WO2024234814A1 - A2o-mbr integrated low-concentration organic wastewater treatment system - Google Patents

Abstract

An A²O-MBR integrated low-concentration organic wastewater treatment system, comprising an anaerobic tank (110), a hydrolysis acidification tank (120), a contact oxidation tank (130), an MBR tank (140), and a disinfection tank (150) which are sequentially communicated with each other. The anaerobic tank (110), the hydrolysis acidification tank (120), and the contact oxidation tank (130) are respectively provided with a filler (250); sludge backflow mechanisms (210) are respectively provided between the MBR tank (140) and the anaerobic tank (110) and between the MBR tank and the contact oxidation tank (130); the anaerobic tank (110) and the contact oxidation tank (130) are respectively provided with a water inlet and distribution device (220); the hydrolysis acidification tank (120) is provided with a water outlet overflow device (230).

Description

An A2O-MBR integrated low-concentration organic wastewater treatment system Technical Field

The present application relates to the technical field of wastewater treatment, and in particular to an A2O-MBR integrated low-concentration organic wastewater treatment system.

Background Art

Most of the small processing plants in my country will clean their products in the later stage, and the wastewater generated is often discharged directly, which not only has a certain impact on the environment, but also leads to a waste of water resources. Faced with increasingly stringent environmental control in the country, the drainage problem of such factories has also become a survival issue for enterprises.

At present, the amount of wastewater generated by most small-scale product processing plants in China is less than 10 tons per day. Due to the constraints of plant land and investment costs, there is basically no complete sewage treatment system, and most of them are directly discharged in violation of regulations. In order to solve the drainage problems of such plants, there is an urgent need for a treatment technology and equipment that is easy to operate, effective, small in footprint and low in cost.

Application Contents

In view of the above problems of the prior art, the purpose of this application is to provide an A2O-MBR integrated low-concentration organic wastewater treatment system with a small footprint and high treatment effect, which effectively solves the technical problem of reusing low-concentration organic wastewater after treatment and solves the problem of wastewater discharge for enterprises.

To achieve the above-mentioned purpose and other related purposes, the present application provides an A2O-MBR integrated low-concentration organic wastewater treatment system, comprising an anaerobic tank, a hydrolysis acidification tank, a contact oxidation tank, an MBR tank and a disinfection tank connected in sequence; the anaerobic tank, the hydrolysis acidification tank and the contact oxidation tank are respectively provided with fillers, the MBR tank is respectively provided with a sludge return mechanism between the anaerobic tank and the contact oxidation tank, the anaerobic tank and the contact oxidation tank are respectively provided with a water inlet distribution device; the hydrolysis acidification tank is provided with a water outlet overflow device.

In some embodiments of the present application, the anaerobic tank is top-influent, the bottom of the anaerobic tank is connected to the bottom of the hydrolysis acidification tank, the hydrolysis acidification tank is top-effluent, and the top of the hydrolysis acidification tank is connected to the contact oxidation tank.

In some embodiments of the present application, the contact oxidation tank comprises a first contact oxidation unit and a second contact oxidation unit which are connected to each other, the top of the hydrolysis acidification tank is connected to the top of the first contact oxidation unit, the bottom of the first contact oxidation unit is connected to the bottom of the second contact oxidation unit, the top of the second contact oxidation unit is connected to the top of the MBR tank, and the bottom of the MBR tank is connected to the disinfection tank.

In some embodiments of the present application, the sludge return mechanism is respectively connected to the water inlet end of the anaerobic tank and the contact oxidation tank. The water inlet and the water outlet of the MBR pool are connected.

In some embodiments of the present application, the filler is a bio-rope filler.

In some embodiments of the present application, the water inlet and water distribution device is a water distribution triangular weir.

In some embodiments of the present application, the water overflow device is an overflow triangular weir.

In some embodiments of the present application, the filler filling rate in the anaerobic tank, the hydrolysis acidification tank, and the contact oxidation tank is 50%-80% of the effective tank capacity.

