Integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device

Abstract

The application discloses an integrated pressurized oxygen-enriched fluidized bed membrane biological reaction device, which comprises a main reactor (1), the upper and lower sides of the main reactor (1) are provided with end covers (11), the inner side of the main reactor (1) is provided with a water distribution plate (2) and an oxygen-enriched air releaser (3) at the bottom, the inner side of the main reactor (1) is sequentially provided with an immersed membrane assembly (4) and a gas-liquid separator (5) from bottom to top at the top, the front side of the main reactor (1) is provided with a jet device (8), the front side of the jet device (8) is respectively provided with a liquid inlet mechanism (6) and an air inlet mechanism (7), the lower side of the immersed membrane assembly (4) is provided with a biological carrier, and the biological carrier is biomass charcoal with a nominal diameter of 2.0-2.5 mm. The device can improve the adhesion effect of the biological membrane and the mixing effect of oxygen and wastewater, and improve the wastewater treatment effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a wastewater treatment device, in particular to an integrated pressurized oxygen-rich fluidized bed membrane bioreactor device. BACKGROUND

[0002] The biological fluidized bed refers to the oxygenated wastewater passing through the fine filter bed from bottom to top, and the filter material covered with biological membrane is used for high-efficiency biological treatment. The membrane biological fluidized bed process is based on the biological fluidized bed, takes activated carbon as the carrier, combines the solid-liquid separation technology of the membrane biological reactor process, integrates the physical adsorption of activated carbon, microbial degradation and high-efficiency separation of the membrane into one, makes the small-molecule organic matter difficult to degrade in the water body and the activated carbon powder in the fluidized state under the aeration condition fully mass transfer, mixing, adsorption and enrichment on the surface of the activated carbon, and reacts and processes the harmful components in the wastewater by microorganisms.

[0003] As disclosed in the patent with application number 201911016982.2, an aerobic biological fluidized bed wastewater treatment device includes a sealed reactor, the reactor is arranged from bottom to top with an aeration unit, a center cylinder and a three-phase separation unit; the center cylinder is provided with a water inlet pipe, the water inlet pipe passes through the reactor and the center cylinder and enters the inside of the center cylinder; the aeration of the aeration unit is toward the space between the outer wall of the center cylinder and the inner wall of the reactor, and pure oxygen is provided by an oxygen aerator, which not only provides the required oxygen for microbial reaction, but also avoids problems such as carrier breakage and loss caused by excessively high aeration intensity. However, it directly transports oxygen and wastewater into the reactor through the oxygen inlet pipe and the water inlet pipe, the mixing effect of oxygen and wastewater is poor, and it uses polyvinyl alcohol hydrogel spherical particles as a biological carrier, which changes the swelling property when treating high-salt and high-toxicity wastewater, affects the adhesion of the biofilm, further affects the activity of microorganisms, and causes the wastewater treatment effect to decrease. SUMMARY

[0004] The present application aims to provide an integrated pressurized oxygen-rich fluidized bed membrane bioreactor device. It can improve the adhesion effect of the biofilm and the mixing effect of oxygen and wastewater, and improve the wastewater treatment effect.

[0005] The technical scheme of the present application is: the integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, comprising a main reactor, the main reactor is provided with a head on the upper and lower sides, the inner bottom of the main reactor is provided with a water distribution plate and an oxygen-enriched air releaser, the inner top of the main reactor is sequentially provided with an immersed membrane assembly and a gas-liquid separator from bottom to top, the front side of the main reactor is provided with a jet device, the jet device is respectively provided with a liquid inlet mechanism and an air inlet mechanism, the lower side of the immersed membrane assembly is provided with a biological carrier, and the biological carrier is biomass charcoal with a nominal diameter of 2.0-2.5 mm.

[0006] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the air inlet mechanism comprises an oxygen-enriched adapter connected to the jet device through a conduit, and the oxygen-enriched adapter is provided with an oxygen generator on the front side.

