A system for treating alkaline wastewater

Abstract

The application relates to the field of wastewater treatment, in particular to an alkaline wastewater treatment system, which comprises: a coagulant adding mechanism arranged on a coagulation tank a, the coagulant adding mechanism being used for mixing coagulant powder and water to proportionally configure the coagulant, a spiral water pipe being arranged on the coagulant adding mechanism, sewage in a sewage collecting tank and the coagulant being pumped into the top of the spiral water pipe to continuously flow and mix, the coagulant adding mechanism being arranged in two groups, and the other group being arranged on a coagulation tank b; and reflux metering pumps arranged on the coagulation tank a and the coagulation tank b, the two reflux metering pumps being communicated with reflux pipes, and the refluxed filter liquor being quantitatively pumped into the coagulation tank a and the coagulation tank b. The application can fully mix the coagulant and the sewage, does not need to arrange large stirring equipment, greatly reduces energy, and additionally, through the arrangement of a precise calculation formula, the filter liquor can be supplemented as the coagulant to the coagulation tank a and the coagulation tank b according to the formula calculation in real time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, and particularly relates to an alkaline wastewater treatment system. BACKGROUND

[0002] Paint spraying wastewater is alkaline wastewater, and a large amount of paint particles are contained in the wastewater, and the water quality is determined by the used paint, solvent and additive. The core of the commonly used paint spraying wastewater treatment method is to add coagulant A and coagulant B for coagulation and sedimentation, and then mud-water separation is performed to complete the treatment process.

[0003] A resource treatment system for alkaline wastewater is disclosed in Chinese Patent No. CN212151865U, which comprises an alkaline wastewater collection tank for collecting alkaline wastewater, a dosing device for adding flocculant to form flocculation with the alkaline wastewater, a first solid-liquid separation system connected with the alkaline wastewater collection tank for solid-liquid separation of the flocculation, a solid acidification system connected with the first solid-liquid separation system, the solid formed by the solid-liquid separation of the first solid-liquid separation system enters the solid acidification system, the solid acidification system has an acid adding device for adding acid to partially dissolve the solid, and a second solid-liquid separation system connected with the solid acidification system. The utility model can greatly improve the recovered TA quality, reduce the amount of flocculant and reduce the generation of solid waste sludge.

[0004] However, the above-mentioned disclosed scheme has the following disadvantages: although it is mentioned that the filtrate after solid-liquid separation is returned to the front section as a coagulant to save the use amount of the coagulant, but the specific use method and means are lacking, and in the actual process, the filtrate after solid-liquid separation has no suitable means to be added to the coagulation tank, which will seriously interfere with the coagulation effect of the coagulation tank and reduce the stability of the wastewater treatment system. In addition, the existing technology adds a stirring device in the coagulation tank, which greatly increases the energy consumption. SUMMARY

[0005] The present application aims to solve the problems of the background art, i.e. the coagulation tank is provided with a stirring device to increase the energy consumption, and the filtrate after solid-liquid separation is returned as a coagulant to easily cause instability of the whole system, and proposes an alkaline wastewater treatment system.

[0006] The technical scheme of the present application is an alkaline wastewater treatment system, which comprises a wastewater collection tank, a coagulation tank a, a coagulation tank b, a sedimentation tank and a mud-water separation device arranged in sequence in the direction of wastewater flow, the mud-water separation device comprising a sludge pump for pumping sludge from the sedimentation tank, a plate-and-frame filter press for filtering the sludge, and a water pump and a return pipe for conveying the filtered liquid from the plate-and-frame filter press to the wastewater collection tank; and further comprising:

[0007] The coagulant adding mechanism is arranged on the coagulation tank a, and is used to mix coagulant powder and water to prepare coagulant in proportion. The mixing power is derived from the impact force of the liquid reflux in the reflux pipe. A spiral water pipe is arranged on the coagulant adding mechanism. The sewage in the sewage collecting tank and the coagulant are pumped into the top of the spiral water pipe to continuously flow and mix. Two sets of coagulant adding mechanisms are arranged, and the other set is arranged on the coagulation tank b.

[0008] The reflux metering pump is arranged on the coagulation tank a and the coagulation tank b through a mounting frame. The two reflux metering pumps are both communicated with the reflux pipe. The filtered liquid is quantitatively pumped into the coagulation tank a and the coagulation tank b according to calculation.

