (3) monitoring data in any link in the treatment process is unqualified, and after time delay is carried out for 30 seconds, controlling an unqualified reflux valve to open, so that the wastewater automatically flows back to the chromium wastewater regulating tank through an unqualified reflux pipe.

S4: precipitation split stream

And (3) conveying the wastewater subjected to flocculation reaction from the chromium-containing wastewater reaction tank 11 to the inclined tube sedimentation tank 3 for sedimentation, continuously carrying out subsequent treatment on supernatant fluid, and discharging sludge into a chromium sludge tank for treatment according to dangerous wastes.

Referring to FIG. 3, the inclined tube settling tank 3 includes a settling tank body 31 designed with a surface load of 0.8-2m3/m2.H and a tank depth of 3.9 meters. The top of the sedimentation tank body 31 is fixedly provided with a Buchell tank 32, and the Buchell tank 32 is arranged at the middle position of the top of the sedimentation tank. One end of the bachel tank 32 is provided with a water inlet end 321, and the other end is provided with a water outlet end 322. In use, wastewater enters the bachelter tank 32 from the water inlet end 321 and flows into the settling tank body 31 from the water outlet end 322. The bachel tank 32 detects the flow rate of the wastewater flowing to the settling tank body 31 and guides the wastewater into the settling tank body 31.

Referring to fig. 3 and 4, a water inlet weir plate 33 is fixedly arranged at the top of the settling tank body 31, and the water inlet weir plate 33 is arranged parallel to the length direction of the settling tank body 31. A plurality of inlet tubes 331 are set firmly to the water inlet weir plate 33 bottom, and inlet tube 331 axis is parallel to each other and vertical setting, and inlet tube 331 is along the length direction evenly distributed of water inlet weir plate 33, inlet tube 331 and water inlet weir plate 33 junction intercommunication. After the wastewater flows into the water inlet weir plate 33 from the bachelter tank 32, the wastewater moves towards the two ends of the water inlet weir plate 33 along the length direction of the water inlet weir plate 33, and enters the sedimentation tank body 31 along the water inlet pipe 331 in the moving process.

Referring to FIG. 3, an inclined plate packing installation position 34 is arranged at the upper part of the sedimentation tank body 31, and a plurality of 0.8mm phi 80mm ethylene propylene copolymer honeycomb inclined tubes are fixedly arranged on the inclined plate packing installation position 34, and are 1m in length and 60-degree in inclination angle.

Referring to fig. 3 and 5, a plurality of mud hoppers 35 are arranged at the bottom of the sedimentation tank body 31, the mud hoppers 35 are distributed along the length direction of the sedimentation tank body 31, the included angle between the hopper walls of the mud hoppers 35 at the bottom of the sedimentation tank body 31 and the horizontal plane is 55-60 degrees, and each mud hopper 35 is provided with an independent mud pipe 351 and an automatic mud valve 352.

Referring to fig. 6, one end of a sludge discharge pipe 351 is fixedly connected to the sludge hopper 35, an automatic sludge discharge valve 352 is fixedly arranged at one end of the sludge discharge pipe 351, which is far away from the sludge hopper 35, and the automatic sludge discharge valve 352 is a pneumatic butterfly valve. The pneumatic butterfly valve is provided with communicating pipe 36 far away from the one end of mud pipe 351, and communicating pipe 36 axis level sets up. A plurality of connecting pipes 361 are fixedly connected to the connecting pipe 36, the connecting pipes 361 are communicated with the connecting pipe 36, one connecting pipe 361 is arranged corresponding to one automatic mud valve 352, and one end of the connecting pipe 361 away from the connecting pipe 36 is fixedly connected with one side of the automatic mud valve 352 away from the mud pipe 351.

Referring to fig. 5, a sludge pump installation site 362 is provided at an end of the communication pipe 36, and a sludge pump is provided at the sludge pump installation site 362. When in use, the automatic mud discharging valve 352 is opened, the mud pumping pump works, and mud at the bottom of the mud bucket 35 sequentially passes through the mud discharging pipe 351, the communicating pipe 36 and the connecting pipe 361 and then is discharged to the outside of the sedimentation tank body 31.

