Microalgae carbon sequestration system and use method thereof

Abstract

The invention belongs to the technical field of microalgae carbon sequestration, and particularly relates to a microalgae carbon sequestration system, which comprises a precipitation sewage tank, a floating algae liquid tank, a primary reaction column and a water purification tank, sewage in the precipitation sewage tank and floating algae liquid in the floating algae liquid tank are respectively put into the primary reaction column for mixing, standing is carried out, and precipitates are formed; purified water in the first-stage reaction column flows into a purified water tank after being discharged. According to the invention, the sewage is precipitated by using the precipitation sewage tank, part of precipitates in the sewage are removed, then floating algae are added into the first-stage reaction column for removing ammonia nitrogen in the sewage, finally the sewage enters the second-stage reaction column, nitrate nitrogen in the sewage is removed by using fixed algae and nitrifying bacteria in the second-stage reaction column, and the whole system is connected in series, so that the sewage treatment efficiency is improved. Ammonia nitrogen and phosphorus in the sewage can be effectively removed.

Description

Technical Field

[0001] This invention belongs to the field of microalgae carbon fixation technology, specifically relating to a microalgae carbon fixation system and its usage method. Background Technology

[0002] Microalgae carbon sequestration technology, as an emerging wastewater treatment method, has unique advantages. Microalgae can utilize nutrients such as nitrogen and phosphorus in wastewater for growth and reproduction, while simultaneously fixing carbon dioxide through photosynthesis, thus achieving carbon emission reduction and realizing the dual benefits of wastewater treatment and carbon sequestration.

[0003] However, existing technologies mostly focus on treating pollutants using single microalgae. Due to the limitations of algal species' metabolic characteristics, they have poor adaptability to different forms of nitrogen in wastewater, making it difficult to meet pollutant discharge standards. In addition, existing processes only treat ammonia nitrogen through microalgae and do not design subsequent treatment units for nitrate nitrogen, resulting in excessive residual nitrate nitrogen in the effluent. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a microalgae carbon fixation system and its usage method. The system utilizes a sedimentation tank to settle wastewater, removing some of the sediment. Then, phytoplankton is added to a primary reaction column to remove ammonia nitrogen. Finally, the wastewater enters a secondary reaction column, where fixed algae and nitrifying bacteria remove nitrate nitrogen. The entire system is connected in series, effectively removing ammonia nitrogen and phosphorus from wastewater.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] A microalgae carbon fixation system includes a sedimentation wastewater tank, a phytoplankton solution tank, a primary reaction column, and a purification water tank. The wastewater in the sedimentation wastewater tank and the phytoplankton solution in the algae solution tank are respectively fed into the primary reaction column, mixed, and allowed to settle to form sediment. The purified water in the primary reaction column flows into the purification water tank after being discharged.

[0007] The output end of the primary reaction column is also equipped with a drain port, and a drain valve is installed on the drain port.

[0008] A secondary reaction column is also provided between the primary reaction column and the water purification tank. The secondary reaction column is filled with fixed algae and nitrifying bacteria.

[0009] The secondary reaction column is also equipped with an air pump. The output end of the air pump extends into the bottom of the secondary reaction column through a ventilation pipe. The air pump provides airflow into the secondary reaction column through the ventilation pipe and drives the fixed algae and nitrifying bacteria in the secondary reaction column to oscillate.

[0010] The output end of the vent pipe has a funnel-shaped structure that is wider at the top and narrower at the bottom. A one-way valve is installed on the vent pipe. The vent pipe uses the one-way valve to input air into the secondary reaction column. The one-way valve prevents water in the secondary reaction column from flowing into the air pump along the vent pipe.

[0011] The carrier for immobilizing algae includes any one of ceramsite, expanded perlite, and polyurethane foam particles.

[0012] The concentration of phytoplankton in the phytoplankton solution is 2-5 g / L.

[0013] The planktonic algae in the algae solution, by mass fraction, include 30-40 parts of Chlorella vulgaris, 25-35 parts of Scenedesmus stenoptera, 15-25 parts of Anabaena spp., and 10-20 parts of Chlamydomonas spp.

[0014] The method of use specifically includes the following steps:

[0015] S1. Wastewater is allowed to settle in the sedimentation tank for 24-48 hours. After settling, the sediment is removed. The wastewater pump in the sedimentation tank and the algae solution pump in the algae solution tank are turned on. The wastewater and algae solution flow into the primary reaction column respectively.

[0016] S2. Wastewater and phytoplankton in the phytoplankton solution are mixed and reacted in the primary reaction column for 8-12 hours to remove ammonia nitrogen from the wastewater;

[0017] S3. Then, the wastewater after primary treatment is fed into the secondary reaction column. The wastewater after primary treatment reacts with fixed algae and nitrifying bacteria for 24-48 hours to remove nitrate nitrogen and obtain purified water. The purified water is then discharged into the water purification tank.

