Surface quasi-class II drinking water source water replenishment regeneration treatment system and method

Abstract

The invention discloses a surface quasi-class II drinking water source water replenishment and regeneration treatment system and method, comprising an aerated grit chamber, a biological treatment section, an MBR tank, an ozone oxidation section, a sludge concentration and decomposition tank, a disinfection section and an artificial wetland section; the biological treatment section comprises a pre-anoxic zone, an anaerobic zone, a primary aerobic zone, a primary anoxic zone, a secondary aerobic zone and a secondary anoxic zone; the water outlet of the aerated grit chamber is respectively connected with the water inlets of the pre-anoxic zone, the anaerobic zone, the primary anoxic zone and the secondary anoxic zone; the water outlet of the secondary aerobic zone is connected with the water inlet of the pre-anoxic zone; the sludge outlet of the MBR tank is connected with the sludge inlet of the primary aerobic zone; the sludge outlet of the MBR is connected with the sludge inlet of the sludge concentration and decomposition tank, the sludge lysate outlet of the sludge concentration and decomposition tank is connected with the pre-anoxic zone, and the residual sludge of the sludge concentration and decomposition tank is processed into a mud cake and enters the artificial wetland. The surface quasi-class II drinking water source water replenishment and regeneration treatment system of the invention has the advantages of good treatment effect and low operation cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, specifically to a drinking water source replenishment and regeneration treatment system based on the surface quasi-class II water quality standard, and also relates to a drinking water source replenishment and regeneration treatment method based on the surface quasi-class II water quality standard. Background Art

[0002] my country's per capita available freshwater resources are insufficient, and water pollution is becoming increasingly serious, affecting people's health and the ecological environment. As a result, water treatment emission standards have become increasingly stringent. Among the conventional indicators of the Beijing Standard for Water Pollutant Emission Standards for Urban Wastewater Treatment Plants (DB11890-2012), except for TN, the surface water Class III water quality standard has been reached; in 2015, the "Opinions on Accelerating the Construction of Ecological Civilization" issued by the Central Committee of the Communist Party of China and the State Council clearly proposed dual restrictions: pollutant emission standards and total amount restrictions. "All regions that have not completed the total amount control task of major pollutant emissions shall implement 'regional restrictions'", especially in environmentally sensitive areas such as nature reserves, resorts and drinking water source protection areas. The implementation of Class III surface water standards (except TN) or higher standards is of practical significance for water resource protection.

[0003] The prior art has difficulties in deep nitrogen and phosphorus removal and removal of difficult-to-degrade organic matter in conventional water treatment process systems, resulting in unsatisfactory sewage treatment effects and high operating costs. In view of this, the present invention is proposed. Summary of the invention

[0004] The present invention provides a drinking water source replenishment and regeneration system with a surface quasi-class II water quality standard for municipal sewage, aiming to solve the difficulties of deep nitrogen and phosphorus removal and removal of refractory organic matter in the current conventional water treatment process system, and realize an integrated system under the municipal sewage surface water level II discharge standard. The present invention also proposes a treatment method for replenishment and regeneration of drinking water sources with a surface quasi-class II water quality standard with good treatment effect and low operating cost.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a surface quasi-class II drinking water source water replenishment and regeneration treatment system, comprising: an aerated grit chamber, a biological treatment section, an MBR tank, a sludge concentration and decomposition tank, an ozone reactor, an ozone tail gas destruction device, an air compressor, an ozone reaction tank, a disinfection tank and an artificial wetland. The biological treatment section comprises a pre-anoxic zone, an anaerobic zone, a primary aerobic zone, a primary anoxic zone, a secondary aerobic zone and a secondary anoxic zone connected in sequence, wherein each of the water inlet of the pre-anoxic zone, the water inlet of the anaerobic zone and the water inlet of the primary anoxic zone and the secondary anoxic zone is connected to the water outlet of the aerated grit chamber, and the water outlet of the secondary aerobic zone is connected to the water inlet of the pre-anoxic zone. The water inlet of the MBR tank is connected to the water outlet of the secondary anoxic zone, the water outlet of the MBR tank is connected to the inlet of the ozone reaction tank, the return sludge outlet of the MBR tank is connected to the return sludge inlet of the primary aerobic zone, and the residual sludge outlet of the MBR tank is connected to the sludge concentration and decomposition tank. The sludge lysate outlet of the sludge concentration and decomposition tank is connected to the pre-anoxic zone; the filter cake produced by the residual sludge of the MBR tank is used as artificial wetland filler. The ozone outlet of the ozone generator is respectively connected to the sludge concentration and decomposition tank and the ozone reaction tank; the ozone generator uses compressed air generated by an air compressor as an air source. The water inlet of the ozone reaction tank is connected to the water outlet of the MBR tank, the water outlet of the ozone reaction tank is connected to the disinfection tank, and the tail gas of the ozone reaction tank is connected to the ozone tail gas destruction device and the MBR tank respectively.

[0006] The water inlet of the disinfection tank is connected with the water outlet of the ozone reaction tank, the outlet of the disinfection tank is connected with the water inlet of the artificial wetland, and the filter cake of the sludge dehydration and filtration is used as the filler of the artificial wetland.

[0007] Furthermore, it further comprises a coarse grid, a fine grid and a membrane grid; the coarse grid is located upstream of the aeration grit chamber, the fine grid is located between the coarse grid and the aeration grit chamber, and the membrane grid is located downstream of the aeration grit chamber.

