High-hardness industrial wastewater softening device

Abstract

The utility model discloses a high-hardness industrial wastewater softening device which comprises an adjusting tank, a 1 # softening reaction tank, a 2 # softening reaction tank, a coagulation reaction tank, a flocculation reaction tank, a guide cylinder, a softening sedimentation tank, a plug-flow reaction area, a sludge concentration tank, a reverse-flow inclined pipe and a softening water outlet tank, an outlet of the regulating tank is communicated with an upper inlet of the 1 # softening reaction tank through a regulating tank water outlet pump, a bottom outlet of the 1 # softening reaction tank is communicated with a bottom inlet of the 2 # softening reaction tank, and an upper outlet of the 2 # softening reaction tank is communicated with an upper inlet of the coagulation reaction tank; a guide cylinder is arranged in the flocculation reaction tank, a bottom outlet of the coagulation reaction tank is communicated with a bottom inlet of the guide cylinder, a bottom outlet of the flocculation reaction tank is communicated with a bottom inlet of the softening sedimentation tank, and an overflow weir of the softening sedimentation tank is communicated with the softening water outlet tank. The device disclosed by the utility model has the advantages of reasonable design, low operation cost, simplicity in equipment operation, stable treatment effect, thorough treatment effect and low treatment cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to a wastewater treatment device, especially a high hardness industrial wastewater softening device. BACKGROUND

[0002] With the increasing of the environmental protection strength of the country, the country requires the industrial wastewater after treatment to reach the control standard of the first level A in GB18918-2002 'Urban Sewage Treatment Plant Pollutant Discharge Standard', wherein the key indicators COD content is less than or equal to 40mg / L, and NH3-N content is less than or equal to 5mg / L. At present, the industrial wastewater treatment mainly adopts the A / O biological treatment process and the MBR membrane combined treatment process with mature technology and high cost performance to reduce the COD and NH3-N values in the effluent, due to the high hardness of part of the industrial wastewater, the high content of calcium, magnesium ions and suspended solids in the water, and the high content of these ions and suspended solids affects the microbial metabolic activity in the A / O treatment process, hinders the growth of microorganisms, causes the MBR membrane to be blocked, and affects the normal and stable operation of the overall system. Therefore, seeking a high-efficiency and low-cost high hardness industrial wastewater softening treatment process is the urgent demand of the current water system treatment. SUMMARY

[0003] The utility model wants to solve the technical problem to provide a high hardness industrial wastewater softening device with good treatment effect.

[0004] In order to solve the above technical problem, the utility model adopts the technical scheme of: including the adjusting pool, 1# softening reaction pool, 2# softening reaction pool, coagulation reaction pool, flocculation reaction pool, flow guide cylinder, softening sedimentation tank, plug flow reaction zone, sludge concentration tank, countercurrent type inclined pipe and softening effluent tank, the outlet of the adjusting pool is connected with the upper inlet of 1# softening reaction pool through the adjusting pool effluent pump, the bottom outlet of 1# softening reaction pool is connected with the bottom inlet of 2# softening reaction pool, and the upper outlet of 2# softening reaction pool is connected with the upper inlet of coagulation reaction pool, the flow guide cylinder is arranged in the flocculation reaction pool, the bottom outlet of coagulation reaction pool is connected with the bottom inlet of the flow guide cylinder, the bottom outlet of flocculation reaction pool is connected with the bottom inlet of softening sedimentation tank, and the overflow weir of softening sedimentation tank is connected with softening effluent tank, the mud scraper is arranged in the softening sedimentation tank, the sludge concentration tank is located at the bottom of the mud scraper, and the bottom outlet of the sludge concentration tank is connected with the bottom inlet of the flow guide cylinder in the flocculation reaction pool through the sludge conveying pump.

[0005] Further, sodium hydroxide dosing device, sodium carbonate dosing device, coagulant dosing device, flocculant dosing device, sulfuric acid dosing device are also provided, the outlet of sodium hydroxide dosing device is connected with 1# softening reaction pool, the outlet of sodium carbonate dosing device is connected with 2# softening reaction pool, the outlet of coagulant dosing device is connected with coagulation reaction pool, the outlet of flocculant dosing device is connected with flocculation reaction pool, and the outlet of sulfuric acid dosing device is connected with softening effluent tank.