[0009] Preferably, the coagulant adding mechanism comprises a mixing assembly and a power assembly. The mixing assembly is used to mix coagulant powder and water in proportion. The power assembly is used to drive the mixing assembly to work.

[0010] Preferably, the mixing assembly comprises a barrel arranged on the coagulation tank a, a partition plate a and a partition plate b arranged in the barrel in parallel, a rotating shaft arranged at the bottom of the barrel and penetrating through the partition plate a, a spiral stirring blade arranged on the rotating shaft, and a coagulant metering pump arranged on the partition plate b and used to pump the liquid coagulant below into the spiral water pipe. A quantitative dosing pipe is arranged on the barrel and penetrates through the partition plate b from above. The quantitative dosing pipe penetrates through the peripheral wall of the barrel and extends into the barrel.

[0011] Preferably, the power assembly comprises a rotating rod arranged on the barrel, a driving fan blade and a driving bevel gear arranged at two ends of the rotating rod, and a driven bevel gear arranged on the rotating shaft. The driven bevel gear is engaged with the driving bevel gear. The rotating rod is inserted into the reflux pipe, and the driving fan blade is driven to rotate by the filtered liquid flowing in the reflux pipe.

[0012] Preferably, the rotating speed of the driven bevel gear is lower than that of the driving bevel gear.

[0013] Preferably, a coagulant concentration detection device is arranged at the position where the sewage in the coagulation tank a flows to the coagulation tank b. A coagulant concentration detection device is arranged at the position where the sewage in the coagulation tank b flows to the sedimentation tank. A coagulant concentration monitoring device is arranged on the reflux pipe to detect the coagulant concentration in the filtered liquid.

[0014] Preferably, the calculation method of the amount of the filtered liquid returned to the coagulation tank a is as follows: the set parameters include the amount V h of the filtered liquid returned to the coagulation tank a, the set value C m of the coagulant concentration at the position where the sewage in the coagulation tank a flows to the coagulation tank b, the current value C d of the coagulant concentration at the position where the sewage in the coagulation tank a flows to the coagulation tank b, the coagulant concentration C h in the filtered liquid, and the water amount V y, the calculation formula is:

[0015]

[0016] Preferably, the calculation method of the amount of backfilling filter liquor to the coagulation tank b is: the set parameters include the amount V of backfilling filter liquor to the coagulation tank b h , the coagulant concentration set value C at the position where the sewage in the coagulation tank b flows to the sedimentation tank m , the coagulant concentration current value C at the position where the sewage in the coagulation tank b flows to the sedimentation tank d , the coagulant concentration in the filter liquor is C h , the water amount V in the coagulation tank b y , the calculation formula is:

[0017]

[0018] Compared with the prior art, the present application has the following beneficial technical effects: after the sewage enters the top of the spiral water pipe and is mixed with the coagulant which is quantitatively and continuously put, the sewage is discharged into the coagulation tank a and the coagulation tank b after flowing in the spiral water pipe, so that the coagulant and the sewage can be fully mixed, without the need to set a large stirring device, thereby greatly reducing the energy consumption, in addition, by setting the precise calculation formula, the backfilling filter liquor can be backfilled as the coagulant to the coagulation tank a and the coagulation tank b according to the formula calculation in real time, so as to maintain the stability of the system and ensure the coagulation effect, and also to reduce the consumption amount of the coagulant. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 and Figure 2 are perspective views of one embodiment of the present application;

[0020] Figure 3 is a partial structure schematic view of Figure 1 ;

[0021] Figure 4 is an internal schematic view of the coagulation tank a;

[0022] Figure 5 is a sectional view of Figure 4 .

[0023] Reference numerals in the attached diagram: 1. Wastewater collection tank; 2. Coagulation tank a; 3. Coagulation tank b; 4. Sedimentation tank; 5. Sludge-water separation device; 6. Return pipe; 7. Water pump; 8. Mounting base; 9. Tank body; 10. Spiral water pipe; 11. Inlet pipe; 12. Baffle a; 13. Baffle b; 14. Rotating shaft; 15. Spiral agitator blade; 16. Coagulant metering pump; 17. Quantitative dosing pipe; 18. Quantitative water dosing pipe; 19. Level gauge; 20. Water guide pipe a; 21. Driven bevel gear; 22. Rotating rod; 23. Actuating fan blade; 24. Driving bevel gear; 25. Water guide pipe b; 26. Final discharge pipe; 27. Mounting frame; 28. Return metering pump. Detailed Implementation

