CN104163497A - Low-dissolved-oxygen magnetic biochemical treatment system and process - Google Patents

Abstract

The invention discloses a low-dissolved oxygen magnetic biochemical treatment system and process, comprising an oxygen-deficient pool, an oxygen-enriched pool and a sedimentation tank connected in sequence. The sedimentation tank is divided into a mud-water separation area and a water outlet area. Water pipes, the oxygen-poor tank is connected to the water inlet pipe, and an aeration device is installed at the bottom of the oxygen-enriched tank, and the aeration device is externally connected to a fan; it also includes: a magnetic drum separator, the inlet of which is connected to the remaining sludge pipe To the bottom of the mud-water separation zone, the outlet is connected to the oxygen-deficient pool through a magnetic substance return pipe; an internal return pump, the inlet of the internal return pump is connected to the end of the oxygen-enriched pool, and the outlet is connected to the front end of the oxygen-deficient pool. On the basis of the original biochemical treatment system, the present invention combines advanced technologies of magnetic carrier, magnetic separation and low-dissolved oxygen nitrosation to improve the denitrification and phosphorus removal effects of waste water and improve the effluent quality of waste water.

Description

A low dissolved oxygen magnetic biochemical treatment system and process

technical field

The invention relates to the technical field of materials and environmental engineering, in particular to a low-dissolved oxygen magnetic biochemical treatment system and process. the

Background technique

In the field of sewage treatment, biochemical treatment systems are widely used and have a long service life. The biochemical system can be mainly divided into activated sludge method and biofilm method, among which biofilm method is an efficient wastewater biological treatment process, and biological carrier is the core part of biofilm method. the

For example, the Chinese invention patent application document with the publication number CN103319054AA discloses a biofilm treatment process for organic wastewater, including the following steps: 1) primary biological treatment: adopting a moving bed biofilm reactor process to carry out pretreated organic wastewater Aerobic-anaerobic biodegradation treatment, the specific surface area of the suspended filler in the reactor is 200-500m ² /m ³ , the density is 0.92-1.0g/L, and the ratio of the bulk volume of the suspended filler to the effective volume of the reactor is 20- 70%; 2) Secondary biological treatment: the organic wastewater is treated with aerobic-anaerobic deep biodegradation by using the fixed-bed biofilm reactor technology, and the organic wastewater flows through the fixed filler in a serpentine shape from top to bottom in the reactor.

The Chinese invention patent application document with the publication number CN103232144A discloses an organic wastewater treatment device, which is mainly a combination device of contact oxidation + artificial wetland + artificial floating island, including: a flexible biofilm contact oxidation pool, and a flexible biofilm carrier is hung in the pool. The aeration head is laid on the bottom of the pool, and the aeration head is connected to the blower room; the flexible biofilm contact oxidation tank is connected to the sedimentation tank, and a sewage submersible pump is installed in the sedimentation tank; the outlet of the sedimentation tank is connected to the artificial wetland, and the artificial wetland There is a water outlet at the end, and an artificial floating island is set in the middle of the artificial wetland. the

The publication number is CN103319054A Chinese invention patent application document discloses a biofilm treatment process and equipment for organic wastewater, the process includes the following steps: 1) primary biological treatment: after pretreatment with moving bed biofilm reactor process 2) secondary biological treatment: use fixed bed biofilm reactor process to treat wastewater. The equipment includes the pool body and the biofilm filler in it. The water inlet is opened on the left side of the pool body, and the water outlet is opened on the right side. A baffle is set on the longitudinal section of the pool body, and an aeration device is installed on the bottom of the pool body on the left side of the baffle plate. There is a sloping plate below, and there is a gap between the bottom of the baffle and the sloping plate. The water outlet of the pool body is connected to the tower body. The top of the tower body has a water inlet, and the bottom end has a water outlet. A plurality of support plates are provided, on which flat-headed vertebral bodies are flatly laid, and overflow ports are staggered on adjacent support plates. the

However, at present, most of the biological carriers of the biofilm method are mainly fixed or semi-fixed fillers, which are mostly made of plastic and fiber materials, and are easy to age and have a long service life. Biofilm methods mainly include biological filter, biological turntable, biological contact oxidation, biological fluidized bed and so on. All kinds of biofilm methods use fixed or semi-fixed biological carriers, so that the biofilm method has the advantages of impact resistance, high load, high biomass, high treatment efficiency, and small size. the

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide a low dissolved oxygen magnetic biochemical treatment system and process, through the low amount of dissolved oxygen, to improve the effect of wastewater treatment and also to achieve wastewater denitrification and sludge reduction Purpose. the