[0006] Further, the 1# softening reaction tank, 2# softening reaction tank, coagulation reaction tank and flocculation reaction tank are all provided with agitators, and the flocculation reaction tank agitator is located at the upper portion of the outlet of the draft tube.

[0007] Further, the bottom outlet of the sludge concentration tank is connected to a sludge treatment system through a sludge conveying pump.

[0008] The beneficial effects of the above technical solution are that the chemical softening, coagulant adding, sludge backflow, mechanical mixing, mechanical flocculation, contact flocculation, high-efficiency precipitation, sludge concentration and other functions are organically combined together, so that the calcium and magnesium ions and the suspended matter content in the treated effluent are reduced, the effluent hardness is controlled to be below 100 mg / L, the effluent turbidity can be controlled to be below 5 mg / L, the hardness removal efficiency reaches 80% to 95%, the suspended matter efficiency reaches 60% to 70%, and the subsequent industrial wastewater treatment is provided with security.

[0009] The utility model has the advantages of reasonable design, low operation cost, simple equipment operation, stable treatment effect, stable operation, complete treatment effect and low treatment cost, can remove Ca 2+ , Mg 2+ ions in water by chemical reaction, further increases the density and settling performance of alum flowers and accelerates the precipitation speed by adding coagulants and flocculants and using a sludge backflow system, and the effluent hardness can be controlled to be below 100 mg / L. BRIEF DESCRIPTION OF DRAWINGS

[0010] The utility model will be further described in detail in combination with the drawings and specific embodiments.

[0011] Figure 1 is the structural schematic diagram of the utility model.

[0012] In the figure: 1, 1# softening reaction tank agitator; 2, 2# softening reaction tank agitator; 3, coagulation reaction tank agitator; 4, flocculation reaction tank agitator; 5, mud scraper; 6, regulating tank effluent pump; 7, sludge delivery pump; 8, external water delivery pump; 9, regulating tank; 10, 1# softening reaction tank; 11, 2# softening reaction tank; 12, coagulation reaction tank; 13, flocculation reaction tank; 14, flow guide cylinder; 15, softening sedimentation tank; 16, plug flow reaction zone; 17, sludge thickening tank; 18, countercurrent inclined pipe; 19, softening effluent tank; 20, sodium hydroxide dosing device; 21, sodium carbonate dosing device; 22, coagulant dosing device; 23, flocculant dosing device; 24, sulfuric acid dosing device. DETAILED DESCRIPTION

[0013] Figure 1 As shown, the high-hardness industrial wastewater softening device includes 1# softening reaction tank agitator 1, 2# softening reaction tank agitator 2, coagulation reaction tank agitator 3, flocculation reaction tank agitator 4, mud scraper 5, regulating tank effluent pump 6, sludge delivery pump 7, external water delivery pump 8, regulating tank 9, 1# softening reaction tank 10, 2# softening reaction tank 11, coagulation reaction tank 12, flocculation reaction tank 13, flow guide cylinder 14, softening sedimentation tank 15, plug flow reaction zone 16, sludge thickening tank 17, countercurrent inclined pipe 18, softening effluent tank 19, sodium hydroxide dosing device 20, sodium carbonate dosing device 21, coagulant dosing device 22, flocculant dosing device 23, and sulfuric acid dosing device 24.

