CN112537845B - A system and method for anaerobic resource utilization of rural sewage - Google Patents

Abstract

The invention discloses a rural sewage anaerobic resource utilization system and a method, the system comprises an anaerobic membrane biological reaction area, two sides of the anaerobic membrane biological reaction area are provided with anaerobic hydrolysis reaction areas communicated with the anaerobic membrane biological reaction area, the interior of the anaerobic hydrolysis reaction area is divided into at least two upflow reaction compartments by folded plates, two-phase separation fillers are transversely arranged in the upflow reaction compartments, a water distribution system and an aeration system are arranged below the anaerobic membrane biological reaction area and the anaerobic hydrolysis reaction area, and a sludge discharge port is arranged below the aeration system. The method comprises the following steps: after being distributed by a water distribution system, sewage flows into the anaerobic hydrolysis reaction area from bottom to top between the folded plates for primary treatment; and the sewage flows into the anaerobic membrane biological reaction zone for further treatment through the anaerobic hydrolysis reaction zone, the sludge is discharged from the sludge discharge port, and the purified water is discharged. The invention has simple structure, stable operation, high reaction efficiency, low energy consumption, low cost and easy start; simple operation and stable operation treatment effect.

Description

A system and method for anaerobic resource utilization of rural sewage

technical field

The invention relates to a sewage treatment system and method, in particular to a system and method for anaerobic resource utilization of rural sewage.

Background technique

The anaerobic wastewater treatment process has good application prospects in the recovery and utilization of energy resources. BOD ₅ in sewage can be converted into energy gas such as biogas through anaerobic treatment, and organic nitrogen in sewage can be converted into ammonia nitrogen through anaerobic treatment. In the case of removing heavy metal ions, pathogenic microorganisms and other pollutant indicators, the effluent can be recycled.

The key to the efficient operation of the anaerobic sewage treatment process is the retention and enrichment of anaerobic microorganisms. Because the proliferation of anaerobic microorganisms is slow, it is necessary to maintain a certain biomass to ensure the reaction efficiency. However, the traditional anaerobic sewage treatment process generally has the problems of long start-up time and loss of anaerobic sludge with the reaction, resulting in low treatment efficiency and poor effluent effect, and it is difficult to meet the needs of recycling. At present, the rural sewage treatment process is mostly anaerobic and aerobic process, which emphasizes treatment and neglects utilization, and the degree of resource utilization is not high.

At present, the traditional high-efficiency anaerobic process mainly realizes the retention and enrichment of anaerobic microorganisms by forming anaerobic granular sludge or forming biofilm on the surface of the carrier. The traditional anaerobic folded-plate reactor has problems such as long start-up time, difficulty in two-phase separation, and unstable treatment effect when treating rural sewage; anaerobic biological filter is easy to block with fillers, low treatment efficiency, and ineffective when treating rural sewage. It is suitable for dealing with high organic load sewage and other problems. Although the anaerobic membrane bioreactor can achieve better effluent effect, the problem of membrane fouling still restricts its development and promotion. Therefore, the traditional anaerobic process to treat rural sewage is difficult to achieve the purpose of water resource utilization.

SUMMARY OF THE INVENTION

Purpose of the invention: One purpose of the present invention is to provide a rural sewage anaerobic resource utilization system with high reaction efficiency, low energy consumption, low cost and less operation space;

Another object of the present invention is to provide a method for utilizing the rural sewage anaerobic resource utilization system.

Technical solution: The anaerobic resource utilization system for rural sewage according to the present invention includes an anaerobic membrane biological reaction zone, and two sides of the anaerobic membrane biological reaction zone are provided with anaerobic hydrolysis devices that communicate with the anaerobic membrane biological reaction zone. The reaction zone, the interior of the anaerobic hydrolysis reaction zone is divided into at least two up-flow reaction compartments by folded plates, and the up-flow reaction compartments are provided with two-phase separation fillers that separate the reaction compartments up and down along the transverse direction, and the The anaerobic membrane biological reaction zone and the anaerobic hydrolysis reaction zone are provided with a water distribution system and an aeration system for realizing the circulating flow of anaerobic sludge inside the reactor, and a sludge discharge port is provided below the aeration system.

