Method and apparatus for dissolved oxygen control for wastewater treatment

Abstract

Disclosed are a dissolved oxygen control method and a dissolved oxygen control device for wastewater treatment. The dissolved oxygen control method comprises: obtaining an ammonia nitrogen content measurement value of effluent from an aerobic zone; determining a compensated oxygen demand based on the ammonia nitrogen content measurement value of the effluent from the aerobic zone and a set value of the ammonia nitrogen content of the effluent from the aerobic zone; determining an actual saturated dissolved oxygen value based on water temperature in the aerobic zone, an oxygen transfer efficiency of a blower and an installation depth of an aeration disc; and determining a compensated gas quantity based on the compensated oxygen demand and the actual saturated dissolved oxygen value. Thus, the dissolved oxygen control method and the dissolved oxygen control device for wastewater treatment according to the embodiments of the present disclosure can control the air volume of the blower when needed, achieving fine control. In addition, the dissolved oxygen control method and the dissolved oxygen control device for wastewater treatment according to the embodiments of the present disclosure can be automatically executed through automatic control technology, thus reducing manual intervention and reducing overall energy consumption.

Description

Technical Field

[0001] This invention relates to wastewater treatment, and more specifically, to a method and apparatus for controlling dissolved oxygen in wastewater treatment. Background Technology

[0002] In urban wastewater treatment, the aerobic zone is a crucial area in wastewater treatment plants for purifying ammonia nitrogen from urban wastewater using aerobic treatment processes. Furthermore, the biological aeration stage within the aerobic zone is a critical step in wastewater treatment. To a certain extent, controlling the aeration rate determines the overall system's treatment efficiency and the wastewater treatment plant's energy consumption level. Therefore, methods and equipment for precisely controlling the aeration rate are being researched. Summary of the Invention

[0003] The purpose of this invention is to provide a dissolved oxygen control method and dissolved oxygen control device that can achieve precise control.

[0004] According to one embodiment of the present invention, a dissolved oxygen control method for wastewater treatment includes: obtaining a measured value of ammonia nitrogen content in the effluent of the aerobic zone; determining a compensating oxygen demand based on the measured value of ammonia nitrogen content in the effluent of the aerobic zone and a set value of ammonia nitrogen content in the effluent of the aerobic zone; determining an actual saturated dissolved oxygen value based on the water temperature of the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc; and determining a compensating gas quantity based on the compensating oxygen demand and the actual saturated dissolved oxygen value.

[0005] Optionally, the step of determining the compensation oxygen demand based on the measured ammonia nitrogen content of the effluent from the aerobic zone and the set value of the ammonia nitrogen content of the effluent from the aerobic zone includes: determining the compensation oxygen demand based on the difference between the measured ammonia nitrogen content of the effluent from the aerobic zone and the set value of the ammonia nitrogen content of the effluent from the aerobic zone, the influent flow rate of the aerobic zone, and the oxygen demand per unit of ammonia nitrogen oxidation.

[0006] Optionally, the step of determining the actual saturated dissolved oxygen value based on the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc includes: determining the actual saturated dissolved oxygen value based on the saturated dissolved oxygen value under standard atmospheric pressure conditions at the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc.

[0007] Optionally, the step of determining the amount of compensation gas based on the compensated oxygen demand and the actual saturated dissolved oxygen value includes: determining the total amount of compensation oxygen required to transfer oxygen to the aerobic tank mixture at the aerobic zone water temperature, the compensated oxygen demand, and the actual saturated dissolved oxygen value; and determining the amount of compensation gas based on the total compensation oxygen and the oxygen transfer efficiency of the blower.

[0008] Optionally, the step of determining the amount of compensating gas based on the total compensated oxygen content and the oxygen transfer efficiency of the blower includes: determining the transfer coefficient based on the ratio of the total compensated oxygen content to the compensated oxygen demand; and determining the amount of compensating gas based on the transfer coefficient, the compensated oxygen demand, and the oxygen transfer efficiency of the blower.