In some embodiments of the present application, the weir load of the water distribution triangular weir and the overflow triangular weir is 1-2 L/(m·s).

In some embodiments of the present application, the sludge return ratio from the MBR tank to the contact oxidation tank is 30%-50%.

In some embodiments of the present application, an immersed MBR membrane is provided in the MBR pool.

In some embodiments of the present application, the MBR membrane in the MBR pool is a hollow fiber membrane made of PTFE, and the membrane flux is 0.3m ³ /m ² ·d-0.5m ³ /m ² ·d.

In some embodiments of the present application, a microporous aeration device is provided in the contact oxidation pond, and the system further comprises an equipment room, wherein a fan is provided in the equipment room, and the fan is connected to the microporous aeration device.

The above technical solution has the following technical effects:

This application improves the wastewater treatment system, adopts A2O-MBR integration, and adopts a combination of biochemical and physicochemical processes at the end. It can not only further degrade COD through high-concentration sludge, but also further remove insoluble COD and SS in the water through the filtration effect of the membrane, thereby ensuring stable effluent water quality and providing a stable guarantee for water reuse. The integrated wastewater treatment device can completely purify pollutants in low-concentration organic wastewater, and the entire system does not require civil construction, the equipment occupies a small area, the construction period is short, the equipment investment and operating costs are low, and the operation and management are simple. The effluent from the equipment can meet the process and product water use standards in the "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB/T 19923-2005), and can be fully reused in production, truly achieving zero wastewater discharge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of an A2O-MBR integrated low-concentration organic wastewater treatment system according to an embodiment of the present application.

Component numbers in the drawings of this application:

110 Anaerobic tank

120                Hydrolysis acidification tank

130 Contact oxidation tank

131 First contact oxidation unit

132                Second contact oxidation unit

140 MBR pool

150                Disinfection pool

160 Equipment room

161                 Fan

210 Sludge return mechanism

220                Water inlet and water distribution device

230                 Water overflow device

240                Microporous aeration device

250 Filling

DETAILED DESCRIPTION

In the description of the present application, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of the present specification are only used to match the contents disclosed in the specification for people familiar with the technology to understand and read, and are not used to limit the limiting conditions that can be implemented in the present application, so they have no technical substantive significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects that can be produced by the present application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed in the present application. At the same time, the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

Furthermore, in the description of the present application, unless otherwise specified, “plurality” means two or more.

As shown in FIG1 , the present application provides an A2O-MBR integrated low-concentration organic wastewater treatment system, comprising an anaerobic tank 110, a hydrolysis acidification tank 120, a contact oxidation tank 130, an MBR tank 140 and a disinfection tank 150 connected in sequence; the anaerobic tank 110, the hydrolysis acidification tank 120, and the contact oxidation tank 130 are respectively provided with fillers 250, and the MBR tank 140 is respectively connected to the anaerobic tank 110, A sludge return mechanism 210 is provided between the contact oxidation tank 130, and the anaerobic tank 110 and the contact oxidation tank 130 are respectively provided with a water inlet and water distribution device 220; the hydrolysis acidification tank 120 is provided with an effluent overflow device 230. Among them, the A2O method is also called the AAO method, which is the abbreviation of the first letters of the English Anaerobic-Anoxic-Oxic (anaerobic-anoxic-aerobic method), and is a commonly used sewage treatment process. The wastewater treated by the A2O method alone is often difficult to operate stably, and the effluent COD and SS fluctuate greatly, so the produced water cannot stably meet the standards of recycled water. The A2O-MBR integration is adopted, and the end adopts a process combining biochemical and physical chemistry, which can not only further degrade COD through high-concentration sludge, but also further remove the insoluble COD and SS in the water through the filtration of the membrane, ensuring the stable effluent water quality, and providing a stable guarantee for water reuse.

