Method for denitrification of wastewater by ion beam superposition biological method

Abstract

The application discloses a method for wastewater denitrification by ion beam superposition biological method, comprising the following steps: (1) air ionization is used to generate charged air particles, and the charged air particles are dissolved into industrial wastewater after being treated by a magnetic field to obtain solution A; the air ionization and the magnetic field treatment are performed by an anion beam device; the magnetic field treatment is a combined frequency magnetic field treatment; (2) the solution A obtained in the step (1) is placed into a wastewater denitrification biochemical tank to perform microbial treatment; the microbial treatment comprises microbial nitrification treatment and denitrification treatment. The method for wastewater denitrification by ion beam superposition biological method can selectively strengthen the action of microbial population and rapidly activate microorganisms by providing charged air particles and biological electromagnetic waves in wastewater; meanwhile, the method can provide the required electrons for reduction of nitrite nitrogen to nitrogen, realize the functions of simultaneous nitrification and denitrification in the case of lacking carbon source, improve the ammonia nitrogen removal efficiency and total nitrogen removal efficiency of low C / N ratio wastewater, and significantly reduce the operation cost.

Description

Technical Field

[0001] This invention relates to the field of water purification, specifically to a method for denitrification of wastewater using an ion beam superposition biological method. Background Technology

[0002] With increasing population density and rapid industrial development, the types and quantities of wastewater are increasing dramatically, leading to more widespread and severe water pollution that threatens human health and safety. Compared to chemical treatment methods, biological methods for wastewater denitrification are less expensive and more environmentally friendly.

[0003] However, traditional biological methods have many limitations, such as the impact of harmful substances on biological activity and populations, or the need to supplement carbon sources when treating wastewater with low C / N ratios (COD / TN). In practical applications, the commissioning process is lengthy and operating costs are high. Currently, denitrification technology mainly uses the AO process within biological methods. In the traditional AO process, AO typically consists of two reactors with different dissolved oxygen rates. In the aerobic biological reactor, nitrifying bacteria use oxygen as an electron acceptor to complete the oxidation reaction of ammonia nitrogen into nitrite and nitrate nitrogen; denitrification usually occurs in an anaerobic or hypoxic environment, where denitrifying bacteria use hydrogen as an electron donor to complete the reduction reaction of nitrate and nitrite nitrogen into nitrogen gas. However, denitrifying bacteria are usually heterotrophic, and their life processes consume carbon sources. Therefore, when carbon sources are insufficient, denitrifying bacteria cannot effectively remove total nitrogen and must be supplemented, leading to high water purification operating costs. As a novel AO process, simultaneous short-cut nitrification and denitrification can achieve nitrification and denitrification in the same reactor by controlling the lower dissolved oxygen. However, its denitrification process still relies on heterotrophic bacteria and still requires a carbon source.

[0004] The primary auxiliary nitrogen removal technology in electrochemical biological processes is cathodic denitrification. This method utilizes cathode current to provide electrons, addressing the electron donor requirement during biological denitrification and thus reducing dependence on carbon sources. This process involves placing electrodes in a biological tank and providing cathode current to assist the biological organisms in achieving denitrification. While some research progress has been made in recent years, the cathode current requires precise control, is prone to inhibiting microbial growth, is difficult to control, and is susceptible to electrode passivation. Furthermore, the biological acclimation period is long, and large-scale application is energy-intensive, thus large-scale industrialization has not yet been reported. Summary of the Invention

[0005] Based on the shortcomings of existing technologies, the purpose of this invention is to provide a method for wastewater denitrification using ion beam superposition biological methods. This method not only has simple preparation steps, but can also be carried out online without affecting normal production. It can realize the simultaneous nitrification and denitrification processes in the same biological treatment tank. This process has low dependence on carbon sources, higher water purification efficiency than the traditional AO process, and is more economical.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for denitrification of wastewater using an ion beam superposition biological method includes the following steps:

[0008] (1) Air is ionized to generate charged air particles, which are then treated by a magnetic field and dissolved in industrial wastewater to obtain solution A; the air ionization and magnetic field treatment are carried out by an anion beam device; the magnetic field treatment is a combined frequency magnetic field treatment.