Referring to fig. 5 and 7, a first water outlet weir plate 37 is fixedly arranged on the inner wall of the top of the settling tank body 31, the first water outlet weir plate 37 is arranged around the inner wall of the settling tank body 31, a plurality of second water outlet weir plates 371 are arranged on the settling tank body 31, the second water outlet weir plates 371 are uniformly distributed along the length direction of the settling tank body 31, and the second water outlet weir plates 371 are arranged on two sides of the water inlet weir plate 33 and perpendicular to the water inlet weir plate 33. One end of the second water outlet weir plate 371 is fixedly connected to the side wall of the water inlet weir plate 33, and the other end of the second water outlet weir plate 371 is fixedly connected and communicated with the first water outlet weir plate 37. The height of the first water outlet weir plate 37 and the height of the second water outlet weir plate 371 are lower than that of the first water inlet weir plate 33. The wastewater entering the settling tank body 31 is layered in the settling tank body 31, so that sludge is settled at the bottom of the mud bucket 35, and the supernatant enters the first water outlet weir plate 37 and the second water outlet weir plate 371.

Referring to fig. 5 and 7, a water outlet pipe 372 is fixedly arranged on the side wall of the top of the sedimentation tank body 31, the water outlet pipe 372 is bent downwards, and the water outlet pipe 372 is arranged corresponding to the end part of the water inlet weir plate 33. The water outlet pipe 372 is communicated with the water outlet weir plate I37, and the supernatant enters the water outlet weir plate I37 or enters the water outlet weir plate II 371 first and then is collected into the water outlet weir plate I37, and then is discharged from the water outlet pipe 372.

Referring to fig. 7, a baffle 332 is fixedly arranged at the end of the water inlet weir plate 33 close to the water outlet pipe 372, the baffle 332 is vertically arranged, and the height of the baffle 332 is higher than that of the side wall of the water outlet weir plate one 37, so as to prevent the wastewater which is not precipitated in the water inlet weir plate 33 from being mixed with the wastewater which is precipitated in the water outlet weir plate one 37.

Referring to fig. 3 and 5, a base 38 is fixedly provided at the bottom of the settling tank body 31 to support the settling tank body 31. The top of the sedimentation tank body 31 is fixedly provided with a plurality of reinforcing rods 39, the reinforcing rods 39 are parallel to the second water outlet weir plate 371, two ends of each reinforcing rod 39 are fixedly connected with the inner wall of the sedimentation tank body 31 respectively and are uniformly distributed along the length direction of the water inlet weir plate 33 so as to strengthen the support of two side walls of the sedimentation tank body 31.

Referring to fig. 8 and 9, a mud pumping pipe 4 is horizontally arranged at the bottom of the mud bucket 35, a plurality of long mud inlet grooves 41 are formed in the side wall of the mud pumping pipe 4, and the mud inlet grooves 41 are uniformly distributed along the axial direction of the mud pumping pipe 4. The end of the mud discharging pipe 351 passes through the bottom wall of the mud bucket 35 and is fixedly connected and communicated with the side wall of the mud pumping pipe 4. When the sludge pump is operated, sludge enters the sludge suction pipe 4 along the sludge inlet groove 41 and is collected in the sludge discharge pipe 351 to discharge the sludge to the outside of the sludge hopper 35.

Referring to fig. 8, 10 and 11, the same cleaning device 5 is provided on both inclined side walls of the hopper 35, and the cleaning device 5 is used for cleaning the sludge on the inner wall of the hopper 35. The cleaning device 5 comprises a mounting bracket 51, the mounting bracket 51 being arranged parallel to the inclined side walls of the hopper 35. The scraper 52 is fixedly arranged on the side wall of the mounting frame 51, the scraper 52 is parallel to the side wall of the mud bucket 35, and one end, away from the mounting frame 51, of the scraper 52 is obliquely arranged and is abutted against the inner wall of the mud bucket 35. When the scraper is used, the mounting frame 51 drives the scraper 52 to move downwards along the inner wall of the mud bucket 35, and the end part of the scraper 52 scrapes down the mud on the inner wall of the mud bucket 35 in the moving process.

