Wastewater treatment control by optimization of microbial metabolic pathways

Abstract

Enhanced control and efficiency in wastewater (11) purification can be achieved by prioritizing the digestive function of microorganisms and selectively prioritizing catabolism over anabolism. A gas-dispersed return sludge (36) is generated using pure oxygen or oxygen containing trace amounts of ozone (63). The pure oxygen or oxygen containing trace amounts of ozone is mixed with the return sludge (35) to produce a gas-liquid mixture, which is then atomized (26) or pumped (22) to immediately convert the reactive gas into ultrafine bubbles. At least a portion of the ultrafine bubbles dissolve in the sludge (35), rapidly raising the oxygen level to a critical level and activating dormant microorganisms. Microorganisms accumulate sufficient cATP upon initial encounter with pollutants to prioritize their digestive function and, upon exposure to pollutants present in the wastewater (11), utilize biochemical pathways different from those used in nature to digest the pollutants.

Description

Technical Field

[0001] This invention relates generally to wastewater purification, and more particularly to a system and method for wastewater treatment control optimized through microbial metabolic pathways. Background Technology

[0002] The activated sludge process is currently widely used for wastewater purification. The activated sludge process is a biochemical treatment and oxidation process that utilizes the reproductive function of sludge to immobilize dissolved organic pollutants in the wastewater into the activated sludge using microorganisms and oxygen. Then, the sludge's digestive function decomposes some of the organic pollutants into water (H2O) and carbon dioxide gas (CO2) for removal. Other pollutants present in the wastewater, such as ammonia, can similarly decompose into water and other byproducts.

[0003] Typical activated sludge wastewater treatment technologies have been around for over a century, but these traditional technologies face numerous challenges. For example, the biochemical purification of organic pollutants largely depends on the number, density, and activity of microorganisms (return sludge). However, to increase the number, density, and activity of microorganisms, the supply of dissolved oxygen must be increased; dissolved oxygen is crucial for microorganisms. Insufficient dissolved oxygen supply may render wastewater treatment ineffective.

[0004] When using the activated sludge process under natural environmental conditions (i.e., 20°C, standard pressure), 1 DO (mg / L) of dissolved oxygen is required to purify 1 BOD (biochemical oxygen demand, mg / L) of organic pollutants within five days. Similarly, at 20°C and standard pressure, 1 DO (mg / L) of dissolved oxygen is required to purify 1 COD (chemical oxygen demand, mg / L) of organic pollutants within 30 minutes to 2 hours. Therefore, under standard environmental conditions, the purification performance of the standard activated sludge process does not exceed 1 BOD / 1 DO, and in the same manner, 1 DO is required to purify 1 COD. In other words, 1 DO of dissolved oxygen is required to purify either 1 BOD or 1 COD of pollutants. The required time is 5 days for 1 BOD of pollutants and 30 minutes to 2 hours for 1 COD of pollutants.

[0005] While numerous improvements and enhancements have been proposed for traditional activated sludge-based wastewater treatment, most are based on naturally occurring environmental conditions. To date, no innovative technologies or methods have been proposed that bring about revolutionary performance improvements.

[0006] The activated sludge process utilizes microorganisms and oxygen to achieve biochemical treatment and oxidation, separating organic pollutants in wastewater in the form of activated sludge. This allows some organic pollutants to be decomposed into water (H2O) and carbon dioxide gas (CO2) for removal. Therefore, the biochemical purification of organic pollutants largely depends on the quantity of returned sludge (microbial community), the density of the microbial community, and the degree of activation of the microbial community.

[0007] One improvement to traditional activated sludge-based wastewater treatment is called "pre-aeration." When using pre-aeration, the return sludge is aerated beforehand, and the resulting activated return sludge (microbial community) is supplied to the aeration tank. However, the capacity improvement from pre-aeration is limited to about 30%, and due to this low improvement rate, the cost of aeration is very high. The additional cost of aeration is approximately 100%, so doubling the cost for a 30% performance improvement is clearly not cost-effective.

[0008] Similarly, another currently used technology is long-term continuous aeration bubbling, in which the wastewater to be purified and returned activated sludge are mixed into a mixture in an aeration tank. Air is supplied to the aeration tank via a blower. Bubbles of approximately 1 mm are generated, which aerate the mixture, causing the air to dissolve into the wastewater, providing oxygen to aerobic microorganisms and activating them, thus enabling them to decompose organic solids in the wastewater more effectively. However, because oxygen is not easily dissolved even through bubbling, the achieved dissolved oxygen concentration is insufficient to result in a significant increase in microorganisms; dissolved oxygen concentrations are typically 2-4 mg / L, similar to levels observed in nature, such as rivers and lakes. While more microorganisms can be provided by increasing the amount of returned sludge introduced into the aeration tank, for this to be effective, such an increase must be accompanied by an increase in the supply of available oxygen, which is not possible without physically altering the existing configuration. Furthermore, any changes to the existing configuration (including the size and production capacity of any oxygen source) currently require guesswork to determine what changes are sufficient to provide the required oxygen, as the precise relationship between the amount of oxygen supplied and the amount of contaminants removed is unknown. Furthermore, providing such a large supply of available oxygen is even more challenging in environments that are not traditionally suited for activated sludge-based water treatment. For example, ocean-going vessels carry large amounts of ballast water, which serves as a suitable environment for the growth of various organisms commonly found in ship intake areas. Ballast water is typically discharged into areas different from the ship's intake area, and the organisms (and other biomass) discharged with it are invasive to the discharge area (and therefore harmful to local habitats). While ships can benefit from ballast water purification via activated sludge, installing long-term continuous aeration bubbling technology on ships would be a significant challenge due to limited space, and the effects of long-term continuous aeration bubbling technology may not be significant enough to produce a substantial difference in ballast water cleanliness due to the low achievable oxygenation levels. Similarly, dairy farm wastewater ponds store large amounts of water contaminated with feces, which is associated with many undesirable phenomena such as anaerobic bacterial growth, foul odors, groundwater contamination, and methane emissions. While these wastewater ponds can benefit from water purification through activated sludge, traditional aeration bubbling technology is not only difficult to install in dairy farm wastewater pond environments, but also cannot achieve the desired water purification effect due to low oxygenation.

[0009] Furthermore, wastewater purification fundamentally relies on the activity of microorganisms (activated sludge), thus facing the problem of excess sludge due to the overgrowth of these microorganisms, and technologies to control this excess are not yet fully realized. In other words, the microorganisms involved in wastewater purification continuously reproduce and then die off through self-oxidation, making it extremely difficult to control and manage the amount of sludge generated and lost. This lack of control and management is considered a key problem of the activated sludge process. As a result, the large amounts of excess sludge generated are concentrated, transported, and incinerated or landfilled, leading to huge treatment costs for eliminating excess sludge and carbon dioxide emissions during incineration.

[0010] In the activated sludge process, the activated sludge (i.e., the microbial community) purifies organic and other pollutants in wastewater primarily through the following functions: reproduction, where the microbial community absorbs organic matter as food, grows and reproduces asexually, and the absorbed substances are separated into microbial aggregates; and digestion, where the microbial community absorbs organic matter and other substances as food and digests the food to release energy, which the microbial community uses to maintain its survival and carry out its life processes. To effectively purify organic and other chemicals in wastewater, the sludge must be activated. However, under normal environmental conditions, the entire microbial community is activated, making it impossible to separately control or manage the digestion and reproduction functions. Under normal conditions, the reproduction function is easily enhanced, producing a large amount of excess sludge. To effectively purify organic and other substances, these two functions must be balanced. Therefore, it is necessary to be able to separately control and manage the digestion and reproduction functions.

[0011] In the activated sludge process, wastewater purification capacity fundamentally depends on the activity of the microbial community (activated sludge). Therefore, while activating microorganisms is essential for improving wastewater purification capacity, wastewater purification technologies that simply activate microorganisms in a haphazard manner lead to overgrowth and excess sludge, which are the most fundamental problems of the activated sludge process.

[0012] Furthermore, even if microorganisms exhibit digestive function to the desired degree, they can do so through various biochemical pathways, and not all biochemical pathways are desirable. For example, under normal conditions (conditions encountered in nature), the digestion of acetic acid by microorganisms proceeds according to the following formula: CH3COOH + 2O2 → 2H2O + 2CO2 + Energy (1) This process treats structurally similar organic pollutants in a similar way. For every molecule of acetic acid digested, this reaction consumes two molecules of diatomic oxygen, rapidly depleting the oxygen required to sustain the reaction. Furthermore, carbon dioxide is a greenhouse gas, and treating activated sludge primarily through this reaction would contribute to global warming, which is undesirable when applied on an industrial scale.