[0009] Optionally, the step of determining the amount of compensation gas based on the total compensation oxygen content and the oxygen transfer efficiency of the blower includes: determining the amount of compensation gas based on the total compensation oxygen content, the oxygen transfer efficiency of the blower, and the mass of oxygen per unit volume of air.

[0010] Optionally, the dissolved oxygen control method further includes: obtaining a dissolved oxygen measurement value at the end of the aerobic zone; and selectively controlling the air volume of the blower based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value.

[0011] Optionally, the step of selectively controlling the blower's airflow based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value includes: not controlling the blower's airflow in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being within a predetermined range; and controlling the blower's airflow based on the amount of compensating gas in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being outside the predetermined range.

[0012] According to one embodiment of the present invention, a dissolved oxygen control device for wastewater treatment includes: an ammonia nitrogen content measuring instrument configured to: obtain a measured value of ammonia nitrogen content in the effluent of the aerobic zone; a compensation oxygen demand determination module configured to: determine a compensation oxygen demand based on the measured value of ammonia nitrogen content in the effluent of the aerobic zone and a set value of ammonia nitrogen content in the effluent of the aerobic zone; a dissolved oxygen determination module configured to: determine an actual saturated dissolved oxygen value based on the water temperature of the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc; and a compensation gas quantity determination module configured to: determine a compensation gas quantity based on the compensation oxygen demand and the actual saturated dissolved oxygen value.

[0013] Optionally, the compensation oxygen demand determination module is configured to: determine the compensation oxygen demand based on the difference between the measured ammonia nitrogen content of the effluent from the aerobic zone and the set value of the ammonia nitrogen content of the effluent from the aerobic zone, the influent flow rate of the aerobic zone, and the oxygen demand per unit of ammonia nitrogen oxidation.

[0014] Optionally, the dissolved oxygen determination module is configured to determine the actual saturated dissolved oxygen value based on the saturated dissolved oxygen value under standard atmospheric pressure conditions at the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc.

[0015] Optionally, the compensation gas quantity determination module is configured to: determine the total compensation oxygen quantity required to transfer oxygen to the aerobic tank mixture at the aerobic zone water temperature, compensation oxygen demand, and actual saturated dissolved oxygen value; and determine the compensation gas quantity based on the total compensation oxygen quantity and the oxygen transfer efficiency of the blower.

[0016] Optionally, the compensation gas quantity determination module is configured to: determine the transfer coefficient based on the ratio of total compensation oxygen quantity to compensation oxygen demand; and determine the compensation gas quantity based on the transfer coefficient, compensation oxygen demand, and the oxygen transfer efficiency of the blower.

[0017] Optionally, the compensation gas quantity determination module is configured to determine the compensation gas quantity based on the total compensation oxygen quantity, the oxygen transfer efficiency of the blower, and the mass of oxygen per unit volume of air.

[0018] Optionally, the dissolved oxygen control device further includes: a dissolved oxygen meter configured to: obtain a dissolved oxygen measurement value at the end of the aerobic zone; and a blower controller configured to: selectively control the airflow of the blower based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen setpoint.

[0019] Optionally, the blower controller is configured to: not control the blower's airflow in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being within a predetermined range; and to control the blower's airflow based on the amount of compensating gas in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being outside the predetermined range.

[0020] According to one embodiment of the present invention, a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the dissolved oxygen control method as described above.

[0021] According to one embodiment of the present invention, a control device includes: a processor; and a memory storing a computer program, which, when executed by the processor, implements the dissolved oxygen control method as described above.

[0022] The dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can accurately calculate the difference between the measured value and the set value of the ammonia nitrogen content in the effluent from the aerobic zone, and then recalculate the amount of compensation gas based on this difference, so that the measured value of the ammonia nitrogen content in the effluent from the aerobic zone meets the requirements. Furthermore, the dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can control the airflow of the blower when needed, achieving refined control. In addition, the dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can be automatically executed through automation control technology, thus reducing manual intervention and lowering overall energy consumption. Attached Figure Description

[0023] The above and / or other aspects of this disclosure will become clearer and more readily understood from the following detailed description taken in conjunction with the accompanying drawings.