[0018] The beneficial effects of this invention are:

[0019] 1. In this invention, the wastewater is first settled in a sedimentation tank to remove some of the sediment. Then, phytoplankton is added to the primary reaction column to remove ammonia nitrogen from the wastewater. Finally, the wastewater enters the secondary reaction column, where fixed algae and nitrifying bacteria remove nitrate nitrogen. The entire system is connected in series and can effectively remove ammonia nitrogen and phosphorus from the wastewater.

[0020] 2. This invention leverages the synergistic effects of different algae's metabolic characteristics. Chlorella and Scenedesmus exhibit highly efficient ammonia nitrogen absorption, Anabaena can convert nitrite nitrogen through nitrogen fixation, and Chlamydomonas enhances the mixed system's adaptability to nitrogen forms. The synergistic effect of these four algae significantly improves the removal rate of ammonia and nitrite nitrogen in wastewater, overcoming the limitations of single algae in removing specific nitrogen forms. Furthermore, the compound system can more stably utilize wastewater nutrients for growth and reproduction, increasing the overall biomass of microalgae and thus enhancing the system's carbon sequestration efficiency and wastewater treatment effect. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] In the attached diagram, 1 is the sedimentation tank, 2 is the algae solution tank, 3 is the primary reaction column, 4 is the water purification tank, 5 is the secondary reaction column, 6 is the air pump, 7 is the vent pipe, 8 is the check valve, 9 is the sewage pump, 10 is the algae solution pump, 11 is the discharge port, and 12 is the discharge valve. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] Specific embodiments, such as Figure 1 As shown, the present invention provides a microalgae carbon fixation system, including a sedimentation wastewater tank 1, a phytoplankton liquid tank 2, a primary reaction column 3, and a purification water tank 4. The wastewater in the sedimentation wastewater tank 1 and the phytoplankton liquid in the algae liquid tank are respectively fed into the primary reaction column 3 for mixing, settling and forming precipitates. The purified water in the primary reaction column 3 flows into the purification water tank 4 after being discharged.

[0025] In this invention, wastewater is first settled in a sedimentation tank 1, allowing suspended particulate matter and some COD in the wastewater to form precipitates. This prevents high COD from inhibiting phytoplankton photosynthesis and prepares the water for subsequent nitrogen removal. The phytoplankton solution is then mixed with the pretreated wastewater in a primary reaction column 3. The phytoplankton grow using ammonia nitrogen as a nutrient and removes ammonia nitrogen through metabolic absorption.

[0026] The output end of the primary reaction column 3 is also provided with a drain port 11, and a drain valve 12 is provided on the drain port 11.

[0027] The precipitate in the primary reaction column 3 can be discharged through the drain outlet 11 and the drain valve 12 to prevent the precipitate from entering the secondary reaction column 5 along with the primary purified water.

[0028] A secondary reaction column 5 is also provided between the primary reaction column 3 and the water purification tank 4. The secondary reaction column 5 is filled with fixed algae and nitrifying bacteria.

[0029] In this invention, the wastewater is first settled in a sedimentation tank 1 to remove some of the sediment. Then, phytoplankton is added to the primary reaction column 3 to remove ammonia nitrogen from the wastewater. Finally, the wastewater enters the secondary reaction column 5, where fixed algae and nitrifying bacteria remove nitrate nitrogen. The entire system is connected in series and can effectively remove ammonia nitrogen and phosphorus from the wastewater.

[0030] The secondary reaction column 5 is also equipped with an air pump 6. The output end of the air pump 6 extends into the bottom of the secondary reaction column 5 through the air pipe 7. The air pump 6 provides airflow into the secondary reaction column 5 through the air pipe 7 and drives the fixed algae and nitrifying bacteria in the secondary reaction column 5 to oscillate.

[0031] Air pump 6 introduces airflow from the bottom of the secondary reaction column 5. The airflow agitates the wastewater, ensuring thorough mixing of fixed algae, nitrifying bacteria, and wastewater, preventing localized wastewater stagnation and algal / bacterial inactivation. Additionally, the oxygen in the airflow provides the aerobic environment necessary for the metabolism of nitrifying bacteria, promoting nitrification. Simultaneously, the carbon dioxide in the airflow can be absorbed by the fixed algae for photosynthesis, increasing microalgal biomass and enhancing carbon fixation capacity.

[0032] The output end of the vent pipe 7 has a funnel-shaped structure that is wider at the top and narrower at the bottom. A one-way valve 8 is installed on the vent pipe 7. Air is introduced into the secondary reaction column 5 through the one-way valve 8. The one-way valve 8 prevents water in the secondary reaction column 5 from flowing into the air pump 6 along the vent pipe 7.

[0033] The vent pipe 7 has a funnel-shaped output end, which allows the airflow to be more evenly distributed at the bottom of the reaction column, which is beneficial for more comprehensive driving of the filter particles to oscillate. The one-way valve 8 can prevent water in the reaction column from flowing back into the air pump 6, ensuring the normal operation and service life of the air pump 6, and avoiding the impact of air pump 6 failure on the normal operation of the system.

[0034] The carrier for immobilizing algae includes any one of ceramsite, expanded perlite, or polyurethane foam particles. The carrier needs to have a loose, porous structure to provide attachment points for the microalgae.