[0024] Example 1

[0025] like Figures 1-3 As shown, the present invention proposes an alkaline wastewater treatment system, comprising a wastewater collection tank 1, a coagulation tank a2, a coagulation tank b3, a sedimentation tank 4, and a sludge-water separation device 5 arranged sequentially in the wastewater flow direction. The coagulation tank b3 and the sedimentation tank 4 are connected by a top-mounted water guide pipe b25. A final discharge pipe 26 is installed at the top of the sedimentation tank 4. Coagulant A is added to the coagulation tank a2, and coagulant B is added to the coagulation tank b3. In this embodiment, coagulant A is PAC (polyaluminum chloride), and coagulant B is PAM (polyacrylonitrile aluminum chloride), an organic polymer used as a coagulant aid. The sludge-water separation device 5 includes a sludge pump to extract sludge from the sedimentation tank 4, a plate and frame filter press to filter the sludge, and the filtrate after treatment by the plate and frame filter press is transported to the wastewater collection tank 1 via a water pump and a return pipe 6. The system also includes:

[0026] A coagulant addition mechanism is installed on the coagulation tank a2. The coagulant addition mechanism is used to mix coagulant powder and water to prepare coagulant in proportion. The power source for mixing is the liquid backflow impact force in the return pipe 6. A spiral water pipe 10 is installed on the coagulant addition mechanism. Sewage and coagulant in the sewage collection tank 1 are pumped into the top of the spiral water pipe 10 for continuous flow and mixing. Specifically, a water pump 7 is installed on the sewage collection tank 1. The water pump 7 pumps sewage into the spiral water pipe 10 through the inlet pipe 11. Two sets of coagulant addition mechanisms are set. The other set is installed on the coagulation tank b3. The two sets of coagulant addition mechanisms add coagulant A and coagulant B to the sewage respectively. The top of the coagulation tank a2 is connected to the top of the next spiral water pipe 10 through the guide pipe a20. In order to save energy, the height of the coagulation tank b3 is lower than that of the coagulation tank a2. Sewage flows into the spiral water pipe 10 from the guide pipe a20 by gravity.

[0027] And backflow metering pump 28, through the mounting bracket 27 is arranged in the coagulation tank a2 and coagulation tank b3, two backflow metering pump 28 are all communicated backflow pipe 6, according to the calculation will backflow filter liquid quantitative pump into coagulation tank a2 and coagulation tank b3, thereby reducing the consumption of coagulant.

[0028] Example two

[0029] As Figure 1 、 Figure 4 and Figure 5 The application proposes a kind of basic wastewater treatment system, compared with example one, the structure of coagulant adding mechanism is introduced in detail in this embodiment.

[0030] Coagulant adding mechanism includes mixing assembly and power component, mixing assembly is used to mix coagulant powder and water according to proportion, and power component is used to drive mixing assembly to work.

[0031] Mixing assembly includes barrel 9 being arranged in coagulation tank a2 by mounting seat 8, baffle a12 and baffle b13 being arranged in barrel 9 in parallel, rotating shaft 14 being rotatably arranged in the bottom of barrel 9 and passing through baffle a12, spiral stirring blade 15 being arranged on rotating shaft 14, and coagulant metering pump 16 being arranged on baffle b13 to pump liquid coagulant in the lower into spiral water pipe 10, and the conveying amount of coagulant and the pumping amount of sewage form a set proportion;Quantitative dosing pipe 17 and quantitative water adding pipe 18 are arranged on barrel 9, quantitative dosing pipe 17 passes through baffle b13 from above, quantitative dosing pipe 17 penetrates into barrel 9 through the peripheral wall of barrel 9, quantitative dosing pipe 17 is communicated with external quantitative dosing equipment, quantitative water adding pipe 18 is communicated with quantitative water adding equipment, coagulant powder and water are mixed between baffle a12 and baffle b13 to be configured into liquid coagulant, and then pumped into spiral water pipe 10 by coagulant metering pump 16, in order to ensure that the input end of coagulant metering pump 16 can smoothly draw coagulant, liquid level meter 19 is arranged on baffle b13, liquid level meter 19 detects the liquid level below baffle b13, ensures the liquid level height, and when the liquid level is too low, timely dosing and water adding are carried out through quantitative dosing pipe 17 and quantitative water adding pipe 18.

