MABR fish and vegetable symbiotic circulating treatment method

Abstract

The invention relates to an MABR fish and vegetable symbiotic circulation treatment method, and relates to the technical field of aquaculture tail water treatment.The symbiotic circulation treatment system is composed of a fishpond, an MABR purification pond, a sedimentation pond, a planting pond and a recycling pond, fishpond wastewater flows into the MABR purification pond in a self-flowing mode, after the wastewater is treated through a membrane layer and a filter material layer in the MABR purification pond, effluent flows into the sedimentation pond in a self-flowing mode, and the planting pond and the recycling pond are recycled. Suspended solids are settled to the bottom, supernate flows into the planting pond to further remove organic matters such as nitrogen and phosphorus, effluent of the planting pond enters the recycling pond, and the disinfected water in the recycling pond flows back to the fishpond through the lifting device, so that a circulating process is completed, and efficient cyclic utilization of the water body is realized. The method disclosed by the invention has the characteristics of stable system, ecological circulation, efficient utilization of resources and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture tail water treatment and relates to a MABR fish-vegetable symbiotic circulation treatment method. Background Art

[0002] Fish-vegetable symbiotic recycling treatment is an ecological circulation system that uses wastewater and its nutrients generated by aquaculture to promote plant growth, and absorbs and degrades pollutants in the water through the roots of plants, thereby improving water quality and forming a closed-loop ecosystem. Compared with traditional aquaculture tailwater treatment methods, the fish-vegetable symbiotic system achieves efficient utilization of water resources and nutrients, reduces water waste and the use of chemical fertilizers, effectively reduces environmental pollution, improves production efficiency, and is widely used in aquaculture, agriculture, and home gardening. With the continuous development of the aquaculture industry, the discharge of aquaculture tailwater has increased year by year. The tailwater contains a large amount of organic matter and nutrients, which will lead to eutrophication of water bodies and imbalance of ecosystems. The excrement of fish in the fish-vegetable symbiotic system provides nutrients for plants, but excessive nutrients such as nitrogen and phosphorus may cause water quality deterioration. The self-purification capacity of the system is limited, which is easy to cause excessive accumulation of organic matter and water hypoxia, affecting the growth of fish and plants in the entire system.

[0003] Patent 2024220263600 mentions a MABR fish-vegetable symbiotic circulation device system, and the present invention further optimizes the process parameters on this basis. Summary of the invention

[0004] The present invention aims to provide a MABR fish-vegetable symbiotic circulation treatment technology, which aims to achieve an ecological treatment method with stable water quality, high efficiency and low cost, in order to solve the problems of poor impact resistance, limited self-purification ability and insufficient dissolved oxygen of the fish-vegetable symbiotic circulation system.

[0005] The MABR fish-vegetable symbiotic circulation treatment process of the present invention adopts a fish pond → MABR purification tank → sedimentation tank → planting tank → reuse tank → fish pond, and applies MABR technology to the fish-vegetable symbiotic circulation system to improve the dissolved oxygen in the water body, improve the water quality, promote the growth of fish and plants, and realize ecological circulation and efficient utilization of resources.

[0006] The present invention is achieved through the following technical solutions: A MABR fish-vegetable symbiotic circulation treatment method, characterized in that: the symbiotic circulation treatment system is mainly composed of a MABR purification tank, a sedimentation tank, a planting tank, a recycling tank and a fish pond, and the treatment method mainly includes the following steps: 1) Construction of MABR purification pool: MABR purification pool is composed of pool body, MABR membrane layer, filter material filtration layer and air supply system. The water flow direction is from top to bottom. The filter material filtration layer is set at the bottom of the MABR membrane layer. The air supply system is set outside the pool body. The air supply pipeline supplies air to the MABR membrane layer, and the valve adjusts the air supply volume. 2) Biofilm inoculation: After the MABR purification pool is constructed, activated sludge and domestic sewage are used to inoculate the MABR biofilm for a period of 2 weeks; 3) Biofilm domestication: Using the tail water of the fish pond, the MABR biofilm is domesticated and cultured by increasing the influent ratio according to the salt concentration gradient, with a cycle of 2 weeks or more; 4) Symbiotic circulation system connection: The wastewater from the fish pond flows into the MABR purification tank, sedimentation tank, planting tank, and reuse tank in sequence, and is then pumped into the fish pond to form a symbiotic circulation system; 5) Process operation: After the biofilm inoculation and domestication are completed, the symbiotic circulation system operates normally. The MABR biofilm adsorbs and degrades carbon and nitrogen, and the filtration layer removes some pollutants. The effluent from the sedimentation tank enters the planting pool. The absorption of plants and the degradation of the soil layer further purify the pollutants. The reuse pool disinfects and buffers the water and then pumps it into the fish pond to achieve efficient recycling of the water. In the step 1), at least one MABR membrane layer and at least one filter material filtration layer are provided; the MABR purification tank has a residence time of 2-3 hours, a pH value of 7-7.5, and a dissolved oxygen of 2-3 mg / L; In step 2), the activated sludge and domestic sewage are inoculated at a ratio of 1:20-1:30, intermittent culture, dissolved oxygen 3-4 mg / L, and sludge concentration 4000-5000 mg / L; In the step 3), the biofilm is acclimated to a salt concentration gradient of 20%, 40%, 60%, 80%, and 100%, and each concentration is acclimated for at least 2 days. The water quality of the MABR membrane effluent in the MABR purification pool is monitored until the effluent meets the design requirements and the biofilm acclimation is completed.