Referring to fig. 11, a high-pressure water pipe 6 is fixedly arranged on a side wall of the mounting frame 51 far away from the inner wall of the mud bucket 35, the high-pressure water pipe 6 is arranged in a rectangular shape in a surrounding mode, and the length direction of the high-pressure water pipe 6 is parallel to the mounting frame 51. The two wide upper parts of the high-pressure water pipe 6 are fixedly provided with end wall cleaning spray heads 61, the end wall cleaning spray heads 61 are communicated with the high-pressure water pipe 6, and the end wall cleaning spray heads 61 are uniformly distributed along the width direction of the high-pressure water pipe 6. When the mounting frame 51 scrapes mud downwards along the inner wall of the mud bucket 35, high-pressure water is sprayed out of the end wall cleaning spray nozzles 61 along the high-pressure water pipe 6, and the sprayed water is impacted on the two vertical end walls of the mud bucket 35, so that the mud falls off from the end walls, and not only can the end walls of the mud bucket 35 be cleaned, but also the treatment efficiency of the mud can be improved.

Referring to fig. 11, a plurality of scraper 52 cleaning nozzles are fixedly arranged in the length direction of the high-pressure water pipe 6, the scraper 52 cleaning nozzles are uniformly distributed along the length direction of the high-pressure water pipe 6, the scraper 52 cleaning nozzles are communicated with the high-pressure water pipe 6, and the opening direction of the scraper 52 cleaning nozzles faces the side wall of the scraper 52. When the mounting frame 51 scrapes mud downwards along the inner wall of the mud bucket 35, high-pressure water is sprayed out of the cleaning nozzle of the scraper 52 along the high-pressure water pipe 6, and the sprayed water impacts the side wall of the scraper 52 to wash up the mud on the scraper 52, so that the effects of scraping mud and cleaning the scraper 52 are realized. The sludge on the scraper 52 is conveniently cleaned so as to improve the working efficiency and the sludge scraping effect of the scraper 52.

Referring to fig. 11, 12 and 13, a plurality of sludge guide mechanisms 7 are fixedly provided on the mounting frame 51, and the sludge guide mechanisms 7 are uniformly provided along the length direction of the mounting frame 51. The sludge guide mechanism 7 includes a mounting bar 71, a water wheel 72, and a rotary vane 73. The mounting rods 71 are uniformly distributed along the length direction of the mounting frame 51, one ends of the mounting rods 71 are fixedly arranged on the side wall of the mounting frame 51, and the other ends of the mounting rods 71 extend in the direction close to the cleaning nozzle of the scraper 52 and are arranged above the high-pressure water pipe 6. The side wall of the water wheel 72 is fixedly arranged at one end, far away from the mounting frame 51, of the mounting rod 71, a rotating shaft 77 is rotationally connected to the middle of the water wheel 72, a blade mounting disc 74 is fixedly arranged at one end, far away from the water wheel 72, of the rotating shaft 77, and the blade mounting disc 74 and the water wheel 72 are coaxially arranged. The rotary blades 73 are arranged around the blade mounting plate 74, and the ends of the rotary blades 73 are fixedly connected to the side walls of the blade mounting plate 74.

Referring to fig. 13, a water supply pipe 75 is fixedly connected to the high-pressure water pipe 6 at a position corresponding to the mounting rod 71, and one end of the water supply pipe 75, which is far away from the high-pressure water pipe 6, passes through the bottom of the water wheel 72 and extends downward after passing out from the top of the water wheel 72. The same water drain pipeline 76 is arranged at one end of all the water supply pipelines 75 far away from the high-pressure water pipe 6, the end parts of the water supply pipelines 75 are inserted into the same water drain pipeline 76 and are communicated with the water drain pipeline 76, and openings at two ends of the water drain pipeline 76 are arranged.

When the sludge treatment device is used, high-pressure water enters the water supply pipeline 75 along the high-pressure water pipe 6 and drives the water wheel 72 to rotate, the water wheel 72 drives the rotary blades 73 to rotate around the rotary shaft 77 through the rotary shaft 77, the rotary blades 73 rotate downwards, the washed sludge is driven to the bottom of the sludge bucket 35, the sludge is conveniently collected to the bottom of the sludge bucket 35, and the sludge treatment efficiency is improved. High pressure water is discharged from the water discharge pipe 76 through the water wheel 72.

