Urine resourceful treatment system and use method thereof

Abstract

The invention discloses a urine resourceful treatment system and a use method thereof, and relates to the technical field of water treatment. According to the method disclosed by the invention, essential nutrient substances are recycled from the separated urine by utilizing anaerobic fermentation and MABR biological nitrification and are converted into a liquid fertilizer, so that nutrients are provided for the growth of aquatic plants. In the anaerobic stage, microorganisms degrade complex organic matters into volatile fatty acids through metabolism, and generated biogas can be used for domestic energy; according to the MABR biological nitrification, ammonium is converted into nitrate, and the pH value is reduced, so that ammonia volatilization is reduced, and the main limitation of direct use is solved. According to the technology, peculiar smell can be eliminated, the content of organic matter can be reduced, the safe and stable liquid fertilizer can be produced and used for planting hydroponic plants, and efficient resource utilization of urine is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sewage treatment, and particularly relates to a urine resource treatment system and a use method thereof. BACKGROUND

[0002] By treating urine separately to recover nutrients rather than remove them, a conventional wastewater treatment plant can save about 50% of the aeration energy and reduce the amount of carbon dioxide emitted during biological oxidation. Urine is an important source of nutrients for agricultural planting, but it is usually not recommended for direct application due to its unpleasant odor, high pH value (about 9.5), and large loss of nutrients through ammonia volatilization. Among the various urine treatment technologies explored, anaerobic fermentation + MABR biological nitrification can effectively recover essential nutrients from separated urine and convert them into liquid fertilizer to provide nutrients for the growth of hydroponic plants. In the anaerobic stage, microorganisms degrade complex organic matter into volatile fatty acids through metabolic action, and the biogas produced can be used for domestic energy; MABR biological nitrification reduces ammonia volatilization by converting ammonium into nitrate and lowering the pH value, thereby addressing the main limitations of direct use. This process also eliminates odors, reduces organic matter content, and produces a safe and stable fertilizer. Importantly, for hydroponic applications, the mixed form of ammonium nitrogen and nitrate nitrogen is more ideal because both forms can be easily absorbed by plants. Ammonium nitrogen provides a fast and energy-efficient nitrogen source, while nitrate nitrogen provides stability and pH balance, together ensuring stable plant growth. SUMMARY

[0003] In summary, the present application provides a urine resource treatment system and a use method thereof. By anaerobic fermentation + MABR biological nitrification, essential nutrients are recovered from separated urine and converted into liquid fertilizer to provide nutrients for the growth of hydroponic plants, and the biogas produced by anaerobic fermentation can be used for domestic energy.

[0004] The present application is achieved by the following technical solutions: A urine resource treatment system, characterized in that it mainly consists of a water inlet tank, a UASB reactor, a gas storage tank, a MABR biological nitrification tank, and a hydroponic planting tank. The water inlet tank collects and stores urine, which is pumped from the bottom of the UASB reactor. The urine flow is adjusted by a valve. The outlet water of the UASB reactor enters the MABR biological nitrification tank. The MABR biological nitrification tank is provided with an outlet at the end. The outlet water flows into the hydroponic planting tank. The hydroponic planting tank is provided with a feeding port at the front end and a discharge port at the end. The treated water is discharged from the discharge port for recycling. The UASB reactor is provided with a heat preservation layer outside and a three-phase separator at the top inside. The gas storage tank is connected to the top of the UASB reactor for collecting and storing biogas produced by anaerobic fermentation. The gas storage tank is provided with a gas delivery pipeline to deliver biogas outside. The MABR biological nitrification tank mainly consists of MABR membrane modules, membrane supports, air supply pipes, gas connection pipes, and aerators. The MABR membrane modules are fixed on the membrane supports, and the aerators are located at the bottom. The aerators receive the air from the outlet of the MABR membrane modules through pipes, and the air volume of the aerators is adjusted by valves. The gas supply equipment is set up separately and supplies gas to the MABR biological nitrification tank through a gas supply pipe. A valve is installed on the gas supply pipe to adjust the gas supply volume. The UASB reactor and MABR biological nitrification tank are equipped with sludge discharge systems at the bottom. The hydroponic planting trough contains one or more aquatic plants, including lettuce, spinach, bok choy, water spinach, and celery. The hydroponic planting trough is equipped with a nutrient solution monitoring and control system to monitor nutrient solution indicators in real time.

