Desulfurization wastewater treatment system

Abstract

The utility model discloses a desulfurization waste water treatment system, including collecting tank, clarification tank, triple box, sludge dryer, filter and SCNF nanofiltration device, SCNF nanofiltration device has water inlet, water outlet and concentrated water outlet, collecting tank has water inlet, collecting tank is communicated with clarification tank, clarification tank upper end has overflow port, clarification tank lower end has first bottom discharge port, the bottom discharge port has second bottom discharge port. The triple box is provided with a first reaction box, a second reaction box and a clear water box which are sequentially communicated, the first reaction box is provided with a second bottom discharge port, the second reaction box is provided with a third bottom discharge port, the first reaction box is communicated with the overflow port of the clarification tank, and the first bottom discharge port, the second bottom discharge port and the third bottom discharge port are all communicated with the sludge dryer; the clear water tank is communicated with the water inlet of the SCNF nanofiltration device, a filter is arranged between the clear water tank and the water inlet of the SCNF nanofiltration device, the concentrated water outlet of the SCNF nanofiltration device is communicated with the collection tank and the clarification tank, the structure is simple, and the desulfurization wastewater treatment efficiency is high.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the desulfurization wastewater treatment technical field especially relates to a kind of desulfurization wastewater treatment systems. BACKGROUND

[0002] Coal power plant desulfurization wastewater is the main source of end wastewater, with high salt, high hardness, complex composition, high suspended solids and other characteristics, especially some areas desulfurization tower using main raw material limestone due to the characteristics of mineral source, dolomite composition proportion is too high, wet desulfurization agent limestone quality is low, cause a large amount of magnesium ion is introduced into slurry desulfurization wastewater, so that end wastewater shows the typical water quality characteristics of "high magnesium, low calcium, high sulfate radical".In addition, market fuel power coal coal quality changes, thermal power unit depth peak shaving boiler combustion condition fluctuation, upstream desulfurization slurry running process and other dynamic factors, end wastewater quality deteriorates more and more fluctuation, bring great challenge to the operation of rear-end desulfurization wastewater zero discharge system, in addition, existing desulfurization wastewater quality deterioration fluctuation disturbs the actual operation of end wastewater zero discharge project, such as equipment corrosion and scale formation is more serious, softening dosing lacks scientific control, reagent reaction efficiency is low, membrane pollution blockage loss is more and more serious and other problems, which will lead to desulfurization wastewater treatment cost increases substantially. UTILITARIAN CONTENT

[0003] In order to solve the above technical problems, the purpose of the utility model is to provide a kind of desulfurization wastewater treatment system, which is simple in structure and can efficiently treat desulfurization wastewater.

[0004] In order to achieve the above purpose, the technical scheme of the utility model is as follows: a kind of desulfurization wastewater treatment system, including collection pool, clarifying tank, three-way box, sludge dryer, filter and SCNF nanofiltration device, the SCNF nanofiltration device has water inlet, water outlet and concentrated water outlet, the collection pool has water inlet, which is used to receive desulfurization wastewater, the collection pool is communicated with the clarifying tank, the clarifying tank is used to add lime slurry, the clarifying tank has overflow port at upper end, the clarifying tank has first bottom discharge port at lower end, the three-way box has first reaction box, second reaction box and clean water tank communicated in sequence, the first reaction box has second bottom discharge port, the second reaction box has third bottom discharge port, the first reaction box is communicated with the overflow port of the clarifying tank, sodium hydroxide is added in the first reaction box, sodium carbonate is added in the second reaction box, the first bottom discharge port, second bottom discharge port and third bottom discharge port are communicated with the sludge dryer, the clean water tank is communicated with the water inlet of the SCNF nanofiltration device, and the filter is further provided between the two, the concentrated water outlet of the SCNF nanofiltration device is communicated with the collection pool and the clarifying tank, and first valve is respectively arranged at the communication place.

