Multi-stage treatment method for hydrogen energy sewage

Abstract

The invention discloses a multistage treatment method for hydrogen energy sewage, and belongs to the technical field of new energy utilization and sewage treatment. Hydrogen generated by electrolyzing water is used for denitrification nitrogen removal of sewage, oxygen generated by electrolyzing water is used for culturing aerobic flora and preparing ozone, and the sewage sequentially passes through an integrated pretreatment (integrated filtration, deoiling and precipitation) organic-inorganic separation device; the method comprises the following steps: culturing bacteria in a biological tank for biodegradation, efficient precipitation, denitrification nitrogen removal, ozone deep treatment (decoloration, COD reduction and disinfection) and sludge deep dehydration treatment, finally reducing the moisture content of the separated sludge to be below 15% for biomass energy power generation, and electrolyzing to prepare hydrogen and oxygen after the sewage with pollutants removed reaches the water purification standard. The sewage treatment process adopted by the invention can realize cyclic utilization of energy and resources, effectively removes organic and inorganic pollutants in sewage step by step, and finally can realize better energy-saving, carbon-reducing and pollution-removing effects.

Description

Technical Field

[0001] The invention belongs to the technical field of new energy utilization and sewage treatment, and specifically relates to a multi-stage treatment method for hydrogen energy sewage. Background Art

[0002] The denitrification process of sewage treatment refers to the process of reducing NO2-N and NO3-N into N2 due to the action of facultative denitrifying bacteria (denitrifying bacteria) under anoxic conditions, which is called denitrification.

[0003] Autotrophic denitrification technology is a new type of environmental bioremediation technology that can achieve deep removal of nitrate nitrogen in water without the need for an external organic carbon source. It has significant advantages such as high denitrification efficiency, low operating cost, and a wide range of applications. It is mainly used as a deep denitrification unit for improving the total nitrogen content of sewage treatment plants and improving the quality of high-nitrate industrial wastewater. The core of the autotrophic denitrification technology is the independently developed coupled bio-electron carrier, functional bacterial agent, and non-carbon source-dependent deep denitrification process system. In the coupled bio-electron carrier, the uniform distribution of alkalinity donors can effectively balance the pH of the denitrification process and achieve self-maintenance of biological activity; the introduction of multiple electron donors can effectively promote the coupling of microbial metabolism and achieve self-activation of the denitrification reaction process. The essence of autotrophic denitrification technology is that multiple electron donors synergistically promote the coupling of microbial metabolism to accelerate the denitrification reaction process, breaking through the technical bottleneck and engineering difficulties of low-cost deep denitrification.

[0004] The concentration of dissolved oxygen (DO) has a great influence on the denitrification reaction. Generally, the DO of the nitrification process is maintained at 2-3 mg / L, and the DO of the denitrification process is maintained at 0.2-0.5 mg / L. The level of dissolved oxygen in the biological reaction tank will inevitably affect the progress of the nitrification reaction. The mass concentration of dissolved oxygen in the aerobic section is generally maintained at 2-3 mg / L, and shall not be lower than 1 mg / L. When the mass concentration of dissolved oxygen is lower than 0.5-0.7 mg / L, the nitrification reaction of ammonia will be inhibited. Denitrification usually needs to be carried out under anoxic conditions. Dissolved oxygen has an inhibitory effect on denitrification, mainly because oxygen competes with nitrate for electron donors, and molecular oxygen also inhibits the synthesis and activity of nitrate reductase.

[0005] Therefore, how to design a method to use hydrogen energy to treat sewage in a graded manner to remove pollutants in the water while achieving the recycling and utilization of resources and energy has become a problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to propose a multi-stage treatment method for hydrogen-powered wastewater, which effectively removes pollutants in wastewater and realizes the recycling of resources and energy through multi-stage treatment processes such as wastewater pretreatment, biodegradation, denitrification treatment and deep dehydration.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] A hydrogen-powered multi-stage wastewater treatment method uses hydrogen produced by water electrolysis for denitrification and denitrification of wastewater, and uses oxygen produced by water electrolysis for cultivating aerobic bacteria and preparing ozone, and removes organic and inorganic pollutants in wastewater through filtration, degreasing, biodegradation, precipitation, denitrification and denitrification, ozone disinfection and sludge deep dehydration treatment in sequence.

[0009] Furthermore, the denitrification process is as follows: H2 is used as an electron donor, CO3 2- 、HCO3 - , CO2 acts as an inorganic carbon source to reduce NO3-N to N2 in an oxygen-deficient environment.