In this embodiment, the anaerobic tank 110, the hydrolysis acidification tank 120, the contact oxidation tank 130, and the MBR tank 140 adopt a plug flow type water inlet to prevent short flow. The anaerobic tank 110 is for upper water inlet, and the bottom of the anaerobic tank 110 is connected to the bottom of the hydrolysis acidification tank 120. The hydrolysis acidification tank 120 is for upper water outlet, and the upper part of the hydrolysis acidification tank 120 is connected to the contact oxidation tank 130. In a specific embodiment, the contact oxidation tank 130 is provided with two grids, and the contact oxidation tank 130 includes a first contact oxidation unit 131 and a second contact oxidation unit 132 which are connected. The top of the hydrolysis acidification tank 120 is connected to the top of the first contact oxidation unit 131, and the bottom of the first contact oxidation unit 131 is connected to the bottom of the second contact oxidation unit 132. Water from the top of the contact oxidation tank 130, that is, the top of the second contact oxidation unit 132 is connected to the top of the MBR tank 140, and the bottom of the MBR tank 140 is connected to the disinfection tank 150. The water from the MBR tank 140 enters the disinfection tank 150, and the clean water is collected after being disinfected by ozone in the disinfection tank 150, and is regularly reused for production. In this embodiment, the advantages of setting the first contact oxidation unit 131 and the second contact oxidation unit 132 are: 1. The hydraulic retention time of the contact oxidation tank is increased, so that the organic matter in the water can be further degraded; 2. The first contact oxidation unit 131 is connected to the second contact oxidation unit 132 at the bottom, and the second contact oxidation unit 132 and the MBR tank are top overflow water, which can effectively control the sludge concentration of the MBR tank and improve the biochemical efficiency.

In this embodiment, the anaerobic tank 110, the hydrolysis acidification tank 120 and the contact oxidation tank 130 are all hung with fillers 250, and the fillers 250 are biological rope fillers. The fillers 250 are made of elastic material and soft material mixed weaving, and the material is reinforced PP and modified alcoholized fiber, which can quickly form a biofilm, improve the mass transfer effect, and make the device more resistant to impact loads.

In this embodiment, the filling rate of the filler 250 in the anaerobic tank 110, the hydrolysis acidification tank 120, and the contact oxidation tank 130 can be, for example, 50%-80%, 50%-70%, or 70%-80% of the effective tank capacity. Among them, the effective tank capacity refers to the volume of water that the pool can actually store. Because when designing a pool, people often worry about overflowing when the pool is full, so they will design an extra height of 0.5m-1m. The volume of the pool is not the water storage volume in the operating state, but the effective pool capacity is. Advantages: The filling rate of the filler 250 in the anaerobic tank 110, the hydrolysis acidification tank 120, and the contact oxidation tank 130 is 50%-80% of the effective tank capacity, which increases the mass transfer effect of water and improves the treatment efficiency of the unit system. It can not only save the volume of the pool, but also increase the impact load of the system.

In this embodiment, an aeration stirring device is provided at the bottom of the hydrolysis acidification tank 120 and the contact oxidation tank 130. The hydrolysis acidification tank 120 adopts a PVC perforated pipe, and the contact oxidation tank 130 adopts a microporous aeration disk made of ABS+EPDM. The aeration pipe is connected to the fan 161, and the fan 161 provides air (oxygen) to the tank. The fan 161 is installed in the equipment room 160.

In this embodiment, the anaerobic tank 110 and the contact oxidation tank 130 are respectively provided with a water inlet and water distribution device 220, and the water inlet and water distribution device 220 is a water distribution triangular weir.

In this embodiment, the hydrolysis acidification tank 120 is provided with a water outlet overflow device 230, and the water outlet overflow device 230 is an overflow triangular weir.

In this embodiment, the load on the water distribution triangular weir and the overflow triangular weir is 1-2L/(m·s), 1-1.5L/(m·s), or 1.5-2L/(m·s). This has the advantage of more uniform water distribution and overflow without short-circuiting.