[0007] Preferably, the bottom of the MABR membrane layer is spaced 100-200 mm from the top of the filtration layer, and the MABR membrane layers are spaced 200-300 mm apart.

[0008] Preferably, the filter material of the filter layer is selected from one or more of quartz sand, fruit shell filter material, medical stone filter material, sea zeolite filter material and volcanic rock filter material, and different types are selected and graded according to the particle size. The residence time is not less than 10-15min, and the backwash intensity is 15-20L / (m 2 ·s).

[0009] Preferably, the sedimentation tank is an inclined tube sedimentation tank, the inner diameter of the inclined tube is 25-50 mm, the length is 0.8-1.2 m, and the residence time is 1-1.5 h.

[0010] Preferably, the reuse pool adopts a corridor plug flow type pool body, and the number of corridors is 2 or more; the first corridor pool body in the front section of the reuse pool is provided with an ultraviolet disinfection system.

[0011] Preferably, the reuse pool is provided with a water quality monitoring device and an adjustable water outlet device.

[0012] The MABR fish-vegetable symbiotic circulation treatment method of the present invention is that the MABR membrane aeration and oxygenation is conducive to the decomposition of pollutants by microorganisms, the filter layer filters impurities, the inclined tube sedimentation tank reduces the suspended solid content, the plant roots in the planting pool absorb nutrients, photosynthesis improves water quality, and the water disinfected in the reuse pool flows back to the fish pond, completing a cycle process and realizing efficient recycling of water bodies. The method of the present invention has the characteristics of high pollutant removal efficiency, stable effect, strong impact resistance, and realizing efficient circulation of water resources and low operating costs. DETAILED DESCRIPTION

[0013] The MABR aquaponics recycling treatment method of the present invention is further described in conjunction with the embodiments.

[0014] The present invention combines the MABR technology with the fish-vegetable symbiotic circulation system. The tail water of the fish pond is purified through the MABR purification tank → sedimentation tank → planting tank → reuse tank, and then returned to the fish pond to improve the water quality, basically achieve zero tail water discharge, and improve the recycling rate of water resources.