[0008] Furthermore, it includes an automatic water inlet control device, the water inlet of the automatic water inlet control device is connected to the water outlet of the aerated grit chamber, and the water outlet of the automatic water inlet control device is connected to each of the water inlet of the pre-anoxic zone, the water inlet of the anaerobic zone, the water inlet of the first anoxic zone and the water inlet of the second anoxic zone.

[0009] Furthermore, the water outlet of the secondary aerobic zone is connected to the water inlet of the pre-anoxic zone.

[0010] Furthermore, it comprises an ozone reaction tank, in which a COD catalytic oxidation filler is arranged.

[0011] The present invention also provides a surface quasi-class II drinking water source water replenishment and regeneration treatment method, comprising the following steps:

[0012] A) Raw water passes through the coarse screen and fine screen and enters the aerated grit tank.

[0013] B) After aeration and sand settling, the effluent is divided into four parts through the membrane grid, namely the first effluent, the second effluent, the third effluent and the fourth effluent; in the pre-anoxic zone, the first effluent is mixed with the return sludge and lysate of the secondary aerobic zone for denitrification, and phosphorus removal agents are added for phosphorus removal.

[0014] C) In the anaerobic zone, the treated first part of the effluent is mixed with the second part of the effluent for anaerobic phosphorus release.

[0015] D) In ​​the primary aerobic zone, the first part of the treated effluent, the second part of the treated effluent and the MBR pool return sludge are mixed to undergo aerobic nitrification to remove ammonia nitrogen; at the same time, aerobic phosphorus absorption is carried out, and total phosphorus is transferred from the liquid to the sludge.

[0016] E) In the primary anoxic zone, the treated first effluent, the treated second effluent and the treated third effluent are mixed, and denitrification continues to remove total nitrogen.

[0017] F) In the secondary aerobic zone, the treated first part of the effluent is mixed with the treated second part of the effluent and the treated third part of the effluent to continue removing ammonia nitrogen.

[0018] G) In the secondary anoxic zone, the treated first effluent, the treated second effluent, the treated third effluent and the treated fourth effluent are mixed, and then an external carbon source is added for deep denitrification.

[0019] H) In the MBR pool, the first treated effluent, the second treated effluent, the third treated effluent and the fourth treated effluent are mixed, and then enzyme-modified activated carbon is added to the MBR pool to remove refractory organic matter, SS is removed by membrane filtration, and the remaining phosphorus-containing sludge is discharged, and finally ozone is added to the MBR pool to reduce membrane clogging and restore the adsorption capacity of the enzyme-modified activated carbon.

[0020] I) Adding a specific COD catalyst into the ozone reaction tank, the remaining ozone after the reaction in the ozone reaction tank is treated by an ozone tail gas destruction device.

[0021] J) The effluent treated by the ozone reaction tank enters the disinfection tank for disinfection to kill bacteria such as E. coli, so that the effluent bacteria are qualified.

[0022] K) the effluent from the disinfection tank enters the artificial wetland; and the remaining sludge in the MBR tank is oxidized and concentrated by ozone, and finally filtered into a mud cake as a wetland filler.

[0023] Furthermore, in step B), the mass percentage of the first part of water is 10% to 30%, the mass percentage of the second part of water is 30% to 50%, the mass percentage of the third part of water is 30% to 50%, and the mass percentage of the fourth part of water is 10%.

[0024] Furthermore, in step H), the sludge return ratio of the MBR pool-primary aerobic zone is 300%-500%; the mixed liquor return ratio of the secondary aerobic zone-pre-anoxic zone is 200%-400%; the bio-enzyme modified activated carbon in the MBR pool is powdered activated carbon with bio-enzymes in the pores, which is specific for difficult-to-degrade organic matter in municipal sewage, and its particle size is 10μm-100μm, and the dosage of the bio-enzyme modified activated carbon is 20mg / L-40mg / L.

[0025] Furthermore, in the ozone reaction tank in step I), the mass ratio of ozone addition / COD removal is 3:1 to 1:1; in the MBR tank, the ozone tail gas dosage is 5 to 10 mg / L; and the ozone dosage of the residual sludge tail gas is: 0.01 to 0.2 gO3 / gVSS.

[0026] The present invention has the following beneficial effects:

[0027] The surface quasi-class II drinking water source water replenishment and regeneration treatment system and method has the following advantages:

[0028] (1) In the improved multi-stage AO-MBR process of the present invention, a phosphorus removal agent is added to the influent to remove part of the TP in the raw water, thereby increasing the C / P ratio of the raw water and creating conditions for the biochemical system to remove TP. This is more economical and energy-saving than the traditional method of adding a carbon source to remove TP, eliminating the need for a subsequent removal system and achieving better effluent effect;

[0029] (2) The entire process adopts a modified multi-stage AO-MBR-bioenzyme modified activated carbon process, which emphasizes integrity. First, for COD removal, easily degradable organic matter is removed by activated sludge, and difficult-to-degrade organic matter gradually diffuses into the bioenzyme modified activated carbon and is removed under the action of specific enzymes; the bioenzyme modified activated carbon system has a synergistic effect on organic matter degradation, forming: adsorption-degradation-adsorption mode, different organic matter removal strategies are different, and the purpose of rational use of microorganisms is achieved; in addition, pre-denitrification protects the anaerobic environment, phosphorus removal effect is higher, and the utilization of segmented water carbon source is more efficient. The use of MBR pools prolongs the sludge retention time, which makes it easy to strengthen different microorganisms in multi-stage AO and easier to cultivate microorganisms suitable for different water qualities. At the same time, as a water supply guarantee unit, it can remove SS and most phosphorus-containing sludge, making the water quality better; the multi-stage AO-MBR-modified bioenzyme process gives full play to the original multi-stage AO denitrification advantages, and at the same time uses the modified bioenzyme-activated sludge system to achieve the removal of difficult-to-degrade organic matter. MBR can intercept SS and remove TP to a high standard;