Referring to fig. 10 and 14, a synchronous driving mechanism 8 is provided on the hopper 35, and the synchronous driving mechanism 8 enables the two mounting frames 51 to move up and down synchronously along the inner wall of the hopper 35. The synchronous driving mechanism 8 comprises two screws 81, the axes of the two screws 81 are parallel to the inner wall of the mud bucket 35, two ends of each screw 81 are rotationally connected with the inner wall of the mud bucket 35, and the screws 81 are in threaded fit with the mounting frame 51. The end of the screw 81 near the bottom penetrates out of the bottom wall of the mud bucket 35 and is fixedly connected with a driven gear 82, a driving gear 83 is meshed between the two driven gears 82, a driving shaft 84 is fixedly connected in the middle of the driving gear 83, and the top end of the driving shaft 84 is rotationally connected with the bottom wall of the mud bucket 35. The bottom end of the driving shaft 84 rotates to be connected with a motor mounting seat 85, and one end, far away from the driving shaft 84, of the motor mounting seat 85 is fixedly connected to the bottom wall of the mud bucket 35. A driving motor 86 is fixedly arranged at the bottom of the motor mounting seat 85, and an output shaft of the driving motor 86 is fixedly connected with the end part of the driving shaft 84.

When the mud bucket 35 is in use, the output shaft of the driving motor 86 rotates to drive the driving shaft 84 to rotate, the driving shaft 84 drives the driving gear 83 to rotate, and the driving gear 83 drives the two driven gears 82 to synchronously rotate, so that the two screws 81 synchronously rotate to drive the mounting frame 51 on the screws 81 to move up and down along the inner wall of the mud bucket 35.

Referring to fig. 10, two guide rods 87 are provided corresponding to each mounting frame 51, which may be several, and only two guide rods are taken as an example here, the axes of the two guide rods 87 are parallel to the axis of the screw 81, two ends of the guide rod 87 are fixedly connected with the mud bucket 35, and the guide rod 87 is in sliding connection with the mounting frame 51. When the mounting frame 51 is driven by the screw 81 to move along the axial direction of the screw 81, the two ends of the mounting frame 51 slide along the axial line of the guide rod 87, so that the up-and-down movement process of the mounting frame 51 is more stable.

Referring to fig. 3, an overhaul platform 9 is fixedly arranged at a position of the sedimentation tank body 31 close to the top, and the overhaul platform 9 is arranged around the outer side wall of the sedimentation tank body 31. The maintenance platform 9 is convenient for the operating personnel to examine and repair the sedimentation tank body 31 and monitor the working process that takes place in it. A plurality of sight glass 91 have been set firmly on the deposit groove body 31 lateral wall, and sight glass 91 is circular, and sight glass 91 is along the length direction evenly distributed of deposit groove body 31, and the sight glass 91 is convenient for the staff grasp the behavior in the mud bucket 35 through sight glass 91.

The embodiment of the inclined tube sedimentation tank 3 is as follows:

first, wastewater enters from the water inlet end 321 of the bachelter tank 32 and flows into the settling tank body 31 from the water outlet end 322. The bachel tank 32 detects the flow rate of the wastewater flowing to the settling tank body 31 and guides the wastewater into the settling tank body 31. After the wastewater flows into the water inlet weir plate 33 from the bachelter tank 32, the wastewater moves towards the two ends of the water inlet weir plate 33 along the length direction of the water inlet weir plate 33, and enters the sedimentation tank body 31 along the water inlet pipe 331 in the moving process. The waste water is layered in the settling tank body 31, and the sludge thereof enters the sludge hopper 35, enters the sludge pumping pipeline 4 along the sludge inlet groove 41 under the action of the sludge pumping pump, and then sequentially passes through the sludge discharge pipe 351, the communicating pipe 36 and the connecting pipe 361, and is discharged to the outside of the settling tank body 31. The supernatant enters the first water outlet weir plate 37 or enters the second water outlet weir plate 371, and is discharged from the water outlet pipe 372 after being collected into the first water outlet weir plate 37.