[0015] A MABR aquaponics recycling treatment method comprises the following steps: 1) Construction of MABR purification pool: MABR purification pool includes pool body, MABR membrane layer, filter layer and air supply system. The water flow direction is from top to bottom. The filter layer is set at the bottom of the MABR membrane layer. The air supply system is set outside the pool body. The air supply pipeline supplies air to the MABR membrane layer, and the valve adjusts the air supply volume. The MABR membrane layer provides a surface for microorganisms to attach and grow, and provides oxygen. The filter layer intercepts and filters impurities such as particles in the wastewater. At least one MABR membrane layer is set, and the number of membrane layers can be flexibly increased according to actual treatment needs and treatment scale. There is at least one filter layer, and different numbers of filter layers can be used for graded filtration of particles in different particle size ranges to improve the filtration effect. The bottom of the MABR membrane layer is 100-200mm away from the top of the filter layer, and the MABR membrane layer is 200-300mm apart. The filter layer is located at the bottom of the MABR membrane layer. 2) Biofilm inoculation: The inoculation ratio of activated sludge and domestic sewage is 1:20-1:30. During the inoculation and cultivation process, intermittent cultivation is adopted, and the three processes of aeration, static sedimentation and water inflow are cyclically carried out, with dissolved oxygen of 3-4 mg / L and sludge concentration of 4000 mg / L -5000 mg / L to accelerate the formation of biofilm. After 2 weeks of inoculation and cultivation, the biofilm reaches a certain thickness and activity; 3) Biofilm domestication: The tailwater of the fish pond is used as the domestication water source. The proportion of the tailwater of the fish pond in the total influent is gradually increased according to the salt content gradient of 20%, 40%, 60%, 80%, and 100% to domesticate the biofilm. The microorganisms in the biofilm gradually adapt to these complex pollutant components during the domestication process. Each concentration gradient is domesticated for at least 2 days. At each concentration stage, the microorganisms adapt to different concentrations of pollutants and reach a relatively stable state by adjusting their own enzyme systems, cell membrane permeability and other physiological mechanisms. At the same time, the water quality of the MABR membrane effluent in the MABR purification pool is monitored until the effluent meets the design requirements and the biofilm domestication is completed; 4) Symbiotic circulation system connection: By utilizing the reasonable elevation difference between the treatment pools in the entire system, the fish pond wastewater flows through the MABR purification pool, sedimentation pool, planting pool, and reuse pool in sequence, and is finally lifted back to the fish pond by a pump, forming a complete and efficient symbiotic circulation system; 5) Process operation: After the biofilm inoculation and domestication are completed, the symbiotic circulation system is operated. According to the water quality of the aquaculture tail water and the circulating water quality requirements, the process operation parameters of each treatment unit are adjusted. The MABR purification tank residence time is 2-3h, the pH value is 7-7.5, the dissolved oxygen is 2-3mg / L, the filter layer residence time is not less than 10-15min, and the backwash intensity is 15-20L / (m 2 ·s), inclined tube sedimentation tank, the inner diameter of the inclined tube is 25mm-50mm, the length is 0.8m-1.2m, the retention time is 1-1.5h, the reuse pool uses a corridor plug flow type pool body, the number of corridors is 2 or more; the first corridor pool body in the front section of the reuse pool is equipped with an ultraviolet disinfection system; the reuse pool is equipped with a water quality monitoring device and an adjustable water outlet device to ensure that the water quality meets the circulating water requirements.

[0016] The filter media for the filter layer usually refers to one or more of quartz sand, fruit shell filter media, medical stone filter media, sea zeolite filter media and volcanic rock filter media. Different types are selected and graded according to the particle size.

[0017] Example 1: MABR aquaponics circulation treatment method for tail water of Penaeus vannamei aquaculture.

[0018] The salinity of the tail water of Penaeus vannamei is 10000mg / L, COD Mn 30mg / L, ammonia nitrogen 5mg / L, total nitrogen 10mg / L.

[0019] 1) Construction of MABR purification pool: Two layers of MABR membrane are set in the pool body, with a membrane interval of 300mm, and the bottom of the MABR membrane layer is 200mm away from the top of the filter layer. The filter material is laid in two layers, and the upper filter material filter layer is located at the bottom of the MABR membrane layer; the filter material filter layer is divided into two layers, the bottom filter material uses volcanic rock filter material with a particle size of 2-5mm, the middle filter material is 300mm thick, and the upper layer uses medical stone filter material with a particle size of 1-2mm, and the layer thickness is 200mm; 2) Biofilm inoculation: Activated sludge from the secondary sedimentation tank of a municipal sewage treatment plant and domestic sewage were used for sludge inoculation, with an inoculation ratio of 1:20. Intermittent culture was used, and the three processes of aeration, static sedimentation and water inflow were circulated. The dissolved oxygen was 4 mg / L, and the aeration was continued for 2 days. Aeration was stopped, static sedimentation was continued for 1 hour, and then 20% of the volume of fresh sewage was introduced into the MABR purification tank. The three processes of aeration, static sedimentation and water inflow were circulated. The inoculation culture lasted for 2 weeks, and the sludge concentration was 4500 mg / L, and the biofilm was initially formed. 3) Biofilm domestication: The biofilm domestication uses shrimp pond tail water as the domestication water source, and the salinity concentration is 2000mg / L, 4000mg / L, 6000mg / L, 8000mg / L, and 10000mg / L in sequence. Each salinity stage lasts for 5 days, and the COD is monitored. Mn , ammonia nitrogen and total nitrogen indicators, up to 10000mg / L salinity stage COD Mn , ammonia nitrogen and total nitrogen water quality indicators meet the effluent requirements, and the biofilm successfully completes the entire salinity gradient acclimatization; 4) Symbiotic circulation system connection: The shrimp pond, MABR purification tank, sedimentation tank, planting tank and reuse tank are connected in sequence with pipes. The height difference of each unit is designed to be 200mm to ensure the self-flow of the system. The lifting pump lifts the water in the reuse tank after ultraviolet disinfection and buffering back to the shrimp pond to form a complete and efficient symbiotic circulation system. Among them, the fan installed in the air supply system is connected to the MABR membrane layer for air supply; the inner diameter of the inclined tube of the inclined tube sedimentation tank is 35mm and the length is 1m; the reuse pool adopts a corridor type, with 3 corridors, and ultraviolet disinfection is set in the first corridor; 5) Process operation: MABR purification tank residence time 3h, pH value 7.1-7.2, dissolved oxygen 3mg / L, filtration layer residence time not less than 15min, backwash intensity 15L / (m 2 ·s), the retention time of the inclined tube sedimentation tank is 1-1.5h, and the water quality of the reuse pool reaches COD Mn 10mg / L, ammonia nitrogen 1mg / L, total nitrogen 3mg / L. When the circulating water requirements are met, turn on the reflux pump to return the treated water to the shrimp pond, forming a complete and efficient symbiotic circulation system.