[0010] Furthermore, the dedicated devices for the filtration process are a coarse grid and an organic-inorganic separation device; the organic-inorganic separation device includes a fine grid, a membrane grid, a grit chamber and a primary sedimentation tank.

[0011] Furthermore, the filtration process separates and removes inorganic impurities and oil particles with a size of more than 100 μm.

[0012] Furthermore, the biodegradation device is a MAS biomultiplication reactor.

[0013] Furthermore, the special device for the sedimentation process is an integrated high-efficiency sedimentation tank; the integrated high-efficiency sedimentation tank includes a secondary sedimentation tank and a high-efficiency sedimentation tank.

[0014] Furthermore, the denitrification and denitrification process device is a hydrogen autotrophic denitrification filter.

[0015] Furthermore, the electricity required for water electrolysis comes from photovoltaic power generation and biomass energy generator power generation.

[0016] Furthermore, the deep dehydration process reduces the sludge moisture content to below 15%.

[0017] Furthermore, any of the above-mentioned multi-stage treatment methods for hydrogen wastewater comprises the following steps:

[0018] (1) The collected sewage is concentrated and initially filtered through a coarse screen to remove insoluble impurities with larger particle sizes, and then the sewage is introduced into an organic-inorganic separation device to separate and remove inorganic impurities and oil with particle sizes larger than 100 μm;

[0019] (2) introducing the wastewater treated by the organic-inorganic separation device into the MAS biomultiplier reactor to remove pollutants in the water;

[0020] (3) The wastewater after microbial treatment enters the integrated high-efficiency sedimentation tank for flocculation and sedimentation;

[0021] (4) After the sludge is settled, the sewage enters the hydrogen autotrophic denitrification filter tank, using H2 as the electron donor and CO3 2- 、HCO3 - , CO2 as an inorganic carbon source, reducing NO3--N to N2 in anoxic environment;

[0022] (5) The wastewater after nitrification treatment then enters the ozone disinfection tank, where ozone is used to further disinfect the wastewater. The treated wastewater can meet the discharge standards, and the effluent is used as the raw material for electrolysis of water. Solar energy is used to provide energy for the electrolysis device, and the pure O2 generated is used for oxygenation and aeration of the biochemical pool, and as an oxygen source for the high-concentration plate-type ozone generator to prepare O3. The generated H2 is stored in the hydrogen energy storage device as energy, and provides a hydrogen source for the hydrogen autotrophic denitrification filter.

[0023] (6) After deflocculation, part of the sludge deposited in the integrated high-efficiency sedimentation tank is recycled into the MAS biomultiplier reactor to supplement the bio-bacteria for the MAS biomultiplier reactor; the other part is collected in the sludge pool and undergoes a deep dehydration process to reduce the moisture content to below 15%.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] 1) The organic-inorganic device of the present invention is a new type of sewage pretreatment equipment, which integrates the functions of fine grids, membrane grids, grit chambers and primary sedimentation tanks, and can effectively separate and remove inorganic impurities and oil with a particle size of more than 100 μm, while retaining the organic content in the sewage to prevent the removal of carbon sources from affecting subsequent reactions.

[0026] 2) The integrated high-efficiency sedimentation tank of the present invention has the functions of a secondary sedimentation tank and a high-efficiency sedimentation tank, and can achieve better sedimentation effect with a shorter residence time, effectively reducing the land use area and investment cost.

[0027] 3) The present invention adopts a multi-stage sewage treatment process of grid filtration, biodegradation, integrated high-efficiency precipitation, hydrogen autotrophic denitrification, ozone disinfection and deep dehydration, combined with the order of the corresponding treatment process, to remove impurities in the sewage, and the effluent is used as the raw material of the electrolysis water process, using photovoltaic power generation as energy, and the sewage with pollutants removed reaches the water purification standard and is electrolyzed into pure hydrogen and oxygen. Hydrogen and oxygen can be reused in each process section, greatly reducing equipment investment and operating energy consumption, and excess hydrogen and oxygen can be stored as energy.

[0028] 4) The sludge produced in the sedimentation stage of the sewage treatment process of the present invention can be used as a supplementary biological bacteria for the MAS biomultiplier reactor after deflocculation; it can also be used as a biomass energy source with the final product obtained from livestock and poultry manure and green waste. The biomass generator is used to generate electricity, and the electric energy is used as a supplementary energy source for the electricity used in the sewage treatment plant, which greatly reduces the power consumption of the entire process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the overall flow chart of the treatment process of the present invention.

