Device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculation precipitation with multi-stage anaerobic treatment

Abstract

The utility model relates to a device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculent precipitation with multi-stage anaerobic treatment, in particular to a device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculent precipitation with multi-stage anaerobic treatment. The problems that existing tin-containing wastewater treatment is large in difficulty, overall treatment steps are complex, treatment cost is high, and more sludge is generated in a traditional treatment method are solved. The device consists of a water inlet pump, a coagulant storage tank, a coagulant adding pump, a coagulation stirring tank, an electric stirrer, a lifting pump, a multi-stage anaerobic reactor, an aeration device and a water outlet pump, an electric stirrer is arranged in the coagulation stirring tank; the multi-stage anaerobic reactor is divided into five biological treatment chambers, namely a first anaerobic biological treatment region, a second anaerobic biological treatment region, a third anaerobic biological treatment region, a facultative biological treatment region and an aerobic biological treatment region from left to right in sequence. The device is used for treating toxic heavy metals in the tin-containing wastewater.

Description

Technical Field

[0001] The utility model relates to a device for treating toxic heavy metals in tin-containing wastewater by utilizing chemical flocculation precipitation combined with multi-stage anaerobic treatment. Background Art

[0002] Tin is a silver-grey metal with a very low content in natural water bodies. The concentration of tin in river water is 10 -3 Tin can cause odor and reduce transparency in water. The World Health Organization considers tin to be non-toxic to human health at concentrations commonly found in drinking water. However, excessive consumption or inhalation of inorganic tin can cause digestive system disorders and neurological damage. In recent years, the rapid development of fields such as tin plating, mirror manufacturing, and printed circuit board manufacturing has drawn attention to the discharge of tin-containing wastewater. If discharged without treatment, tin ions may be converted into organic tin, which poses even more serious hazards.

[0003] At present, the main methods for treating tin-containing wastewater at home and abroad are chemical precipitation, ion exchange, membrane separation and biological methods. Chemical precipitation is based on the solubility product principle, which makes the elements in water form insoluble salts and then separate from the liquid phase for removal. It is simple to operate and economical to apply. It is suitable for treating large amounts of wastewater with high salt content. However, when used alone, the removal rate is low, solid-liquid separation is difficult, and the amount of sludge is large, which increases the difficulty of subsequent treatment processes. Ion exchange is to make Sn 2+ Tin is removed by exchanging with exchangeable ions on the ion exchanger or undergoing physical and chemical adsorption with the adsorbent. The ion exchange method has high resin stability, high selectivity for metal ions, good separation effect, and small sludge volume. However, it is affected by competing ions and raw water quality, making resin recycling difficult. Membrane separation technology uses selective permeable membranes and pressure differences as a driving force to achieve solid-liquid separation. It has the advantages of good effluent quality, stable process, no phase change of materials, and energy saving. However, it has high requirements for raw water quality and is restricted by membrane pollution. It usually needs to be used in combination with other processes or the addition of agents to alleviate membrane pollution. Biological treatment methods include phytoremediation and microbial methods. Phytoremediation relies on plants and microorganisms growing in their root systems to jointly purify the environment. Microbial methods use microorganisms as biological adsorbents to adsorb metal elements to remove tin. Currently, there is little research on relying on animals to remove heavy metals. Utility Model Content

[0004] The purpose of this utility model is to provide a device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculation and precipitation with multi-stage anaerobic treatment, so as to solve the problems of existing tin-containing wastewater treatment, such as the difficulty in treatment, the complexity of the overall treatment steps, the high treatment cost, and the large amount of sludge generated in traditional treatment methods.