[0009] (2) The solution A obtained in step (1) is placed into a biochemical wastewater denitrification tank for microbial treatment; the microbial treatment includes microbial nitrification and denitrification.

[0010] When microbial treatment is carried out in the wastewater denitrification tank, the charged air particles in solution A can provide electron donors for the reduction of nitrite nitrogen to nitrogen gas after the microorganisms complete the nitrification reaction, that is, after converting ammonia nitrogen in wastewater into nitrite nitrogen. This process is achieved without relying on heterotrophic bacteria to complete the denitrification process, realizing the simultaneous nitrification and denitrification processes. This significantly shortens the process of removing nitrate nitrogen from domestic and industrial wastewater with low C / N ratios, saves energy consumption, and improves denitrification efficiency.

[0011] This invention uses an anion beam device to ionize air to generate electrons, which are then processed by a combined frequency electromagnetic field to generate electromagnetic waves of a relevant frequency. These electromagnetic waves are then injected into wastewater. The electromagnetic waves can effectively enhance the life activity of microorganisms. The electrons carried by the air particles can provide the electron supply required for the reduction of nitrite nitrogen to nitrogen gas during denitrification, without relying on a carbon source. This reduces the cost of carbon sources in the water purification process and greatly improves the treatment efficiency of wastewater with a low C / N ratio.

[0012] Preferably, the voltage of the anion beam device in step (1) during ionization is 10,000 to 200,000 V. The voltage range is a corresponding preferred value set according to the amount of electrons required for the reduction of pollutant concentration in the water and the electron kinetic energy during the reduction of nitrate nitrogen.

[0013] Preferably, the electromagnetic field strength of the anion beam device in step (1) during magnetic field treatment is 20 μt to 20 mt, and the combined frequency of the electromagnetic field is 7 to 200 kHz, generating electromagnetic waves of the corresponding frequency. The anion beam device treats the wastewater with a specific frequency electromagnetic field and generates the required electromagnetic waves. To avoid the anion beam being too weak or too strong and causing damage to microorganisms, the electromagnetic field strength is controlled within the range of 20 μt to 20 mt for the water body undergoing wastewater denitrification as needed. The combined frequency range of the electromagnetic field is a preferred range selected by programming based on the growth characteristics of microorganisms. The charged air particles and electromagnetic waves can help improve the treatment efficiency of microorganisms after entering the wastewater. The electromagnetic waves, through superposition with the electromagnetic waves of microorganisms, can promote the reproduction speed and biodiversity of microorganisms, and quickly activate microorganisms, shortening the acclimatization time of microorganisms. At the same time, the charged air particles provided can solve the carbon source dependence problem in the denitrification process. More preferably, the anion beam device preferably uses the charged particle accelerator described in patent ZL201821420081.0.

[0014] Preferably, in step (1), the charged air particles, after being treated in a magnetic field, are dissolved into the wastewater via an aerodynamic device; the aerodynamic device is a blower or a negative pressure jet device. By dissolving the charged air particles in the water body through the blower or negative pressure jet device, due to the conductivity of ions, electrons in the charged gas can be quickly released into the water body and participate in the denitrification reaction.

[0015] Preferably, the microorganisms used in step (2) are nitrifying bacteria and autotrophic denitrifying bacteria, including one or more of Bacillus, photosynthetic bacteria, Gram-negative bacteria, and non-sulfur green bacteria; the temperature of the water in the biochemical wastewater denitrification tank is 10–38°C, the pH is 7–9.5, and the dissolved oxygen content is 0.5–6 mg / L. Compared to the traditional AO process where nitrification and denitrification need to be carried out under different oxygen conditions, the microorganisms can achieve simultaneous nitrification and denitrification in the same wastewater treatment tank under the action of charged air particles. Under the above-mentioned conditions, the microorganisms have better biological characteristics, activity, and diversity than traditional AO reactors, and the denitrification process does not depend on a carbon source. Preferably, the temperature of the water in the biochemical wastewater denitrification tank during the microbial treatment in step (2) is 15–35°C. Within the above-mentioned preferred temperature range, the microbial treatment has better treatment efficiency.