In this process, the output shaft of the driving motor 86 rotates to drive the driving shaft 84 to rotate, the driving shaft 84 drives the driving gear 83 to rotate, and the driving gear 83 drives the two driven gears 82 to synchronously rotate, so that the two screws 81 synchronously rotate to drive the mounting frame 51 on the screws 81 to move up and down along the inner wall of the mud bucket 35.

The mounting frame 51 drives the scraper 52 to move downwards along the inner wall of the mud bucket 35, and the end part of the scraper 52 scrapes down the mud on the inner wall of the mud bucket 35 in the moving process.

When the mounting frame 51 scrapes mud downwards along the inner wall of the mud bucket 35, high-pressure water is sprayed out of the cleaning nozzle of the scraper 52 along the high-pressure water pipe 6, and the sprayed water impacts the side wall of the scraper 52 to wash up the mud on the scraper 52, so that the effects of scraping mud and cleaning the scraper 52 are realized. The sludge on the scraper 52 is conveniently cleaned so as to improve the working efficiency and the sludge scraping effect of the scraper 52.

Meanwhile, high-pressure water enters the water supply pipeline 75 along the high-pressure water pipe 6 and drives the water wheel 72 to rotate, the water wheel 72 drives the rotary blades 73 to rotate around the rotary shaft 77 through the rotary shaft 77, the rotary blades 73 rotate downwards, the washed sludge is driven to the bottom of the sludge bucket 35, sludge is conveniently collected to the bottom of the sludge bucket 35, and the sludge treatment efficiency is improved. High pressure water is discharged from the water discharge pipe 76 through the water wheel 72.

When the mounting frame 51 scrapes mud downwards along the inner wall of the mud bucket 35, high-pressure water is sprayed out of the end wall cleaning spray nozzles 61 along the high-pressure water pipe 6, and the sprayed water is impacted on the two vertical end walls of the mud bucket 35, so that the mud falls off from the end walls, and not only can the end walls of the mud bucket 35 be cleaned, but also the treatment efficiency of the mud can be improved.

The pollutant factors of various pretreated waste water are reduced to a great extent, but the waste water also contains partial ammonia nitrogen, organic matters and other substances, and simultaneously contains trace heavy metal ions, so that the emission standard cannot be met. Further advanced treatment is needed to be discharged. The chromium-containing wastewater advanced treatment process comprises the steps S5-S8.

S5: pulse electric flocculation treatment

The pretreated wastewater containing chromium, nickel, lead, copper, cyanogen and silver is discharged into intermediate water I, and after reaching a certain liquid level, a lifting pump is started to lift the wastewater into an electric flocculation device 21. In this stage, organic matters in the wastewater are oxidized, ammonia nitrogen is degraded and simultaneously a part of heavy metals are coagulated under the action of current between polar plates, and the electric flocculation device 21 is provided with an automatic pole changing system and automatically changes direction according to the sewage characteristics for 60-120 minutes. The sludge discharge motor valve automatically discharges a sludge portion to the sludge land 12 every time the pole is changed. The bottom is provided with automatic microporous aeration, and the electrode plate can be flushed in an aeration state when the electrode is replaced each time.

S6: air floatation integrated treatment

The electrolyzed wastewater enters an air floatation integrated tank 22, and under the double functions of precipitation and dissolved air floatation, the clarified liquid is discharged into a circulating oxidation tank 23, and the sludge is discharged into a sludge tank.

S7: cyclic oxidation treatment

Sodium hypochlorite and ozone are quantitatively added into the circulating oxidation tank 23, and circulating treatment is carried out for 30-40min through a circulating water pump, so that ammonia nitrogen and organic matters in the wastewater are further reduced. The ozone generator with the concentration of 500g/h is used, and the produced water ozone enters the circulating oxidation tank 23 for dissolved gas oxidation. The flow of the circulating water pump is 2 times of the normal treatment capacity water quantity.

In the scheme, the front section adopts the electric flocculation process to remove the wastewater, ammonia nitrogen in the wastewater is removed, and the rest ammonia nitrogen is removed by adding sodium hypochlorite in the system. The reaction equation is as follows: 2nh3+3naclo→n2 ++3h2o+3nacl.