[0005] A device for treating toxic heavy metals in tin-containing wastewater by utilizing chemical flocculation and precipitation combined with multi-stage anaerobic treatment comprises an inlet pump, a coagulant storage tank, a coagulant dosing pump, a coagulation and stirring tank, an electric stirrer, a lift pump, a multi-stage anaerobic reactor, an aeration device, and an outlet pump. The coagulation and stirring tank is provided with an electric stirrer. The multi-stage anaerobic reactor is divided into five biological treatment chambers, which are, from left to right, a first anaerobic biological treatment zone, a second anaerobic biological treatment zone, a third anaerobic biological treatment zone, a facultative biological treatment zone, and an aerobic biological treatment zone. The aeration device is provided in the aerobic biological treatment zone. The outlet of the inlet pump is connected to the water inlet of the coagulation and stirring tank. The outlet of the coagulant storage tank is connected to the feed port of the coagulation and stirring tank via a coagulant dosing pump. The outlet of the coagulation and stirring tank is connected to the water inlet of the first anaerobic biological treatment zone via a lift pump. The effluent of the aerobic biological treatment zone is discharged via the outlet pump.

[0006] The beneficial effects of the utility model are:

[0007] This utility model removes other metallic impurities and easily degradable tin ions from tin-containing wastewater by adding precipitants, coagulants, and flocculants during the coagulation stage. Furthermore, a sulfate-based multi-stage anaerobic biological treatment enhances the removal of recalcitrant heavy metal compounds, such as organotin. Sulfate-reducing bacteria in the acclimated sludge are utilized to degrade the complex structure of recalcitrant heavy metal compounds while simultaneously removing organic matter and the readily degradable heavy metal tin ions after conversion through biochemical reactions. This device efficiently treats recalcitrant tin-containing wastewater without leaving significant amounts of toxic and harmful heavy metal ions. Furthermore, the device biologically recovers the heavy metal tin from the tin-containing wastewater into the sludge, which can then be further processed to recover the heavy metal tin, achieving resource recovery and utilization. This utility model helps reduce the complexity of tin-containing wastewater treatment and paves the way for heavy metal recovery and subsequent treatment of tin-containing wastewater. This utility model not only effectively removes heavy metals from tin-containing wastewater, but also occupies a small footprint, does not cause environmental pollution or human poisoning, and has a low investment cost. It helps circuit board manufacturers reduce costs and increase efficiency, improve the overall treatment efficiency of tin-containing wastewater, reduce treatment costs, and reduce the discharge of toxic heavy metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The utility model is a structural schematic diagram of a device for treating toxic heavy metals in tin-containing wastewater by utilizing chemical flocculation precipitation combined with multi-stage anaerobic treatment. DETAILED DESCRIPTION

[0009] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any combination of the specific implementation methods.

[0010] Specific implementation method 1: Figure 1 Specifically describe this embodiment. This embodiment is a device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation and precipitation combined with multi-stage anaerobic treatment. The device is composed of an inlet pump 1, a coagulant storage tank 2, a coagulant dosing pump 3, a coagulation and stirring tank 4, an electric stirrer 5, a lifting pump 6, a multi-stage anaerobic reactor 7, an aeration device 8 and an outlet pump 10. The coagulation and stirring tank 4 is provided with an electric stirrer 5. The multi-stage anaerobic reactor 7 is divided into 5 biological treatment chambers, which are the first anaerobic biological treatment area, the second anaerobic biological treatment area, and the second biological treatment area from left to right. treatment area, the third anaerobic biological treatment area, the facultative biological treatment area, and the aerobic biological treatment area; the aeration device 8 is arranged in the aerobic biological treatment area; the outlet of the water inlet pump 1 is connected to the water inlet of the coagulation stirring tank 4; the outlet of the coagulant storage tank 2 is connected to the feed port of the coagulation stirring tank 4 through the coagulant dosing pump 3; the outlet of the coagulation stirring tank 4 is connected to the water inlet of the first anaerobic biological treatment area through the lifting pump 6; the effluent of the aerobic biological treatment area is discharged through the outlet pump 10.

[0011] In this embodiment, a feeding port is provided on the upper part of the coagulation stirring tank for adding the precipitant Na2CO3 and the flocculant polyphenylamide PAM.