Preferably, the anaerobic hydrolysis reaction zone composed of folded plates in the present invention improves hydraulic conditions, strengthens anaerobic hydrolysis, and improves the efficiency of organic matter treatment; two-phase separation fillers are arranged between the folded plates to divide the anaerobic hydrolysis reaction zone into upper and lower parts Two parts, each of which specifically domesticates a different microbial population, allowing for the separation of acidogenic and methanogenic phases. The two-phase separation packing realizes two-phase separation, while retaining nutrients such as nitrogen and phosphorus. Compared with the traditional anaerobic sewage treatment process, it can obtain better effluent quality. The treated water can be reused for irrigation water, etc., to realize sewage treatment. resource utilization.

Preferably, the volume of the upper part of the two-phase separation packing is larger than the volume of the lower part. The two-phase separation packing divides the anaerobic hydrolysis reaction into upper and lower parts, the lower part is the acid-producing phase, the upper part is the methane-producing phase, and the volume ratio of the upper and lower parts is preferably 2:1; the two-phase separation packing adopts a three-dimensional mesh packing, and the water flow is Three-dimensional flow, no clogging, no agglomeration, 95% porosity, the lower part adopts glass fiber reinforced plastic mesh support plate, because the sewage rises in twists and turns between the folded plates, it is easier to contact the filler, so that the solid-liquid and gas-liquid are easier to separate, so the filler can not be used. Inclined arrangement.

Preferably, the anaerobic membrane biological reaction zone includes a membrane module, and two sides of the membrane module are provided with guide plates for guiding the gas generated by the aeration system. The membrane module adopts hollow fiber ultrafiltration membrane, which can trap the anaerobic microbial flora in the anaerobic hydrolysis reaction zone to ensure the concentration of anaerobic microorganisms and improve the reaction efficiency; the membrane module can also trap the sewage containing macromolecular organic matter, It continues to degrade in the anaerobic hydrolysis reaction zone. Through the filtration of the membrane module, the separation of the hydraulic retention time and the biological solids retention time is realized, which greatly improves the reaction efficiency of the system. Compared with the traditional process, the anaerobic membrane biological reaction zone of the present invention reduces the operation space and the number of unit operations, and is easy to expand the scale and selectively recover and separate nutrients and resources.

Preferably, the tops of the folded plate, the deflector and the membrane assembly are lowered in sequence, and the cradles of the folded plate, the deflector and the membrane assembly are raised in sequence. The invention changes the push-flow water inflow of the traditional anaerobic folded plate, and the water is evenly fed through the bottom of the reactor, so that the sewage flows from bottom to top, the unique folded plate structure improves the hydraulic conditions, and strengthens the anaerobic sludge and sewage. The circulating flow in the inner cavity of the reactor promotes mass transfer, reduces the organic load of sewage, and effectively alleviates the problem of membrane fouling.

Preferably, the anaerobic membrane biological reaction zone is connected to a water outlet, one end of the water outlet is connected to the water outlet monitoring device and the outlet water pressurizing pump, and the other end of the water outlet is connected to the water inlet for realizing water circulation.

Preferably, a gas collecting hood for collecting biogas is arranged above the anaerobic hydrolysis reaction zone, and an exhaust pipe and a gas release valve are connected to the gas collecting hood.

Preferably, a biogas treatment device is connected to the gas collecting hood, and the biogas treatment device is connected to the aeration system through a gas compressor for supplying gas to the aeration system. The anaerobic sludge in the inner chamber of the reactor decomposes the organic matter in the sewage into inorganic matter, and the generated biogas is aerated through the aeration device at the bottom of the system after treatment and collection, which not only slows down the membrane pollution, but also enhances the anaerobic sludge. Circulation flow in the reactor.

Preferably, the water distribution system is connected to a water inlet arranged below the anaerobic hydrolysis reaction zone, and the water inlet is connected to a water inlet monitoring device and a peristaltic pump. The water distribution of sewage from the water distribution system at the bottom can make the sewage and anaerobic sludge fully contact and enter the anaerobic membrane biological reaction zone, improve the degradation effect of sewage, improve the anti-shock load capacity of the system, reduce the organic load of sewage entering the membrane module, slow down Membrane fouling.

Preferably, the anaerobic hydrolysis reaction zone is provided with a multifunctional display meter for monitoring the reaction state of the system.