[0016] The beneficial effects of this invention are as follows: The ion beam superposition biological method for wastewater denitrification described in this invention dissolves charged air particles generated through ionization and magnetic field treatment into the wastewater, simultaneously providing electron donors and electromagnetic waves for biological growth. This effectively enhances the activity of microbial communities, rapidly activating microorganisms during water treatment and shortening their acclimatization time. Furthermore, during the microbial denitrification process, the electrons carried by the air particles act as electron donors in the reduction of nitrite nitrogen into nitrogen gas, reducing the conversion of nitrite to nitrate nitrogen and achieving short-range denitrification. This also reduces dependence on carbon sources, significantly improving the treatment efficiency and economic benefits of low C / N ratio domestic and industrial wastewater. In addition, this method can be widely and efficiently applied to river management and aquaculture wastewater treatment. Attached Figure Description

[0017] Figure 1 A graph showing the carbon source input data for wastewater treatment in Embodiment 4 of the present invention. Detailed Implementation

[0018] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0019] Example 1

[0020] A specific embodiment of the method for wastewater denitrification using anion beam superposition bioelectricity as described in this invention includes the following steps:

[0021] (1) Air is ionized to generate charged air particles, which are then treated by a combined frequency magnetic field and dissolved in wastewater by a blower to obtain solution A; the ionization and magnetic field treatment are carried out by an anion beam device; the voltage of the anion beam device during ionization is 200000V, and the amount of charged air particles generated during ionization is 120 mega-equivalents; the electromagnetic field strength of the anion beam device during magnetic field treatment is 20mt, and the combined frequency of the electromagnetic field is 7~200kHz.

[0022] (2) The solution A obtained in step (1) is placed in the biochemical wastewater denitrification tank for microbial treatment for 8 hours; the microbial treatment includes microbial nitrification and denitrification; the microorganisms are Bacillus, photosynthetic bacteria, Gram-negative bacteria and non-sulfur green bacteria, the water volume in the biochemical wastewater denitrification tank is 10 tons, the water temperature is 25℃, the pH is 8, and the dissolved oxygen content is 3mg / L.

[0023] Example 2

[0024] A specific embodiment of the method for wastewater denitrification using an ion beam superposition biological method according to the present invention includes the following steps:

[0025] (1) Air is ionized to generate charged air particles, which are then treated by a combined frequency magnetic field and dissolved in wastewater by a blower to obtain solution A; the ionization and magnetic field treatment are carried out by an anion beam device; the voltage of the anion beam device during ionization is 100,000V, and the amount of charged air particles generated during ionization is 60 mega-equivalents; the electromagnetic field strength of the anion beam device during magnetic field treatment is 200μt, and the combined frequency of the electromagnetic field is 7~200kHz.

[0026] (2) The difference between step (2) in this embodiment and step (2) in embodiment 1 is only in the different solution A.

[0027] Example 3

[0028] A specific embodiment of the method for wastewater denitrification using an ion beam superposition biological method according to the present invention includes the following steps:

[0029] (1) Air is ionized to generate charged air particles, which are then treated by a combined frequency magnetic field and dissolved in wastewater by a blower to obtain solution A; the ionization and magnetic field treatment are carried out by an anion beam device; the voltage of the anion beam device during ionization is 50000V, and the amount of charged air particles generated during ionization is 20 mega-equivalents; the electromagnetic field strength of the anion beam device during magnetic field treatment is 20μt, and the combined frequency of the electromagnetic field is 7~200kHz.

[0030] (2) The difference between step (2) in this embodiment and step (2) in embodiment 1 is only in the different solution A.

[0031] Comparative Example 1

[0032] The only difference between this comparative example and Example 1 is that the charged air particles generated by air ionization are directly dissolved into the wastewater by a blower without being treated by a combined frequency magnetic field.

[0033] The total nitrogen concentration of the wastewater before treatment described in Examples 1-3 and Comparative Example 1, as well as the treated wastewater at the effluent outlet of the biochemical denitrification tank after 8 hours and 16 hours of treatment, was tested according to GB11894-1989. The test results are shown in Figure 1.