[0012] Working process: The tin-containing wastewater produced by the circuit board wastewater production line is pumped into the coagulation agitator by the water inlet pump 1 after simple filtration treatment. When the coagulation agitator is filled with tin-containing wastewater, 90 mg / L of precipitant Na2CO3 is added into the coagulation agitator tank 4 and the electric agitator 5 is turned on to stir for 30 minutes, and then left to stand for 1 hour. This step is to allow part of the easily degradable tin in the tin-containing wastewater to precipitate first. After the chemical sludge is discharged through the pipe at the bottom, the coagulant in the coagulant storage tank 2 is pumped into the coagulation agitator tank 4 through the coagulant dosing pump 3 for Coagulation treatment is carried out, and the coagulant is ferric chloride, and its addition amount is 2.90mg / L. Then, the electric stirrer 5 is turned on and stirred for 60min, and then 100ppm of flocculant polyphenylene amide PAM is added into the coagulation stirring tank 4 and stirred for 60min, and then left to stand for 120min. After the coagulation is completed, the chemical sludge at the bottom of the coagulation stirring tank 4 is distributed to the sludge tank for drying and subsequent harmless treatment, and the supernatant in the coagulation stirring tank 4 is pumped into the multi-stage anaerobic reactor 7 by the lifting pump 6; in the multi-stage anaerobic reactor 7, the first four zones are filled with one-third of the zone. The activated sludge is obtained by acclimating and culturing the sludge from urban domestic sewage treated by a sewage treatment plant. The acclimation agent is 200 mg / L glucose, 100 mg / L sodium sulfate, 20 mg / L urea, 5 mg / L potassium dihydrogen phosphate, 0.05 mg / L copper sulfate, 0.04 mg / L zinc chloride, and 0.01 mg / L manganese sulfate. The acclimation agent is added once every three days and stirred for 30 minutes. After anaerobic acclimation for 30 days, the sludge can be added to the multi-stage anaerobic reactor 7 to treat tin-containing wastewater. The hydraulic retention time of the multi-stage anaerobic reactor 7 is 1 hour. The HRT is 12 hours. The water treated in the aerobic biological treatment zone is returned to the facultative biological treatment zone through the reflux pump 9 to improve the denitrification treatment efficiency of the facultative biological treatment zone. At the same time, the effluent from the aerobic biological treatment zone is discharged through the effluent pump 10 for further treatment or discharge in compliance with the standards. The sludge in the anaerobic biological treatment zone is replaced every three months. The heavy metal tin in the tin-containing wastewater is fixed in the sludge by the sulfate-reducing bacteria in the sludge. The replaced sludge can be further smelted to extract the available heavy metal tin, so as to achieve the effect of resource utilization.

[0013] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the water inlet pump 1, coagulant storage tank 2, coagulant dosing pump 3, coagulation stirring tank 4, electric stirrer 5, lift pump 6, multi-stage anaerobic reactor 7, aeration device 8, and water outlet pump 10 are arranged horizontally. Other components are the same as specific embodiment 1.

[0014] Specific embodiment 3: This embodiment differs from specific embodiment 1 in that the upper half of the coagulation and mixing tank 4 is a rectangular parallelepiped, 1 meter long, 1 meter wide, and 2 meters high; and an inverted triangular collection tank for collecting chemical sludge is provided at the bottom of the coagulation and mixing tank 4, with a depth of 1 meter. Other configurations are the same as specific embodiment 1.

[0015] Specific embodiment 4: This embodiment differs from specific embodiment 1 in that ferric chloride is contained in the coagulant storage tank 2. Other aspects are the same as those of specific embodiment 1.

[0016] Specific embodiment 5: This embodiment differs from specific embodiment 1 in that the multi-stage anaerobic reactor 7 has a total length of 3 m, a total height of 2 m, and a total width of 1.5 m. Other features are the same as those of specific embodiment 1.

[0017] Specific embodiment 6: This embodiment differs from specific embodiment 1 in that the hydraulic retention time (HRT) of the multi-stage anaerobic reactor 7 is 12 hours. Other aspects are the same as those of specific embodiment 1.

[0018] Specific embodiment 7: This embodiment differs from specific embodiment 1 in that the aeration volume of the aeration device 8 is 20 L / min. Other aspects are the same as specific embodiment 1.

[0019] The aeration head of the aeration device 8 of this embodiment is placed in the aerobic biological treatment zone to provide sufficient oxygen.