[0013] Similarly, the digestive function of other types of pollutants under normal conditions can produce undesirable byproducts. For example, under normal conditions, microorganisms digest ammonia according to the following formula: 4NH3 + 7O2 → 4NO2 + 6H2O + Energy (2) NO2 (nitrous oxide) is also a greenhouse gas, and long-term industrial-scale wastewater treatment using this reaction will significantly contribute to global warming. Furthermore, for every four ammonia molecules digested, the reaction consumes seven diatomic oxygen molecules, rapidly depleting the amount of oxygen available to sustain wastewater treatment and requiring additional effort to maintain the necessary oxygen concentration in the treated wastewater.

[0014] However, currently, there is a lack of available technologies to address these issues. Specifically, the microbial community undergoes a continuous cycle: it grows through reproduction and then dies off through digestion, and effectively separating and managing the growth and death of the microbial community caused by these two functions is considered an extremely difficult problem. Furthermore, current technologies cannot guide the digestive function through pathways that do not produce undesirable byproducts or consume excessive amounts of oxygen.

[0015] Digestive and reproductive functions are associated with the metabolic processes of microorganisms. As mentioned above, conventional activated sludge technology primarily utilizes the metabolism of aerobic microbial colonies (activated sludge) to decompose organic and other wastes present in wastewater. Metabolism includes catabolism (breaking down compounds to release energy) and anabolism (using energy to build compounds). Catabolism occurs as follows: organic and other wastes (also called pollutants) that serve as food for the microbial colonies combine with dissolved oxygen, providing the necessary energy for the microbial colonies to maintain their survival and activity, as well as for the anabolism through which the microorganisms replicate. Anabolism, which leads to microbial replication, can proceed using the energy released by the catabolism pathway through which microorganisms decompose the organic and other wastes that serve as their food. In conventional activated sludge technology, the primary metabolic process is catabolism, which requires an external source of dissolved oxygen (DO). The microbial colonies (activated sludge) utilize dissolved oxygen to obtain the energy needed for their survival and life activities. The energy released during catabolism is stored in the cells of microorganisms as they convert adenosine diphosphate (ADP) into adenosine triphosphate (ATP), and when excess ATP is available, it is stored as cellular ATP (cATP). In the conventional activated sludge technology described above, the supply of dissolved oxygen (DO) is extremely low, and therefore the energy released from the digested pollutants is also extremely low. Thus, under conventional technologies such as long-term continuous aeration bubbling, the small amount of energy released from catabolism is immediately and entirely used for anabolism, leaving no excess energy stored in the cells of the microorganisms as cATP.

[0016] Therefore, a method is needed to control the metabolic pathways and purification functions of the microbial community in activated sludge, so that the purification effect can be utilized technically and in various industrial environments. Summary of the Invention

[0017] First, the systems and methods described below allow for the separate control and management of microbial reproductive and digestive functions, thereby limiting the generation of excess sludge—both key factors in activated sludge-based wastewater treatment. Second, in the activated sludge process, 1 DO (dissolved oxygen) is defined as the unit of purifying 1 BOD or 1 COD. The systems and methods described below, by limiting reproductive function and enhancing digestive function, allow for the purification of far greater amounts of organic matter than conventional methods, where 1 DO can only purify no more than 1 BOD or 1 COD. Third, and particularly, the systems and methods described below allow for the separate control and management of metabolic processes through reproductive and digestive functions in activated sludge-based wastewater treatment, allowing digestive function via catabolism to take precedence over reproductive function via anabolism. Furthermore, the systems and methods described below allow for the guidance of digestive function through biochemical pathways that do not produce undesirable byproducts such as greenhouse gases and do not consume as much oxygen as under conventional conditions. Fourth, the systems and methods described below can be readily and inexpensively adapted to activated sludge-based wastewater treatment facilities currently in use worldwide, as well as other environments that can benefit from activated sludge-based purification, such as ships or dairy farms.

[0018] The systems and methods described below focus on the digestive function of microbial communities, which absorb organic matter as food and decompose it to sustain life and provide energy. By generating or providing a near-starvation state independent of a specific number of microorganisms and food, the systems and methods encourage the microbial community to exhibit more of its digestive function than its reproductive function. Specifically, the systems and methods described below generate conditions not found in nature to highly activate the microbial community, providing an extreme starvation environment that causes the microorganisms to exhibit digestive function exceeding reproductive function, resulting in a much higher amount of organic matter that 1DO can digest than the maximum achievable in conventional activated sludge-based purification (1BOD or 1COD). Therefore, by generating or providing conditions not found in nature, the systems and methods described below strongly and highly stimulate the activated sludge (microbial community) purifying organic matter and other substances in wastewater, separately controlling and maintaining the reproductive and digestive functions of the microorganisms, thereby producing a breakthrough and unimaginable effect in nature. Furthermore, under these conditions that do not exist in nature, digestion utilizes biochemical pathways that consume less oxygen (if any) than under natural conditions, and produces inert byproducts such as amorphous carbon or diatomic nitrogen (N2) in addition to water.

[0019] Some features of the systems and methods described below may include: using pure oxygen (O2) or oxygen containing trace amounts of ozone (O3) as the reactive gas; supersaturating the return sludge with pure oxygen (at least 10 mg / L DO); dissolving trace amounts of ozone (less than 0.5 mg / L) in the return sludge; supplying the aerobic reactor with return sludge containing pure oxygen or an oxygen / ozone mixture, the amount of pure oxygen or the oxygen / ozone mixture being at least 10% of the wastewater to be treated; and activating the entire microbial community (all return activated sludge).

[0020] Microbial communities are activated by providing these characteristics, either individually or in combination (including providing all conditions). Activation occurs when the organic matter serving as food for the microorganisms is cut off. When the activated microbial community reaches an extreme state of near-starvation, regardless of the amount of food or the number of microorganisms, the microorganisms begin to absorb organic matter to their capacity limits, and they prioritize their digestive functions through pathways that result in the maximum amount of energy and the minimum amount of waste, thus deepening the degree of wastewater purification. The extreme state of near-starvation here refers to a state in which highly activated microorganisms enter an extremely near-starvation state, pushing them to a point of extreme food craving, after which they suddenly encounter food (in the form of a mixture of returned sludge and wastewater). As a result, the reproductive function of the microorganisms is inhibited, and the production of large amounts of excess sludge is prevented. Specifically, by forcing the microorganisms into a near-starvation state, the naturally possessed functions of the microorganisms can be controlled and monitored. In particular, the following systems and methods allow operators to prioritize the digestion of microorganisms over reproduction, which inhibits the production of excess sludge.

[0021] Furthermore, due to the strong activation of microorganisms by introducing reactive gases into the gas-dispersed return sludge, high levels of pre-aeration are observed, resulting in a significant increase in wastewater treatment capacity. This increased capacity allows for the use of much smaller aerobic reactors, eliminating the costly and energy-intensive bubbling and stirring processes necessary in conventional activated sludge-based technologies due to the poor water solubility of oxygen. Moreover, the high activation of the microbial community under environmental conditions not found in nature allows for wastewater purification with significantly higher efficiency and in much shorter time compared to conventional activated sludge processes, where organic matter is defined by BOD and COD.

[0022] The systems and methods described below can be easily implemented on any existing wastewater treatment facility with very little investment, and can be retrofitted, offering industrial energy savings and economic benefits globally. In particular, these systems and methods allow operators to address the enormous energy consumption and the need for large aeration systems caused by inefficient bubbling of insoluble air as a reactive gas, while simultaneously solving the problem of large amounts of excess sludge generated during wastewater treatment, potentially bringing significant economic benefits worldwide. Furthermore, with the world's population rapidly concentrating in cities, this invention revitalizes activated sludge-based processes as a low-cost, high-efficiency, and low-energy urban infrastructure technology.

[0023] In one embodiment, a system and method for wastewater treatment control optimized via microbial metabolic pathways are provided. A sludge containing microorganisms is provided, capable of performing digestive functions through one or more catabolic pathways to digest one or more contaminants to obtain energy and store the energy as ATP, wherein the sludge is substantially free of contaminants. User input is received via a computer, the user input including at least one of the digestion time and degree of digestion of one or more contaminants. Based on the user input, a time period is determined by the computer within which at least one reactive gas needs to dissolve to a predetermined concentration in the sludge. The at least one reactive gas supplied to the sludge is generated by a computer-controlled gas generator. A gas-dispersed return sludge is formed by dissolving at least one reactive gas at least partially in the sludge to achieve a predetermined concentration in the sludge within the determined time period using a computer-controlled atomizer or pump. The gas-dispersed return sludge is mixed with wastewater containing one or more contaminants under computer control to form a mixture, wherein when encountering contaminants in the wastewater, the microorganisms store a certain amount of ATP within an initial time period, the initial time period depending on a determined time, and wherein the microorganisms perform digestive functions in other time periods based on the amount of ATP generated and stored in the initial time period.