[0030] (3) Appropriate amount of bio-enzyme-modified activated carbon is added to the MBR pool 3, and it works together with microorganisms and ozone to form a virtuous cycle of "adsorption-desorption-adsorption", thereby enhancing COD removal. At the same time, an appropriate amount of ozone reaction pool tail gas is introduced into the membrane pool, and it works together with powdered bio-enzyme-modified activated carbon to reduce the fouling of membrane fibers by extracellular polymeric organic matter.

[0031] (4) The excess sludge concentration and decomposition tank utilizes the ozone generated by the ozone generator to destroy the sludge cell wall, and the lysed material is used as a carbon source for denitrification. At the same time, the sludge treated with ozone is easier to dehydrate, and the dehydrated mud cake is used as a filler for artificial wetlands to utilize the sludge as a resource;

[0032] (5) The ozone reaction pool uses ozone to further reduce the refractory organic matter in the sewage, improve the biodegradability of the wastewater, and create conditions for further biodegradation of COD in artificial wetlands. At the same time, the ozone tail gas is used as a reagent to inhibit the fouling of the membrane fibers in the membrane pool, and the treatment effect is obvious, which can realize the resource utilization of waste;

[0033] (6) As a means of deep treatment, the artificial wetland further absorbs nutrients such as nitrogen and phosphorus in sewage. At the same time, the artificial wetland uses sludge as filler, fully utilizes the nitrogen and phosphorus substances contained in the sludge, turns waste into treasure, and realizes sludge resource utilization. At the same time, artificial landscapes can be built to achieve the natural combination of sewage treatment and artificial landscapes, which has positive significance for ecological environment protection and restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the surface quasi-class II drinking water source water replenishment and regeneration treatment system of the present invention.

[0035] Figure 2 It is a flow chart of the surface quasi-class II drinking water source water replenishment and regeneration treatment method of the present invention. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0037] Example 1

[0038] like Figure 1 As shown, the surface quasi-class II drinking water source replenishment and regeneration treatment system of the present invention includes an aerated grit chamber 1, a biological treatment section 2, an MBR tank 3, a sludge concentration and decomposition tank 4, an ozone generator 5, an ozone reaction tank 6, a disinfection tank 7 and an artificial wetland 8.

[0039] The biological treatment section 2 includes a pre-anoxic zone 21, an anaerobic zone 22, a primary aerobic zone 23, a primary anoxic zone 24, a secondary aerobic zone 25 and a secondary anoxic zone 26 which are connected in sequence. The water outlet of the aerated grit chamber 1 is connected to the water inlet of the pre-anoxic zone 21, the water inlet of the anaerobic zone 22, the water inlet of the primary anoxic zone 24 and the water inlet of the secondary anoxic zone 26, respectively, and the water outlet of the secondary aerobic zone 25 is connected to the water inlet of the pre-anoxic zone 21.

[0040] The sludge outlet of the MBR tank 3 is connected to the sludge inlet of the primary aerobic zone 23. The sludge inlet of the sludge concentration and decomposition tank 4 is connected to the sludge outlet of the MBR tank 3, and the sludge lysate outlet of the sludge concentration and decomposition tank 4 is connected to the pre-anoxic zone 21. The filter cake produced by the sludge concentration and decomposition tank 4 is used for the artificial wetland 8.

[0041] The water outlet of MBR pool 3 is connected with the water inlet of ozone reaction pool 6, the water outlet of ozone reaction pool 6 is connected with the water inlet of disinfection pool 7, and the water outlet of disinfection pool 7 is connected with the wetland water inlet 8. The gas inlet of ozone reaction pool 6 is connected with the outlet of ozone generator 4, and the tail gas outlet of ozone reaction pool 6 is connected with ozone tail gas destruction device 61 and the ozone tail gas inlet of MBR pool 3 respectively.

[0042] The ozone outlet of the ozone generator 5 is communicated with the ozone air inlet of the sludge concentration and decomposition tank 4 and the ozone reaction tank 6 respectively, wherein the ozone generator uses compressed air generated by an air compressor as an air source.

[0043] The municipal sewage deep treatment system according to the embodiment of the present invention can distribute the water volume of municipal sewage and improve the utilization rate of carbon sources in sewage by connecting the water outlet of the aeration grit chamber 1 to the water inlet of the pre-anoxic zone 21, the water inlet of the anaerobic zone 22, the water inlet of the primary anoxic zone 24 and the water inlet of the secondary anoxic zone 26. Specifically, the municipal sewage flowing out of the aeration grit chamber 1 is distributed into the first part of the effluent (flowing into the pre-anoxic zone 21), the second part of the effluent (flowing into the anaerobic zone 22), the third part of the effluent (flowing into the primary anoxic zone 24) and the fourth part of the effluent (flowing into the secondary anoxic zone 26).