[0005] The beneficial effects of the above technical solution are that the collection tank shell transports the desulfurization wastewater to the clarifying tank after the desulfurization wastewater is adjusted, the desulfurization wastewater reacts with calcium hydroxide in the clarifying tank to generate magnesium hydroxide precipitate and calcium sulfate precipitate, which can remove magnesium ions and sulfate ions in the desulfurization wastewater, and the upper wastewater of the clarifying tank is continuously sent to the triple tank for further removal of magnesium ions and calcium ions in the wastewater, sodium hydroxide is added to the first reaction tank to further convert residual magnesium ions in the wastewater into magnesium hydroxide precipitate, sodium carbonate is added to the second reaction tank to convert residual calcium ions in the wastewater into calcium carbonate precipitate, and finally, the clean water treated by the triple tank is filtered through the filter and then subjected to nanofiltration treatment by the SCNF nanofiltration device, wherein the SCNF nanofiltration device allows monovalent ions to pass through but retains divalent ions, at this time, the wastewater discharged from the concentrated water outlet of the SCNF nanofiltration device contains a large amount of divalent ions, and such concentrated wastewater can be sent to further sewage treatment or returned to the collection tank and the clarifying tank for conditioning of the desulfurization wastewater.

[0006] The collection tank is provided in multiple, and the multiple collection tanks are in communication with the clarifying tank, and a second valve is arranged at the communication position.

[0007] The beneficial effects of the above technical solution are that multiple collection tanks can be provided to batch condition the desulfurization wastewater, and desulfurization wastewater from different sources can be adjusted to meet the process requirements of the entire desulfurization wastewater treatment system.

[0008] The above technical solution further comprises a slurry preparation tank and a circulating pump corresponding to the clarifying tank, the bottom of the slurry preparation tank is in communication with the clarifying tank, the water inlet of the circulating pump is in communication with the clarifying tank, and the water outlet of the circulating pump is in communication with the slurry preparation tank, and the slurry preparation tank is used to add slaked lime and water to prepare lime slurry and directly discharge into the clarifying tank.

[0009] The beneficial effects of the above technical solution are that the slaked lime can be prepared into lime slurry in the slurry preparation tank, and then directly discharged into the clarifying tank for reaction with the desulfurization wastewater.

[0010] The filter in the above technical solution is a tubular membrane filter.

[0011] The beneficial effects of the above technical solution are that the tubular membrane filter has good adaptability to the high suspension characteristics of the front-end water, has high filtration efficiency, can realize closed filtration of the wastewater, and occupies less land.

[0012] The first water quality monitor is arranged at the water inlet of the collection tank.

[0013] The beneficial effects of the above technical solution are that the first water quality monitor can monitor the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value of the desulfurization wastewater flowing into the collection tank, so that the indicators of the incoming water in the collection tank can be known in a timely manner to adjust the desulfurization wastewater in the collection tank.

[0014] The collection tank in the above technical solution is provided with a second water quality monitor.

[0015] The beneficial effects of the above technical solution are that the Mg 2+ concentration and SO4 2+ concentration in the collection tank can be detected in real time to know the concentration difference between the two.

[0016] The communication part of the clarification tank and the collection tank in the above technical solution is provided with a third water quality monitor, and the communication part of the clarification tank and the first reaction box is provided with a fourth water quality monitor.

[0017] The beneficial effects of the above technical solution are that the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value at the water inlet and outlet of the clarification tank can be monitored in real time.

[0018] The clarification tank in the above technical solution is provided with a plurality of fifth water quality monitors from shallow to deep.

[0019] The beneficial effects of the above technical solution are that the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value in the sewage at different depths in the clarification tank can be monitored in real time.

[0020] The first reaction box, the second reaction box and the clean water tank in the above technical solution are all provided with a sixth water quality monitor.

[0021] The beneficial effects of the above technical solution are that the magnesium ions and calcium ions in the desulfurization wastewater can be further removed by adding sodium hydroxide and sodium carbonate in the three-way box in sequence, so that the processing pressure of the subsequent SCNF nanofiltration device can be reduced.

[0022] The water outlet and the concentrated water outlet of the SCNF nanofiltration device in the above technical solution are both provided with a seventh water quality monitor.