S8: quartz sand and activated carbon purification treatment

The wastewater after the cyclic oxidation firstly enters the intermediate water tank II 24 and then sequentially passes through the quartz sand filter 25 and the activated carbon filter 26, so that the wastewater is discharged into the buffer water tank 27 to be discharged after being filtered by quartz sand and adsorbed by activated carbon.

Wherein, the quartz sand filter 25 is used for filtering out impurities such as fine particles, suspended matters, colloid and the like in raw water, the main filter layer is natural quartz sand with the thickness of 0.5-1.2 mm, the supporting layer is natural quartz sand with the thickness of 2-3 mm, and the filtering speed is 12 m/h. When the filter is used for a period of time, the pressure difference between the inlet and the outlet increases, and the filter should be backwashed at the moment, so in the system, a backwashed pump is arranged in a buffer water tank 27, and the filter is backwashed by adopting high flow rate and large water quantity, and is usually cleaned for 5-10 minutes.

The main function of the activated carbon filter 26 is to use the efficient adsorption capacity of the special shell activated carbon to remove residual chlorine in water and to adsorb organic matters, oils, surfactants and the like in water. The activated carbon tank also needs to be backwashed regularly, so that special requirements are made on the hardness of the activated carbon, namely, the activated carbon with the shell is adopted, and the iodine adsorption value is more than 900 mg/g.

The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims

1. A chromium-containing industrial wastewater treatment process is characterized in that:

s1, collecting chromium-containing wastewater: collecting wastewater generated in a production workshop into a chromium-containing wastewater regulating tank (1), regulating the homogenizing average amount of the wastewater by using an air stirring device, and then lifting the wastewater into a chromium-containing wastewater reaction tank (11);

s2, chemical reduction treatment: the pH value of the wastewater is regulated to 2-3 by automatically controlling the adding amount of acid through a pH automatic control system, and meanwhile, the adding amount of a reducing agent is controlled through an ORP automatic control system, so that the ORP value of the wastewater is between 230 and 320mv, and the reaction time is about 15-25min;

s3, flocculation reaction: automatically controlling the addition amount of alkali by a PH automatic control system, adjusting the PH value of the wastewater to 7.5-8.5, simultaneously controlling a dosing pump by a PLC, quantitatively adding PAC and PAM into a chromium-containing wastewater reaction tank (11) by the dosing pump, and performing flocculation reaction;

s4, precipitation and split flow: delivering the wastewater subjected to flocculation reaction from the chromium-containing wastewater reaction tank (11) to the inclined tube precipitation tank (3) for precipitation, continuously carrying out subsequent treatment on supernatant fluid, and discharging sludge into a chromium sludge tank for treatment according to dangerous waste;

s5, pulse electric flocculation treatment: oxidizing organic matters in the wastewater, degrading ammonia nitrogen and coagulating a part of heavy metals through the action of current between polar plates;

s6, air floatation integrated treatment: the electrolyzed wastewater enters an air floatation integrated tank (22), and under the double functions of precipitation and dissolved air floatation, clarified liquid is discharged into a circulating oxidation tank (23), and sludge is discharged into a sludge tank;

s7, cyclic oxidation treatment: sodium hypochlorite and ozone are quantitatively added into the circulating oxidation tank (23), and circulating treatment is carried out for 30-40min through a circulating water pump, so that ammonia nitrogen and organic matters in the wastewater are further reduced;

s8, purifying quartz sand and activated carbon: the wastewater after the cyclic oxidation passes through a quartz sand filter (25) and an activated carbon filter (26), so that the wastewater is filtered by quartz sand and adsorbed by activated carbon and then is discharged into a buffer water tank (27) to be in a state of waiting to be discharged;

wherein the inclined tube sedimentation tank (3) used in the S4 comprises a sedimentation tank body (31), a plurality of mud hoppers (35) are arranged at the bottom of the sedimentation tank body (31),

the two inclined side walls of the mud bucket (35) are respectively provided with the same cleaning device (5), the cleaning devices (5) are used for cleaning mud on the inner wall of the mud bucket (35), each cleaning device (5) comprises a mounting frame (51), each mounting frame (51) is parallel to the inclined side wall of the mud bucket (35), each mounting frame (51) is fixedly provided with a scraper (52), each scraper (52) is parallel to the side wall of the mud bucket (35), and one end of each scraper (52) away from each mounting frame (51) is inclined and is abutted against the inner wall of the mud bucket (35);