[0044] The C / N of municipal sewage in my country is relatively low, and the organic carbon source in municipal sewage is not enough to support the denitrification reaction. In the existing A2 / O process, in order to ensure that the TN of the effluent meets the standard, it is necessary to add additional carbon sources (such as methanol or ethanol, etc.) during the denitrification reaction, which greatly increases the treatment cost. According to the surface quasi-class II drinking water source replenishment treatment system of the present invention, by connecting the sludge lysate outlet of the sludge concentration and decomposition tank 4 with the pre-anoxic zone 21, the sludge lysate can be used as a carbon source for the denitrification reaction and put into the pre-anoxic tank 21, so as to reduce the additional addition of carbon sources when performing denitrification reaction on municipal sewage, thereby not only reducing the treatment cost, but also having a significant sludge reduction effect, reducing the cost of sludge treatment and disposal; at the same time, adding a dephosphorization agent to eliminate excess TP is more conducive to the biochemical phosphorus removal of the remaining total phosphorus.

[0045] According to the surface quasi-class II drinking water source replenishment treatment system of the present invention, by setting the secondary aerobic zone 25 and the secondary anoxic zone 26, after the municipal sewage is aerobic treated, the municipal sewage can also be anoxic treated and aerated treated. By performing the anoxic treatment, the municipal sewage can be further denitrified to further remove inorganic nitrogen in the municipal sewage. The aeration treatment can blow off the remaining nitrogen, and at the same time, the aeration can improve the sedimentation performance of the sludge and further remove organic matter.

[0046] According to the surface quasi-class II drinking water source replenishment treatment system of the present invention, by setting a pre-anoxic zone 21 upstream of the anaerobic zone 22, and setting a secondary anoxic zone 26 to return sludge to the pre-anoxic zone 21, the protection of the subsequent anaerobic environment is ensured. The anoxic treatment performs denitrification and denitrification, which can effectively remove NO3-N, thereby ensuring that the subsequent phosphorus release reaction is fully carried out and maximizing the biochemical phosphorus removal capacity.

[0047] According to the present invention, adding an appropriate amount of ozone tail gas from the ozone reaction tank 6 into the MBR pool 3 can degrade the microbial extracellular polymer organic matter adhering to the surface of the membrane fibers. Combined with the aeration and scrubbing of bio-enzyme-modified activated carbon, it can effectively reduce the fouling of the membrane fibers by phosphorus removal agents and pollutants, and at the same time realize the utilization of tail gas waste.

[0048] According to the present invention, the residual sludge in the MBR pool 3 is treated with ozone in the sludge concentration and decomposition tank, the lysed substance is used as a carbon source, and the sludge is easy to dehydrate. The sludge after filter pressing contains activated carbon, alumina and other substances that are easy to support and expand the pores and is rich in nitrogen and phosphorus substances. As the filler of the subsequent artificial wetland 8, it has the functions of containing water, being breathable, fixing and supporting, and providing nutrients.

[0049] The treatment of the artificial wetland 8 according to the present invention can achieve the purpose of deep removal of nitrogen and phosphorus. At the same time, SS and COD are treated by the wetland to further reduce the toxicity of microorganisms and water quality, and the water quality is softened to achieve the purpose of deep purification.

[0050] Therefore, the surface quasi-class II drinking water source water replenishment treatment system of the present invention has the advantages of good treatment effect and low operating cost, etc. The effluent can meet the requirements of Standard A in Table 1 of the "Water Pollutant Discharge Standard for Urban Sewage Treatment Plants" (DB11 / 890-2012), and the requirements of this standard for BOD5, COD, NH3-N and TP are the same as the water quality standards of Class II water bodies in the "Surface Water Environmental Quality Standard" (GB3838-2002).

[0051] Example 2

[0052] In this embodiment, the surface quasi-class II drinking water source replenishment treatment system of the present invention includes a coarse screen (not shown in the figure), a fine screen (not shown in the figure), an aerated grit tank 1, a water inlet automatic control device (not shown in the figure), a biological treatment section 2, an MBR tank 3, a sludge concentration and decomposition tank 4, an ozone generator 5, an ozone reaction tank 6, a disinfection tank 7 and an artificial wetland 8.

[0053] The coarse screen is located upstream of the aerated grit chamber 1, and the fine screen is located between the coarse screen and the aerated grit chamber 1. In other words, the municipal sewage flows through the coarse screen, the fine screen and the aerated grit chamber 1 in sequence. Among them, the net distance between the bars of the coarse screen is 20 mm, and the flow rate of the municipal sewage passing the screen is 0.8 m / s; the gap between the bars of the fine screen is 3 mm, and the flow rate of the municipal sewage passing the screen is 0.8 m / s.

[0054] After simple pretreatment by coarse screens and fine screens, municipal sewage enters the aeration grit chamber 1. By aerating and gritting the municipal sewage, not only can most of the inorganic particles in the municipal sewage be removed, but also organic matter adhering to the inorganic particles can be allowed to enter the municipal sewage, thereby increasing the organic carbon source content in the municipal sewage. The hydraulic retention time of the aeration grit chamber 1 is 8 minutes.

[0055] Advantageously, the surface quasi-Class II drinking water source replenishment and regeneration treatment system does not have a primary sedimentation tank, thereby reducing the loss of organic carbon sources and providing as much carbon source as possible for subsequent enhanced biological nitrogen removal and phosphorus removal.