[0024] Figure 1 This is a flowchart of a dissolved oxygen control method for wastewater treatment according to an embodiment of the present disclosure.

[0025] Figure 2 This is a flowchart of a method for determining the amount of compensating gas based on the compensated oxygen demand and the actual saturated dissolved oxygen value, according to an embodiment of the present disclosure.

[0026] Figure 3 This is a flowchart of a method for determining the amount of compensating gas based on the total compensating oxygen amount and the oxygen transfer efficiency of the blower, according to embodiments of the present disclosure.

[0027] Figure 4 This is a flowchart of a dissolved oxygen control method for wastewater treatment according to an embodiment of the present disclosure.

[0028] Figure 5 This is a flowchart of a method for selectively controlling the air volume of a blower according to embodiments of the present disclosure.

[0029] Figure 6 This is a flowchart of a dissolved oxygen control device for wastewater treatment according to an embodiment of the present disclosure.

[0030] Figure 7 This is a block diagram illustrating a control device for wastewater treatment according to an embodiment of the present invention.

[0031] Throughout the accompanying drawings and detailed embodiments, unless otherwise described or provided, the same reference numerals will be understood to denote the same elements, features, and structures. The drawings may not be to scale, and for clarity, illustration, and convenience, the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0032] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for the sake of clarity and conciseness, descriptions of features known upon understanding this disclosure may be omitted.

[0033] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be clear upon understanding the disclosure of this application.

[0034] Throughout this specification, when a component is described as "connected to" or "attached to" another component, the component may be directly "connected to" or "attached to" the other component, or there may be one or more other components in between. Conversely, when an element is described as "directly connected to" or "directly attached to" another element, there may be no other elements in between. Similarly, similar expressions (e.g., "between" and "immediately between," and "adjacent to" and "closely adjacent to") should be interpreted in the same manner. As used herein, the term "and / or" includes any one of the relevant listed items or any combination of any two or more of the relevant listed items.

[0035] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0036] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the features, quantities, operations, components, elements, and / or combinations thereof stated therein, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0037] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as understood based on the disclosure of this application and as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and in the disclosure of this application, and shall not be interpreted ideally or overly formally. The use of the term “may” herein with respect to examples or embodiments (e.g., regarding what an example or embodiment may include or implement) indicates the existence of at least one example or embodiment that includes or implements such a feature, while not all examples are limited thereto.

[0038] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0039] Figure 1 This is a flowchart of a dissolved oxygen control method for wastewater treatment according to an embodiment of the present disclosure.

[0040] Reference Figure 1 In step S100, the ammonia nitrogen content of the effluent from the aerobic zone can be measured. According to an embodiment of this disclosure, the ammonia nitrogen content of the effluent from the aerobic zone can be obtained by periodically monitoring the solution at the aerobic zone effluent outlet in real time using an ammonia nitrogen content measuring instrument located near the outlet of the aerobic zone.

[0041] In step S200, the compensated oxygen demand can be determined based on the measured ammonia nitrogen content of the aerobic zone effluent and the set value of the ammonia nitrogen content of the aerobic zone effluent. It should be understood that the set value of the ammonia nitrogen content of the aerobic zone effluent may not be a fixed value, but may vary according to the relevant regulations of different countries or regions.

[0042] For example, the relationship between the compensated oxygen demand and the measured value of ammonia nitrogen content in the effluent of the aerobic zone and the set value of ammonia nitrogen content in the effluent of the aerobic zone is shown in Formula 1 below.