[0024] Other embodiments of the invention will be apparent to those skilled in the art from the following detailed description, wherein embodiments of the invention are described by way of example of the best mode contemplated for carrying out the invention. It should be understood that the invention is capable of other and different embodiments, and that several details thereof can be modified in various obvious ways without departing from the spirit and scope of the invention. Therefore, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. Attached Figure Description

[0025] Figure 1A-1B The diagram illustrates a system for wastewater treatment control optimized via microbial metabolic pathways, according to two embodiments.

[0026] Figure 2A-2B The flowchart illustrates a method for wastewater treatment control optimized via microbial metabolic pathways, according to one embodiment.

[0027] Figure 3 The flowchart illustrates, according to one embodiment, the process of forming gas-dispersed return sludge and returning the gas-dispersed return sludge to the aerobic reactor for use in... Figure 2A-2B The process in the method. Detailed Implementation

[0028] Traditionally, the relationship between the amount of oxygen supplied to microorganisms and the amount of pollutants in wastewater that these microorganisms can decompose using oxygen is considered linear. Therefore, regardless of the total oxygen concentration, it is assumed that 1 mg / L of DO can promote the decomposition of 1 BOD or 1 COD of pollutants. Specifically, in conventional standard activated sludge technology, air is used for bubbling in bubbles approximately 1 mm in diameter, and the supply of dissolved oxygen is very low. The microorganisms used in this process are in an anoxic state when encountering pollutants in the wastewater and can only obtain and store cATP from the pollutants at a very slow rate. Under these conditions, the microorganisms preferentially pursue anabolism through reproductive function, multiplying and producing excess sludge, which, as mentioned above, is quite challenging to treat. Furthermore, the preferential reproductive function slows down the purification of wastewater pollutants.

[0029] As further described below, at high oxygen concentrations achievable using the systems and methods described below, this relationship is no longer linear, and the achievable wastewater purification effect far exceeds that achievable through activated sludge-based purification when oxygen is maintained at natural levels (2-4 mg / L). This effect increases the rate at which wastewater can be purified and reduces the cost of purification. In particular, microorganisms in the sludge can be rapidly supplied with reactive gases (e.g., oxygen) at levels far exceeding those in nature, allowing them to quickly acquire and store large amounts of cATP upon initial encounter with pollutants in the wastewater. Avoiding hypoxia and storing large amounts of cATP, microorganisms can preferentially further digest pollutants through catabolism, thereby accelerating the rate (and extent) of pollutant digestion in the water.

[0030] When placed in environments of food scarcity or in enclosed environments leading to near starvation, microorganisms, upon contact with food, preferentially exhibit their digestive abilities over their reproductive capacity. The enhanced detoxification capacity of microorganisms in the presence of high oxygen levels is achieved by prioritizing their digestive functions over their reproductive capabilities. When the amount of available consumable matter (e.g., organic pollutants) is small relative to the microbial population, microorganisms (hereinafter also referred to as microbes), such as bacteria and protozoa, prioritize their digestive functions. Conversely, when the amount of consumable matter is large enough to meet the energy needs of the existing microbial population and any additional populations, the microorganisms prioritize their reproductive functions over digestion, and they reproduce asexually. In the following description, microorganisms exhibiting both digestive and reproductive functions can include aerobic microorganisms, facultative anaerobic microorganisms, and opportunistic microorganisms. Figure 1A-1B The diagram illustrates a system 10 for wastewater treatment control optimized via controlled microbial metabolic pathways, according to two embodiments. (Reference) Figure 1A The system 10 in the illustrated embodiment includes a settling tank (also known as a sedimentation tank or grit chamber) 12, an equalization tank 14, a mixer / distributor 15, one or more aerobic reaction tanks (also known as aeration tanks) 16, a sludge settling tank 18, a sludge storage tank 20, an atomizer 24, and a treated water treatment unit 73. Reference Figure 1B The system 10 shown includes a settling tank (also called a sedimentation tank or grit chamber) 12, an equalization tank 14, a mixer / distributor 15, one or more aerobic reaction tanks (also called aeration tanks) 16, a sludge settling tank 18, a sludge storage tank 20, a pump 22, and a treated water treatment unit 73, as well as one or more speed control valves 136. The pump 22 may be a cavitation pump or other type of pump. In another embodiment, one or more speed control valves 136 are also present. Figure 1A In system 10, at the inlet and outlet of atomizer 24.

[0031] The sludge storage tank 20 and one or more aerobic reactors 16 are connected via a return sludge conduit 26, which is configured to supply return sludge settled in the sludge storage tank 20 to a mixer / distributor 15 and ultimately to one or more aerobic reactors 16. An atomizer 24 or pump 22 is arranged linearly along the return sludge conduit 26. Therefore, the return sludge 35 passing through the return sludge conduit 26 is atomized by the atomizer 24 (in reference...). Figure 1A In the embodiment of system 10 shown) or pump (in reference) Figure 1B In the embodiment of system 10 shown, the system acts as a gas-dispersed return sludge 36, which is then supplied as gas-dispersed return sludge 36 to mixer / distributor 15 and one or more aerobic reaction tanks 16.

[0032] System 10 also includes an oxygen and ozone generator 28, which provides at least one reactive gas 37 (oxygen, possibly with added ozone) for addition to the return sludge 35. An oxygen supply pipe 30 and an ozone supply pipe 32, connected to the oxygen and ozone generator 28, are connected to one or more pipes that are part of the return sludge conduit 26 and to the atomizer 24 (in reference). Figure 1A (in the embodiment of system 10 shown) or pump 22 (in reference) Figure 1B The upstream (entry) side of the system 10 shown in the embodiment.

[0033] Furthermore, pump 22 includes multiple orifices 137 connected to oxygen supply line 30, ozone supply line 32, and return sludge line 26. Orifices 136 are further connected to control valves 137. Control valve 137, connected to the orifice serving as the pump inlet, controls the rate at which oxygen, ozone, and return sludge 35 enter pump 22, thus providing an additional mechanism for precisely controlling the ratio of reactive gas 37 to return sludge 37 within pump 22 and the percentage of these gases 37 dispersed in the return sludge as gas exits pump 22. Additionally, control valve 137 at the orifice serving as the pump outlet allows control over the timing and amount of gas dispersed in the return sludge 36 as gas exits pump, further controlling the amount of mixture 17 formed, as described below. In another embodiment, the orifice of atomizer 24 may similarly be connected to control valve 136, and the entry and exit of substances into and from atomizer 24 may be similarly controlled via valve 136.

[0034] For the oxygen and ozone generator 28, the oxygen and ozone generator of U.S. Patent No. 7,105,092 can be used. Other types of generators are possible. In one embodiment, the total amount of gas generated by the oxygen and ozone generator 28 includes not less than 90% oxygen, and the ozone concentration in the gas dispersion returned to the sludge 36 does not exceed 0.5 mg / L, and the oxygen concentration exceeds 10 mg / L.

[0035] The sludge return pipe 26 is connected only to the mixer / distributor 15 (and therefore to one or more aerobic reaction tanks 16), and not to the settling tank 12, equalization tank 14, and sludge settling tank 18. The technical reasons are discussed below.

[0036] As further described below, first refer to Figure 2A-2B The wastewater (raw sewage) 11 used for treatment enters the settling tank 12, where gravel and other inorganic solids settle and separate. The wastewater 11 flows from the settling tank 12 into the equalization tank 14, where the load and conditions of the incoming raw sewage are regulated, for example by automatic dilution, although other adjustments are possible, and the organic solids present in the wastewater are dissolved by anaerobic microorganisms.

[0037] Wastewater 11 flows from equalization tank 14 into mixer / distributor 15. Mixer / distributor 15 (hereinafter also referred to as "mixer") receives wastewater 11 supplied from equalization tank 14 and also receives gas-dispersed return sludge 36 supplied via return sludge conduit 26, mixes the two together, and supplies the mixture of gas-dispersed return sludge 36 and wastewater 11 ("mixture 17") to one or more aerobic reactors 16. Here, due to the reactive gases contained in the gas-dispersed return sludge 36 supplied to the aerobic reactor 16 (and initially to mixer 15), aeration by bubbling using air as the reactive gas becomes unnecessary. Mixer 15 may include components necessary to perform this function, such as a tank for temporarily containing mixture 17, connections to the aerobic reactor 16, and one or more pumps for pumping mixture 17 to one or more aerobic reactors 16. When multiple aerobic reactors 16 exist, the mixer / distributor 15 can be appropriately managed to allocate resources according to the treatment capacity of each aerobic reactor. In a facility with only one aerobic reactor, the mixer / distributor 15 can be completely omitted, and wastewater 11 and gas-dispersed return sludge 36 can be directly pumped into the aerobic reactor 16, where they form a mixed liquor 17.