[0034] Table 1

[0035]

[0036] As can be seen from Table 1, the wastewater denitrification methods using ion beam superposition biological methods described in Examples 1-3 can all effectively purify wastewater. This indicates that by dissolving charged air particles generated through ionization and magnetic field treatment into the wastewater, and simultaneously providing electron donors and electromagnetic waves for biological growth, the role of microbial populations can be effectively enhanced. At the same time, during the microbial denitrification process, the electrons carried by the air particles serve as electron suppliers to participate in the process of reducing nitrite nitrogen to nitrogen removal, thereby reducing the conversion of nitrite nitrogen to nitrate nitrogen, achieving denitrification treatment, and significantly improving water purification efficiency.

[0037] Example 4

[0038] To verify that the anion beam superimposed bioelectric method for wastewater denitrification described in this invention can effectively reduce the carbon source dosage for treating low C / N ratio wastewater using the traditional AO process in existing wastewater treatment systems, an online retrofit of the ion beam superimposed biological method for wastewater denitrification was conducted on a 40,000-ton domestic wastewater treatment line (AO process) in Tai'an, Shandong Province. The carbon source dosage and average value were tested, statistically analyzed, and compared under the condition that the daily total nitrogen content of the wastewater met the discharge standard. The implementation period was from May 1st to July 20th, 2020, with the original wastewater treatment line's treatment process from May 1st to June 15th, 2020. The obtained data on carbon source dosage... As a comparison, from June 16th to July 9th, 2020, the secondary nitrification tank in the original AO process system of the wastewater treatment line was converted into a biochemical wastewater denitrification tank as described in this invention, and the method described in this invention was implemented. The ionization and magnetic field treatment were carried out using an anion beam device; the voltage of the anion beam device during ionization was 50000V, the electromagnetic field strength of the anion beam device during magnetic field treatment was 100μt, and the combination frequency of the electromagnetic field was 7-200kHz; from July 10th to July 20th, 2020, the implementation of the method described in this invention was stopped, and the original AO process wastewater treatment line was reused. The difference between the ion beam superimposed biological method for wastewater denitrification in this embodiment and Example 1, besides the above-mentioned parameter differences, is that the wastewater, after dissolving charged air particles and corresponding electromagnetic waves, flows directly into the biochemical wastewater denitrification tank through the wastewater treatment line channel. The statistical results of the carbon source dosage and average value of the above tests are as follows: Figure 1 As shown. From Figure 1It can be seen that the average daily carbon source input required for wastewater denitrification using a traditional AO process wastewater treatment line is 4.4 tons. However, after simultaneously using the ion beam superimposed biological method described in this invention for wastewater denitrification, the daily carbon source input required to meet discharge standards is significantly reduced, with an average input of only 1.25 tons during the test period. Furthermore, when the method described in this invention is discontinued and the original AO process wastewater treatment line is reused for wastewater denitrification, the average carbon source input rebounds to 3.42 tons. This demonstrates that the ion beam superimposed biological method for wastewater denitrification described in this invention can effectively reduce the carbon source input for wastewater denitrification in traditional AO industrial processes, thereby lowering wastewater treatment costs.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for wastewater denitrification using an ion beam superposition biological method, characterized in that, Includes the following steps: (1) Air is ionized to generate charged air particles, which are then treated by a combined frequency magnetic field and dissolved in wastewater by a blower to obtain solution A; the ionization and magnetic field treatment are carried out by an anion beam device; the voltage of the anion beam device during ionization is 200,000V, and the amount of charged air particles generated during ionization is 120 mega-equivalents; the magnetic field strength of the anion beam device during magnetic field treatment is 20mT, and the combined frequency of the magnetic field is 7-200kHz; (2) Solution A obtained in step (1) is placed in a wastewater denitrification tank for microbial treatment for 8 hours; the microbial treatment includes microbial nitrification and denitrification; the microorganisms are Bacillus and photosynthetic bacteria, the water volume in the wastewater denitrification tank is 10 tons, the water temperature is 25℃, the pH is 8, and the dissolved oxygen content is 3mg / L.

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