The method for treating sewage using the above-mentioned rural sewage anaerobic resource utilization system includes the following steps:

(S1) After the sewage is distributed by the water distribution system, it flows into the anaerobic hydrolysis reaction zone from bottom to top between the folded plates for primary treatment;

(S2) The sewage in the anaerobic hydrolysis reaction zone flows into the anaerobic membrane biological reaction zone for further treatment, the sludge is discharged from the sludge discharge port, and the purified water is discharged.

Beneficial effects: Compared with the prior art, the present invention achieves the following remarkable effects: 1. The structure is simple, the reaction is efficient, low energy consumption, low cost, and easy to start. Compared with the traditional sewage treatment process, the device of the present invention reduces the operating space and is easier to operate. Expanded scale and selective recycling of resources are more suitable for sewage treatment. 2. The anaerobic baffle plate reactor and the anaerobic membrane bioreactor are organically combined, and the integrated design is adopted to give full play to the advantages of the anaerobic baffle plate technology and the anaerobic membrane bioreactor; 3. The method of the present invention is simple and easy to operate. The treatment effect is stable and efficient.

Description of drawings

FIG. 1 is a schematic structural diagram of the system of the present invention.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings.

As shown in FIG. 1 , the present invention provides a rural sewage anaerobic resource utilization system, including an anaerobic membrane biological reaction zone, and two sides of the anaerobic membrane biological reaction zone are provided with an anaerobic membrane biological reaction zone. Connected anaerobic hydrolysis reaction zone.

The anaerobic hydrolysis reaction zone is provided with 8 identical zigzag folded plates 5 in the vertical direction, and four folded plates 5 are arranged on each side with the anaerobic membrane biological reaction zone as the center, and the two folded plates 5 on each side are parallel to each other. And they are arranged at equal distances, so that the water flow is disturbed between the folded plates 5, which is conducive to the full contact between the sewage and the anaerobic sludge. Two-phase separation packing 22 is arranged between the two folded plates 5 on each side along the horizontal direction, and the anaerobic hydrolysis reaction is divided into upper and lower parts. 1; The two-phase separation packing 22 adopts three-dimensional mesh packing, the water flow is three-dimensional, does not block, does not agglomerate, the porosity is 95%, and the lower part adopts the glass fiber reinforced plastic mesh support plate. Contact with the packing makes it easier to separate solid-liquid and gas-liquid, so the packing can be arranged without tilting. A multi-function display meter 7 is installed in the anaerobic hydrolysis reaction area to monitor the reaction status of the system, such as pH, temperature, etc., to prevent the pH from being too low due to acidification of the system by anaerobic hydrolysis.

The anaerobic membrane biological reaction zone includes a membrane module 4. The membrane module 4 adopts a hollow fiber ultrafiltration membrane with a membrane pore size of 0.2 μm and an initial membrane flux of 60L/m ² *h, which is arranged in the vertical direction; both sides of the membrane module 4 A deflector 6 is installed for guiding the gas generated by the aeration system. After the sewage passes through the anaerobic hydrolysis reaction zone, the content of suspended solids and macromolecular organic matter is greatly reduced, and then enters the membrane module 4 for efficient solid-liquid separation, and the suspended solids and pathogenic microorganisms are retained, so that the effluent can be directly reused. Recycling of sewage; the anaerobic membrane biological reaction zone is set in the center of the system, and the two sides are anaerobic hydrolysis reaction zones. On the one hand, the sewage undergoes anaerobic hydrolysis to remove macromolecular organic matter, and then enters the membrane module 4, which can reduce membrane pollution. It can ensure a higher membrane flux; on the other hand, it can improve the anti-shock load capacity of the system and ensure the treatment effect of the system. The tops of the folded plate 5, the deflector 6 and the membrane module 4 are lowered in turn, and the folds of the folded plate 5, the deflector 6 and the cubby of the membrane module 4 are raised in turn, so setting up a diversion gradient, which is conducive to enhancing sewage and pollution. The disturbance of anaerobic sludge promotes the circulating flow of sewage and anaerobic sludge in the reactor.

The aeration system includes a microporous aeration head 17 and a microporous aeration pipe 18, which are arranged below the membrane module 4 and the anaerobic hydrolysis reaction zone. pollution, prolong the service life of the membrane module 4, wash the two-phase separation packing 22, prevent the packing from clogging, and strengthen the water flow disturbance.