In this embodiment, an immersed MBR membrane is provided in the MBR pool 140, and the installed MBR membrane is made of PTFE material. Specifically, the MBR membrane is a hollow fiber membrane made of PTFE material, and the membrane flux is ^0.3m3 / ^m2 ·d- ^0.5m3 / ^m2 ·d, which can not only ensure the service life of the MBR membrane, but also meet the normal water production of the system and save equipment investment.

The MBR membrane is made of PTFE, which has the advantages of strong hydrophilicity and large flux. The MBR process is adopted at the end, which reduces the setting of the secondary sedimentation tank and saves equipment land. At the same time, a small amount of biological enzyme is added in the MBR pool 140 during operation. The iodine value of the added biological enzyme is 800. After the addition of the biological enzyme, the COD and chromaticity of the effluent from the MBR pool 140 are further reduced.

In this embodiment, a sludge return mechanism 210 is provided between the MBR tank 140 and the contact oxidation tank 130 , and an airlift sludge return mechanism is used to realize sludge return. The sludge returns to the water inlet end of the contact oxidation tank 130 to replenish the sludge in the contact oxidation tank 130 .

In this embodiment, the MBR tank 140 and the anaerobic tank 110 are connected through a sludge return mechanism 210 to return the excess sludge to the anaerobic tank 110 for anaerobic digestion. In a specific embodiment, the excess sludge generated by the biochemical system is discharged to the water inlet of the anaerobic tank 110 through an airlift sludge return mechanism, so that the sludge is decomposed into CH ₄ , CO ₂ and H ₂ O by anaerobic bacteria and facultative aerobic bacteria under anaerobic conditions, so that the sludge discharge of the device is basically zero, reducing the operating cost.

In a specific embodiment, the sludge return mechanism 210 is respectively connected to the water inlet of the anaerobic tank 110, the water inlet of the contact oxidation tank 130, and the water outlet of the MBR tank 140.

In this embodiment, a control valve is provided on the pipeline from the sludge return mechanism 210 to the contact oxidation tank 130 to control whether the sludge flows back into the contact oxidation tank 130. A control valve is provided on the pipeline from the sludge return mechanism 210 to the water inlet end of the anaerobic tank 110 to control whether the sludge enters the anaerobic tank.

In this embodiment, the disinfection method used in the disinfection pool 150 is ozone disinfection.

The method for treating low-concentration organic wastewater using the low-concentration organic wastewater treatment system of the present invention is as follows: The organic wastewater is sent to the water distribution weir provided in the anaerobic tank 110, and then the wastewater flows through the hydrolysis acidification tank 120, the contact oxidation tank 130, the MBR tank 140 and the disinfection tank 150 in sequence. The sludge in the MBR tank 140 is returned to the contact oxidation tank 130 through the sludge return mechanism, and the remaining sludge in the MBR tank 140 is regularly discharged to the anaerobic tank 110 for anaerobic digestion.

The sludge return ratio of the sludge return mechanism to the contact oxidation tank is 50%. The sludge return ratio refers to the amount of sludge returned from the MBR tank to the contact oxidation tank, which is defined as the ratio of the return sludge amount to the influent amount.

The sludge return mechanism returns the sludge to the anaerobic tank for digestion once a week, and the sludge discharge volume is 5% of the daily water intake. The excess sludge produced by the MBR is discharged to the water inlet of the anaerobic tank through the sludge return pipeline regularly, so that the sludge is decomposed into _CH4 , _CO2 and _H2O by anaerobic and facultative aerobic bacteria under anaerobic conditions.

The amount of ozone added to the disinfection pool 150 is 5 mg/L, which sterilizes and removes odor in the water. Examples 1, 2, and 3 correspond to three sets of parallel experimental data under the conditions of the above sludge return ratio, sludge discharge cycle, and ozone amount.