[0014] Figure 1As shown, the outlet of the conditioning tank 9 of the high-hardness industrial wastewater softening device is communicated with the upper inlet of the 1# softening reaction tank 10 through the conditioning tank outlet pump 6, the bottom outlet of the 1# softening reaction tank 10 is communicated with the bottom inlet of the 2# softening reaction tank 11, and the upper outlet of the 2# softening reaction tank 11 is communicated with the upper inlet of the coagulation reaction tank 12. The flow guide cylinder 14 is vertically arranged in the flocculation reaction tank 13, the bottom outlet of the coagulation reaction tank 12 is communicated with the bottom inlet of the flow guide cylinder 14, and the bottom outlet of the flocculation reaction tank 13 is communicated with the bottom inlet of the softening sedimentation tank 15; the inner upper portion of the softening sedimentation tank 15 is provided with a countercurrent inclined pipe, the upper end of the softening sedimentation tank is provided with a plurality of water collecting troughs at equal intervals, the top of the water collecting trough is provided with an overflow weir, and the overflow weir is communicated with the softening outlet tank 19; the bottom outlet of the softening outlet tank 19 is communicated with the outside sending water pump 8 to send the softened industrial wastewater for external treatment. The softening sedimentation tank 15 is provided with a sludge level meter and a sludge sampling port, the sludge level meter is preferably an ultrasonic sludge level meter, and the installation position is selected at the position where the sludge-water interface is clear; when the flocculation and sedimentation effect is poor, the sludge level meter will display a large value; the sludge sampling port is arranged from bottom to top, and the sludge position is generally required to be located at about 20% of the height of the tank bottom; if the sludge level is too low, the sludge will backflow into the clear water, and the flocculation effect will be poor; if the sludge level is too high, the sludge scraper will be overloaded, and the motor or the turning rake and other components will be damaged. The softening sedimentation tank 15 is provided with a sludge scraper 5 in the center, the bottom of the center of the sludge scraper 5 is a sludge thickening tank 17, and the sludge scraper 5 transports the sediment at the bottom of the softening sedimentation tank 15 to the sludge thickening tank 17. The sludge thickening tank 17 is a downwardly tapering conical shape, the taper angle is in the range of 45°-65°, and the preferred angle is 55°; since the sludge thickening tank is a reverse conical shape, the sludge can slide down the conical wall under the action of gravity for gravity thickening. The bottom outlet of the sludge thickening tank 17 is communicated with the bottom inlet of the flow guide cylinder 14 in the flocculation reaction tank 13 through the sludge conveying pump 7, and the bottom outlet of the sludge thickening tank 17 is also communicated with the sludge treatment system through the sludge conveying pump 7. Since the backflow sludge has the characteristics of high viscosity, impurities, poor flowability, and block-shaped solid, the sludge conveying pump 7 adopts a single-rod conveying pump. The 1# softening reaction tank 10, the 2# softening reaction tank 11, and the softening outlet tank 19 are all provided with pH online detectors to ensure the required pH value of the reaction.

[0015] Figure 1As shown, the outlet 1 of the sodium hydroxide dosing device 20 of the high-hardness industrial wastewater softening device is communicated with the 1# softening reaction tank 10, the outlet of the sodium carbonate dosing device 21 is communicated with the 2# softening reaction tank 11, the outlet of the coagulant dosing device 22 is communicated with the coagulation reaction tank 12, the outlet of the flocculant dosing device 23 is communicated with the flocculation reaction tank 13, and the outlet of the sulfuric acid dosing device 24 is communicated with the softened water tank 19. Each dosing device adopts an integrated dosing device integrating dosing, stirring, liquid conveying and automatic control, which mainly comprises a solution tank, a stirring tank (with a stirrer), a metering pump, a liquid level meter, an electric control cabinet, a pipeline, a valve, a safety valve, a check valve, a pressure gauge, a filter, a base, a staircase and the like. Each dosing device is prepared in the stirring tank according to the required concentration of the medicament, and after being uniformly stirred by the stirrer, the prepared solution is conveyed to the dosing point or the designated system by the metering pump (dosing pump). The metering pump adopts a diaphragm type, which can ensure accurate metering and prolong the service life.

[0016] Figure 1 As shown, the 1# softening reaction tank 10 is provided with a 1# softening reaction tank stirrer 1, the 2# softening reaction tank 11 is provided with a 2# softening reaction tank stirrer 2, the coagulation reaction tank 12 is provided with a coagulation reaction tank stirrer 3, and the flocculation reaction tank 13 is provided with a flocculation reaction tank stirrer 4; the flocculation reaction tank stirrer 4 is located directly above the upper outlet of the flow guide cylinder 14. Different types of stirrers are used in each reaction tank according to the different medicaments and reaction rates, the 1# softening reaction tank stirrer 1 is a paddle type, the 2# softening reaction tank stirrer 2 is a frame type, the coagulation reaction tank stirrer 3 is a spiral type, and the flocculation reaction tank stirrer 4 is a propelling type. The stirring motors of each stirrer are variable frequency motors, which can be adjusted in time according to the conditions in each reaction tank.