[0056] The water outlet of the aerated grit chamber 1 is connected to the water inlet of the water inlet automatic control device, and the water outlet of the water inlet automatic control device is respectively connected to the water inlet of the pre-anoxic zone 21, the water inlet of the anaerobic zone 22, the water inlet of the primary anoxic zone 24, and the water inlet of the secondary anoxic zone 26. In other words, the water inlet automatic control device is a flow monitoring and adjustment device provided between the water outlet of the aerated grit chamber 1, the water inlet of the pre-anoxic zone 21, the water inlet of the anaerobic zone 22, the water inlet of the primary anoxic zone 24, and the water inlet of the secondary anoxic zone 26. In this way, the municipal sewage can be diverted, thereby improving the utilization rate of the organic carbon source in the municipal sewage.

[0057] Among them, the municipal sewage is divided into the first part of the effluent flowing into the pre-anoxic zone 21, the second part of the effluent flowing into the anaerobic zone 22, the third part of the effluent flowing into the primary anoxic zone 24, and the fourth part of the effluent flowing into the secondary anoxic zone 26. That is to say, the municipal sewage deep treatment regeneration and reuse system adopts a multi-point water inlet method. The volume percentage of the first part of the effluent is 10%-30%, the volume percentage of the second part of the effluent is 30%-50%, the volume percentage of the third part of the effluent is 30~50%, and the volume percentage of the fourth part of the effluent is about 10%. The water inlet automatic control device can automatically adjust the volume percentages of the first part of the effluent, the second part of the effluent, the third part of the effluent and the fourth part of the effluent according to the total amount of water inlet, so as to ensure that the water inlet flow distribution is more flexible and accurate. In other words, the above volume distribution can be achieved based on the water inlet automatic control device.

[0058] like Figure 1 As shown, the biological treatment section 2 includes a pre-anoxic zone 21, an anaerobic zone 22, a primary aerobic zone 23, a primary anoxic zone 24, a secondary aerobic zone 25 and a secondary anoxic zone 26 connected in sequence. The first part of the effluent flows into the pre-anoxic zone 21.

[0059] Specifically, the biological treatment and membrane pool can be designed as a rectangular pool, and a biological phosphorus removal and nitrogen removal reaction pool is used, which is composed of an independent and separately controllable pre-anoxic zone 21, an anaerobic zone 22, a primary aerobic zone 23, a primary anoxic zone 24, a secondary aerobic zone 25, a secondary anoxic zone 26, and an MBR pool 3. The hydraulic retention time of the biological treatment section 2 is 26.5 hours, and the volume ratio of the pre-anoxic zone 21, the anaerobic zone 22, the primary aerobic zone 23, the primary anoxic zone 24, the secondary aerobic zone 25, and the secondary anoxic zone 26 can be 1:1:2:1.27:1.7:1.12:0.88.

[0060] In the existing A2 / O process, the sludge discharged from the sedimentation tank (i.e., the return sludge) carries a large amount of NO3-N and directly flows back to the anaerobic zone, which seriously affects the phosphorus release of the anaerobic zone, thereby severely limiting the phosphorus removal capacity of the anaerobic zone. In this process, the pre-anoxic zone 21 preferentially uses a carbon source to remove nitrate nitrogen from the return sludge, protects the environment of the subsequent anaerobic zone 22 from being destroyed, and uses lysed substances as a carbon source to enhance the denitrification effect. Advantageously, the sludge return ratio of the return sludge is 200% to 400%. At the same time, a phosphorus removal agent is added to remove part of the TP, improve the C / P ratio of the entire system, and facilitate phosphorus removal. Advantageously, the phosphorus removal agents are PFS and PAC, and the dosage is 20 mg / L to 40 mg / L.

[0061] After the reaction in the pre-anoxic zone 21, the first part of the effluent flows into the anaerobic zone 22 and is mixed with the second part of the effluent. In the anaerobic zone 22, the first part of the effluent and the second part of the effluent are anaerobically treated to perform a phosphorus release reaction. By adding new municipal sewage, that is, adding municipal sewage that has not been anaerobically treated, during the phosphorus release reaction, it can be ensured that the phosphorus release reaction is fully performed.

[0062] Then, the first part of the effluent and the second part of the effluent after the anaerobic treatment and the MBR pool return sludge enter the primary aerobic zone 23 for nitrification reaction to remove ammonia nitrogen and sludge TP absorption. Preferably, the dissolved oxygen is 0.5-3 mg / L and the sludge concentration is 3500 mg / L-5000 mg / L.

[0063] After treatment in the primary aerobic zone 23, the first and second effluent treatment solutions enter the primary anoxic zone and are mixed with the third effluent. The third effluent is used to bring carbon sources in the raw water in the primary anoxic zone 24 to remove nitrate nitrogen produced by the first and second effluents by denitrification. Preferably, the reaction sludge concentration is 3500 mg / L to 5000 mg / L, and the return ratio from the MBR tank 3 to the primary aerobic tank is 300% to 500%.

[0064] After the reaction in the primary anoxic zone 24, the first, second and third effluents enter the secondary aerobic zone 25 to continue nitrification and phosphorus absorption, and remove the residual ammonia nitrogen in the first and second effluents and the ammonia nitrogen produced by the third effluent. Preferably, the required dissolved oxygen is 0.5-3 mg / L, and the sludge concentration is 3500 mg / L-5000 mg / L.

[0065] Afterwards, the first, second, third and fourth effluents undergo secondary anoxic reaction, and the nitrate nitrogen contained in the first, second and third effluents is deeply denitrified under the condition that the raw water of the fourth effluent provides the carbon source. At the same time, the amount of external carbon source input is adjusted in time according to needs, and the amount of external carbon source added / nitrate nitrogen removed is 4:1~8:1, and the sludge concentration is 3500mg / L~5000mg / L.