[0023] The beneficial effects of the above technical solution are that the SO42+ Concentration is monitored in order to determine whether the SCNF nanofiltration device is operating normally, and the concentrated water SO4 2+ Concentration is monitored in order to determine whether the SCNF nanofiltration device is operating normally, and the concentrated water SO4 BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A structure schematic view of the desulfurization wastewater treatment system according to the embodiment of the present application is shown in the figure.

[0025] Figure 2 A structure schematic view of the clarifier according to the embodiment of the present application is shown in the figure.

[0026] Figure 3 A setting schematic view of the water quality monitors according to the embodiment of the present application is shown in the figure.

[0027] In the figure: 1, collection tank; 2, clarifier; 21, slurry preparation tank; 22, circulating pump; 3, three-way tank; 31, first reaction tank; 32, second reaction tank; 33, clean water tank; 4, sludge dryer; 5, filter; 6, SCNF nanofiltration device; 61, water outlet; 62, concentrated water outlet; 71, first valve; 72, second valve; 73, third valve; 74, fourth valve; 81, first water quality monitor; 82, second water quality monitor; 83, third water quality monitor; 84, fourth water quality monitor; 85, fifth water quality monitor; 86, sixth water quality monitor; 87, seventh water quality monitor; 9, incoming water pipe. DETAILED DESCRIPTION

[0028] The principles and features of the present application will be described below in conjunction with the accompanying drawings, and the examples are only used to explain the present application and are not used to limit the scope of the present application. In the following paragraphs, the present application is described in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present application will be more apparent from the following description and claims. It should be noted that the drawings are very simplified and use non-precise proportions, only to facilitate and clarify the purpose of assisting the description of the embodiments of the present application.

[0029] As Figure 1As shown, the embodiment provides a desulfurization wastewater treatment system, which comprises a collecting tank 1, a clarifying tank 2, a triple tank 3, a sludge dryer 4, a filter 5 and an SCNF nanofiltration device 6, the SCNF nanofiltration device 6 has a water inlet, a water outlet and a concentrated water outlet, the collecting tank 1 has a water inlet for receiving desulfurization wastewater, the collecting tank 1 is communicated with the clarifying tank 2, lime slurry is added in the clarifying tank 2, the upper end of the clarifying tank 2 has an overflow port, the lower end of the clarifying tank 2 has a first bottom discharge port, the triple tank 3 has a first reaction tank 31, a second reaction tank 32 and a clean water tank 33 communicated in sequence, the first reaction tank 31 has a second bottom discharge port, the second reaction tank 32 has a third bottom discharge port, the first reaction tank 31 is communicated with the overflow port of the clarifying tank 2, sodium hydroxide is added in the first reaction tank 31, sodium carbonate is added in the second reaction tank 32, the first bottom discharge port, the second bottom discharge port and the third bottom discharge port are communicated with the sludge dryer 4, the clean water tank 33 is communicated with the water inlet of the SCNF nanofiltration device 6, and the filter 5 is further arranged between the two, the concentrated water outlet of the SCNF nanofiltration device 6 is communicated with the collecting tank 1 and the clarifying tank 2, and a first valve 71 is arranged at the communication position, so that the desulfurization wastewater is transported to the clarifying tank after being adjusted in the collecting tank, and the desulfurization wastewater reacts with calcium hydroxide in the clarifying tank to generate magnesium hydroxide precipitate and calcium sulfate precipitate, so that the magnesium ions and the sulfate ions in the desulfurization wastewater can be removed, and the upper wastewater in the clarifying tank is continuously sent to the triple tank for further removing the magnesium ions and the calcium ions in the wastewater, the sodium hydroxide added in the first reaction tank can further convert the residual magnesium ions in the wastewater into magnesium hydroxide precipitate, and the sodium carbonate added in the second reaction tank can convert the residual calcium ions in the wastewater into calcium carbonate precipitate, and finally the clean water treated by the triple tank is filtered by the filter and then treated by the SCNF nanofiltration device, wherein the SCNF nanofiltration device allows monovalent ions to pass through but retains divalent ions, at this time, the wastewater discharged from the concentrated water outlet of the SCNF nanofiltration device contains a large amount of divalent ions, and such concentrated wastewater can be sent to further wastewater treatment (that is, the concentrated water outlet 62 can also be communicated with a downstream wastewater treatment device, and a first valve 71 is arranged at the communication position, or the concentrated wastewater can be sent back to the collecting tank and the clarifying tank to adjust the desulfurization wastewater), and the wastewater discharged from the water outlet 61 of the SCNF nanofiltration device 6 can be sent to a downstream process for harmless treatment.