[0038] As further described below, the microbial community in the gas-dispersed return sludge 36 has been activated by oxygen (possibly containing trace amounts of ozone) supplied via gas generator 28 and rapidly dissolved in the gas-dispersed return sludge by pump 22 or atomizer 24. In one embodiment, the dissolved oxygen level achieved in a short time is an oxygen concentration of 10 mg / L to 50 mg / L within 2-4 seconds, although other concentration and time values ​​are possible in another embodiment. The time required for dissolution depends on the operating intensity of pump 22 or atomizer 24. The gas-dispersed return sludge 36 is completely free of or contains very low levels of organic contaminants (and other contaminants that can be digested for energy) that can be digested by activated microorganisms. Under these conditions, once activated by the rapid dissolution level of at least one reactive gas 27, experience has shown that microorganisms preferentially pursue catabolic pathways by sacrificing their reproductive functions for their digestive functions, even if the complete or near-complete absence of digestible matter prevents the microorganisms from utilizing their digestive functions at this time. Once the gas-dispersed return sludge 36 is mixed with wastewater containing digestible organic pollutants (and other pollutants that can be digested to produce energy, such as ammonia), the microorganisms, previously "lacking" digestible material, begin to exhibit digestive function at a rate higher than their suppressed reproductive function. Specifically, during the initial phase of encountering pollutants in wastewater 11, the microorganisms acquire and store sufficient cATP through pollutant digestion, allowing them to continue preferentially performing digestive function in subsequent time periods. The length of the initial phase can depend on several parameters, such as the temperature of wastewater 11 and the type of pollutant being digested, although other parameters influencing the length of the initial phase are also possible. This prioritization, in turn, allows for a shorter time for pollutant digestion and a shorter degree of digestion (the degree being the percentage of digestible pollutants present in wastewater 11 that are digested). Furthermore, since the time it takes for dissolved oxygen (and optionally ozone) levels to reach the desired level is controllable by controlling the operating intensity of atomizer 24 or pump 22, it allows for control over the degree to which digestive function is prioritized over reproductive function, which in turn allows for control over the time required for pollutant digestion and the degree of pollutant digestion. As further described below with reference to equations (3) and (4), the byproducts and oxygen demand of digestion differ from those under conventional conditions. The prioritization of digestion over reproduction continues in one or more aerobic reactors 16 until the energy needs of the microorganisms are met. At this point, if any undigested organic pollutants (or other absorbable pollutants) remain in the mixed liquor 17, the microorganisms may also begin to exhibit reproductive function to produce sludge 21. Once the digestible or absorbable pollutants in the mixed liquor have been completely or substantially consumed, at least some of the microorganisms (e.g., most or all of the microorganisms in the mixed liquor) enter a dormant state (where biochemical processes within the microorganisms are significantly slowed or ceased) due to the lack of other digestible substances.

[0039] Once a retention time has elapsed—which can be experimentally determined to be sufficient for the digestion (and possibly consumption through reproductive function) of organic pollutants (and other pollutants, such as ammonia, to which they can perform these functions) in the mixed liquor 17—it is pumped from the aerobic reaction tank 16 to the sludge settling tank 18, where it separates into a supernatant and sludge 21. The sludge 21 is collected in a sludge storage tank 20 and, as further described below, returned to the aerobic reaction tank 16 in the form of a gas-dispersed return sludge 36 for recycling. In another embodiment, the sludge storage tank 20 may be omitted from system 10, and the outlet side of the sludge settling tank 18 and the mixer / distributor 15 are connected to the return sludge conduit 26.

[0040] The supernatant, as treated water 72, is pumped from the sludge settling tank 18 and then pumped to the treated water treatment unit 73 for further treatment. This treatment may include disinfection, for example, as described in U.S. Patent No. 10,287,194, issued May 14, 2019, to Ohki et al., the disclosure of which is incorporated herein by reference, although disinfection of the treated water 73 may be performed in other ways. Further treatment may be performed at unit 73. Reference Figure 1A and 1B Although unit 73 is shown as a single physical structure, it can also be composed of multiple spatially separated components. The water treated by unit 73 is discharged from system 10 as purified water 74, which is then suitable for drinking and other uses.

[0041] In addition, excess sludge is pumped out from the wastewater management system as residual sludge 27.

[0042] At least a portion of the sludge from sludge settling tank 18 enters atomizer 24 (in reference) via return sludge pipe 26 in the form of return sludge 35. Figure 1A (in the embodiment of system 10 shown) or pump 22 (in reference) Figure 1B In an embodiment of system 10 shown, pure oxygen or pure oxygen containing trace amounts of ozone is mixed into the return sludge 35 before the inlet point of atomizer pump 24 or pump 22 to form gas-dispersed return sludge 36.

[0043] The generation of gas-dispersed return sludge 36 can be achieved by using an atomizer 24 (in reference). Figure 1A (in the embodiment of system 10 shown) or pump 22 (in reference) Figure 1B In the embodiment of system 10 shown, the atomizer or pump is operated to dissolve at least one reactive gas under pressure (at least 0.05 MPa higher than the current sewage water pressure). Specifically, a gas-liquid mixture (a mixture of at least one reactive gas 37 and return sludge 35) is formed in the return sludge conduit 26 and pumped to the atomizer 24 (in reference...). Figure 1A In the embodiment of system 10 shown, the atomizer has the function of stirring and mixing the above-mentioned gas-liquid mixture under high pressure (approximately 0.0981–5.394 MPa (1–55 kg / cm²)). Then, cavitation or 20–12000 kHz ultrasound, or both, are used to induce the generation of ultrafine bubbles with a diameter of 1 nm–30000 nm in the gas-liquid mixture, further initiating oxygen radicalization and hydroxyl radicalization. A portion of the ultrafine bubbles dissolves in the gas-dispersed sludge, raising the dissolved oxygen level to a critical threshold of at least 10 mg / L (or 0.01–0.5 mg / L if ozone is used), while the remainder is stored as ultrafine bubbles along with the sludge 36. Therefore, the atomizer 24 can instantaneously convert the required amount of reactive gas 37 into ultrafine bubbles, rapidly dissolve a portion of the reactive gas, and then disperse, fix, and store the excess reactive gas in the liquid as ultrafine bubbles. Experience shows that raising the dissolved oxygen level to a critical threshold (at least 10 mg / L) activates the microorganisms in sludge 36, bringing them out of dormancy. While the microorganisms are now activated and ready to digest organic and other digestible contaminants (and prioritize their digestive function over their reproductive function), the level of digestible contaminants (or other digestible organic matter) in the gas-dispersed return sludge 36 is zero or close to zero (insufficient to satisfy the microorganisms' prioritized digestive function), thus forcing the microorganisms into a state of extreme starvation.

[0044] In one embodiment, the atomizer 24 may be an OHR mixer sold by OHR Laboratories, Ltd. (536-1 Noda, Iruma City, Saitama Prefecture, Japan 358-0054). In another embodiment, other commercially available or proprietary atomizers 24 may be used.

[0045] Similarly, in reference Figure 1BIn the embodiment of system 10 shown, instead of entering atomizer 24, a mixture of return sludge 35 and at least one reactive gas 37 enters pump 22. In one embodiment, the pump may be a cavitation pump. Cavitation is the formation of gas chambers in a liquid. In a pump, cavitation is caused by the impeller of the pump moving through the liquid, creating a low-pressure area as the liquid accelerates and passes over the blades, causing the liquid to vaporize and form small bubbles. While cavitation is generally undesirable because it can damage pump components, pump 22, while suffering greater wear due to cavitation, utilizes the cavitation effect to help dissolve at least one reactive gas 37 in the return sludge to produce gas-dispersed return sludge 36. In particular, the impeller of pump 22 rotates at a speed high enough to cut the formed bubbles into many smaller bubbles, thereby forming ultrafine bubbles with diameters of 1 nm to 30,000 nm. Pump 22 operates at high pressure, which promotes the dissolution of at least one reactive gas 37 in the return sludge 35. In one embodiment, the pressure inside pump 22 is between 0.0981 MPa and 5.394 MPa, although other pressure values ​​are also possible. In another embodiment, pump 22 may utilize a mechanism other than cavitation to generate ultrafine bubbles.

[0046] The gas-dispersed return sludge 36 is returned only to the mixer / distributor 15 and one or more aerobic reactors 16, and not to the settling tank 12, equalization tank 14, or sludge settling tank 18. The return flow rate of the gas-dispersed return sludge 36 is uniformly controlled and managed to maximize the total CO2 emission reduction, treatment cost reduction, and energy consumption reduction of the entire wastewater treatment system. Because the wastewater treatment capacity of one or more aerobic reactors 16 is significantly increased, the aerobic reactors 16 can be very small.