[0017] Figure 1 As shown, the treatment process of the high-hardness industrial wastewater softening device is as follows:

[0018] (1) The high-hardness industrial wastewater buffered by the adjusting tank 9 enters the 1# softening reaction tank 10 to remove Mg 2+ , and a certain concentration of sodium hydroxide solution is added at the stirring center of the 1# softening reaction tank 10. The speed of the 1# softening reaction tank stirrer 1 is adjusted to control the mixing of the added sodium hydroxide and the industrial wastewater, thereby ensuring the removal effect of Mg 2+ . The removed Mg 2+ enters the subsequent 2# softening reaction tank 11 in the form of magnesium hydroxide particles, and a certain concentration of sodium carbonate solution is added at the stirring center of the 2# softening reaction tank 11. The speed of the 2# softening reaction tank stirrer 2 is adjusted to control the mixing of the added sodium carbonate and the industrial wastewater, thereby ensuring the removal effect of Ca 2+The removal effect of Ca 2+ The calcium carbonate particles enter the coagulation reaction tank 12, and the magnesium hydroxide and calcium carbonate particles in the industrial wastewater are in the form of suspended solids.

[0019] The pH value of the 1# softening reaction tank 10 and the 2# softening reaction tank 11 is maintained at about 11 during operation. At a high pH value, the softening reaction is facilitated, the removal efficiency of Ca 2+ , Mg 2+ is improved, and the coagulant and flocculant facilitate the coagulation and flocculation reactions at a high pH value.

[0020] (2) The suspended solids generated after the chemical softening enter the coagulation reaction tank 12, and a coagulant solution of a certain concentration is added. The coagulant solution is added at the stirring center of the coagulation reaction tank 12, and the speed of the stirrer 3 of the coagulation reaction tank is adjusted to control the mixing of the coagulant and the industrial wastewater, so that the suspended solids in the industrial wastewater undergo a coagulation reaction to generate small alunite flowers. After the small alunite flowers are generated, a flocculant solution of a certain concentration is added in the flocculation reaction tank 13. The flocculant solution is added at the stirring center of the flocculation reaction tank 13, and the speed of the stirrer 4 of the flocculation reaction tank is adjusted to increase, compact, and uniform the small alunite flowers. In order to increase the flocculation reaction effect, part of the sludge generated in the subsequent softening sedimentation tank 15 is backflowed to the flocculation reaction tank 13. Since the backflowed sludge is concentrated, the concentration is high, and the floc is also compact. This large and compact floc helps the unreacted flocculant to continue to participate in the flocculation reaction, accelerating the sludge sedimentation. Under the action of the flocculant and the backflowed sludge, the industrial wastewater in the flocculation reaction tank 13 forms a high-concentration suspended sludge layer to increase the particle collision opportunity and effectively adsorb colloids, suspended solids, emulsified oil, COD, and metal ions and other pollutants.

[0021] The coagulant is mostly polyferric sulfate (PFS) and polyaluminum chloride (PAC), and the flocculant is mostly polyacrylamide (PAM). When the suspended solids of the incoming water are very low, the coagulant and the flocculant can not be added or can be intermittently added. The dosage of the coagulant and the flocculant can be determined by beaker tests.