[0030] Figure 2 This is a process diagram for the full process of photovoltaic water electrolysis of the present invention. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0032] like Figure 1 As shown, a device used in a multi-stage hydrogen wastewater treatment method includes: a coarse screen, an organic-inorganic separation device (integrating the functions of a fine screen, a membrane screen, a grit chamber and a primary sedimentation tank), a MAS biomultiplier reactor, an integrated high-efficiency sedimentation tank (capable of simultaneously realizing the functions of a secondary sedimentation tank and a high-efficiency sedimentation tank), a hydrogen autotrophic denitrification filter, an ozone disinfection tank, an electrolytic water device, a hydrogen energy storage device, a pool top photovoltaic, a high-concentration plate ozone generator and a sludge tank; wherein the grid pitch of the coarse screen is 25 to 40 mm.

[0033] Example 1

[0034] A multi-stage treatment method for hydrogen wastewater, such as Figure 1 As shown, the steps are as follows:

[0035] (1) The collected sewage is concentrated and initially filtered through a coarse screen to remove insoluble impurities with larger particle sizes (screen residue, grit, etc.), and then the sewage is introduced into an organic-inorganic separation device. Since the organic-inorganic device integrates the functions of a fine screen, a membrane screen, a grit chamber, and a primary sedimentation tank, it can effectively separate and remove inorganic impurities and oil with a particle size of more than 100 μm, while retaining the organic content in the sewage to prevent excessive removal of carbon sources, thereby affecting subsequent biodegradation. Therefore, after the sewage is treated by the organic-inorganic separation device, the sewage contains almost no impurities with a particle size of more than 100 μm.

[0036] (2) The wastewater treated by the organic-inorganic separation device is introduced into the MAS biomultiplier reactor to remove pollutants in the water. At the same time, by controlling the number of dominant microbial flora and the low dissolved oxygen environment, simultaneous nitrification and denitrification conditions are created in the reactor to achieve biological denitrification in the biochemical pool.

[0037] (3) The wastewater after microbial treatment enters the integrated high-efficiency sedimentation tank. Since the integrated high-efficiency sedimentation tank has the functions of both the secondary sedimentation tank and the high-efficiency sedimentation tank, it can achieve better sedimentation effect with a shorter residence time, effectively reducing the land use area and investment cost.

[0038] (4) After the sludge is settled, the sewage enters the hydrogen autotrophic denitrification filter tank, using H2 as the electron donor and CO3 2- 、HCO3 - , CO2 as an inorganic carbon source, reducing NO3--N to N2 in anoxic environment. Compared with other existing autotrophic denitrification technologies, the reduced H2 used as an electron donor is less affected by water quality and is easy to use. The hydrogen autotrophic denitrification process includes the oxidation of H and the reduction of N. Compared with other self-oxygen denitrification processes, it does not produce new pollutants.

[0039] (5) The wastewater after nitrification treatment then enters the ozone disinfection tank, where ozone is used to further disinfect the wastewater. The treated wastewater can meet the discharge standards, and the effluent is used as the raw material for electrolyzed water. The photovoltaic electrolysis water full process is used, such as Figure 2 As shown in the figure, the photovoltaic installed on the top of the pool can absorb solar energy and convert it into electricity to provide energy for the electrolytic water device. The raw material of electrolytic water is the effluent from ozone disinfection treatment. The pure O2 produced is used for oxygenation and aeration of the biochemical pool, and the high-concentration plate ozone generator is used as the oxygen source for preparing O3; the H2 produced is stored in the hydrogen energy storage device as energy, and provides hydrogen source for the hydrogen autotrophic denitrification filter.

[0040] (6) After the sludge deposited in the integrated high-efficiency sedimentation tank is deflocculated, part of it is recycled into the MAS biomultiplier reactor to supplement the biomass for the MAS biomultiplier reactor; the other part is collected in the sludge pool and undergoes a deep dehydration process to reduce the moisture content to below 15%. While treating the sludge, livestock and poultry manure, green waste, etc. can be simultaneously treated. The final product is used as biomass energy, and a biomass generator is used at the tail end to generate electricity, and the electricity is used as a supplementary energy for the sewage treatment plant.