A low-dissolved oxygen magnetic biochemical treatment system, including an oxygen-poor tank, an oxygen-rich tank and a sedimentation tank connected in sequence, the sedimentation tank is divided into a mud-water separation area and a water outlet area, the water outlet area is connected to a water outlet pipe, and the oxygen-depleted tank The pool is connected to the water inlet pipe, and the bottom of the oxygen-enriched pool is provided with an aeration device, and the aeration device is connected to an external fan; it also includes:

Magnetic drum separator, the inlet of the magnetic drum separator is connected to the bottom of the mud-water separation zone through the remaining sludge pipe, and the outlet is connected to the oxygen-poor tank through the magnetic material return pipe;

An internal reflux pump, the inlet of the internal reflux pump is connected to the end of the oxygen-enriched pool, and the outlet is connected to the front end of the oxygen-deficient pool. the

On the basis of the original biochemical treatment system, the present invention combines advanced technologies of magnetic carrier, magnetic separation and low-dissolved oxygen nitrosation to improve the denitrification and phosphorus removal effects of waste water and improve the effluent quality of waste water. The magnetic carrier biochemical, low-dissolved oxygen nitrosation and biochemical treatment technologies are integrated into one system. This system can effectively remove ammonia nitrogen and total phosphorus in wastewater, improve the sedimentation performance of wastewater, and reduce sludge sludge. The amount of production brings the biochemical treatment system to a new era. the

This system can be used in various sewage biochemical treatment facilities. It can not only be used in the biochemical treatment system of urban sewage treatment plants, so that urban wastewater can better meet the discharge standards and reduce environmental pollution; it can also be used in the biochemical treatment systems of sewage stations of various industrial enterprises to improve the removal rate of wastewater , reduce the generation rate of sludge, and improve the environmental protection and economic benefits of the enterprise. the

The magnetic drum separator adopted in the present invention is improved on the basis of conventional magnetic drum separators, and magnetic field strengths of different strengths are adopted according to different characteristics of waste water, and the recovery efficiency of magnetic substances is above 90%. For example, the magnetic field strength of domestic sewage can be selected as 240mT, and the magnetic field strength of printing and dyeing wastewater can be selected as 480mT. the

Preferably, the water outlet area is divided into an upper water outlet area and a lower water outlet area, the upper water outlet area is connected to the water outlet pipe, and the lower water outlet area is connected to an external return pump, and the other end of the external return flow pump is connected to the oxygen-poor pool. the

Further preferably, the volume ratio of the upper water outlet area to the lower water outlet area is 1:1. the

As a preference, inclined plate packing is arranged in the mud-water separation zone. the

As a preference, the outlet of the magnetic drum separator is also connected with a residual sludge discharge pipe. the

Under the combination of the above-mentioned preferred conditions, the system of the present invention has a better treatment effect on wastewater. the

The present invention also provides a process for wastewater treatment utilizing the low dissolved oxygen magnetic biochemical treatment system, comprising the following steps:

The magnetic carrier is added to the oxygen-poor tank and the oxygen-rich tank, and the activated sludge is loaded on the magnetic carrier during the commissioning process to form a magnetic carrier-loaded activated sludge;

The waste water enters the mud-water separation area after being treated in the oxygen-poor pool and the oxygen-enriched pool in turn, and the clear water enters the water outlet area after the mud-water separation, and is finally discharged by the outlet pipe;

The sludge after mud-water separation is sent to the magnetic drum separator for separation, and the separated magnetic carrier is returned to the oxygen-poor tank, and the remaining sludge is discharged; 

During the reaction process, oxygen is supplied to the oxygen-enriched tank through the fan and aeration device, and the oxygen capacity in the oxygen-enriched tank is maintained at 1-2 mg/L; The return pump returns the sludge at the bottom of the effluent area to the oxygen-poor tank. the

Because the invention is loaded with magnetic substances, it can not only reduce the oxygen capacity of the oxygen-enriched pool, but also reduce energy consumption. At the same time, lower dissolved oxygen can promote the reproduction of nitrifying bacteria and denitrifying bacteria in wastewater, improve the removal rate of ammonia nitrogen in wastewater, and achieve the effect of nitrogen removal in wastewater. In addition, since the activated sludge becomes the activated sludge loaded by the magnetic carrier, while the activity of the activated sludge is improved, the load of the activated sludge can also be increased, which can greatly reduce the amount of sludge produced. the