[0007] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the oxygen-enriched adapter is provided with an oxygen content online control device, and the volume fraction of the oxygen-enriched concentration in the oxygen-enriched adapter is 35%-40%. The oxygen content online control device comprises an oxygen monitor 6 arranged on the oxygen-enriched adapter, and the oxygen-enriched adapter is connected to the exhaust port of the gas-liquid separator on the upper end of the main reactor through a conduit.

[0008] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the liquid inlet mechanism comprises a circulating pump connected to the jet device, and the circulating pump is provided with a pretreatment device at the front end.

[0009] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the height-diameter ratio of the main reactor is not less than 12, and the pressure in the main reactor 1 is not less than 1.0 kg / cm 2 .

[0010] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the head is a head with a pressure resistance of 6 kg / cm 2 .

[0011] In the aforementioned integrated pressurized oxygen-enriched fluidized bed membrane bioreactor device, the gas-water volume ratio in the jet device is 1:3.

[0012] The oxygen-enriched air releaser comprises an annular plate arranged on the upper side of the water distribution plate, and the annular plate is provided with staggered disturbance tubes, the annular plate comprises two oppositely arranged mounting plates with semicircular cross sections, the mounting plates are sequentially provided with a sealing layer and a supporting layer in the diameter-reducing direction, one end of the supporting layer is provided with a clamping block, the other end of the supporting layer is provided with a clamping groove corresponding to the clamping block, a pair of vertical through holes are arranged on the clamping block and the clamping groove, a fixing pin is arranged in the vertical through hole, and the inner wall of the supporting layer is provided with staggered mounting holes.

[0013] Compared with the prior art, the application has the following advantages:

[0014] 1. The application controls the oxygen content in the sewage entering the main reactor through the jet device control and the air inlet mechanism control, and the jet device can improve the mixing effect of oxygen and sewage, and then the oxygen-enriched air releaser is used for releasing, so that the sewage and air drive the biological carrier to move and fully contact, the microorganisms on the biological carrier can improve the activity and improve the treatment effect, when the oxygen-enriched concentration in the oxygen-enriched adapter is 35%-40% by volume fraction, the dissolved oxygen in the main reactor can be maintained at 2-3 mg / L, and the microorganisms can have a better treatment effect;

[0015] 2. The biological carrier is selected as biomass charcoal, the physical property change is small when the biomass charcoal is used for treating high-salt and high-waste water, and when the nominal diameter is 2.0-2.5 mm, the water absorption rate and the specific surface area will increase, which will be more conducive to the adhesion of the biofilm on the surface of the biomass charcoal particles, so as to improve the microbial activity. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of the application;

[0017] Figure 2 is a COD degradation condition diagram of actual chemical and pharmaceutical wastewater in the main reactor of the application;

[0018] Figure 3 is a COD degradation condition diagram of laboratory-prepared high-concentration salt and toxic organic wastewater in the main reactor of the application;

[0019] Figure 4 is a structural schematic diagram of the oxygen-enriched air releaser of the application.

[0020] The labels in the attached diagram are as follows: 1-Main reactor, 2-Water distribution plate, 3-Oxygen-enriched air releaser, 4-Immersed membrane assembly, 5-Gas-liquid separator, 6-Liquid inlet mechanism, 7-Air inlet mechanism, 8-Ejector, 9-Oxygen-enriched adapter, 10-Oxygen generator, 11-End cap, 12-Break tube, 13-Circulation pump, 14-Annular plate, 15-Mounting plate, 16-Sealing layer, 17-Support layer, 18-Card, 19-Card slot, 20-Vertical through hole, 21-Fixing pin, 22-Mounting hole. Detailed Implementation

[0021] Example. An integrated pressurized oxygen-enriched fluidized bed membrane bioreactor is configured as follows: Figure 1 As shown, the reactor includes a main reactor 1, which has end caps 11 on both the upper and lower sides. A water distribution plate 2 and an oxygen-enriched air releaser 3 are provided on the bottom inner side of the main reactor 1. From bottom to top, a submerged membrane assembly 4 and a gas-liquid separator 5 are provided on the top inner side of the main reactor 1. An ejector 8 is provided on the front side of the main reactor 1, and a liquid inlet mechanism 6 and an air inlet mechanism 7 are provided on the front side of the ejector 8. A biological carrier is provided on the lower side of the submerged membrane assembly 4. The biological carrier is biochar with a nominal diameter of 2-3 mm. The biological carrier is located between the oxygen-enriched air releaser 3 and the submerged membrane assembly 4. The biological carrier can fully react with the uniformly mixed organic wastewater and oxygen-enriched air to effectively treat the organic wastewater.