[0030] The sludge dryer in the embodiment can adopt a plate-and-frame filter press, which mainly dries the precipitates discharged from the clarifying tank, the first reaction tank and the second reaction tank for convenient transportation.

[0031] The first bottom discharge port, the second bottom discharge port and the third bottom discharge port in the embodiment are all provided with a third valve 73.

[0032] The collecting pool 1 is provided with multiple collecting pools 1, the multiple collecting pools 1 are all communicated with the clarifying pool 2, and a second valve 72 is arranged at the communication position, multiple collecting pools can be arranged to batch condition the desulfurization wastewater, and desulfurization wastewater from different sources can be mixed to meet the process requirements of the whole desulfurization wastewater treatment system.

[0033] As shown in the figure, Figure 2 The technology scheme further comprises a slurry tank 21 corresponding to the clarifying pool 2 and a circulating pump 22, the bottom of the slurry tank 21 is communicated with the clarifying pool 2, the water inlet of the circulating pump 22 is communicated with the clarifying pool 2, the water outlet of the circulating pump 22 is communicated with the slurry tank 21, and the slurry tank 21 is used to add lime and water to prepare lime slurry and directly discharge into the clarifying pool 2, so that the lime can be prepared into lime slurry in the slurry tank, and then directly discharged into the clarifying pool to react with the desulfurization wastewater.

[0034] The filter 5 is a tubular membrane filter (specifically, a microporous tubular membrane filter), which has good adaptability to the high suspension characteristics of the front-end water, high filtration efficiency, and small footprint.

[0035] As shown in the figure, Figure 3 The water inlet of the collecting pool 1 is provided with a first water quality monitor 81, so that the first water quality monitor can monitor the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value of the desulfurization wastewater entering the collecting pool, so that the indicators of the water in the collecting pool can be known in time to condition the desulfurization wastewater in the collecting pool.

[0036] Specifically, for large-scale thermal power plants, the desulfurization wastewater sources are usually more than one, at this time, multiple water pipes 9 can be arranged to respectively discharge desulfurization wastewater from different sources into the collecting pool (one water pipe 9 corresponds to one desulfurization wastewater source), each water pipe 9 is communicated with multiple collecting pools, and a fourth valve 74 is arranged at the communication position, at this time, the first water quality monitor is also multiple, and the multiple first water quality monitors correspond to the multiple water pipes one by one, each first water quality monitor is used to monitor the water quality parameters in the corresponding water pipe (so that each collecting pool can be conditioned according to the water quality indicators in the different water pipes as a reference, so that the desulfurization wastewater in the collecting pool meets the process requirements), preferably, the water pipes can be 2 or 3.

[0037] The collecting pool 1 is provided with multiple collecting pools 1, the multiple collecting pools 1 are all communicated with the clarifying pool 2, and a second valve 72 is arranged at the communication position, multiple collecting pools can be arranged to batch condition the desulfurization wastewater, and desulfurization wastewater from different sources can be mixed to meet the process requirements of the whole desulfurization wastewater treatment system.2+ concentration and SO4 2+ concentration, to know the concentration difference between the two.

[0038] The communication between the clarifier 2 and the collection tank 1 is provided with a third water quality monitor 83, and the communication between the clarifier 2 and the first reaction box 31 is provided with a fourth water quality monitor 84, so that the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value are monitored in real time.