[0035] The concentration of planktonic microalgae in the phytoplankton solution is 2-5 g / L.

[0036] The planktonic microalgae in the phytoplankton solution, by mass fraction, include 30-40 parts of Chlorella vulgaris, 25-35 parts of Scenedesmus stenoptera, 15-25 parts of Anabaena spp., and 10-20 parts of Chlamydomonas spp.

[0037] This invention leverages the synergistic effects of different algae's metabolic characteristics. Chlorella and Scenedesmus exhibit highly efficient ammonia nitrogen absorption, Anabaena can convert nitrite nitrogen through nitrogen fixation, and Chlamydomonas enhances the mixed system's adaptability to nitrogen forms. The synergistic effect of these four algae significantly improves the removal rate of ammonia and nitrite nitrogen in wastewater, overcoming the limitations of single algae in removing specific nitrogen forms. Furthermore, the compound system can more stably utilize wastewater nutrients for growth and reproduction, increasing the overall biomass of microalgae, thereby enhancing the system's carbon sequestration efficiency and wastewater treatment effect.

[0038] The method of use specifically includes the following steps:

[0039] S1. Wastewater is allowed to settle in sedimentation tank 1 for 24-48 hours. After settling, the sediment is removed. Then, the wastewater pump 9 in sedimentation tank 1 and the algae solution pump 10 in algae solution tank 2 are turned on. The wastewater and algae solution flow into the primary reaction column 3 respectively.

[0040] S2. Wastewater and planktonic microalgae in the phytoplankton solution are mixed and reacted in primary reaction column 3 for 8-12 hours to remove ammonia nitrogen from the wastewater;

[0041] S3. Then, the wastewater after primary treatment is fed into the secondary reaction column 5. The wastewater after primary treatment reacts with fixed algae and nitrifying bacteria for 24-48 hours to remove nitrate nitrogen and obtain purified water. The purified water is then discharged into the water purification tank 4.

Claims

1. A microalgae carbon fixation system comprising a sedimentation sewage pool (1), a planktonic algae liquid pool (2), a first reaction column (3) and a clean water pool (4), characterized in that, The sewage in the sedimentation sewage tank (1) and the planktonic algae liquid in the algae liquid tank are respectively fed into the first reaction column (3) to mix, stand and form a precipitate, and the purified water in the first reaction column (3) flows into the purified water tank (4) after being discharged.

2. The microalgal carbon sequestration system of claim 1, wherein, The output end of the first reaction column (3) is further provided with a sewage discharge port (11), and the sewage discharge port (11) is provided with a sewage discharge valve (12).

3. The microalgal carbon sequestration system of claim 1, wherein, The first reaction column (3) and the purified water tank (4) are further provided with a second reaction column (5), and the second reaction column (5) is filled with fixed algae and nitrifying bacteria.

4. The microalgal carbon sequestration system of claim 3, wherein, The second reaction column (5) is further provided with an air pump (6), and the output end of the air pump (6) extends into the bottom of the second reaction column (5) through an air pipe (7), and the air pump (6) drives the fixed algae and nitrifying bacteria in the second reaction column (5) to oscillate by providing air flow into the second reaction column (5) through the air pipe (7).

5. The microalgal carbon capture system of claim 4, wherein, The output end of the air pipe (7) is in the shape of a horn mouth structure which is wide at the top and narrow at the bottom, and the air pipe (7) is provided with a one-way valve (8), the air pipe (7) inputs air into the second reaction column (5) through the one-way valve (8), and the one-way valve (8) prevents water in the second reaction column (5) from flowing into the air pump (6) through the air pipe (7).

6. The microalgal carbon sequestration system of claim 3, wherein, The carrier of the fixed algae includes any one of ceramsite, expanded perlite and polyurethane foam particles.

7. The microalgal carbon sequestration system of claim 1, wherein, The concentration of the planktonic algae in the planktonic algae liquid is 2-5g / L.

8. The microalgal carbon sequestration system of claim 1, wherein, The planktonic algae in the planktonic algae liquid includes, by mass fraction, 30-40 parts of chlorella, 25-35 parts of desmodesmus, 15-25 parts of fishy algae and 10-20 parts of chlamydomonas.

9. A method of using a microalgal nitrogen fixation system according to claim 3, wherein, The use method specifically includes the following steps: S1, the sewage is deposited in the sedimentation sewage tank (1), and after being deposited for 24-48h, the sediment is removed, the sewage pump (9) of the sedimentation sewage tank (1) and the algae liquid pump (10) of the planktonic algae liquid tank (2) are opened, and the sewage and the planktonic algae liquid flow into the first reaction column (3) respectively; S2, the sewage and the planktonic algae in the planktonic algae liquid are mixed and reacted in the first reaction column (3) for 8-12h to remove ammonia nitrogen in the sewage; S3, then the sewage treated by the first stage is fed into the second reaction column (5), and the sewage treated by the first stage is reacted with the fixed algae and nitrifying bacteria for 24-48h to remove nitrate nitrogen and obtain purified water, and the purified water is discharged into the purified water tank (4).

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