[0020] Specific embodiment 8: This embodiment differs from specific embodiment 1 in that the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the third anaerobic biological treatment zone, and the facultative biological treatment zone are each filled with activated sludge at two-thirds of the area. Other aspects are the same as specific embodiment 1.

[0021] Specific embodiment 9: This embodiment differs from specific embodiment 8 in that a reflux outlet is provided at the bottom of the aerobic biological treatment zone, and a reflux inlet is provided at the bottom of the facultative biological treatment zone, and the reflux outlet and the reflux inlet are connected via a reflux pump 9. Other aspects are the same as specific embodiment 8.

[0022] Specific embodiment 10: This embodiment differs from specific embodiment 1 in that the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the third anaerobic biological treatment zone, the facultative biological treatment zone, and the aerobic biological treatment zone are connected in the form of overflow. Other aspects are the same as specific embodiment 1.

Claims

1. A device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculation and precipitation with multi-stage anaerobic treatment, characterized in that The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation and precipitation combined with multi-stage anaerobic treatment comprises a water inlet pump (1), a coagulant storage tank (2), a coagulant dosing pump (3), a coagulation and stirring tank (4), an electric stirrer (5), a lifting pump (6), a multi-stage anaerobic reactor (7), an aeration device (8) and a water outlet pump (10); the coagulation and stirring tank (4) is provided with an electric stirrer (5); the multi-stage anaerobic reactor (7) is divided into five biological treatment chambers, which are, from left to right, the first anaerobic biological treatment zone, the second ... first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the first anaerobic biological treatment zone, the second The invention relates to an anaerobic biological treatment zone, a third anaerobic biological treatment zone, a facultative biological treatment zone, and an aerobic biological treatment zone; the aeration device (8) is arranged in the aerobic biological treatment zone; the water outlet of the water inlet pump (1) is connected to the water inlet of the coagulation stirring tank (4); the water outlet of the coagulant storage tank (2) is connected to the feed port of the coagulation stirring tank (4) through a coagulant dosing pump (3); the water outlet of the coagulation stirring tank (4) is connected to the water inlet of the first anaerobic biological treatment zone through a lifting pump (6); and the effluent of the aerobic biological treatment zone is discharged through an effluent pump (10).

2. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The water inlet pump (1), coagulant storage tank (2), coagulant dosing pump (3), coagulation stirring tank (4), electric stirrer (5), lifting pump (6), multi-stage anaerobic reactor (7), aeration device (8) and water outlet pump (10) are arranged horizontally.

3. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The upper part of the coagulation and stirring tank (4) is a rectangular parallelepiped with a length of 1m, a width of 1m and a height of 2m; an inverted triangle collecting tank for collecting chemical sludge is provided at the bottom of the coagulation and stirring tank (4), and the tank depth is 1m.

4. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The coagulant storage tank (2) is filled with ferric chloride.

5. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The multi-stage anaerobic reactor (7) has a total length of 3 m, a total height of 2 m, and a total width of 1.5 m.

6. The device for treating toxic heavy metals in tin-containing wastewater by combining chemical flocculation and precipitation with multi-stage anaerobic treatment according to claim 1, characterized in that The hydraulic retention time (HRT) of the multi-stage anaerobic reactor (7) is 12 hours.

7. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The aeration capacity of the aeration device (8) is 20 L / min.

8. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the third anaerobic biological treatment zone and the facultative biological treatment zone are respectively filled with two-thirds of the activated sludge in the area.

9. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation and precipitation combined with multi-stage anaerobic treatment according to claim 8, characterized in that The bottom of the aerobic biological treatment zone is provided with a reflux outlet, and the bottom of the facultative biological treatment zone is provided with a reflux inlet, and the reflux outlet and the reflux inlet are connected via a reflux pump (9).

10. The device for treating toxic heavy metals in tin-containing wastewater by using chemical flocculation and precipitation combined with multi-stage anaerobic treatment according to claim 1, characterized in that The first anaerobic biological treatment zone, the second anaerobic biological treatment zone, the third anaerobic biological treatment zone, the facultative biological treatment zone and the aerobic biological treatment zone are connected in the form of overflow.

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