[0039] The fifth water quality monitor 85 is arranged in the clarifier 2 from shallow to deep, so that the Mg 2+ concentration, SO4 2+ concentration, Ca 2+ concentration and pH value are monitored in real time. Since the volume of the clarifier is large, by arranging a plurality of fifth water quality monitors 85, the clarifier can be monitored from multiple points (the later monitoring results can be weighted average, so that the accuracy of detecting the content of each ion in the clarifier can be improved).

[0040] The first reaction box 31, the second reaction box 32 and the clear water tank 33 are all provided with a sixth water quality monitor 86, so that the magnesium ions and calcium ions in the desulfurization wastewater can be further removed by adding sodium hydroxide and sodium carbonate in the three tanks in sequence, so that the processing pressure of the subsequent SCNF nanofiltration device 6 can be reduced.

[0041] The water outlet and the concentrated water outlet of the SCNF nanofiltration device 6 are both provided with a seventh water quality monitor 87, so that the SO4 2+ concentration in the water at the water outlet and the concentrated water outlet of the SCNF nanofiltration device 6 can be monitored, so as to judge whether the SCNF nanofiltration device is running normally, and the SO4 2+ concentration of the concentrated water can be monitored in time, so as to guide the control of the direction of the nanofiltration concentrated water (specifically, if the SO4 2+ concentration at the water outlet of the SCNF nanofiltration device 6 is over standard, it indicates that the SCNF nanofiltration device 6 is not running normally, and after knowing the SO4 2+ concentration at the concentrated water outlet of the SCNF nanofiltration device 6, the concentrated water discharged from the concentrated water outlet can be discharged to the downstream sewage treatment equipment or discharged into the collection tank or the clarifier to condition the desulfurization wastewater).

[0042] The first water quality monitor 81, the third water quality monitor 83, the fourth water quality monitor 84, the fifth water quality monitor 85 and the sixth water quality monitor 86 in the embodiment all include Mg 2+ concentration detection sensor, SO4 2+ concentration detection sensor, Ca 2+ concentration detection sensor and pH detection probe, while the second water quality monitor only includes Mg 2+ concentration detection sensor and SO4 2+ concentration detection sensor, the seventh water quality monitor 87 can only include SO4 2+ concentration detection sensor, which all belong to the prior art and will not be described here.

[0043] In the embodiment, when there are multiple collection tanks, each of the collection tanks is independently configured with a second water quality monitor, and the second water quality monitor in the embodiment mainly monitors the concentration of Mg 2+ and SO4 2+ concentration in the collection tank.

[0044] When the concentration of sulfate ions (nSO4 2- , mmol / L) in the collection tank is higher than the concentration of magnesium ions (nMg 2+ , mmol / L), there are two cases as follows:

[0045] Case A: 0<(nSO4 2- -nMg 2+ )<50 mmol / L, the existing water collection direction of the collection tank can be maintained;

[0046] Case B: (nSO4 2- -nMg 2+ )>50 mmol / L, then the desulfurization water of the “high magnesium and low sulfate” type is switched to flow into the collection tank, and the concentrated water discharged by the SCNF nanofiltration device 6 is not recovered into the collection tank until the relationship between the concentration of sulfate ions and the concentration of magnesium ions in the collection tank satisfies the above case A.

[0047] When the concentration of sulfate ions (nSO4 2- , mmol / L) in the collection tank is lower than the concentration of magnesium ions (nMg 2+ , mmol / L), there are two cases as follows:

[0048] Case C: 0<(nMg 2+ -nSO4 2- )<100 mmol / L, the existing water collection direction of the collection tank can be maintained;

[0049] Case D: (nMg2+ - nSO4 2- ) > 100 mmol / L, the concentrated water discharged by the SCNF nanofiltration device 6 is collected into the collection tank; when it is monitored that the concentration of sulfate ions in the concentrated water discharged by the SCNF nanofiltration device 6 is lower than the magnesium ion content of the incoming water of the collection tank, then the sodium sulfate medicament needs to be supplemented into the collection tank according to the ion concentration difference of the collection tank, until the relationship between the concentration of sulfate ions and the concentration of magnesium ions in the collection tank meets the above case C.