[0041] The present invention adopts a multi-stage sewage treatment process of mechanical filtration, biodegradation, integrated high-efficiency precipitation, hydrogen autotrophic denitrification, ozone disinfection and sludge deep dehydration, and combines the order of the corresponding treatment process to remove organic and inorganic pollutants in sewage. The effluent is then used as the raw material of the electrolysis water process, and photovoltaic power generation is used as energy. The sewage with impurities removed reaches the water purification standard and is electrolyzed into pure hydrogen and oxygen. The obtained hydrogen is used for denitrification in the hydrogen autotrophic denitrification filter stage of the sewage treatment process, and the obtained oxygen is used for oxygenation and aeration in the biochemical pool on the one hand, which is conducive to the reproduction of biological bacteria; on the other hand, it is used as an oxygen source for preparing O3 by a high-concentration plate ozone generator, and O3 is prepared using pure oxygen, and then ozone is used for deep treatment of sewage. The sludge produced in the precipitation stage of the sewage treatment process can be used as a supplement to biological bacteria after deflocculation; it can also be used as a biomass energy source with the final product biomass pellet fuel obtained from livestock and poultry manure and green garbage, and a biomass generator is used to generate electricity, and the electric energy is used as a supplementary energy for the electricity used in the sewage treatment plant. Finally, the recycling of resources and energy is realized.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-stage treatment method for hydrogen wastewater, characterized in that: The hydrogen produced by electrolysis of water is used for denitrification and denitrification of sewage, and the oxygen produced by electrolysis of water is used to cultivate aerobic bacteria and prepare ozone. The organic and inorganic pollutants in the sewage are removed through filtration, degreasing, biodegradation, sedimentation, denitrification and denitrification, ozone disinfection and sludge deep dehydration.

2. The multi-stage treatment method for hydrogen wastewater according to claim 1 is characterized in that: The denitrification process is as follows: H2 is used as an electron donor, CO3 2- 、HCO3 - , CO2 acts as an inorganic carbon source to reduce NO3-N to N2 in an oxygen-deficient environment.

3. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The special devices for the filtration process are a coarse grid and an organic-inorganic separation device; the organic-inorganic separation device includes a fine grid, a membrane grid, a grit chamber and a primary sedimentation tank.

4. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The filtration process separates and removes inorganic impurities and oil particles larger than 100μm.

5. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The biodegradation device is a MAS biomultiplier reactor.

6. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The special device for the sedimentation process is an integrated high-efficiency sedimentation tank; the integrated high-efficiency sedimentation tank includes a secondary sedimentation tank and a high-efficiency sedimentation tank.

7. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The denitrification and denitrification process device is a hydrogen autotrophic denitrification filter.

8. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The electricity required for water electrolysis comes from photovoltaic power generation and biomass energy generators.

9. A multi-stage hydrogen wastewater treatment method according to claim 1, characterized in that: The deep dehydration process reduces the sludge moisture content to below 15%.

10. The multi-stage treatment method for hydrogen wastewater according to any one of claims 1 to 9, characterized in that: Here are the steps: (1) The collected sewage is concentrated and initially filtered through a coarse screen to remove insoluble impurities with larger particle sizes, and then the sewage is introduced into an organic-inorganic separation device to separate and remove inorganic impurities and oil with particle sizes larger than 100 μm; (2) introducing the wastewater treated by the organic-inorganic separation device into the MAS biomultiplier reactor to remove pollutants in the water; (3) The wastewater after microbial treatment enters the integrated high-efficiency sedimentation tank for flocculation and sedimentation; (4) After the sludge is settled, the sewage enters the hydrogen autotrophic denitrification filter tank, using H2 as the electron donor and CO3 2- 、HCO3 - , CO2 as an inorganic carbon source, reducing NO3--N to N2 in anoxic environment; (5) The wastewater after nitrification treatment then enters the ozone disinfection tank, where ozone is used to further disinfect the wastewater. The treated wastewater can meet the discharge standards, and the effluent is used as the raw material for electrolysis of water. Solar energy is used to provide energy for the electrolysis device, and the pure O2 generated is used for oxygenation and aeration of the biochemical pool, and as an oxygen source for the high-concentration plate-type ozone generator to prepare O3. The generated H2 is stored in the hydrogen energy storage device as energy, and provides a hydrogen source for the hydrogen autotrophic denitrification filter. (6) After deflocculation, part of the sludge deposited in the integrated high-efficiency sedimentation tank is recycled into the MAS biomultiplier reactor to supplement the bio-bacteria for the MAS biomultiplier reactor; the other part is collected in the sludge pool and undergoes a deep dehydration process to reduce the moisture content to below 15%.

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