[0032] Power component includes rotating rod 22 being rotatably arranged on barrel 9, driving fan blade 23 and driving bevel gear 24 being arranged at both ends of rotating rod 22, and driven bevel gear 21 being arranged on rotating shaft 14, driven bevel gear 21 and driving bevel gear 24 are engaged, rotating rod 22 is inserted into backflow pipe 6, and driving fan blade 23 is driven to rotate by the filter liquid flowing in backflow pipe 6.The rotating speed of driven bevel gear 21 is lower than that of driving bevel gear 24, so that the speed reduction rotation is completed, and the rotating speed of spiral stirring blade 15 is prevented from being too high to damage the composition of coagulant.

[0033] Example three

[0034] AsFigure 1 Compared with the first embodiment or the second embodiment, the present embodiment introduces in detail how the filter pressing liquid is supplemented into the coagulation tank a2 and the coagulation tank b3.

[0035] The coagulant concentration detection device is arranged at the position where the sewage in the coagulation tank a2 flows to the coagulation tank b3, i.e. the end of the coagulation reaction, and the coagulant concentration detection device is arranged at the position where the sewage in the coagulation tank b3 flows to the sedimentation tank 4, i.e. the end of the coagulation reaction, and the coagulant concentration monitoring device in the filter pressing liquid is arranged on the reflux pipe 6.

[0036] The calculation method of the amount of filter pressing liquid supplemented into the coagulation tank a2 is as follows: the set parameters include the amount V of filter pressing liquid supplemented into the coagulation tank a2, h the set value C of the coagulant concentration at the position where the sewage in the coagulation tank a2 flows to the coagulation tank b3, m the current value C of the coagulant concentration at the position where the sewage in the coagulation tank a2 flows to the coagulation tank b3, d the coagulant concentration in the filter pressing liquid, specifically the coagulant A concentration C, h the water volume V in the coagulation tank a2, y and the calculation formula is:

[0037]

[0038] The calculation method of the amount of filter pressing liquid supplemented into the coagulation tank b3 is as follows: the set parameters include the amount V of filter pressing liquid supplemented into the coagulation tank b3, h the set value C of the coagulant concentration at the position where the sewage in the coagulation tank b3 flows to the sedimentation tank 4, m the current value C of the coagulant concentration at the position where the sewage in the coagulation tank b3 flows to the sedimentation tank 4, d the coagulant concentration in the filter pressing liquid, specifically the coagulant B concentration C, h the water volume V in the coagulation tank b3, y and the calculation formula is:

[0039]

[0040] The formula is illustrated as follows:

[0041] The coagulant concentration is set to be 10 mg / L.

[0042] The current coagulant concentration in the coagulation tank is 9 mg / L.

[0043] The coagulant concentration in the filter pressing liquid is 20 mg / L.

[0044] The sewage volume in the coagulation tank a2 and the coagulation tank b3 is 1000 L.

[0045] These values are substituted into the formula:

[0046] That is, when the coagulant is put in the set amount, the coagulant content in the wastewater at the end of the coagulation reaction does not reach the set value, at this time, it indicates that the coagulant content is lacking, by supplementing the filter press filtrate to the corresponding coagulation tank for use as a coagulant, thereby reducing the consumption of coagulant, and the coagulant and water ratio does not need to be adjusted in real time, but the filter press filtrate is used to correct the coagulation reaction.

[0047] Example four

[0048] Compared with example one or example two or example three, the embodiment details the control system.

[0049] The control system is in data transmission connection with each coagulant concentration detection device and the liquid level meter 19, and the control system is in control connection with the water pump 7, the coagulant metering pump 16 and the backflow metering pump 28.

[0050] In summary, when the wastewater enters the top of the spiral water pipe 10 and mixes with the coagulant put in quantitatively and continuously, and then flows into the coagulation tank a2 and the coagulation tank b3, the coagulant and the wastewater can be fully mixed, without the need to set large stirring equipment, greatly reducing the energy consumption, in addition, by setting the accurate calculation formula, the filter press filtrate can be supplemented as a coagulant to the coagulation tank a2 and the coagulation tank b3 according to the formula calculation in real time, maintaining the stability of the system and ensuring the coagulation effect, and also reducing the consumption of coagulant.