[0066] After being treated in the secondary anoxic zone 26, the first part of the effluent, the second part of the effluent, the third part of the effluent, and the fourth part of the cement water mixture enter the MBR pool 3. Under this aeration condition, the residual ammonia nitrogen is removed to meet the standard. At the same time, biological activated carbon is added to remove deeply difficult-to-degrade organic matter to meet the COD standard.

[0067] The tail gas from the ozone reaction pool is introduced into the MBR pool 3 to work with the enzyme-modified activated carbon to remove organic matter adhering to the membrane surface and delay the fouling of the membrane. At the same time, ozone reacts with organic matter inside the activated carbon to restore the adsorption performance of the enzyme-modified activated carbon. Ozone breaks the chain of difficult-to-degrade organic matter into smaller, easily decomposable organic matter, thereby enhancing the COD removal capacity.

[0068] Preferably, the enzyme-modified activated carbon is powdered activated carbon with a particle size of 10 μm to 100 μm, and the dosage of the enzyme-modified activated carbon is 20 mg / L to 40 mg / L. In the MBR pool, the ozone tail gas dosage is 5 to 10 mg / L; the sludge concentration is 6000 mg / L to 12000 mg / L, and the sludge age is 10 days to 25 days.

[0069] The MBR excess sludge enters the sludge concentration and decomposition tank 4, and ozone is introduced by the ozone generator 5 to decompose the sludge. Preferably, the ozone addition concentration is 0.01-0.2gO3 / gVSS. After dehydration, the moisture content is less than 80%. After the sludge passes the test, it is used as artificial wetland filler. The extracellular solution enters the pre-anoxic tank 21.

[0070] The effluent from the MBR pool 3 enters the ozone reaction pool 6, in which a catalyst filler is arranged, the filtration rate is set to 3m / h to 6m / h, the ozone dosage is 20mg / L to 30mg / L, and the residence time is 1 to 2h. Preferably, the mass ratio of ozone dosage to COD removal is 3:1 to 1:1;

[0071] The effluent from the ozone reaction pool 6 enters the disinfection pool 7. The disinfectant used in the disinfection pool 7 is sodium hypochlorite, and the residence time is 4h to 8h. The concentration of sodium hypochlorite is 5 to 10 mg / L.

[0072] After passing through the disinfection pool 7, the effluent enters the artificial wetland 8. The hydraulic load of the artificial wetland is 0.45m 3 / m2 d, total hydraulic retention time: 3.1d, plants selected include reed, cattail, yellow iris and reed, which have well-developed root systems, strong pollution resistance and strong pollution removal ability and are suitable for the local environment.

[0073] Table 1 - Influent and effluent quality of the surface Class II drinking water source replenishment and regeneration treatment system.

[0074] project CODcr <![CDATA[BOD5]]> SS TN <![CDATA[NH3-N]]> TP Escherichia coli Influent water quality (mg / L) 400 250 300 50 35 6.5 2000 Outlet water quality (mg / L) 15 3 5 10 0.5 0.1 ---

[0075] Example 3

[0076] like Figure 2 As shown, a surface quasi-class II drinking water source replenishment and regeneration treatment method comprises the following steps:

[0077] A) Municipal sewage passes through coarse and fine screens, and aeration and sand settling are performed on the sewage. By aeration and sand settling of municipal sewage, not only can most of the inorganic particles in the municipal sewage be removed, but also the organic matter adhering to the inorganic particles can be allowed to enter the municipal sewage, thereby increasing the organic carbon source content in the municipal sewage.

[0078] B) After aeration and sand settling, the water discharged through the membrane grid is divided into four parts, namely the first part of the water, the second part of the water, the third part of the water and the fourth part of the water. In the pre-anoxic zone 21, the first part of the water is mixed with the return sludge of the secondary aerobic zone 25 for denitrification and denitrification, and a dephosphorization agent is added to remove phosphorus.

[0079] C) In the anaerobic zone 22, the treated first part of the effluent is mixed with the second part of the effluent for anaerobic phosphorus release.

[0080] D) In ​​the primary aerobic zone, the first part of the treated effluent, the second part of the treated effluent and the return sludge from MBR pool 3 are mixed to undergo aerobic nitrification to remove ammonia nitrogen; at the same time, aerobic phosphorus absorption is carried out, and total phosphorus is transferred from the liquid to the sludge.

[0081] E) In the primary anoxic zone 24, the treated first effluent, the treated second effluent and the treated third effluent are mixed, and denitrification continues to remove total nitrogen.

[0082] F) In the secondary aerobic zone 25, the treated first effluent is mixed with the treated second effluent and the treated third effluent to continue ammonia nitrogen removal and deep phosphorus removal.

[0083] G) In the secondary anoxic zone 26, the treated first effluent, the treated second effluent, the treated third effluent and the treated fourth effluent are mixed, and then an external carbon source is added for deep denitrification.

[0084] H) In the MBR pool 3, the treated first part of the effluent, the treated second part of the effluent, the treated third part of the effluent and the treated fourth part of the effluent are mixed, and then the enzyme-modified activated carbon is added to the MBR pool 3 to remove the difficult-to-degrade organic matter, the membrane is filtered to remove SS, and the remaining phosphorus-containing sludge is discharged, and finally ozone is added to the MBR pool 3 to reduce membrane clogging and restore the adsorption capacity of the enzyme-modified activated carbon.