The oxygen capacity in the oxygen-enriched pool in the present invention is 1-2 mg/L. Generally, the oxygen capacity of the oxygen-enriched pool is 2-4 mg/L, but the present invention selects the oxygen capacity as 1-2 mg/L, which is beneficial to reduce energy consumption. the

Preferably, the dosage of the magnetic carrier in the oxygen-poor tank and the oxygen-rich tank is 1-3 g/L. the

Preferably, the hydraulic retention time of the wastewater in the oxygen-poor tank is 2-4 hours, and the hydraulic retention time of the oxygen-enriched tank is 8-24 hours. the

The hydraulic retention time varies according to different wastewater properties. Generally speaking, the residence time of the oxygen-poor pool is about 2 to 4 hours, and the residence time of the oxygen-enriched pool is about 8 to 24 hours. the

Further preferably, the oxygen capacity in the oxygen-enriched pool is 1-2 mg/L; the dosage of the magnetic carrier in the oxygen-deficient pool and the oxygen-enriched pool is 1-3 g/L; the hydraulic retention of the wastewater in the oxygen-deficient pool The time is 2 to 4 hours, and the hydraulic retention time of the oxygen-enriched pool is 8 to 24 hours. the

The oxygen content in the oxygen-enriched pool is lower than that in the ordinary oxygen-enriched pool, which is beneficial to the reproduction of nitrifying bacteria and denitrifying bacteria, improves the removal rate of ammonia nitrogen in wastewater, and achieves the effect of nitrogen removal in wastewater; Sludge is activated sludge loaded by magnetic carrier. Magnetic carrier can not only improve the activity of activated sludge, but also increase the load of activated sludge, which can greatly reduce the amount of sludge produced. achieve the goal of emission reduction. the

Preferably, the particle size of the magnetic substance is 500 mesh to 800 mesh, and the specific gravity is 2.5. The magnetic carrier of the present invention is beneficial to the growth of microorganisms. the

The magnetic substance used in this process is a catalyst that can assist the growth of organisms. The magnetic substance commonly used in this field can be used, and the self-improved magnetic carrier can also be used. The self-improved magnetic carrier has better effect. Through the magnetic field of the magnetic carrier, the adsorption and degradation of some degrading bacteria can be strengthened, thereby improving the pollutant treatment effect of wastewater. the

The particle size of the magnetic substance is controlled at 500 mesh to 800 mesh, and the specific gravity is about 2.5. It needs to be modified by surface activity. The modification method is through magnetization and burning. The modified magnetic substance can increase the surface area and roughness. , which is more conducive to the growth of microorganisms. In addition, under the action of a strong magnetic field strength, the sedimentation performance of the sludge is effectively improved, and the sludge structure is improved. Since the surface of the magnetic powder is charged, the magnetic powder has a strong adsorption effect on the bacterial micelles in the sludge. Gradually form a compact magnetic powder aggregate structure, which reduces the loss of free bacteria, and the biomass increases faster, which increases the sludge concentration in the bioreactor and overcomes sludge swelling. The specific gravity of magnetic activated sludge is larger than that of different activated sludge. The sedimentation separation effect is good, and the water quality of the effluent is improved. the

Dissolved oxygen in water is the key to the decomposition of organic matter in water. The oxygen production rate of the magnetized water sample is higher than that of the original water sample. The reason is that the magnetic powder reduces the oxygen consumption capacity of the organic matter in the wastewater, so the addition of the magnetic powder also helps to reduce the dissolved oxygen. . the

The beneficial effect that the present invention has compared with prior art is:

1) This system integrates several technological methods of magnetic carrier, magnetic separation, and low dissolved oxygen nitrosation. the

2) The magnetic carrier of this system is recovered in the system through the magnetic drum separator, so the consumption of the magnetic carrier is extremely small and the cost of sewage treatment is reduced. the

3) This system uses magnetic material as the growth carrier of bacteria, which is a flow-type membrane biological method. the

4) This system uses magnetic material as the growth carrier of bacteria, which can improve the growth cycle of bacteria, reduce the production of excess sludge, reduce the production of biochemical sludge, and reduce the secondary pollution of sludge to the environment. the

5) This system adopts low dissolved oxygen nitrosation technology and uses magnetic carrier as an intermediate to make the nitrogen and phosphorus removal effect of wastewater reach the best state. The low dissolved oxygen in the oxygen-enriched pool is kept at 1-2mg/L. the