[0005] The method of using the above-mentioned urine resource recovery system includes the following steps: (1) System biofilm acclimatization: Use domestic sewage and activated sludge to inoculate microorganisms in the UASB reactor and MABR biological nitrification tank. After the MABR biological nitrification tank is aerated for 24 hours, the entire system is intermittently fed with water. The acclimatization period is 10-20 days. During this period, the influent load is gradually increased until the microorganisms adapt to the urine environment. (2) System commissioning and start-up: Water is continuously introduced from the inlet tank. In the initial stage, the total hydraulic retention time of the UASB reactor and the MABR biological nitrification tank is 20 days. During the commissioning period, the time is reduced by 2 days each time. Each adjustment cycle is set to 3-6 days, and the time is gradually shortened to the target hydraulic retention time. The target hydraulic retention time is 2-4 days in the UASB reactor and 1-2 days in the MABR biological nitrification tank. (3) Stable system operation: After the system reaches the target residence time, it enters the stable operation stage. The nutrient solution indicators in the hydroponic planting tank are monitored in real time through the nutrient solution monitoring and control system. When the nutrient solution concentration exceeds the set range, the nutrient solution is stopped from being added, and the residence time of the treated urine in the hydroponic planting tank is extended. After the urine treatment reaches the design, it is discharged from the system through the discharge port. In the initial stage of biofilm acclimatization of the system, the influent load is 20% of the design load, and it is increased by 10%-20% every 2 days until the design load is reached. During the system commissioning and startup phase, before each reduction in hydraulic retention time, it is necessary to monitor the effluent quality indicators of the MABR biological nitrification tank to reduce the impact of high load on aquatic plants in the hydroponic planting trough.

[0006] Further, the pressure of the MABR membrane assembly in the MABR biological nitrification tank is maintained between 0.02 MPa and 0.10 MPa, and the dissolved oxygen in the MABR biological nitrification tank is maintained between 2.0 mg / L and 3.0 mg / L.

[0007] Further, the nutrient solution index is 8 mg / L to 15 mg / L of ammonium nitrogen and 30 mg / L to 55 mg / L of nitrate nitrogen.

[0008] The application discloses a urine resource treatment system and a use method thereof, and recovers essential nutrients from separated urine through anaerobic fermentation and MABR biological nitrification, and converts the essential nutrients into liquid fertilizer to provide nutrients for the growth of water planting plants. In the anaerobic stage, microorganisms degrade complex organic matter into volatile fatty acids through metabolic action, and biogas generated thereby can be used for daily life; the MABR biological nitrification converts ammonium nitrogen in the urine into nitrate, effectively inhibits ammonia volatilization along with the decrease of pH value, and overcomes the problem of direct application of the urine. The process not only can eliminate odor and reduce the content of organic matter, but also can produce safe and stable liquid fertilizer for water planting plant planting, and realizes efficient resource utilization of the urine. BRIEF DESCRIPTION OF DRAWINGS

[0009] ATTACHED Figure 1 It is a facade structure schematic diagram of the application.

[0010] In the figure: 1, water inlet tank, 2, water pump, 3, valve, 4, UASB reactor, 5, aerator, 6, MABR membrane assembly, 7, membrane support, 8, sludge discharge system, 9, feeding port, 10, water planting tank, 11, gas storage tank, 12, gas conveying pipeline, 13, thermal insulation layer, 14, three-phase separator, 15, gas supply equipment, 16, MABR biological nitrification tank, 17, water outlet, 18, aquatic plant, 19, monitoring and control system, 20, discharge port. DETAILED DESCRIPTION

[0011] In order to make the technical means, creative features, purposes and effects realized by the application easy to understand, the application is further described below in combination with specific embodiments.