[0022] The air intake mechanism 7 includes an oxygen-enriched adapter 9 connected to the jet injector 8 via a conduit, and an oxygen generator 10 is provided on the front side of the oxygen-enriched adapter 9.

[0023] The oxygen-enriched adapter 9 is equipped with an online oxygen content control device, and the volume fraction of oxygen enrichment in the oxygen-enriched adapter 9 is 35%-40%. The oxygen-enriched adapter is also equipped with an oxygen concentration detection device, which controls the oxygen generator and air intake ratio by detecting the oxygen concentration, thereby achieving accurate control of the oxygen concentration.

[0024] The liquid inlet mechanism 6 includes a circulation pump 13 connected to the ejector 8.

[0025] The height-to-diameter ratio of the main reactor 1 is not less than 12, and the pressure in the main reactor 1 is not less than 1.0 kg / cm². 2 .

[0026] The end cap 11 has a pressure resistance of 6 kg / cm². 2 The cap.

[0027] The gas-water volume ratio in the jet ejector is 1:3.

[0028] The oxygen-enriched air release device 3 comprises an annular plate 14 arranged on the upper side of the water distribution plate 2, and the annular plate 14 is provided with staggered disturbance tubes 12.

[0029] The oxygen is generated by the oxygen generator, and the oxygen concentration in the oxygen-enriched adapter is detected and regulated, so that the oxygen concentration in the oxygen-enriched adapter is maintained at 35-40%. The oxygen-enriched adapter is provided with an oxygen concentration detection device. By detecting the oxygen concentration, the oxygen generator and the air inlet ratio are controlled to accurately control the oxygen concentration. Then the sewage and the oxygen-enriched air are mixed by the jet device and sent into the main reactor 1. The gas-water ratio in the jet device 8 is 1:3. After being sent into the main reactor 1, the air and the sewage are sent out by the water distribution plate 2. The sewage and the air after being sent out will collide with the disturbance tube 12, so that the air, the sewage and the biological carrier are mixed more uniformly, and the treatment effect of the biological carrier on the sewage is improved. During the cleaning and replacement of the disturbance tube 12, the fixing pin 21 can be removed first, and then the clamping block 18 is separated from the clamping groove 19, so that the disturbance tube 12 can be replaced. The sealing layer 16 can be made of rubber material, which can improve the sealing performance with the side wall of the main reactor and prevent the biological carrier from entering between the annular plate 14 and the main reactor 1. Then the sewage is separated by the submerged membrane assembly 4. The submerged membrane assembly is a conventional choice, so it is not described in detail here. Then the gas-liquid separator is used to realize gas-liquid separation. The gas can be returned to the oxygen-enriched adapter 9 to reduce the oxygen production cost

[0030] Experimental example 1: Biomass charcoal particle size research.

[0031] ①, Determination of true density and bulk density.

[0032] The mass-volume method is used to determine the true density and bulk density of the biomass charcoal. The true density determination steps are as follows: first, grind the biomass charcoal, remove impurities, and put it into a 105℃ oven to dry to constant weight. Then take the mass m s of the dried biomass charcoal powder into a specific gravity bottle. Fill the specific gravity bottle with distilled water to 1 / 2 of the capacity, and then water bath for 30 minutes to remove bubbles and cool to room temperature. Then take distilled water to the scale line of the specific gravity bottle and water bath (temperature is 20℃) for more than 30 minutes. After the water bath is finished, make sure that the liquid level in the specific gravity bottle is just at the scale line, wipe it dry, and weigh it, which is recorded as m1. Finally, use the same specific gravity bottle to fill only distilled water, and water bath at 20℃ for more than 30 minutes. Wipe it dry and weigh it, which is recorded as m2. The calculation formula of true density is:

[0033]

[0034] Ps—true density of biomass char, kg / m 3 ;

[0035] m s —mass of biomass char, g;

[0036] p—density of distilled water at 20°C, kg / m 3 ;

[0037] m1—mass of pycnometer with distilled water and biomass char, g;

[0038] m2—mass of pycnometer with distilled water, g.