[0085] I) The ozone reaction tank 6 further removes refractory organic matter under the action of a catalyst to make the COD meet the standard. The excess tail gas after the reaction is treated by the ozone tail gas destruction device 61, and the rest is introduced into the MBR tank 3.

[0086] J) The effluent treated by the ozone reaction tank enters the disinfection tank 7 for disinfection to kill bacteria such as Escherichia coli, so that the effluent bacteria are qualified.

[0087] K) In the artificial wetland 8, the residual sludge in the aforementioned MBR pool 3 is subjected to ozone oxidation treatment and then concentrated, filtered, etc. to produce qualified mud cake as wetland filler; the first part of the water is effluent, the second part of the water is effluent, the third part of the water is effluent, and the fourth part of the water is effluent, the residual SS is intercepted, and nitrogen, phosphorus, etc. are continuously absorbed, and the water quality is purified.

[0088] Compared with the traditional six-stage ultrafiltration process, this system has the following advantages:

[0089] First, add an appropriate amount of bio-enzyme modified activated carbon to the membrane pool, and the bio-enzyme modified activated carbon and activated sludge establish a new symbiotic system. The two promote each other and have stronger removal capacity than traditional processes. 1) The activated sludge has a higher concentration than the bio-enzyme modified activated carbon, and first decomposes the easily degradable organic matter to complete various functional metabolisms (such as nitrogen removal, phosphorus removal and microbial growth); 2) As the reaction gradually proceeds, the subsequent difficult-to-degrade organic matter gradually diffuses into the bio-enzyme-activated carbon to continue to be specifically degraded. The pre-degradation of activated sludge provides conditions for the specific degradation of bio-enzyme modified activated carbon, saving energy for reagents, and bio-enzyme modified activated carbon deeply removes organic matter, inhibits aerobic heterotrophic bacteria, promotes the growth of nitrifying bacteria, and is beneficial to the removal of ammonia nitrogen; 3) In the bio-enzyme-activated carbon system, the difficult-to-degrade organic matter undergoes a dynamic equilibrium process of "adsorption-degradation-adsorption", which improves the removal capacity of difficult-to-degrade organic matter and achieves a synergistic effect.

[0090] Second, the appropriate amount of tail gas from the ozone reaction pool 6 is introduced into the MBR pool 3, which strengthens the degradation and mineralization ability of the membrane surface to organic matter such as extracellular polymers, reduces the viscosity of organic matter, and greatly improves the anti-fouling and clogging ability of the membrane. At the same time, under the combined effect of appropriate amount of activated carbon flushing, the degree of fouling and clogging of the membrane is reduced, and the input of ozone degrades the organic matter adsorbed inside the activated carbon, improving the recovery ability of the activated carbon.

[0091] Third, the remaining sludge is treated with ozone to destroy the sludge cell walls. Part of the sludge lysate is used as a carbon source for denitrification to save carbon source. After ozone treatment, sludge filtration and dehydration becomes easier and the amount of sludge is significantly reduced. At the same time, ozone oxidizes and harmlessly treats bacteria and heavy metals.

[0092] Fourth, the filter cake formed contains rich elements such as nitrogen and phosphorus. The aluminum salt added during dehydration can change the properties of the sludge and form a porous structure. The sludge cake can be used in artificial wetlands8, turning waste into treasure and realizing sludge resource utilization.

[0093] Fifth, staged water intake can improve the utilization rate of organic carbon sources in raw water.

[0094] Sixth, advance the hypoxia to improve the nitrate denitrification capacity and ensure a good anaerobic environment.

[0095] Therefore, the drinking water source replenishment treatment method based on the surface quasi-class II water quality standard according to the embodiment of the present invention has the advantages of good treatment effect and low operating cost. By using the drinking water source replenishment treatment method based on the surface quasi-class II water quality standard according to the embodiment of the present invention to treat municipal sewage, the effluent can meet the requirements of standard A in Table 1 of the "Water Pollutant Discharge Standard for Urban Sewage Treatment Plants" (DB11 / 890-2012), and the requirements of this standard for BOD5, COD, NH3-N and TP are the same as the water quality standards of Class II water bodies in the "Surface Water Environmental Quality Standard" (GB3838-2002).

[0096] The invention concept is described in detail using specific examples herein, and the description of the above embodiments is only used to help understand the core idea of ​​the invention. It should be pointed out that any obvious modification, equivalent substitution or other improvement made by a person of ordinary skill in the art without departing from the invention concept should be included in the protection scope of the present invention.