[0012] The urine resource treatment system is mainly composed of a water inlet tank 1, a UASB reactor 4, a gas storage tank 11, a MABR biological nitrification tank 16 and a water planting tank 10. The urine is collected and stored in the water inlet tank 1, and the urine is introduced into the UASB reactor 4 from the bottom through a water pump 2. The urine flow is adjusted by a valve 3. The water outlet of the UASB reactor 4 is introduced into the MABR biological nitrification tank 16. The MABR biological nitrification tank 16 is provided with a water outlet 17 at the end. The water outlet is introduced into the water planting tank 10. The water planting tank 10 is provided with a feeding port 9 at the front end and a discharge port 20 at the end. The treated water is discharged from the discharge port 20 and recycled. The UASB reactor 4 is provided with an external heat preservation layer 13 and an internal three-phase separator 14 at the top. The gas storage tank 11 is connected with the top of the UASB reactor 4 and is used for collecting and storing biogas generated by anaerobic fermentation. The gas storage tank 11 is provided with a gas conveying pipeline 12 for conveying the biogas outward. The MABR biological nitrification tank 16 is mainly composed of a MABR membrane assembly 6, a membrane support 7, a gas supply pipe, a gas connecting pipe and an aerator 5. The MABR membrane assembly 6 is fixed on the membrane support 7. The aerator 5 is arranged at the bottom and receives the gas outlet end of the MABR membrane assembly 6 through the pipeline. The amount of gas of the aerator 5 is adjusted by the valve 3. A gas supply device 15 is separately arranged and supplies gas to the MABR biological nitrification tank 16 through the gas supply pipe. The valve 3 arranged on the gas supply pipe adjusts the amount of gas supply. The UASB reactor 4 and the MABR biological nitrification tank 16 are provided with a sludge discharge system 8 at the bottom. The water planting tank 10 is planted with one or more aquatic plants 18 of lettuce, spinach, Chinese cabbage, water spinach and celery. The water planting tank 10 is provided with a nutrient solution monitoring and control system 19 for monitoring the nutrient solution index in real time.

[0013] The use method of the urine resource treatment system is as follows. (1) System membrane domestication: the mixed solution of activated sludge and domestic sewage is injected into the UASB reactor 4 and the MABR biological nitrification tank 16. The water inlet valve 3 of the MABR biological nitrification tank 16 is closed, the gas supply device 15 is opened, the amount of aeration is adjusted to maintain the dissolved oxygen at 2.0 mg / L-3.0 mg / L, and the aeration is carried out for 24 h. The intermittent water inlet mode is started, the water inlet time is controlled at 2 h per day, the water inlet load is 20% of the design load, the water inlet load is increased by 10%-20% every 2 days, and the domestication is continued for 10-20 days until the design load is reached. During the period, the removal rates of the effluent COD and ammonia nitrogen are monitored to be greater than or equal to 60% and 50% respectively, and the domestication is completed. (2) System debugging start: continuous water inflow from the water inflow tank 1, the total hydraulic retention time of the UASB reactor 4 and the MABR bio-nitrification tank 16 is 20d in the initial stage, the debugging period is reduced by 2d each time, each adjustment period is set to 3d-6d, and the target hydraulic retention time is gradually shortened to 2d-4d in the UASB reactor 4 and 1d-2d in the MABR bio-nitrification tank 16; before each reduction of the hydraulic retention time, the water quality indicators of the MABR bio-nitrification tank 16 are monitored to reduce the impact of high load on the aquatic plants 18 in the water planting tank 10; (3) System stable operation: after the system reaches the target retention time, it enters the stable operation stage, the nutrient solution monitoring and control system 19 is used to monitor the nutrient solution indicators in the water planting tank 10 in real time, when the nutrient solution concentration exceeds the set range, the nutrient solution stops being put in, the retention time of the urine treatment in the water planting tank 10 is prolonged, and the urine treatment is discharged from the discharge port 20 after reaching the design.

[0014] In the stable operation stage of the above steps, the pressure of the MABR membrane assembly 6 in the MABR bio-nitrification tank 16 is maintained at 0.02MPa-0.10Mpa, and the dissolved oxygen in the MABR bio-nitrification tank 16 is maintained at 2.0mg / L-3.0mg / L; the nutrient solution indicators are ammonium nitrogen 8mg / L-15mg / L and nitrate nitrogen 30mg / L-55mg / L.

[0015] Example 1: The urine collected by the urine separation toilet has a pH value of 9.2-9.6, an ammonia nitrogen concentration of 900mg / L-1100mg / L, and a COD concentration of 4000mg / L-5000mg / L, which is continuously fed from the bottom of the UASB reactor 4 at a flow rate of 1m 3 / h by the water pump 2; the urine stays in the UASB reactor 4 for 2 days, the microorganisms degrade organic matter to produce volatile fatty acids and biogas, the biogas is separated by the three-phase separator 14 and stored in the gas storage tank 11 for cooking, heating and other life energy; the UASB reactor 4 effluent flows into the MABR bio-nitrification tank 16 by itself, stays for 1d, maintains the dissolved oxygen in the tank at 2.5mg / L, and the pressure of the MABR membrane assembly 6 is stable at 0.06MPa; the nitrifying bacteria convert ammonium nitrogen into nitrate, the effluent pH value is reduced to 6.3-7.2, and the ammonia nitrogen removal rate reaches 90%. The MABR bio-nitrification tank 16 effluent flows into the water planting tank 10 through the effluent outlet 17, the tank is planted with Chinese cabbage and water spinach, and the nutrient solution monitoring and control system 19 is used for real-time monitoring, the ammonium nitrogen is 8mg / L-15mg / L, the nitrate nitrogen is 30mg / L-55mg / L, the nutrient solution stops being put in when the nutrient solution concentration exceeds the set range; when the urine treatment reaches the design, it is discharged from the discharge port 20.