[0039] Bulk density determination procedure: first, take a clean and dried beaker with a volume of V and weigh it as m1. Then, place the biomass char naturally in the beaker until it reaches the scale line of the beaker, and weigh the total weight of the beaker and biomass char as m2. The bulk density calculation formula is:

[0040]

[0041] ②, average particle size.

[0042] In order to simply represent the size of the average size of biomass char, the average particle size is often calculated. The specific operation steps are as follows: select a clean and dry beaker with a mass of m1, and fill it with a certain amount of biomass char particles, and weigh the total weight as m2. Then, count the biomass char particles in the beaker, and record it as n. The average particle size calculation formula is

[0043]

[0044] D—average particle size of biomass char, m;

[0045] m—mass of beaker, g;

[0046] m2—total mass of biomass char and beaker, g;

[0047] n—number of quantified biomass char;

[0048] p—true density of biomass char, kg / m 3 .

[0049] ③, water absorption rate determination. The water absorption rate is calculated as a mass ratio (w / w). The determination procedure is as follows: take a certain amount of dried biomass char to a constant weight, and weigh it as m1, then place it in distilled water at room temperature for 48 h, take it out, wipe off the surface moisture of the biomass char, and immediately weigh it as m2. The biomass char particle water absorption rate calculation formula is:

[0050]

[0051] wherein: ω - water absorption rate of biochar, %;

[0052] m1 - dry biochar mass, g;

[0053] m2 - biochar mass after soaking, g.

[0054] (4) Specific surface area determination.

[0055] Specific surface area is an important factor affecting biofilm formation on the bio-carrier. The determination method used in this experiment refers to "Gas Adsorption BET Method for Determining Specific Surface Area of Solid Materials (GB / T 19587-2004)". This standard is applicable to the determination of specific surface area of porous materials and the study of bio-fluidized bed treatment of organic wastewater using biochar as a carrier. First, the single-layer saturated adsorption capacity is calculated according to the BET equation. BET equation:

[0056]

[0057] wherein: P / P0 - relative pressure;

[0058] V - adsorption volume (standard state), cm 3 ;

[0059] C - BET constant;

[0060] Vm - single-layer saturated adsorption capacity under standard state, cm 3 .

[0061] The specific surface area calculation formula is as follows:

[0062]

[0063] wherein: S - specific surface area, m 2 / g;

[0064] σ - nitrogen molecule cross-sectional area at 77K temperature, 1.62×10-19m 2 ;

[0065] N - Avogadro's constant, 6.62×10 23 / mol;

[0066] V0 - volume of 1 mol of nitrogen gas under standard state, 22.414 L / mol.

[0067] The true density, bulk density, water absorption, average particle size and specific surface area of the biomass charcoal particles with a particle size of 2.0-2.5 mm were measured according to the above method. The physical properties of the biomass charcoal particles with a particle size of 2.5-3.0 mm, 3.0-3.5 mm and 3.5-4.0 mm are shown in the following table.

[0068] Comparison table of physical properties of biomass charcoal particles

[0069]

[0070] As shown in the above table, compared with the biomass charcoal particles with a particle size of 2.0-2.5 mm, the water absorption and specific surface area of the biomass charcoal particles with a particle size of 2.0-2.5 mm are increased. The decrease of the average particle size and the increase of the water absorption and specific surface area will be more conducive to the attachment of the biofilm on the surface of the biomass charcoal particles.

[0071] Experimental Example 2, continuous pilot experiment of the present application.