[0050] The addition amount of each medicament (calcium hydroxide, sodium sulfate, sodium hydroxide and sodium carbonate) in the collection tank and the triple tank in the embodiment can be adjusted according to the detection results of each water quality monitor, so that the addition amount of the medicament is more accurate, and the medicament addition is avoided or the medicament addition is avoided.

[0051] In the embodiment, the "water quality monitors" refer to the first water quality monitor 81, the third water quality monitor 83, the fourth water quality monitor 84, the fifth water quality monitor 85, the sixth water quality monitor 86 and the seventh water quality monitor 87.

[0052] Among them, according to the principle of medicament softening reaction: the main reaction equation of chemical softening is as follows:

[0053] Ca (OH) 2→ Ca 2+ + 2OH - Reaction formula 1

[0054] 2OH - + Mg 2+ → Mg (OH) 2↓ Reaction formula 2

[0055] Ca 2+ + SO4 2- → CaSO4↓ Reaction formula 3

[0056] 2NaOH + Mg 2+ → Mg (OH) 2↓ Reaction formula 4

[0057] Na2CO3 + Ca 2+ → CaCO3↓ Reaction formula 5

[0058] Among them, reaction formula 1-reaction formula 3 is carried out in the clarification tank, reaction formula 4 is carried out in the first reaction tank, and reaction formula 5 is carried out in the second reaction tank.

[0059] According to the theoretical medicament addition amount calculation principle:

[0060] When the sulfate ions need to be compensated in the collection tank, the sodium sulfate powder medicament is added into the collection tank to achieve it. Specifically, the addition amount of sodium sulfate is: according to the SO4 2- concentration and Mg 2+concentration reaches (nMg 2+ <100mmol / L) < nSO4 2- < nMg 2+ control until;

[0061] The lime dosage in the clarification tank is calculated according to the frequency of adding lime powder, that is, m = nMg 2+ *V*74.09*10 -3 ; in the formula,

[0062] m - the amount of Ca(OH)2in kg / h after conversion of the purity of lime;

[0063] nMg 2+ - the concentration of Mg 2+ in the wastewater in the clarification tank, mmol / L;

[0064] V - the flow rate of wastewater treatment in the clarification tank, tons / hour;

[0065] 74.09 - the molecular weight of calcium hydroxide, g / mol;

[0066] The first reaction tank and the second reaction tank are respectively added with sodium hydroxide and sodium carbonate, and the dosages are respectively calculated according to the monitoring results of the corresponding sixth monitoring instrument to meet the requirement that the total hardness of calcium and magnesium ions in the tank is less than 100 mg / L (calculated in terms of calcium carbonate).

[0067] The main reagent consumption theoretical calculation formula in this embodiment is: reagent cost = lime cost + sodium hydroxide cost + sodium carbonate cost

[0068] To achieve the water quality treatment effluent target, the main reagent cost is as follows: the lime cost is determined by the type of raw water and the collection method, the sodium hydroxide cost is determined by the residual magnesium ion content after lime treatment, and the sodium carbonate cost is determined by the residual calcium ion content.

[0069] The goal of the desulfurization wastewater conditioning in the collection tank in this embodiment is to balance the concentrations of magnesium ions and sulfate ions in the collection tank, and the balance of the concentrations of magnesium ions and sulfate ions in the collection tank determines the removal efficiency of sulfate ions, magnesium ions and calcium ions, thereby determining the consumption cost of sodium hydroxide and sodium carbonate.

[0070] In this embodiment, due to the market prices of lime, sodium sulfate, sodium hydroxide and sodium carbonate, the market prices of lime and sodium sulfate are relatively low, and the prices of sodium hydroxide and sodium carbonate are relatively high. The addition of calcium hydroxide in the clarification tank is calculated according to the aforementioned theoretical dosing amount calculation principle, so that the added calcium hydroxide can theoretically provide OH - Mg 2+The replaced calcium ions combine with sulfate ions in the wastewater to promote precipitation according to the principle of chemical reaction equilibrium movement, so that the excessive growth of free calcium ions in the clarifying tank is avoided, and the cost of sodium hydroxide and sodium carbonate consumed for removing residual magnesium ions and calcium ions is minimized.