6) This system uses magnetic carrier as the growth carrier of the bacteria, and uses the density difference of the magnetic carrier to make the muddy water easier to separate and increase the sedimentation rate to improve the water quality of the effluent. the

7) This system can be used not only in the biochemical treatment system of urban sewage treatment plants, but also in the biochemical sewage treatment system of enterprise sewage stations, with a wide range of applications. the

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention. the

The reference signs shown in the figure are as follows:

1-Water inlet pipe 2-Oxygen-poor pool 3-Oxygen-enriched pool

4- Internal return pump 5- Internal return pipe 6- Aeration device

7-Aeration pipe 8-Fan 9-Mud-water separation area

10-Sloping plate packing 11-Outlet tank 12-Excess sludge pump

13-Excess sludge pipe 14-Magnetic drum separator 15-Excess sludge discharge pipe 

16-Magnetic substance return pipe 17-Water outlet area 18-Water outlet pipe

19-External return pump 20-External return pipe. the

Detailed ways

As shown in Figure 1, a low-dissolved oxygen magnetic biochemical treatment system includes an oxygen-poor tank 2, an oxygen-rich tank 3 and a sedimentation tank connected in sequence. The sedimentation tank is divided into a mud-water separation zone 9 and an outlet zone 17, and a mud-water separation zone 9 It is connected with the oxygen-enriched pool 3. the

The oxygen-poor pool 2 is connected to the water inlet pipe 1, the bottom of the oxygen-enriched pool 3 is provided with an aeration device 6, and the outside of the oxygen-enriched pool 3 is provided with a fan 8, and the fan 8 is connected to the aeration device 6 through the aeration pipe 7, and the end of the oxygen-enriched pool 3 is connected to the The front ends of the oxygen-depleted pool 2 are connected by an internal return pump 4 and an internal return pipe 5, and the sludge at the end of the oxygen-enriched pool is returned to the front end of the oxygen-deficient pool. the

Sloping plate packing 10 is arranged in the mud-water separation area 9, and a water outlet tank 11 is arranged above the inclined plate packing 10. The water outlet tank is connected to the water outlet area 17, and the water outlet area 17 is divided into upper and lower water outlet areas. The volume ratio is 1:1, the upper water outlet area is connected to the water outlet pipe 18 , and the lower water outlet area is connected to the oxygen-poor pool 2 through the external return pump 19 and the external return pipe 20 . the

The bottom of the mud-water separation zone 9 is connected to a magnetic drum separator 14 through an excess sludge pump 12 and an excess sludge pipe 13. The outlet of the magnetic drum separator 14 is divided into two paths, one of which is connected to the The oxygen-deficient pool 2 has a surplus sludge discharge pipe 15 along the way. the

Process flow of the present invention is as follows:

Wastewater enters the system after pre-treatment or from the workshop collection system. First, the water inlet pipe enters the anoxic pool, and at the same time, the internal and external reflux liquid or magnetic substances are injected into the anoxic pool at the same time. The wastewater enters the oxygen-enriched pool after being reacted by the oxygen-poor bacteria in the oxygen-poor pool. The oxygen-enriched pool uses a blower and an aeration device to provide dissolved oxygen to the oxygen-enriched pool to provide conditions for the survival of oxygen-enriched bacteria. the

The wastewater stays in the oxygen-enriched tank for a certain period of time to degrade the organic matter in the wastewater and then enters the mud-water separation area. The wastewater enters from the bottom, and the mud-water separation is carried out through the inclined plate packing in the mud-water separation area. The sludge settles at the bottom, and the supernatant comes out from the upper part. The sink enters the subsequent outlet area. Among them, there is an excess sludge discharge system at the bottom of the mud-water separation area, including excess sludge pumps, excess sludge pipes, magnetic drum separators, excess sludge discharge pipes, and magnetic substance return pipes connected in sequence. The excess sludge passes through the excess sludge The pump is pumped into the magnetic drum separator through the excess sludge pipe, and the magnetic drum separator separates the excess sludge and magnetic substances, and the excess sludge is sent to subsequent treatment and disposal, and the magnetic substances return to the oxygen-poor pool. the

Among them, the magnetic drum separator has a recovery efficiency of more than 90% of magnetic substances. After the wastewater is separated from the mud and water, the supernatant enters the water outlet area. There are two water outlet areas. One is the upper part with an outlet pipe, and part of the outlet water is discharged or goes to subsequent treatment. Another water outlet area is that the bottom is provided with an external return device, including an external return pump and an external return pipe. The external return effluent returns to the oxygen-poor tank through the external return pump and the external return pipe. The ratio of the two water outlet areas of the water outlet area is 1:1. the