The lower side wall of the system is provided with a water inlet 3. One end of the water inlet 3 is sequentially connected with a water inlet monitoring device 2 and a water inlet peristaltic pump 1, and the other end is connected with a water distribution system. The water distribution system includes an anaerobic membrane biological reaction zone and anaerobic hydrolysis. The water distribution pipes 19 below the reaction zone are uniformly distributed with water distribution ports 20 . The membrane module is connected to the water outlet 12 through a negative pressure pipeline. One end of the water outlet 12 is connected to the pressurizing pump 15 and the water outlet monitoring device 14, and the other end is connected to the water inlet 3 to form a return pipeline. A control valve is set on the return pipeline to maintain the organic flow in the system. The load is relatively stable. Above the anaerobic membrane biological reaction zone and the anaerobic hydrolysis reaction zone, a gas collecting hood 11 is provided. The gas collecting hood 11 is provided with a gas release valve 8 and an exhaust port 9, and the exhaust pipe discharges the gas. A biogas treatment device 13 is connected to the gas collecting hood 11, and a gas compressor 16 is arranged between the biogas treatment device 13 and the aeration system, and the gas is transported into the microporous aeration pipe 18, and the gas is passed upward through the microporous aeration head 17. Aeration. A mud discharge port 21 is provided under the aeration system and the water distribution pipe 19. The two sides of the mud discharge port 21 are arranged with inclined planes, and the inclined plane and the horizontal plane form an angle of 60°.

The method for utilizing the above-mentioned rural sewage anaerobic resource utilization system includes the following steps:

(1) The sewage is distributed through the bottom water distribution system. The water distribution pipe 19 runs through the entire reactor. The sewage rises evenly from the bottom to the top from the water distribution port, which has the effect of uniform water distribution. The key link for the smooth operation of the reactor;

(2) The anaerobic sludge is inoculated in the anaerobic hydrolysis reaction zone, and the sewage passes through the anaerobic hydrolysis reaction zone to remove part of the BOD5 and suspended solids in the water; the water flow spirals up between the two folded plates 5, which strengthens the contact between the sewage and the anaerobic microorganisms , to ensure the effect of anaerobic reaction and improve the efficiency of anaerobic hydrolysis; two-phase separation packing 22 is arranged transversely through the folded plate 5, and the anaerobic hydrolysis reaction is divided into upper and lower parts, and the residence time of sewage in the upper part is longer than that in the lower part, and the anaerobic hydrolysis reaction is divided into the upper part and the lower part. The hydraulic retention time of the oxygen hydrolysis reaction zone is 6-10h;

Among them, a small amount of oyster shell powder can be added to the methane-producing phase sludge in the upper part of the anaerobic hydrolysis reaction zone. The oyster shell powder contains calcium, magnesium, iron and other elements and various amino acid components, which can promote the growth of methanogens, thereby accelerating the methane biosynthesis;

The biogas generated by the sewage in the anaerobic hydrolysis reaction zone enters the gas collecting hood 11. After the gas in the gas collecting hood 11 reaches a certain amount, it is transported to the biogas treatment device 13 by the exhaust pipe 9, and then passes through the gas compressor 16 through the gas circulation pipeline. It is sent to the aeration system, and the microporous aeration head 17 aerates the membrane module 4 and the two-phase separation packing 22, and the microporous aeration intensity is 3-5L/m ² *s. The resource utilization of the membrane has the effect of saving energy, alleviating membrane pollution, and prolonging the life of the membrane module;

The aeration system adopts intermittent aeration. In every 10min cycle, the effluent is 7-8min and the aeration is 2-3min; after the aeration flushing, the membrane flux is obviously recovered, and the membrane flux after flushing can be restored to the original 85% to 90% of membrane flux;

Part of the biogas generated by the anaerobic hydrolysis of sewage is collected by the gas collection device, and part of it enters the aeration system as a gas source for aeration. Promote mass transfer and improve the degradation rate of sewage;

(3) The sewage in the anaerobic hydrolysis reaction zone flows into the anaerobic membrane biological reaction zone, and most of the suspended solids, macromolecular organic matter and pathogenic microorganisms are removed by the interception effect of the ultrafiltration membrane in the membrane module 4;