[0071] The above is only a preferred embodiment of the present application, and does not limit the present application in any form; any person skilled in the art can smoothly implement the present application according to the above description and the drawings; however, any equivalent changes, modifications and evolutions made by those skilled in the art within the scope of the technical scheme of the present application, using the above disclosed technical content, are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolutions made according to the essential technology of the present application to the above embodiments are still within the protection scope of the technical scheme of the present application.

Claims

1. A desulfurization wastewater treatment system, characterized in that: The invention comprises a collecting tank (1), a clarifier (2), a triple tank (3), a sludge dryer (4), a filter (5) and a SCNF nanofiltration device (6), wherein the SCNF nanofiltration device (6) has a water inlet, a water outlet and a concentrated water outlet, the collecting tank (1) has a water inlet for receiving desulfurization wastewater, the collecting tank (1) is connected to the clarifier (2), the clarifier (2) is used to add lime slurry, the upper end of the clarifier (2) has an overflow port, the lower end of the clarifier (2) has a first bottom outlet, the triple tank (3) has a first reaction box (31), a second reaction box (32) and a clean water tank (33) which are connected in sequence, the first reaction box (31) has The second bottom outlet is provided, the second reaction box (32) has a third bottom outlet, the first reaction box (31) is connected to the overflow port of the clarifier (2), the first reaction box (31) is used to add sodium hydroxide, and the second reaction box (32) is used to add sodium carbonate. The first bottom outlet, the second bottom outlet and the third bottom outlet are all connected to the sludge dryer (4), the clean water tank (33) is connected to the water inlet of the SCNF nanofiltration device (6), and the filter (5) is also provided between the two. The concentrated water outlet of the SCNF nanofiltration device (6) is connected to the collection tank (1) and the clarifier (2), and a first valve (71) is provided at each connection point.

2. The desulfurization wastewater treatment system according to claim 1, characterized in that: There are multiple collection tanks (1), and each of the multiple collection tanks (1) is connected to the clarification tank (2), and a second valve (72) is provided at each connection point.

3. The desulfurization wastewater treatment system according to claim 1, characterized in that: A slurry preparation tank (21) and a circulation pump (22) corresponding to the clarifier (2) are also provided. The bottom of the slurry preparation tank (21) is communicated with the clarifier (2), the water inlet of the circulation pump (22) is communicated with the clarifier (2), and the water outlet of the circulation pump (22) is communicated with the slurry preparation tank (21). The slaked lime and water are added into the slurry preparation tank (21) to prepare lime slurry and discharge the slurry directly into the clarifier (2).

4. The desulfurization wastewater treatment system according to claim 1, characterized in that: The filter (5) is a tubular membrane filter.

5. The desulfurization wastewater treatment system according to claim 1, characterized in that: A first water quality monitor (81) is provided at the water inlet of the collection pool (1).

6. The desulfurization wastewater treatment system according to claim 1, characterized in that: A second water quality monitor (82) is provided in the collection pool (1).

7. The desulfurization wastewater treatment system according to claim 1, characterized in that: A third water quality monitor (83) is provided at the connection point between the clarification tank (2) and the collection tank (1), and a fourth water quality monitor (84) is provided at the connection point between the clarification tank (2) and the first reaction box (31).

8. The desulfurization wastewater treatment system according to claim 1, characterized in that: A plurality of fifth water quality monitors (85) are sequentially arranged in the clarification tank (2) from shallow to deep.

9. The desulfurization wastewater treatment system according to claim 1, characterized in that: The first reaction box (31), the second reaction box (32) and the clean water tank (33) are all provided with a sixth water quality monitor (86).

10. The desulfurization wastewater treatment system according to claim 1, characterized in that: A seventh water quality monitor (87) is provided at both the water production port and the concentrated water outlet of the SCNF nanofiltration device (6).

Images