[0047] As the microbial community in the gas-dispersed return sludge 36 is processed by atomizer 24 or pump 22 and subsequently supplied to one or more aerobic reaction tanks 16, it is activated by the oxygen (and possibly ozone) received by the microorganisms. For example, when the gas-dispersed return sludge enters the aerobic reaction tank 16 (or, if a mixer / distributor 15 is used, the mixer 15), the activated microorganisms are already in a state of extreme near-starvation, causing them to autonomously prioritize digestion over reproduction. Therefore, providing a high oxygen (or oxygen containing trace amounts of ozone) level allows the operator to separately control and manage the catabolism and anabolism processes of the microorganisms through the reproductive and digestive functions of the microbial community, prioritizing digestion over reproduction. In this application, the term "reproductive function" of the microbial community is defined as the function in which the microorganisms absorb organic matter contained in the wastewater 11 as food, grow and then reproduce, causing the organic matter to separate into aggregates of matter and microorganisms, thereby purifying the wastewater. The "digestive function" of microbial colonies is defined as follows: microorganisms absorb organic matter contained in wastewater as food, and then decompose and digest it to obtain energy to maintain their activity and life processes.

[0048] When the oxygen concentration in the aerobic reactor 16 reaches a specific critical threshold, the high activation of microorganisms is particularly significant. At this point, at least 10% by volume of gas-dispersed return sludge 36 is present in the mixed liquor 17, and the gas-dispersed return sludge has a dissolved oxygen of at least 10 mg / L (a level achievable using atomizer 24 or pump 22). Once this threshold is reached, 1 DO (mg / L) is sufficient to decompose more pollutants than those contained in 1 BOD or 1 COD when the dissolved oxygen in the aerobic reactor 16 is at a lower level. Under these conditions, it has been experimentally shown that the amount of pollutants degraded by the microorganisms in the aerobic reactor 16 exceeds 20 times the amount of pollutants degraded by the same microorganisms when the oxygen concentration is close to naturally occurring levels (2-4 mg / L). The critical threshold for adding gas-dispersed return sludge 36 to the aerobic reactor 16 varies proportionally with different oxygen concentrations. Knowing this effect allows for very precise calculation of the amount of gas-dispersed return sludge 36 required to purify a specific volume of wastewater 11, allowing for a reduction in the generation of unnecessary excess sludge 27. Similarly, knowing the volume of the gas-dispersed return sludge 36 and the volume of the wastewater 11 to be treated allows for the rational design of the dimensions of the system 10 components, reducing waste and lowering the cost of constructing the system 10. The exact ratio of the volume of the gas-dispersed return sludge 36 to the volume of the wastewater 11 can be set based on the degree of pollution of the wastewater 11 being treated. For example, when the wastewater 11 comes from the bilge of a ship, a volume of 10% of the volume of the wastewater 11 to be treated is sufficient. However, when the wastewater 11 comes from a sewage treatment plant or other highly polluted sources, the volume of the gas-dispersed return sludge 36 may need to be much higher, for example, 40% of the volume of the wastewater 11.

[0049] Since the formation of ultrafine bubbles plays an important role in the activation of microorganisms, additional explanations regarding bubble formation and use are provided below. Regarding the slowing effect on the rising speed of bubbles in a liquid, which can be achieved by generating ultrafine bubbles, bubbles with a diameter of approximately 30 μm rise at approximately 1 m / hr in a liquid, while bubbles with a diameter of approximately 1 μm rise at less than 0.005 m / hr (Stokes' law applies to spherical bubbles). Within this speed range, the bubbles remain in the liquid for a sufficiently long time to immediately and at the desired location replenish the dissolved oxygen consumed by the biochemical reactions of pollutants in the wastewater to be treated. Furthermore, since the bubbles can be uniformly and abundantly dispersed in the form of ultrafine bubbles, a bubble storage function is also achieved at the same locations where oxygen is consumed.

[0050] In this way, the required reactive gases (including oxygen or oxygen and ozone) can be supplied and stored for an extremely long period of time, neither in excess nor in deficiency, thereby shortening and promoting biochemical reactions, and also allowing the supply to be intermittent rather than continuous during the time period required for biochemical reactions to take place.

[0051] As described above, the atomizer 24 or pump 22 is used to disperse the gas into the liquid in the form of ultrafine bubbles. To achieve ultrafine bubble size and integrate these bubbles into the liquid, mechanical stirring and shearing are insufficient to reach the nanoscale. Only by increasing the velocity of the gas-liquid two-phase flow through pressurization and utilizing the synergistic effect of cavitation and ultrasound to generate vortex stirring with the liquid can the bubbles be broken down to an ultrafine state and integrated into the mixture. Pressure conditions are crucial for dissolving and maintaining the gas in a dissolved state; higher pressures are known to be more advantageous. Considering all these factors, the pressure range selected for the atomizer 24 or pump 22 is 0.0981 MPa–5.394 MPa (1–55 kg / cm²).

[0052] While operating at low pressure during simple sludge recirculation (without the addition of reactive gas) helps avoid damaging the microorganisms present in the activated sludge, maintaining low pressure becomes meaningless when reactive gas is added to the sludge. The pursuit of the highest achievable pressure (approximately 5.5 MPa) is due to the effective utilization of the synergistic oxidation and decomposition effect between cavitation and ultrasound during sludge oxidation and decomposition using reactive gas containing high-density ozone. Cavitation and ultrasound at high pressure lead to the self-oxidation and decomposition of ozone, with oxygen and hydroxyl radicals playing a role. For large-capacity wastewater treatment using activated sludge process 40 and system 10, carefully selected, readily and economically usable ultrasonic frequencies have been chosen, resulting in a frequency of 20 kHz for the low-pressure range and 12000 kHz for the high-pressure range (approximately 5.5 MPa). In another embodiment, other frequencies within the 20 kHz–12000 kHz range are possible.

[0053] For the oxygen and ozone generator 28, an ozone generator or similar device can be used to regulate the oxygen supply and ozone generation. For example, by employing an ozone generating element (including electrodes mounted to bosses made of dielectric material) and a high-frequency, high-voltage power supply (which applies high-frequency alternating current to the ozone generating element while simultaneously supplying oxygen-enriched gas to it) and using a regulator to control the voltage and / or frequency of the power supply to regulate the amount of ozone generated, an oxygen / ozone circulation generator that regulates the supply of oxygen and ozone can be implemented to address fluctuations in wastewater quality and load caused by morning, daytime, or nighttime conditions, or by dry or rainy weather, or to address processes primarily based on oxygen supply and processes primarily based on... The process involves ozone oxidation and decomposition. For the reactive gas containing oxygen to be supplied, either oxygen-enriched air or pure oxygen is acceptable. The supplied gas can also be pumped without ozone generation. Of course, the operation of the oxygen / ozone cycle generator can also be paused. Furthermore, although the oxygen and ozone generator 28 are represented as a single unit, in another embodiment, the system 10 may include multiple generators 28, one generator 28 providing ozone and another providing oxygen, with the gases supplied by both generators being supplied to the return sludge conduit 26 to mix with the return sludge 35.

[0054] In activated sludge processes, the microorganisms that perform biochemical reactions, along with a portion of the sludge (return sludge), are returned to the wastewater inlet side, allowing the microorganisms to be recycled. If the wastewater 11 to be treated contains a high concentration of organic matter, and therefore requires accelerated microbial biochemical reactions, it is desirable to maximize the amount of dissolved oxygen in the wastewater 11 or to rapidly replenish dissolved oxygen based on the amount consumed. System 10 performs well in this regard, using atomizer 24 or pump 22 to inject the required amount of oxygen (or oxygen containing trace amounts of ozone) into the water carrying the return sludge back to the aerobic reaction tank 16. Because atomizer 24 or pump 22 supplies a large amount of oxygen (or oxygen containing trace amounts of ozone) in a dissolved state and in the form of ultrafine bubbles in a very short time, the microbial biochemical reactions are significantly accelerated.

[0055] As mentioned earlier, ultrafine bubbles take a long time to float to the surface of the aerobic reactor 16. During this time, the ultrafine bubbles in the aerobic reactor 16 disperse and are stored in the form of ultrafine bubbles, continuously replenishing dissolved oxygen. By maintaining a high dissolved oxygen content in the aerobic reactor 16, the microbial biochemical reactions can be significantly accelerated. Due to the action of the microbial biochemical reactions within the aerobic reactor 16, some of the organic matter in the wastewater is digested, releasing carbon dioxide and water, while some of the organic matter is consumed by activated sludge microorganisms; the microorganisms multiply, producing activated sludge. In this case, not only by adding oxygen to the wastewater, but also by selectively adding and utilizing trace amounts (e.g., up to 0.01–0.5 mg / L = ppm) of ozone, the microorganisms carrying out the microbial biochemical reactions can be activated to a greater extent.