Claims

1. A surface quasi-class II drinking water source replenishment and regeneration treatment system, characterized by: It includes aeration grit chamber, biological treatment section, MBR tank, sludge concentration and decomposition tank, ozone generator, ozone tail gas destruction device, ozone reaction tank, disinfection tank and artificial wetland; The biological treatment section comprises a pre-anoxic zone, an anaerobic zone, a primary aerobic zone, a primary anoxic zone, a secondary aerobic zone and a secondary anoxic zone which are connected in sequence, wherein each of the water inlet of the pre-anoxic zone, the water inlet of the anaerobic zone and the water inlets of the primary anoxic zone and the secondary anoxic zone is connected to the water outlet of the aerated grit chamber, and the water outlet of the secondary aerobic zone is connected to the water inlet of the pre-anoxic zone; The water inlet of the MBR pool is connected to the water outlet of the secondary anoxic zone, the water outlet of the MBR pool is connected to the inlet of the ozone reaction pool, the return sludge outlet of the MBR pool is connected to the return sludge inlet of the primary aerobic zone, the residual sludge outlet of the MBR pool is connected to the sludge concentration and decomposition pool, and enzyme-modified activated carbon is added into the MBR pool; The sludge lysate outlet of the sludge concentration and decomposition tank is connected to the pre-anoxic zone; the filter cake produced by the excess sludge in the MBR tank is used as artificial wetland filler; The ozone outlet of the ozone generator is connected to the sludge concentration and decomposition tank and the ozone reaction tank respectively; the water inlet of the ozone reaction tank is connected to the water outlet of the MBR tank, the water outlet of the ozone reaction tank is connected to the disinfection tank, and the tail gas of the ozone reaction tank is connected to the ozone tail gas destruction device and the MBR tank respectively; The water inlet of the disinfection tank is connected to the water outlet of the ozone reaction tank, the outlet of the disinfection tank is connected to the water inlet of the artificial wetland, and the filter cake of the sludge dehydration and filtration is used as the filler of the artificial wetland; The water outlet of the aerated grit chamber is respectively connected to the water inlet of the pre-anoxic zone, the water inlet of the anaerobic zone, the water inlet of the primary anoxic zone and the water inlet of the secondary anoxic zone, and the water outlet of the secondary aerobic zone is connected to the water inlet of the pre-anoxic zone; It also includes a coarse grid, a fine grid and a membrane grid; the coarse grid is located upstream of the aeration grit chamber, the fine grid is located between the coarse grid and the aeration grit chamber, and the membrane grid is located downstream of the aeration grit chamber.

2. The surface quasi-class II drinking water source water replenishment and regeneration treatment system according to claim 1 is characterized by: It comprises an automatic water inlet control device, the water inlet of the automatic water inlet control device is connected with the water outlet of the aerated grit chamber, and the water outlet of the automatic water inlet control device is connected with each of the water inlet of the pre-anoxic zone, the water inlet of the anaerobic zone, the water inlet of the primary anoxic zone and the water inlet of the secondary anoxic zone.

3. The surface quasi-class II drinking water source water replenishment and regeneration treatment system according to claim 1 is characterized by: It includes an ozone reaction tank with COD catalytic oxidation filler arranged inside.

4. A method for replenishing and regenerating surface Class II drinking water, characterized in that: The following steps are involved: A) Raw water passes through the coarse screen and fine screen and enters the aerated grit chamber; B) After aeration and sand settling, the effluent is divided into four parts through the membrane grid, namely the first effluent, the second effluent, the third effluent and the fourth effluent; in the pre-anoxic zone, the first effluent is mixed with the return sludge and lysate of the secondary aerobic zone for denitrification, and phosphorus removal agents are added for phosphorus removal; C) In the anaerobic zone, the treated first part of the effluent is mixed with the second part of the effluent for anaerobic phosphorus release; D) In ​​the primary aerobic zone, the treated first effluent, the treated second effluent and the MBR pool return sludge are mixed to undergo aerobic nitrification to remove ammonia nitrogen; at the same time, aerobic phosphorus absorption is carried out, and total phosphorus is transferred from the liquid to the sludge; E) In the primary anoxic zone, the treated first effluent, the treated second effluent and the treated third effluent are mixed, and denitrification continues to remove total nitrogen; F) In the secondary aerobic zone, the treated first effluent is mixed with the treated second effluent and the treated third effluent to continue removing ammonia nitrogen; J) In the secondary anoxic zone, the treated first effluent, the treated second effluent, the treated third effluent and the treated fourth effluent are mixed, and then an external carbon source is added for deep denitrification; H) In the MBR pool, the treated first effluent, the treated second effluent, the treated third effluent and the treated fourth effluent are mixed, and then the enzyme-modified activated carbon is added to the MBR pool, the remaining phosphorus-containing sludge is discharged, and finally ozone is added to the MBR pool; I) Adding a specific COD catalyst into the ozone reaction tank, the remaining ozone after the reaction in the ozone reaction tank is treated by an ozone tail gas destruction device; J) The effluent treated by the ozone reaction tank enters the disinfection tank for disinfection; K) The effluent from the disinfection tank enters the artificial wetland; and the remaining sludge in the MBR tank is oxidized and concentrated by ozone, and finally filtered into mud cake as wetland filler.

5. The surface quasi-class II drinking water source replenishment and regeneration treatment method according to claim 4 is characterized by: In step B), the mass percentage of the first part of water is 10% to 30%, the mass percentage of the second part of water is 30% to 50%, the mass percentage of the third part of water is 30% to 50%, and the mass percentage of the fourth part of water is 10%.

6. The surface quasi-class II drinking water source replenishment and regeneration treatment method according to claim 4 is characterized by: In step H), the sludge return ratio from the MBR pool to the primary aerobic zone is 300% to 500%; the mixed liquor return ratio from the secondary aerobic zone to the pre-anoxic zone is 200% to 400%; the bio-enzyme modified activated carbon in the MBR pool is powdered activated carbon with bio-enzymes in the pores, with a particle size of 10 μm to 100 μm, and the dosage of the bio-enzyme modified activated carbon is 20 mg / L to 40 mg / L.

7. The surface quasi-class II drinking water source replenishment and regeneration treatment method according to claim 4 is characterized by: In the ozone reaction tank in step I), the mass ratio of ozone addition / COD removal is 3:1 to 1:1; in the MBR tank, the ozone tail gas dosage is 5 to 10 mg / L; the ozone dosage of the residual sludge tail gas is: 0.01 to 0.2 g O3 / g VSS.

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