[0072] For chemical and pharmaceutical wastewater, the halogenated hydrocarbon concentration is 5000-10000 mg / L, the total salt concentration is 10000-15000 mg / L, and the CODcr concentration is 500-1400 mg / L after preliminary treatment. The continuous experiment is carried out on the high-toxicity and high-salt chemical organic wastewater.

[0073] ①, the amount of biofilm on the surface of the biological carrier.

[0074] In the process of measuring the concentration of activated sludge, the concentration of active microorganisms is used as a more accurate representation in theory. It is measured in mgVSS / g carrier. The specific measurement steps are as follows:

[0075] A certain amount of biomass charcoal particles with biofilm after being taken from the reactor is placed in a small beaker, the weight of the beaker is W1, distilled water is added to the beaker to wash away the suspended microorganisms, and the washing is repeated for 3 times. Then distilled water is added to the beaker to submerge the biofilm carrier particles, and the beaker is placed in an ultrasonic instrument for ultrasonic treatment for 2 hours. Then the solution is poured into a clean evaporating dish. The same amount of distilled water is added to the small beaker, and the solution is ultrasonically treated for 2 hours and then poured into the evaporating dish. The beaker is washed with a small amount of distilled water for several times, and the washing liquid is poured into the evaporating dish. The washing liquid is evaporated. Then the cleaned carrier, beaker and evaporating dish are placed in a 105℃ oven and dried to constant weight. The total weight of the carrier and beaker is W2, the total weight of the biofilm and evaporating dish is W3, and finally the evaporating dish is placed in a 600℃ muffle furnace and burned for about 40 minutes to constant weight. The cooled weight is recorded as W4. The calculation formula of the amount of biofilm on the surface of the biological carrier is:

[0076]

[0077] In the formula, VSS is the volatile suspended solid, mg.

[0078] W1 - the mass of the beaker, g;

[0079] W2 - the total weight of the carrier and the beaker after the biofilm is stripped, g;

[0080] W3 - the total weight of the stripped biofilm and the evaporating dish after drying at 105°C, mg;

[0081] W4 - the total weight of the evaporating dish and the residue after muffle furnace calcination, mg.

[0082] Through observation and research on the formation process of the reactor biofilm, it is determined that the unit carrier biomass in the main reaction zone is about 5.3-11.8 mg VSS / g carrier.

[0083] 2, COD degradation in the main reactor.

[0084] In order to investigate whether the biological fluidized bed reactor is running normally, when the oxygen enrichment concentration is set to 35-40% by volume fraction, the dissolved oxygen in the main reaction zone is maintained at 2-3 mg / L, sampling analysis is taken every 24 h, the system COD concentration is determined and the removal rate is calculated, and the specific results are shown in Figure 2 .

[0085] According to Figure 2 , the average COD concentration in the experimental influent is 957 mg / L, and the average COD removal rate gradually increases from 28.26% to 65.74% in the middle and late stages of the start-up of the application, and finally stabilizes at about 60%, and the effluent COD concentration stabilizes at about 430 mg / L. When the oxygen enrichment concentration is set to 35-40% by volume fraction, the dissolved oxygen concentration in the main reaction zone is maintained at 2-3 mg / L, and the microorganisms can have good COD treatment effect, and in the process of long-term operation, the application can maintain a COD removal rate of about 60%, and the equipment runs stably and reliably. The COD removal rate in the process of treating high-salt and high-toxicity organic wastewater using a conventional membrane biological reaction device is only 5-15%, so the salt and toxicity tolerance of the microorganisms of the application is obviously improved, and the treatment effect of high-salt and high-toxicity organic wastewater is good.

[0086] Experimental Example 3, continuous trial operation experiment of the application on laboratory prepared high-concentration salt and toxicity organic wastewater.