[0056] Furthermore, under the conditions produced in System 10 of Figure 1, the digestive function exhibited by microorganisms in the aerobic reactor proceeds through different biochemical pathways (and therefore through different chemical reactions) than under natural conditions. In particular, in addition to water, at least some biochemical pathways result in the production of inert compounds, such as amorphous carbon or diatomic nitrogen (N2). For example, under the conditions produced in System 10, the digestion of acetic acid proceeds according to the following formula: CH3COOH→2C+2H2O+Energy (3) Compared to equation (1) above, the chemical reaction of equation (3) occurring in the aerobic reaction tank 16 under the conditions produced in system 10 does not require external oxygen, thus allowing the reaction to proceed until the energy requirements of the microorganisms are met, after which they can exhibit reproductive function. Furthermore, unlike the reaction in equation (1), this reaction does not produce carbon dioxide, but rather inert amorphous carbon, which can be easily removed from the mixture 17. Although this reaction does not require oxygen, the same microorganisms in the mixture 17 can also perform aerobic digestion of other compounds. For example, ammonia digestion proceeds through a different chemical reaction than in equation (2), but is still aerobic. Therefore, under the conditions produced in system 10, ammonia digestion in the aerobic reaction tank 16 proceeds according to the following equation: 4NH3 + 3O2 = 2N2 + 6H2O + energy (4) Compared to the reaction in Equation (2), which uses 7 molecules of diatomic oxygen, the reaction in Equation (4) uses only 3 molecules of diatomic oxygen, allowing the oxygen within the ultrafine bubbles in the mixture 17 to sustain the reaction for a longer period. Furthermore, instead of producing nitrogen dioxide in Equation (2), the reaction in Equation (4) produces diatomic nitrogen, which does not cause the same environmental problems as nitrogen dioxide. Similar reactions can also be carried out using phosphorus-containing compounds (e.g., phospholipids) and sulfur-containing compounds. Similarly, similar reactions can be carried out using other biodegradable substances, including cellulose and other carbohydrates, fats and oils, and various types of proteins. In summary, under the conditions produced in the aerobic reaction tank 16, microorganisms preferentially (if not completely converted) utilize biochemical pathways to digest a variety (if not all) of pollutants, which consume less oxygen and produce different end products compared to biochemical pathways that digest the same pollutants under natural conditions. Moreover, at least some of the biochemical pathways utilizing less oxygen can proceed faster than pathways utilizing more oxygen to degrade the same pollutants.

[0057] In one embodiment, the components of the system 10 described above can be controlled independently of each other. In another embodiment, the system 10 includes a controller 39, which is connected, for example, via a wired or wireless connection to at least the sludge settling tank 20, the oxygen and ozone generator 28, and the atomizer 24 (see reference 20). Figure 1A(in the embodiment of system 10 shown) or pump 22 (in reference) Figure 1BIn the embodiment of system 10 shown, control valve 136 is connected to pump 22 (or atomizer 24, if a valve is used on atomizer 24). Controller 39 can also be similarly connected to other machines in system 10. Controller 39 can receive input from the operator of system 10 (also referred to as “user input”), based on which controller 39 determines and controls the operation of other components of system 10. For example, user input may include the amount of gas-dispersed return sludge 36 to be delivered to aerobic reactor 16 and control the sludge settling tank, oxygen and ozone generator 28, pump 22, or atomizer 24 to deliver the desired amount of gas-dispersed return sludge 36. Alternatively, controller 39 may receive wastewater treatment characteristics from the operator, such as the operator’s desired level of wastewater treatment (e.g., percentage of contaminants to be digested), the operator’s desired wastewater treatment time, and desired wastewater treatment capacity, and determine the amount of gas-dispersed return sludge 36 to be delivered to aerobic reactor 16 and any other treatment parameters required to achieve the desired characteristics. The determined quantity can then be delivered under the control of controller 39, and similarly, other components of system 10 can be controlled to determine the desired parameters. Specifically, when treatment time, treatment level, or both are part of the user input, in addition to the amount of gas-dispersed return sludge 37 to be delivered, controller 39 also determines the time required for the oxygen concentration in the gas-dispersed return sludge to rise to a threshold of at least 10 mg / L to achieve the desired treatment time or level (or both), and controls the operating intensity of atomizer 24 and pump 22 (including control valve 136) to achieve the desired result. For example, if a higher treatment level and a shorter treatment time are specified in the user input, the time to reach the threshold oxygen concentration in the gas-dispersed return sludge can be set to 2 seconds. If a longer time range or a lower treatment level is provided as part of the user input, the controller can set the time to reach the threshold oxygen concentration of at least 10 mg / L to 3 or 4 seconds (or other values ​​between 2 and 4 seconds). Similarly, controller 39 can alter the amount of oxygen (and ozone) introduced into sludge 35 by controlling control valve 136 on oxygen and ozone generator 28 and pump 22 (or atomizer 24). Therefore, based on the treatment time and treatment level (or both) provided as part of the user input, controller 39 can determine the amount of oxygen (and optionally ozone) to be supplied to pump 22 or atomizer 24, and increase the amount supplied (by controlling generator 28 and valve 136) if faster treatment and a higher degree of digestion of contaminants in wastewater 11 is desired. Furthermore, user input includes whether the user desires additional sludge 35 and how much additional sludge 35 is desired; if a large amount of sludge 35 is to be produced, the computer can set the time to reach a critical concentration of at least 10 mg / L of oxygen to be more than 4 seconds.Controller 39 can be a computing device, such as a personal computer, smartphone, laptop, or tablet, although other types of computing devices are possible. Controller 39 may include components common in general-purpose programmable computing devices, such as a central processing unit (CPU), memory, input / output ports, network interfaces, and non-volatile memory, although other components are possible. The CPU can execute computer-executable code, which can be implemented as modules. Modules can be implemented as computer programs or procedures, written in a conventional programming language as source code and presented as object code or bytecode for execution by the CPU. Alternatively, modules can also be implemented in hardware, as integrated circuits or burned into read-only memory components. Various implementations of source code, object code, and bytecode can be stored on computer-readable storage media, such as floppy disks, hard disks, digital video optical discs (DVDs), random access memory (RAM), read-only memory (ROM), and similar storage media. Other types of modules and module functions, as well as other physical hardware components, are possible.

[0058] Controller 39 can be controlled by an operator on-site or remotely. For example, controller 39 can be connected to an internet network such as the Internet or a cellular network, and connected user devices (such as smartphones, although other user devices are possible) allow remote commands to be issued to controller 39 and provide remote control of system 10 to the operator.

[0059] Other embodiments of controller 39 are also possible.

[0060] When system 10 has not been operating recently, there may not always be available gas-dispersed return sludge 36 to be added to the aerobic reactor 36 and to provide the microorganisms required for aerobic reactions. In this case, system 10 can utilize inoculum sludge—sludge 21 input into system 10 from external sources such as other wastewater treatment systems (e.g., into return sludge pipe 26), although other external sources are possible. The inoculum sludge is converted into gas-dispersed return sludge 36 by treatment by atomizer 24 (or pump 22) and oxygen and ozone generator 28, and then supplied to aerobic reactor 16 for the treatment of wastewater 11. Since the microorganisms present in activated sludge 21 are significantly different from those produced by sludge 21 based on the geographical origin of wastewater 11, the inoculum sludge introduced into system 10 is selected based on the geographical location of the inoculum sludge source 21. Preferably, the inoculum sludge comes from the same or similar geographical location as the wastewater 11 being treated by system 10 to avoid introducing exogenous microorganisms that could negatively impact aerobic reactions.

[0061] System 10 can be generated by most existing water treatment facilities by retrofitting certain parts of system 10 onto existing equipment. In particular, atomizer 24 or pump 22, as well as oxygen and ozone generator 28, can be retrofitted into existing wastewater treatment plants, thus enabling the widespread use of system 10 and the methods described in this application. Similarly, Figure 1A and 1B System 10 can even be adapted to environments that traditionally do not even use activated sludge-based purification. For example, ( Figure 1A System 10 (or 1B) can be installed in the bilge of a ship. When the ship is at sea, the bilge water (including ballast water) continuously passes through system 10 to reduce the amount of contaminants (including dead animals and their excrement) present in the bilge water. Alternatively, in addition to installing system 10 on the ship, ( Figure 1A (Or 1B) System 10 can also be installed in a port, whereby when a ship is docked, the ship's bilge water is transferred to a tank connected to System 10. The bilge water is then purified by System 10 and returned to the ship or otherwise treated. Similarly, ( Figure 1A The system 10 (or 1B) can also be installed in the dairy farm wastewater pond. By using the system 10, water contaminated by dairy farm manure is purified, thereby inhibiting the growth of anaerobic bacteria in the water and reducing odor, groundwater pollution, methane emissions, and other undesirable effects of dairy farm water pollution.