[0016] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the essence of the present application should be covered within the protection scope of the present application.

Claims

1. A urine resource recovery system, characterized by: The system mainly comprises a water inlet tank, a UASB reactor, a gas storage tank, a MABR bio-nitrification tank and a water planting tank. The water inlet tank collects and stores urine. The urine is pumped from the bottom of the UASB reactor. The urine flow is adjusted by a valve. The effluent of the UASB reactor enters the MABR bio-nitrification tank. The MABR bio-nitrification tank is provided with an effluent outlet at the end. The effluent flows into the water planting tank. The water planting tank is provided with a feeding port at the front end and a discharge port at the end. The treated water is discharged from the discharge port for recycling. The UASB reactor is provided with a heat preservation layer outside and a three-phase separator at the top inside. The gas storage tank is connected with the top of the UASB reactor for collecting and storing biogas generated by anaerobic fermentation. The gas storage tank is provided with a gas conveying pipeline for conveying the biogas outside. The MABR bio-nitrification tank mainly comprises a MABR membrane assembly, a membrane support, a gas supply pipe, a gas connecting pipe and an aerator. The MABR membrane assembly is fixed on the membrane support. The aerator is arranged at the bottom and receives the gas outlet end of the MABR membrane assembly through the pipeline. The gas amount of the aerator is adjusted by a valve. The gas supply equipment is separately arranged and supplies gas to the MABR bio-nitrification tank through the gas supply pipe. The gas supply pipe is provided with a valve for adjusting the gas supply amount. The UASB reactor and the MABR bio-nitrification tank are provided with a sludge discharge system at the bottom. The water planting tank is planted with one or more than one kind of aquatic plants such as lettuce, spinach, Chinese cabbage, water spinach and celery. The water planting tank is provided with a nutrient solution monitoring and control system for monitoring the nutrient solution index in real time.

2. A method of using the urine resource recovery system of claim 1, characterized by: The system comprises the following steps: (1) System biofilm cultivation and domestication: the UASB reactor and the MABR bio-nitrification tank are inoculated with microorganisms by using domestic sewage and activated sludge. After the MABR bio-nitrification tank is covered and exposed for 24 hours, the whole system is intermittently fed. The domestication period is 10-20 days. During the period, the water inflow load is gradually increased until the microorganisms adapt to the urine environment. (2) System debugging and starting: the water inlet tank is continuously fed. The total hydraulic retention time of the UASB reactor and the MABR bio-nitrification tank is 20 days in the initial stage. The debugging period is reduced by 2 days each time. Each adjustment period is set to 3-6 days. The target hydraulic retention time is gradually shortened. The hydraulic retention time in the UASB reactor is 2-4 days. The hydraulic retention time in the MABR bio-nitrification tank is 1-2 days. (3) System stable operation: after the system reaches the target retention time, it enters the stable operation stage. The nutrient solution index in the water planting tank is monitored in real time by the nutrient solution monitoring and control system. When the nutrient solution concentration exceeds the set range, the nutrient solution stops being fed. The retention time of the treated urine in the water planting tank is prolonged. The urine treatment is discharged from the discharge port of the system after reaching the design. In the initial stage of the system biofilm cultivation and domestication, the water inflow load is 20% of the design load. The load is increased by 10-20% every 2 days until the design load is reached. In the system debugging and starting stage, before the hydraulic retention time is shortened each time, the effluent water quality index of the MABR bio-nitrification tank needs to be monitored to reduce the impact of high load on the aquatic plants in the water planting tank.

3. The method of using a urine resource recovery system of claim 2, wherein: The pressure of the MABR membrane assembly in the MABR biological nitrification tank is maintained between 0.02 MPa and 0.10 MPa, and the dissolved oxygen in the MABR biological nitrification tank is maintained between 2.0 mg / L and 3.0 mg / L.

4. The method of using a urine resource recovery system of claim 2, wherein: The index of the nutrient solution is that the ammonium nitrogen is 8 mg / L-15 mg / L, and the nitrate nitrogen is 30 mg / L-55 mg / L.

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