The oxygen capacity in the oxygen-enriched pool is 1-2mg/L; the dosage of magnetic carrier in the oxygen-poor pool and the oxygen-enriched pool is 1-3g/L; the hydraulic retention time of wastewater in the oxygen-poor pool is 2-4h, The hydraulic retention time of the pool is 8 to 24 hours; the particle size of the magnetic material is 500 mesh to 800 mesh, and the specific gravity is 2.5. the

Example 1

This process is applied to a sewage treatment station of a printing and dyeing enterprise. The sewage station of this enterprise has 2 sets of parallel treatment systems, one adopts ordinary biochemical treatment process, and the other adopts this process. -Oxygen-enriched tank-secondary sedimentation tank, the ordinary group does not add magnetic carrier, and the dissolved oxygen is controlled at 2-4mg/L, and the other group is added with magnetic carrier, and the dissolved oxygen is controlled at 1-2mg/L. The effluent indicators of the two groups of treatment are shown in the table below:

Table 1 The effluent index unit of the two groups of treatment systems of the sewage station: mg/L

Note: Compared with ordinary biochemical treatment, the indicators of COD, ammonia nitrogen and SS in the effluent quality of this process are relatively improved by 20%. the

Claims (9)

1. one kind low dissolved oxygen magnetic biochemical treatment system, comprise the oxygen deprivation pond, oxygen enrichment pond and the settling tank that connect successively, in described settling tank, be divided into mud-water separation district and exhalant region, described exhalant region connects rising pipe, described oxygen deprivation pond connects water inlet pipe, bottom, described oxygen enrichment pond arranges aerating apparatus, the external blower fan of this aerating apparatus; It is characterized in that, also comprise:

Magnetic drum separator, the entrance of this magnetic drum separator is connected to bottom, described mud-water separation district by excess sludge pipe, and outlet is connected to described oxygen deprivation pond by magnetic substance return line;

Internal reflux pump, the entrance of this internal reflux pump connects oxygen enrichment pond end, and outlet connects oxygen deprivation pond front end.

2. low dissolved oxygen magnetic biochemical treatment system according to claim 1, it is characterized in that, in described exhalant region, be divided into upper and lower two outlet areas, rising pipe described in upper water-out joint area, lower outlet area connects an external reflux pump, and the other end of this external reflux pump is connected to oxygen deprivation pond.

3. low dissolved oxygen magnetic biochemical treatment system according to claim 2, is characterized in that, the volume ratio of Yu Xia outlet area, described upper water-out region is 1:1.

4. low dissolved oxygen magnetic biochemical treatment system according to claim 1, is characterized in that, described mud-water separation arranges inclined plate packing in district.

5. low dissolved oxygen magnetic biochemical treatment system according to claim 1, is characterized in that, the outlet of described magnetic drum separator also connects a road excess sludge discharge pipe.

6. utilize the technique that low dissolved oxygen magnetic biochemical treatment system carries out wastewater treatment described in the arbitrary claim of claim 1～5, it is characterized in that, comprise the steps:

In oxygen deprivation pond and oxygen enrichment pond, add magnetic carrier, in debug process, active sludge loads on and on this magnetic carrier, forms magnetic carrier supported active mud;

Described waste water enters mud-water separation district successively after oxygen deprivation pond and the processing of oxygen enrichment pond, and after mud-water separation, clear water enters exhalant region, is finally got rid of by rising pipe;

Mud after mud-water separation is sent in magnetic drum separator and is separated, and separates the magnetic carrier obtaining and is back in oxygen deprivation pond, excess sludge discharge;

In reaction process by blower fan and aerating apparatus to oxygen supply in oxygen enrichment pond, the oxygen capacity maintaining in oxygen enrichment pond is 1～2mg/L; By internal reflux pump by the sludge reflux of oxygen enrichment pond end to oxygen deprivation pond, external reflux pump by the sludge reflux of exhalant region bottom to oxygen deprivation pond.

7. technique according to claim 6, is characterized in that, the dosage of magnetic carrier in oxygen deprivation pond and oxygen enrichment pond is 1～3g/L.

8. technique according to claim 6, is characterized in that, described waste water is 2～4h at the hydraulic detention time in oxygen deprivation pond, and the hydraulic detention time in oxygen enrichment pond is 8～24h.

9. technique according to claim 6, is characterized in that, described magnetic substance particle diameter is 500 order～800 orders, and proportion is 2.5.