(4) The sludge produced by the sewage in the anaerobic hydrolysis zone is discharged through the sludge discharge port 21 at the bottom of the reactor, and the sludge is collected and utilized for resource utilization;

The sewage passes through the interception and filtration of the membrane module 4 in the anaerobic membrane biological reaction zone to achieve high-efficiency purification of the sewage and reach the standard of resource utilization. Resource utilization such as crop irrigation and landscape water; the total hydraulic retention time of the system is 8 to 12 hours, and the system water temperature is maintained at 34 to 37 °C during the entire operation process;

The water quality monitoring device 14 installed at the water outlet 12 detects the water quality. If the COD load is too high, part of the effluent from the membrane module 4 will return to the water inlet through the circulation pipeline between the water outlet and the water inlet to ensure that the organic load of the sewage entering the system is relatively high. Stable, slow down the acidification of the system and ensure the stable operation of the system. When the turbidity of the stable effluent of the system is less than 0.6NTU and COD is less than 80mg/L, the quality of the effluent can reach the reuse standard.

Claims (7)

1. The utility model provides a rural sewage anaerobism resource utilization system, its characterized in that, includes anaerobic membrane bioreaction district, anaerobic membrane bioreaction district's both sides are provided with the communicating anaerobic hydrolysis reaction zone with anaerobic membrane bioreaction district, anaerobic hydrolysis reaction district is inside to be separated for two at least upflow reaction compartments through folded plate (5), upflow reaction compartment is along transversely being provided with two-phase separation filler (22) with reaction compartment partition from top to bottom, and two-phase separation filler is upper and lower two parts with anaerobic hydrolysis reaction district, and the lower part is the acid production phase, and upper portion is the methane production phase, and upper portion and lower part volume ratio are 2: 1;

a water distribution system and an aeration system for realizing the circular flow of anaerobic sludge in the reactor are arranged below the anaerobic membrane biological reaction zone and the anaerobic hydrolysis reaction zone, and a sludge discharge port (21) is arranged below the aeration system;

the anaerobic membrane biological reaction zone comprises a membrane component (4), and guide plates (6) for guiding the flow of the gas generated by the aeration system are arranged on two sides of the membrane component (4); the tops of the folded plate (5), the guide plate (6) and the membrane assembly (4) are sequentially lowered, and the bottoms of the folded plate (5), the guide plate (6) and the membrane assembly (4) are sequentially raised.

2. The rural sewage anaerobic resource utilization system according to claim 1, wherein the anaerobic membrane biological reaction region is connected with a water outlet (12), one end of the water outlet (12) is connected with a water outlet monitoring device (14) and a water outlet pressure pump (15), and the other end of the water outlet (12) is connected with a water inlet (3) for realizing water circulation.

3. The rural sewage anaerobic resource utilization system of claim 1, wherein a gas collecting hood (11) for collecting biogas is arranged above the anaerobic hydrolysis reaction zone, and an exhaust pipe (9) and an air release valve (8) are connected to the gas collecting hood (11).

4. The rural sewage anaerobic resource utilization system according to claim 3, wherein a biogas treatment device (13) is connected to the gas collecting hood (11), and the biogas treatment device (13) is connected to the aeration system through a gas compressor (16) and used for supplying gas to the aeration system.

5. The rural sewage anaerobic resource utilization system of claim 1, wherein the water distribution system is connected with a water inlet (3) arranged below the anaerobic hydrolysis reaction zone, and the water inlet (3) is connected with a water inlet monitoring device (2) and a peristaltic pump (1).

6. The rural sewage anaerobic resource utilization system of claim 1, wherein the anaerobic hydrolysis reaction zone is provided with a multifunctional display meter (7) for monitoring the reaction state of the system.

7. A method for treating sewage by using the anaerobic resource utilization system for rural sewage of claim 1, which is characterized by comprising the following steps:

(S1) the sewage flows into the anaerobic hydrolysis reaction zone from bottom to top between the folded plates (5) after being distributed by a water distribution system for primary treatment;

(S2) the sewage flows into the anaerobic membrane biological reaction zone through the anaerobic hydrolysis reaction zone for further treatment, the sludge is discharged from a sludge discharge port, and the purified water is discharged.

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