[0062] As described above, controlling the time taken for oxygen (and optionally ozone) to dissolve in the gas-dispersed return sludge 36 to reach a critical concentration, the concentration reached within that time, and the amount of gas-dispersed return sludge 36 used to form the mixed liquor allows the operator to enhance control over wastewater purification. In particular, these parameters determine whether the microorganisms exhibit only digestive functions or, once they obtain the necessary energy, can continue to exhibit reproductive functions and produce sludge 21 in the presence of other pollutants and oxygen. Figure 2A-2B This is a flowchart illustrating a method 40 for wastewater treatment control optimized via microbial metabolic pathways, according to one embodiment. It can be used... Figure 1A or Figure 1B System 10 executes this method. Optionally, if there is no gas-dispersed return sludge 36 in the aerobic reactor at the start of method 40, then refer to the above. Figure 1A-1BThe inoculated sludge is added to system 10, converting it into gas-dispersed return sludge 36, which is then supplied to one or more aerobic reactors (step 41). The load on the wastewater 11 to be treated is determined, as well as the time required for the oxygen concentration in the gas-dispersed return sludge 36 to reach a critical concentration of at least 10 mg / L (and optionally, the exact oxygen concentration required within that time), and the amount of gas-dispersed return sludge 36 to be delivered to the aerobic reactor 16 (step 42). The amount of gas-dispersed return sludge 36 can be determined based on the load and other desired characteristics of the wastewater treatment, such as the degree of purification and treatment rate, although other characteristics are possible. Another characteristic is whether the goal of wastewater treatment is solely to digest pollutants (organic and other degradable pollutants, such as ammonia) through digestion, or whether it is desirable to generate some additional sludge 21. Therefore, if the goal of wastewater treatment is to purely digest organic pollutants (and other pollutants that can be digested to produce energy, such as ammonia), producing minimal or no sludge 21, the volume ratio of the gas-dispersed return sludge 36 to the wastewater 11 will be greater than in cases where at least some sludge 21 is desired. However, since a certain amount of sludge 21 is required for subsequent purification cycles, the volume ratio of the gas-dispersed return sludge 36 to the wastewater 11 can be reduced, allowing the microorganisms to exhibit their reproductive function after digestion saturation. Even at the same location, the levels of pollutants (organic and other digestible pollutants) in the wastewater 11 will vary over time. These levels will also vary based on the source of the wastewater 11 (and therefore the geographical location from which the wastewater 11 originates). Similarly, the digestive and reproductive capacity of the microbial community varies depending on the strains of microorganisms that constitute the community in the sludge 36, with different strains existing in different geographical regions. Furthermore, the precise level of dissolved reactive gases in the gas-dispersed return sludge 36 affects the digestive capacity of the microorganisms in the sludge 36, thereby affecting the amount of sludge 36 required to achieve the purification goal. The optimal sludge quantity for a specific purpose can be experimentally determined due to variations related to different geographical locations and reactive gas levels, as further described below. To remove as much organic contaminant as possible while producing the minimum amount of sludge, it has generally been proven sufficient that the volume ratio of the gas-dispersed return sludge 36 (with at least 10 mg / L dissolved oxygen) in the mixed liquor 17 to the volume of wastewater 11 is 10%, and may be greater than 10% when the wastewater is particularly heavily contaminated, as stated above. Similarly, if the user input specifies a short treatment time and a high degree of digestion for the contaminants, thus requiring priority for digestion, the time required for the oxygen in the gas-dispersed return sludge to reach a critical threshold of at least 10 mg / L is set between 2 and 4 seconds to allow the microorganisms to prioritize digestion. The time and degree of digestion can be further reduced by increasing the oxygen level in the gas-dispersed return sludge to just above 10 mg / L.Conversely, if in addition to digesting pollutants, it is desirable to generate a large amount of sludge 35, then the time to reach a critical concentration of at least 10 mg / L can exceed 4 seconds.

[0063] Optionally, if there is an opportunity to physically set up or modify the equipment used to treat wastewater 11 (e.g. Figure 1A-1B By setting up the system, the equipment parameters required to handle a specific wastewater load can be determined, such as equipment size (although other parameters are also possible), and these parameters can be optionally implemented based on that determination (step 43). This determination may be particularly important when setting up equipment for the first time in environments where activated sludge-based purification is not traditionally employed (e.g., on ships, in ports, or in dairy farms).

[0064] Wastewater 11 enters sedimentation tank 12, where gravel and other inorganic solids settle and separate (step 44). Subsequently, wastewater 11 enters equalization tank 14, where the load and conditions of the original wastewater 11 are adjusted, and solid organic matter is dissolved by anaerobic microorganisms (step 45).

[0065] Next, if one or more aerobic reactors are part of system 10, wastewater 11 may flow through mixer / distributor 15 into one or more aerobic reactors 16, where wastewater 11 (raw wastewater) is added to gas-dispersed return sludge 36 and mixed to form mixed liquor 17 (if a mixer / distributor is included, mixed liquor 17 is formed in mixer-distributor 15 and supplied to one or more aerobic reactors 16, where most of the biochemical (aerobic and other types of digestion) consumption of organic pollutants (and other degradable pollutants) takes place) (step 46). Thus, if any aeration was previously performed by bubbling using air as the reactive gas, such aeration is no longer necessary due to the reactive gas contained in gas-dispersed return sludge 36. Dissolved oxygen (DO) (possibly containing trace amounts of ozone) is supplied to tank 16 via gas-dispersed sludge return 36. After step 45, undissolved organic solids are oxidized. Simultaneously, biochemical treatment occurs through an aerobic microbial community, digesting dissolved organic (and other digestible) pollutants in wastewater 11 into water (H2O) and other byproducts, such as inert compounds like amorphous carbon or diatomic nitrogen (N2), which are easily removed. If the digestive function of the microorganisms has been satisfied and they may exhibit reproductive function, some pollutants can be fixed in additional sludge 21 by the microorganisms through their reproductive function (step 47). After the consumption of organic pollutants is completed through digestion and, possibly, reproduction, the microorganisms enter a dormant state.

[0066] Through the action of atomizer 24 or pump 22, oxygen and ozone generator 28, and possibly valve 136, the dissolved oxygen content in the gas-dispersed return sludge 36 is raised to a critical level (at least 10 mg / L) within a short period of time (2-4 seconds). This critical level activates the microbial community in the gas-dispersed return sludge 36 from a dormant state. Although the microorganisms are now activated and ready to digest organic pollutants and other pollutants (and prioritize digestion over reproduction) and catabolism precedes anabolism, the level of organic pollutants (and other pollutants that can be digested to extract energy) is zero (the pollutants have already been completely consumed in one or more aerobic reaction vessels) or close to zero (insufficient to satisfy the microorganisms' prioritized digestion), thus forcing the microorganisms into a near-starvation extreme state. The activated microbial community present in the gas-dispersed return sludge 36 is supplied to a mixer / distributor 15 (if present in system 10), and the activated microbial community is mixed with wastewater 11 through the mixer / distributor 15 to form a mixed liquor 17, which is supplied to one or more aerobic reactors 16 (or, if system 10 does not include a mixer / distributor 15, the mixed liquor 17 is formed in the aerobic reactor 16). Within the aerobic reactor, the microorganisms continue to autonomously prioritize their digestive functions over their reproductive functions. The efficiency of oxygen (DO) utilization in the digestive function of the microbial community is extremely high. Therefore, the activated microbial community in one or more aerobic reactors is fully utilized. Thus, the activated microbial community in one or more aerobic reactors 16 is able to purify significantly more organic matter per 1 DO than the amounts typically defined as 1 BOD or 1 COD in activated sludge processes.

[0067] Next, the mixed liquor 17 enters the settling tank 18, where it settles and separates into sludge 21 and supernatant (step 48). The settled sludge 21 is collected in the sludge storage tank 20 (step 49) and returned to the aerobic reaction tank 16 in the form of gas-dispersed return sludge 36 for recycling (step 50), as described below. Figure 3 Further details are provided.

[0068] The remaining sludge 27 is discharged from the sludge storage tank 20 and system 10 (step 51). The supernatant is removed as treated water 72 and undergoes further treatment at the treated water treatment unit 73, and then discharged from the system as purified water 74 (step 52). Disinfection can be performed as described in U.S. Patent No. 10,287,194 to Ohki et al., issued May 14, 2019, the disclosure of which is incorporated herein by reference, although disinfection may be performed in other ways.

[0069] Optionally, the amount of sludge 21 collected in the sludge storage tank can be measured (e.g., by weighing the sludge 21), and the measurement result is used to adjust the ratio of gas-dispersed return sludge 36 to wastewater 11 used to form the mixed liquor 17 in subsequent repetitions of method 40 (step 53). For example, if the measured amount exceeds the desired amount of sludge 21, the ratio of the amount of gas-dispersed return sludge 36 to wastewater 11 used to form the mixed liquor 17 can be increased in subsequent runs of method 40 (thereby reducing the total amount of biodegradable contaminants available to microorganisms and increasing the likelihood that all biodegradable contaminants will be degraded by microorganisms through digestion). Alternatively, if the amount of sludge 21 produced is insufficient, the ratio of the amount of gas-dispersed return sludge 36 to wastewater 11 used to form the mixed liquor 17 can be reduced in subsequent runs of method 40 (thereby increasing the amount of biodegradable contaminants available to microorganisms, which can be used for microbial reproduction after digestion).