[0087] In order to further test the effect of the application on the treatment of high-salt and high-toxicity organic wastewater, the laboratory is configured with high-salt and high-toxicity organic wastewater, and the halogenated hydrocarbon concentration is measured to be 50000-60000 mg / L, the CODcr concentration is measured to be 45000-60000 mg / L, the total nitrogen content is measured to be 1000-2000 mg / L, and the total salt content is measured to be 100000-150000 mg / L. In order to investigate whether the biological fluidized bed reactor is running normally, when the oxygen enrichment concentration is set to 35-40% by volume fraction, the dissolved oxygen in the main reaction zone will be maintained at 2-3 mg / L, sampling analysis is taken every 24 h, the system COD concentration is measured and the removal rate is calculated, and the specific results are shown in Table 1. Figure 3

[0088] According to the water quality index record, when the oxygen enrichment concentration is set to 35-40% by volume fraction, the dissolved oxygen in the main reaction zone will be maintained at 2-3 mg / L, which can meet the needs of microbial growth. According to the water quality index record, Figure 3 It can be seen that the average COD concentration of the experimental influent is 52457.14 mg / L, and the average COD removal rate gradually stabilizes at about 65% during the start-up process of the application. When the oxygen enrichment concentration is set to 35-40% by volume fraction, the dissolved oxygen concentration in the main reaction zone will be maintained at 2-3 mg / L, and the microorganisms can have good COD treatment effect. In the process of long-term treatment of organic wastewater with extremely high concentration of salt and toxicity, the application can maintain a COD removal rate of about 65%, and the equipment runs stably and reliably. The use of conventional membrane biological reaction device measures that the COD removal rate during the treatment of laboratory-configured organic wastewater is only 5-10%, so the salt and toxicity tolerance of the microorganisms in the application is obviously improved, and the treatment effect of high-salt and high-toxicity organic wastewater is good.​

Claims

1. An integrated pressurized oxygen-enriched fluidized bed membrane bioreactor, characterized in that, The reactor includes a main reactor (1), which has end caps (11) on both the upper and lower sides. A water distribution plate (2) and an oxygen-enriched air release device (3) are located at the bottom inner side of the main reactor (1). A submerged membrane assembly (4) and a gas-liquid separator (5) are sequentially arranged from bottom to top on the top inner side of the main reactor (1). An ejector (8) is located at the front of the main reactor (1), and a liquid inlet mechanism (6) and an air inlet mechanism (7) are located at the front of the ejector (8). A biological carrier, consisting of biochar with a nominal diameter of 2.0-2.5 mm, is located below the submerged membrane assembly (4). The air inlet mechanism (7) includes an oxygen-enriched adapter (9) connected to the ejector (8) via a conduit. An oxygen generator (10) is located at the front of the oxygen-enriched adapter (9). An online oxygen content control device is installed on the oxygen-enriched adapter (9). The volume fraction of oxygen concentration in the adapter (9) is 35%-40%; the oxygen-enriched air releaser (3) includes an annular plate (14) on the upper side of the water distribution plate (2), and staggered turbulence pipes (12) are provided between the annular plates (14). The annular plate (14) includes two mounting plates (15) arranged opposite each other and with a semi-circular cross section. The mounting plate (15) is provided with a sealing layer (16) and a support layer (17) in sequence along the direction of decreasing diameter. One end of the support layer (17) is provided with a locking block (18), and the other end of the support layer (17) is provided with a slot (19) corresponding to the locking block (18). The locking block (18) and the slot (19) are provided with vertical through holes (20) facing each other. A fixing pin (21) is provided in the vertical through hole (20). The inner wall of the support layer (17) is provided with staggered mounting holes (22).

2. The integrated pressurized oxygen-enriched fluidized bed membrane bioreactor according to claim 1, characterized in that: The liquid inlet mechanism (6) includes a circulation pump (13) connected to the jet injector (8).

3. The integrated pressurized oxygen-enriched fluidized bed membrane bioreactor according to claim 1, characterized in that: The height-to-diameter ratio of the main reactor (1) is not less than 12, and the pressure in the main reactor (1) is not less than 1.0 kg / cm². 2 .

4. The integrated pressurized oxygen-enriched fluidized bed membrane bioreactor according to claim 1, characterized in that: The end cap (11) is a pressure-resistant end cap with a pressure resistance of 6 kg / cm².

5. The integrated pressurized oxygen-enriched fluidized bed membrane bioreactor according to claim 1, characterized in that: The gas-water volume ratio in the jet ejector (8) is 1:3.

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