[0022] (3) The effluent after flocculation reaction tank 13 enters the plug flow reaction zone 16 slowly, and the generated alum flower can further contact each other in the plug flow reaction zone 16 and then enter the softening sedimentation tank 15. Most of the generated alum flower is gathered and concentrated into sludge at the bottom of the tank by gravity sedimentation in the softening sedimentation tank 15; the remaining unsedimented alum flower enters the countercurrent inclined pipe at the top of the softening sedimentation tank 15 with the effluent, and the unsedimented alum flower continues to settle to the bottom of the softening sedimentation tank 15 by the action of the inclined pipe. The softening sedimentation tank 15 is provided with a sludge stirring device to uniformly transport the sludge in the sedimentation tank to the conical sludge concentration tank 17 at the middle bottom. The concentrated sludge is transported by the sludge transport pump 7, part of which is sent to the flocculation reaction tank 13, and the excess part is sent to the sludge treatment system. The softening sedimentation tank 15 is provided with an ultrasonic sludge level meter, and the amount of sludge in the softening sedimentation tank 15 is controlled by the sludge transport pump 7 to control the concentration of the concentrated sludge. The effluent of the softening sedimentation tank 15 overflows from the top to the softening effluent tank 19. The industrial wastewater in the softening effluent tank 19 is added with excess NaOH and Na2CO3 to increase the pH value of the water body. In order to ensure the normal operation of the subsequent water treatment process, a certain concentration of sulfuric acid is added in the softening effluent tank 19 to adjust the pH value and maintain the pH value at 7-8.5 for neutralizing the water body.

[0023] (4) The sludge reflux ratio of the device is generally 3%-7% of the influent amount. When the sludge settling performance is poor and the sludge flocculation is small, the sludge reflux ratio can be reduced to improve the bottom sludge concentration and change the settling performance.

Claims

1. A high hardness industrial wastewater softening apparatus, characterized by: It includes the adjusting pool (9), 1# softening reaction pool (10), 2# softening reaction pool (11), coagulation reaction pool (12), flocculation reaction pool (13), flow guide cylinder (14), softening sedimentation tank (15), plug flow reaction zone (16), sludge concentration tank (17), countercurrent inclined pipe (18) and softening effluent tank (19); The outlet of the adjusting pool (9) is communicated with the upper inlet of 1# softening reaction pool (10) through the adjusting pool effluent pump (6), the bottom outlet of 1# softening reaction pool (10) is communicated with the bottom inlet of 2# softening reaction pool (11), and the upper outlet of 2# softening reaction pool (11) is communicated with the upper inlet of coagulation reaction pool (12); The flow guide cylinder (14) is arranged in the flocculation reaction pool (13), the bottom outlet of coagulation reaction pool (12) is communicated with the bottom inlet of flow guide cylinder (14), the bottom outlet of flocculation reaction pool (13) is communicated with the bottom inlet of softening sedimentation tank (15), and the overflow weir of softening sedimentation tank (15) is communicated with softening effluent tank (19); The sludge thickener (5) is arranged in the softening sedimentation tank (15), the sludge concentration tank (17) is located at the bottom of the sludge thickener (5), and the bottom outlet of the sludge concentration tank (17) is communicated with the bottom inlet of the flow guide cylinder (14) in the flocculation reaction pool (13) through the sludge conveying pump (7).

2. A high hardness industrial wastewater softening device according to claim 1, characterized in that: There are also sodium hydroxide dosing device (20), sodium carbonate dosing device (21), coagulant dosing device (22), flocculant dosing device (23) and sulfuric acid dosing device (24); The outlet of the sodium hydroxide dosing device (20) is communicated with 1# softening reaction pool (10), the outlet of the sodium carbonate dosing device (21) is communicated with 2# softening reaction pool (11), the outlet of the coagulant dosing device (22) is communicated with coagulation reaction pool (12), the outlet of the flocculant dosing device (23) is communicated with flocculation reaction pool (13), and the outlet of the sulfuric acid dosing device (24) is communicated with softening effluent tank (19).

3. A high hardness industrial wastewater softening device according to claim 1, characterized in that: The 1# softening reaction pool (10), 2# softening reaction pool (11), coagulation reaction pool (12) and flocculation reaction pool (13) are all provided with stirrers; The flocculation reaction pool stirrer (4) of the flocculation reaction pool (13) is located at the upper portion of the upper outlet of the flow guide cylinder (14).

4. A high hardness industrial wastewater softening device according to claim 1, 2 or 3, characterized in that: The bottom outlet of the sludge concentration tank (17) is also communicated with a sludge treatment system through the sludge conveying pump (7).

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