The integrated treatment device in the above example was used to treat low-concentration organic wastewater, and then the various indicators of the inlet and outlet water of the device were tested respectively. The test results are shown in the following table:

From the data in the above table, we can know that after the low-concentration organic wastewater is treated by the A ² O-MBR integrated low-concentration organic wastewater treatment device, the effluent fully meets the process and product water standards in "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB/T 19923-2005) and can be reused in production.

In summary, the A2O-MBR integrated low-concentration organic wastewater treatment system provided in the embodiment of the present application enables the integrated wastewater treatment device to completely purify the pollutants in the low-concentration organic wastewater, and the entire system does not require civil construction, the equipment occupies a small area, the construction period is short, the equipment investment and operating costs are low, the operation and management are simple, and the equipment effluent can meet the process and product water standards in the "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB/T 19923-2005), and can be fully reused in production, truly achieving zero wastewater discharge.

In summary, the present application effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above embodiments are only illustrative of the principles and effects of the present application and are not intended to limit the present application. Those skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims (10)

An A2O-MBR integrated low-concentration organic wastewater treatment system, characterized in that it comprises an anaerobic tank (110), a hydrolysis acidification tank (120), a contact oxidation tank (130), an MBR tank (140) and a disinfection tank (150) which are connected in sequence; the anaerobic tank (110), the hydrolysis acidification tank (120) and the contact oxidation tank (130) are respectively provided with fillers (250); a sludge return mechanism (210) is respectively provided between the MBR tank (140) and the anaerobic tank (110) and the contact oxidation tank (130); the anaerobic tank (110) and the contact oxidation tank (130) are respectively provided with a water inlet distribution device (220); and the hydrolysis acidification tank (120) is provided with a water outlet overflow device (230). The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1 is characterized in that the anaerobic tank (110) is top-influent, the bottom of the anaerobic tank (110) is connected to the bottom of the hydrolysis acidification tank (120), the hydrolysis acidification tank (120) is top-effluent, and the top of the hydrolysis acidification tank (120) is connected to the contact oxidation tank (130). The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 2 is characterized in that the contact oxidation tank (130) includes a first contact oxidation unit (131) and a second contact oxidation unit (132) that are connected, the top of the hydrolysis acidification tank (120) is connected to the top of the first contact oxidation unit (131), the bottom of the first contact oxidation unit (131) is connected to the bottom of the second contact oxidation unit (132), the top of the second contact oxidation unit (132) is connected to the top of the MBR tank (140), and the bottom of the MBR tank (140) is connected to the disinfection tank (150). The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1 is characterized in that the sludge return mechanism (210) is respectively connected to the water inlet end of the anaerobic tank (110), the water inlet end of the contact oxidation tank (130), and the water outlet end of the MBR tank (140). The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1, characterized in that the filler (250) is a biological rope filler; And/or, the water inlet and water distribution device (220) is a water distribution triangular weir; And/or, the water outlet overflow device (230) is an overflow triangular weir. The A2O-MBR integrated low-concentration organic wastewater treatment system as described in claim 1 is characterized in that the filling rate of the filler (250) in the anaerobic tank (110), the hydrolysis acidification tank (120), and the contact oxidation tank (130) is 50%-80% of the effective tank capacity. The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 5 is characterized in that the weir load of the water distribution triangular weir and the overflow triangular weir is 1-2L/(m·s). The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1 is characterized in that the sludge return ratio of the MBR pool (140) to the contact oxidation pool (130) is 30%-50%. The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1, characterized in that the MBR An immersed MBR membrane is provided in the pool (140); And/or, the MBR membrane in the MBR pool (140) is a hollow fiber membrane made of PTFE, and the membrane flux is ^0.3m3 / ^m2 ·d- ^0.5m3 / ^m2 ·d. The A2O-MBR integrated low-concentration organic wastewater treatment system according to claim 1 is characterized in that a microporous aeration device (240) is provided in the contact oxidation tank (130), and the system further comprises an equipment room (160), a fan (161) is provided in the equipment room (160), and the fan (161) is connected to the microporous aeration device (240).