[0020] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A MABR aquaponics recycling treatment method, characterized by: The symbiotic circulation treatment system is mainly composed of MABR purification tank, sedimentation tank, planting tank, reuse tank and fish pond. The treatment method mainly includes the following steps: 1) Construction of MABR purification pool: MABR purification pool is composed of pool body, MABR membrane layer, filter material filtration layer and air supply system. The water flow direction is from top to bottom. The filter material filtration layer is set at the bottom of the MABR membrane layer. The air supply system is set outside the pool body. The air supply pipeline supplies air to the MABR membrane layer, and the valve adjusts the air supply volume. 2) Biofilm inoculation: After the MABR purification pool is constructed, activated sludge and domestic sewage are used to inoculate the MABR biofilm for a period of 2 weeks; 3) Biofilm domestication: Using the tail water of the fish pond, the MABR biofilm is domesticated and cultured by increasing the influent ratio according to the salt concentration gradient, with a cycle of 2 weeks or more; 4) Symbiotic circulation system connection: The wastewater from the fish pond flows into the MABR purification tank, sedimentation tank, planting tank, and reuse tank in sequence, and is then pumped into the fish pond to form a symbiotic circulation system; 5) Process operation: After the biofilm inoculation and domestication are completed, the symbiotic circulation system operates normally. The MABR biofilm adsorbs and degrades carbon and nitrogen, and the filtration layer removes some pollutants. The effluent from the sedimentation tank enters the planting pool. The absorption of plants and the degradation of the soil layer further purify the pollutants. The reuse pool disinfects and buffers the water and then pumps it into the fish pond to achieve efficient recycling of the water. In the step 1), at least one MABR membrane layer and at least one filter material filtration layer are provided; the MABR purification tank has a residence time of 2-3 hours, a pH value of 7-7.5, and a dissolved oxygen of 2-3 mg / L; In step 2), the activated sludge and domestic sewage are inoculated at a ratio of 1:20-1:30, intermittent culture, dissolved oxygen 3-4 mg / L, and sludge concentration 4000-5000 mg / L; In step 3), the biofilm is acclimated to a salinity concentration gradient of 20%, 40%, 60%, 80%, and 100%, and each concentration is acclimated for at least 2 days. The water quality of the MABR membrane effluent in the MABR purification pool is monitored until the effluent meets the design requirements and the biofilm acclimation is completed.

2. The MABR aquaponics recycling treatment method according to claim 1, characterized in that: The bottom of the MABR membrane layer is spaced 100mm-200mm from the top of the filter layer, and the MABR membrane layers are spaced 200mm-300mm apart.

3. The MABR aquaponics circulation treatment method according to claim 1, characterized in that: The filter material of the filter layer is usually selected from one or more of quartz sand, fruit shell filter material, medical stone filter material, sea zeolite filter material and volcanic rock filter material. Different types are selected and graded according to the particle size. The residence time is not less than 10-15min, and the backwash intensity is 15-20L / (m 2 ·s).

4. The MABR aquaponics circulation treatment method according to claim 1, characterized in that: The sedimentation tank is an inclined tube sedimentation tank with an inner diameter of 25-50 mm, a length of 0.8-1.2 m, and a residence time of 1-1.5 h.

5. The MABR aquaponics recycling treatment method according to claim 1, characterized in that: The reuse pool adopts a corridor plug flow type pool body, and the number of corridors is 2 or more; the first corridor pool body in the front section of the reuse pool is equipped with an ultraviolet disinfection system.

6. The MABR aquaponics recycling treatment method according to claim 1, characterized in that: The reuse pool is provided with a water quality monitoring device and an adjustable water outlet device.