[0070] If there is more wastewater 11 to be treated (step 54), then determine whether the amount of solid contaminants (organic and inorganic) in the next batch of wastewater 11 to be treated requires action by performing steps 44 and 45 (step 55). This determination can be made by comparing the level of solids with one or more thresholds, although other types of determinations are possible. If the level requires action (step 55), the method returns to step 44. If the level does not require action (step 55), method 40 returns to step 46. If there is no more wastewater 11 to be treated (step 52), method 40 ends.

[0071] The gas-dispersed return sludge 36 may be supplied to one or more aerobic reactors 16 via mixer / distributor 15, allowing the aerobic microorganisms in the aerobic reactor 16 to reach optimal levels. Figure 3 The flowchart illustrates, according to one embodiment, the formation of gas-dispersed return sludge and the return of the gas-dispersed return sludge to one or more aerobic reaction tanks 16 for use in... Figure 2A-2B The process of the method.

[0072] The reactive gas (pure oxygen or oxygen containing trace amounts of ozone) is generated by the oxygen and ozone generator 28 (step 61). As described above, the atomizer 24 or pump 22 is installed along the return sludge pipe 26. Once the reactive gas is introduced into the return sludge 35 through the return sludge pipe 26 or through the valve 136 into the pump 22 (or atomizer 24), the return sludge 35 is converted into a gas-liquid mixture (step 62). When this gas-liquid mixture (sludge) passes through the atomizer 24 or pump 22, the reactive gas in the gas-liquid mixture (sludge) is instantaneously converted into ultrafine bubbles (bubble diameter less than 30 μm, ideally less than 1 μm), and a portion of them dissolve within a defined time (e.g., 2 seconds to 4 seconds) (step 63). This achieves a supersaturated DO value of 10-50 mg / L (or 0.01-0.5 mg / L ozone if ozone is also produced), with the remaining gas dispersed, fixed, and stored in the sludge as ultrafine bubbles. This provides a way to supplement the supply of dissolved reactive gases and continue the digestion of degradable pollutants.

[0073] This gas-dispersed return sludge 36 containing reactive gases is supplied only to one or more aerobic reaction tanks 16 (possibly via a mixer / distributor 15) via an atomizer 24 or a pump 22, where the gas-dispersed return sludge 36 forms a partial mixture 17 with the wastewater 11 (step 64), ending process 60.

[0074] As described above, once the gas-dispersed return sludge is added to one or more aerobic reaction tanks 16, any bubbling in the aerobic reaction tank 16 can be stopped. Alternatively, in cases where bubbling is required to prevent sludge settling, bubbling aeration can be minimal and can be performed intermittently and for short periods.

[0075] While the invention has been specifically shown and described with reference to its embodiments, those skilled in the art will understand that the above and other changes in form and detail may be made without departing from the spirit and scope of the invention.

Claims

1. A method (40) for wastewater treatment control optimized through microbial metabolic pathways, comprising: Provide (41) sludge containing microorganisms capable of digesting one or more pollutants through one or more catabolic pathways to obtain energy and store energy in the form of adenosine triphosphate (ATP), wherein the sludge (35) is substantially free of said one or more pollutants; The computer (39) receives (42) user input, which includes at least one of the digestion time and degree of digestion of one or more contaminants. Based on user input, a computer (39) determines (42) a time within which at least one reactive gas (37) needs to dissolve to a predetermined concentration in the sludge (35); At least one reactive gas (37) is generated (61) by a gas generator (28) controlled by a computer (39) and supplied to the sludge (35); Under the control of a computer (39), at least one reactive gas (37) is at least partially dissolved in sludge (35) within a defined time by one of an atomizer (24) or a pump (22) to achieve a predetermined concentration in the sludge (35) to form (63) gas dispersion return sludge (36). Under the control of a computer (39), a mixture (46) (17) is formed by mixing gas-dispersed reflux sludge (36) with wastewater (11) containing one or more pollutants, wherein when encountering pollutants in the wastewater (11), microorganisms store a certain amount of ATP in an initial time period, the initial time period depending on the determined time, and wherein the microorganisms perform digestive functions in other time periods based on the amount of ATP produced and stored in the initial time period.

2. The method (40) according to claim 1, further comprising: The correlation between the rate at which at least one reactive gas (37) dissolves in sludge (35) to a predetermined concentration and the extent to which it performs a digestive function when it encounters one or more contaminant microorganisms after dissolution (42), wherein the time is determined using the correlation.

3. The method (40) according to claim 2, wherein the predetermined concentration is included in a predetermined concentration range, and further includes selecting (42) the predetermined concentration from the predetermined concentration range based on user input.

4. The method (40) according to claim 1, wherein the microorganisms preferentially perform the digestion function when the time for at least one reactive gas (37) in the sludge (35) to reach a predetermined concentration does not exceed 4 seconds.

5. The method (40) according to claim 1, wherein the catabolic pathway by which the microorganism performs its digestive function depends on the amount of ATP stored.

6. The method (40) according to claim 1, wherein at least one reactive gas (37) comprises oxygen and trace amounts of ozone, and the predetermined concentration of oxygen is at least 10 mg / L.

7. The method (40) according to claim 1, wherein the wastewater (11) originates from a dairy farm, and at least one of the gas generator and the pump (22) and the atomizer (264) is located in the dairy farm.

8. The method (40) according to claim 1, wherein the wastewater (11) originates from the ship, and at least one of the gas generator and the pump (22) and the atomizer (24) is located on the ship.

9. The method (40) according to claim 1, further comprising: The rate at which at least one reactive gas is supplied to one of the pump and the atomizer is controlled by a gas velocity volume control valve (136) located at the inlet of one of the pump (22) and the atomizer (24).

10. The method (40) according to claim 1, wherein a mixer / distributor (15) is used to form a mixture (17) under the control of a computer (39).

11. A system (10) for wastewater treatment control optimized through microbial metabolic pathways, comprising: Computer (39), its configuration is as follows: Receive (42) user input, which includes at least one of the digestion time and degree of digestion of one or more pollutants by microorganisms in sludge (35), wherein the microorganisms are able to perform digestive functions through one or more catabolic pathways to digest one or more pollutants to obtain energy and store energy in the form of adenosine triphosphate (ATP), wherein the sludge (35) is substantially free of pollutants; Based on user input, determine (42) a time period during which at least one reactive gas (37) needs to be dissolved in the sludge to a predetermined concentration; A gas generator (28), under the control of a computer (39), is configured to generate at least one reactive gas (37), which is supplied to the sludge (35); The machine, under the control of a computer (39) and including one of an atomizer (24) or a pump (22), is configured as follows: A gas dispersion reflux sludge (36) is formed by dissolving at least one reactive gas (37) in sludge (35) for a defined time to achieve a predetermined concentration in sludge (35); By providing gas to disperse the reflux sludge (36) to mix with wastewater (11) containing one or more pollutants, a mixture (46) (17) is formed, wherein when encountering pollutants in the wastewater (11), the microorganisms store a certain amount of ATP for an initial time period, the initial time period depending on the determined time, and wherein the microorganisms perform digestive functions in other time periods based on the amount of ATP produced and stored in the initial time period.

12. The system (10) according to claim 11, wherein the computer (39) is further configured to: The correlation between the rate at which at least one reactive gas (37) dissolves in sludge (35) to a predetermined concentration and the extent to which microorganisms perform digestive functions when the at least one reactive gas (37) encounters one or more contaminants after dissolution, wherein the correlation is used to determine time.

13. The system (10) of claim 12, wherein the predetermined concentration is included in a predetermined concentration range, and the computer is further configured to select (42) the predetermined concentration from the predetermined concentration range based on user input.

14. The system (10) according to claim 11, wherein the catabolic pathway by which the microorganisms perform their digestive function depends on the amount of ATP stored.

15. The system (10) according to claim 11, wherein the microorganisms preferentially perform the digestion function when the time for at least one reactive gas (37) in the sludge (35) to reach a predetermined concentration does not exceed 4 seconds.

16. The system (10) according to claim 11, wherein at least one reactive gas (37) comprises oxygen and trace amounts of ozone, and the predetermined concentration of oxygen is at least 10 mg / L.

17. The system (10) according to claim 11, wherein the wastewater (11) originates from a dairy farm, and at least one of the gas generator (28) and the pump (22) and the atomizer (24) is located in the dairy farm.

18. The system (10) according to claim 11, wherein the wastewater (11) originates from the ship, and at least one of the gas generator (28) and the pump (22) and the atomizer (24) is located on the ship.

19. The system (10) according to claim 11, further comprising: A gas velocity-volume control valve (136) located at the inlet of the machine is configured to control the rate at which at least one reactive gas (37) is supplied to the pump (22).

20. The system (10) according to claim 11, wherein, under the control of a computer (17), the machine supplies gas-dispersed reflux sludge (36) to a mixer / distributor (15).

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