the side wall of the mounting frame (51) far away from the inner wall of the mud bucket (35) is fixedly provided with a high-pressure water pipe (6), the high-pressure water pipe (6) is fixedly provided with an end wall cleaning spray head (61), and the end wall cleaning spray head (61) is communicated with the high-pressure water pipe (6);

a plurality of scraper cleaning spray heads (62) are fixedly arranged in the length direction of the high-pressure water pipe (6), and the scraper cleaning spray heads (62) are communicated with the high-pressure water pipe (6);

a plurality of silt guiding mechanisms (7) are fixedly arranged on the mounting frame (51), the silt guiding mechanisms (7) are uniformly arranged along the length direction of the mounting frame (51), each silt guiding mechanism (7) comprises a mounting rod (71), a water wheel (72) and rotating blades (73), the mounting rods (71) are uniformly distributed along the length direction of the mounting frame (51), one ends of the mounting rods (71) are fixedly arranged on the side wall of the mounting frame (51), the other ends of the mounting rods (71) extend towards the direction close to the scraper cleaning spray heads (62) and are arranged above the high-pressure water pipes (6), the side wall of the water wheel (72) is fixedly arranged at one end, far away from the mounting frame (51), of the mounting rod (71), a rotating shaft (77) is rotationally connected with the middle part of the water wheel (72), one end, far away from the water wheel (72), of the rotating shaft (77) is fixedly provided with a blade mounting disc (74), the blade mounting disc (74) is coaxially arranged with the water wheel (72), the rotating blades (73) are fixedly arranged around the blade mounting disc (74), and the end parts of the rotating blades (73) are fixedly connected on the side wall of the blade mounting disc (74).

The position of the high-pressure water pipe (6) corresponding to the mounting rod (71) is fixedly connected with a water supply pipeline (75), high-pressure water enters the water supply pipeline (75) along the high-pressure water pipe (6) and drives the water wheel (72) to rotate, the water wheel (72) drives the rotary blades (73) to rotate around the rotary shaft (77) through the rotary shaft (77), and the rotary blades (73) rotate downwards to drive the washed sludge to the bottom of the sludge hopper (35), so that the sludge is conveniently collected to the bottom of the sludge hopper (35);

the mud bucket (35) is provided with a synchronous driving mechanism (8) which is used for synchronously driving the two scrapers (52) to move along the inner wall of the mud bucket (35).

2. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

the synchronous driving mechanism (8) comprises two screws (81), the axis of each screw (81) is parallel to the side wall of the mud bucket (35), the screws (81) are in rotary connection with the mud bucket (35), the screws (81) are in threaded fit with the scraper (52), and driven gears (82) are fixedly arranged on the screws (81);

the driving gear (83), the driving gear (83) is in rotary connection with the mud bucket (35), and the driving gear (83) is meshed with the two driven gears (82);

the driving motor (86), the driving motor (86) is fixedly connected with the mud bucket (35), and the output shaft of the driving motor (86) is fixedly connected with the driving gear (83).

3. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

the scraper (52) is connected with a guide rod (87) in a sliding manner, the axis of the guide rod (87) is parallel to the axis of the screw rod (81), and the guide rod (87) is fixedly connected to the mud bucket (35).

4. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

the top of the sedimentation tank body (31) is fixedly provided with a Buchell tank (32).

5. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

an aeration pipe is arranged at the bottom of the chromium-containing wastewater regulating tank (1).

6. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

the chromium-containing wastewater reaction tank (11) is provided with an unqualified reflux valve and an unqualified reflux pipe;

the reaction process in the chromium-containing reaction tank is controlled in a closed loop manner by a Programmable Logic Controller (PLC), a PH meter, an ORP meter and an administration pump.

7. The chromium-containing industrial wastewater treatment process according to claim 1, wherein:

and an ethylene-propylene copolymer honeycomb inclined tube is fixedly arranged at the upper part of the precipitation tank body (31).