[0051] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited thereto, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. An alkaline wastewater treatment system comprising, in the direction of flow of wastewater, a wastewater collection tank (1), a coagulation tank a (2), a coagulation tank b (3), a sedimentation tank (4), and a sludge-water separation device (5) in this order, the sludge-water separation device (5) comprising a sludge pump for pumping sludge from the sedimentation tank (4), a plate-and-frame filter press for filtering the sludge, and a water pump and a return pipe (6) for delivering the filtrate from the plate-and-frame filter press to the wastewater collection tank (1), characterized in that, Also included are: A coagulant adding mechanism is arranged on the coagulation tank a (2), which is used to mix coagulant powder and water to be proportioned into coagulant, and the power source of the mixing is the liquid backflow impact force in the backflow pipe (6). A spiral water pipe (10) is arranged on the coagulant adding mechanism. The sewage in the sewage collection tank (1) and the coagulant are pumped into the top of the spiral water pipe (10) for continuous flow mixing. Two sets of coagulant adding mechanisms are arranged, and the other set is arranged on the coagulation tank b (3). The sewage in the coagulation tank a (2) and the coagulant are pumped into the top of the spiral water pipe (10) on the coagulation tank b (3); And a backflow metering pump (28) is arranged on the coagulation tank a (2) and the coagulation tank b (3) through a mounting bracket (27). Both backflow metering pumps (28) are connected to the backflow pipe (6). According to the calculated amount of backflow filtrate, the backflow filtrate is quantitatively pumped into the coagulation tank a (2) and the coagulation tank b (3). Method for calculating the amount of backfeed of press filtrate into coagulation tank a (2): Set parameters include the amount V of backfeed of press filtrate into coagulation tank a (2) h , the set value C of coagulant concentration at the position where the wastewater flowing on coagulation tank a (2) flows to coagulation tank b (3) m , the current value C of coagulant concentration at the position where the wastewater flowing on coagulation tank a (2) flows to coagulation tank b (3) d , the coagulant concentration C in press filtrate h , the amount V of water in coagulation tank a (2) y , and the calculation formula is: Method for calculating the amount of back-feeding of the press filtrate into the coagulation tank b (3): the set parameters include the amount V' of back-feeding of the press filtrate into the coagulation tank b (3) h , the set value C' of the coagulant concentration at the position where the wastewater flows from the coagulation tank b (3) to the sedimentation tank (4) m , the current value C' of the coagulant concentration at the position where the wastewater flows from the coagulation tank b (3) to the sedimentation tank (4) d , the coagulant concentration in the press filtrate is C' h , the amount V' of water in the coagulation tank b (3) y , and the calculation formula is:

2. The alkaline wastewater treatment system of claim 1, wherein The coagulant adding mechanism includes a mixing assembly and a power assembly. The mixing assembly is used to mix coagulant powder and water in proportion. The power assembly is used to drive the mixing assembly to work.

3. The alkaline wastewater treatment system of claim 2, wherein The mixing assembly includes a barrel (9) arranged on the coagulation tank, a partition plate a (12) and a partition plate b (13) arranged side by side in the barrel (9), a rotating shaft (14) rotatably arranged at the bottom of the barrel (9) and penetrating through the partition plate a (12), a spiral stirring blade (15) arranged on the rotating shaft (14), and a coagulant metering pump (16) arranged on the partition plate b (13) to pump the liquid coagulant below into the spiral water pipe (10). The barrel (9) is provided with a quantitative dosing pipe (17) and a quantitative water adding pipe (18). The quantitative dosing pipe (17) penetrates through the partition plate b (13) from above. The quantitative dosing pipe (17) penetrates through the peripheral wall of the barrel (9) and extends into the barrel (9).

4. The alkaline wastewater treatment system of claim 3, wherein The power assembly includes a rotating rod (22) rotatably arranged on the barrel (9), a driving fan blade (23) and a driving bevel gear (24) arranged at both ends of the rotating rod (22) respectively, and a driven bevel gear (21) arranged on the rotating shaft (14). The driven bevel gear (21) and the driving bevel gear (24) are engaged. The rotating rod (22) is inserted into the backflow pipe (6) and driven by the rotating driving fan blade (23) by the flow of the backflow filtrate in the backflow pipe (6).

5. The alkaline wastewater treatment system of claim 4, wherein The rotation speed of the driven bevel gear (21) is lower than that of the driving bevel gear (24).

6. The alkaline wastewater treatment system of claim 1, wherein Coagulant concentration detection equipment is arranged at the position where the sewage in the coagulation tank a (2) flows to the coagulation tank b (3). Coagulant concentration detection equipment is arranged at the position where the sewage in the coagulation tank b (3) flows to the sedimentation tank (4). Coagulant concentration monitoring equipment is arranged on the backflow pipe (6) to detect the coagulant concentration in the backflow filtrate.

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