[0043] O 补偿需氧量 =F1(C 出水 C 设定 ) Formula 1

[0044] In Formula 1, O 补偿需氧量 Indicates the compensation oxygen demand, C 出水 C represents the measured ammonia nitrogen content in the effluent from the aerobic zone. 设定 This indicates the setpoint for ammonia nitrogen content in the effluent from the aerobic zone, and F1(C) 出水 C 设定 ) indicates the compensation oxygen demand O 补偿需氧量 C is the measured value of ammonia nitrogen content in the effluent from the aerobic zone. 出水 The set value C for ammonia nitrogen content in the effluent from the aerobic zone 设定 The function.

[0045] In one embodiment, the compensated oxygen demand can be determined based on the difference between the measured ammonia nitrogen content of the effluent from the aerobic zone and the set ammonia nitrogen content of the effluent from the aerobic zone, the influent flow rate of the aerobic zone, and the oxygen demand for oxidizing a unit of ammonia nitrogen. In this embodiment, the influent flow rate of the aerobic zone can be obtained by periodically monitoring the flow rate of the water at the inlet of the aerobic zone using a flow meter installed near the inlet, and the oxygen demand for oxidizing a unit of ammonia nitrogen can be determined by the chemical reaction formula used to oxidize ammonia nitrogen in the wastewater.

[0046] For example, the relationship between the compensated oxygen demand, the difference between the measured value of ammonia nitrogen content in the effluent of the aerobic zone and the set value of ammonia nitrogen content in the effluent of the aerobic zone, the influent flow rate of the aerobic zone, and the oxygen demand for oxidizing a unit of ammonia nitrogen is shown in Formula 2 below.

[0047] O 补偿需氧量 =F2(C 出水 -C 设定 Q 进水 a 单位需氧量 ) Formula 2

[0048] In Formula 2, C 出水 -C 设定 Q represents the difference between the measured ammonia nitrogen content in the effluent from the aerobic zone and the set value for ammonia nitrogen content in the effluent from the aerobic zone. 进水 This indicates the influent flow rate to the aerobic zone, where 'a' represents the oxygen demand for oxidizing a unit of ammonia nitrogen, and F2(C 出水 -C 设定 Q 进水 a 单位需氧量 ) indicates the compensation oxygen demand O 补偿需氧量 C is the difference between the measured ammonia nitrogen content in the effluent from the aerobic zone and the set value for ammonia nitrogen content in the effluent from the aerobic zone. 出水 -C 设定 , Aerobic zone influent flow rate Q 进水 and the oxygen demand (a) for oxidizing a unit of ammonia nitrogen 单位需氧量 The function. In one example, the oxygen demand 'a' for oxidizing one unit of ammonia nitrogen. 单位需氧量 It could be 4.57. However, it should be understood that this disclosure is not limited thereto. For example, the oxygen demand a for oxidizing one unit of ammonia nitrogen. 单位需氧量 It can vary depending on the composition of the wastewater.

[0049] In one example, the compensated oxygen demand O 补偿需氧量 It can be determined by the following formula 3.

[0050] O 补偿需氧量 =(C 出水 -C 设定 )×Q 进水 ×a 单位需氧量 Formula 3

[0051] In other words, as shown in Formula 3 above, the compensation oxygen demand O 补偿需氧量 This can be equal to the difference C between the measured ammonia nitrogen content in the effluent from the aerobic zone and the set value for the ammonia nitrogen content in the effluent from the aerobic zone. 出水 -C 设定 , Aerobic zone influent flow rate Q 进水 and the oxygen demand (a) for oxidizing a unit of ammonia nitrogen 单位需氧量 The product of the three.

[0052] In step S300, the actual saturated dissolved oxygen value can be determined based on the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration discs. According to embodiments of this disclosure, the aerobic zone water temperature can be obtained by periodically monitoring the water temperature in the aerobic zone in real time using a thermometer located in the center of the aerobic zone; the oxygen transfer efficiency of the blower can be obtained by consulting the blower's product manual or by direct experimental measurement; the installation depth of the aeration discs can be obtained from the design standards of the wastewater treatment plant or by actual measurement; and the actual saturated dissolved oxygen value represents the saturated dissolved oxygen value of the mixed solution in the aerobic zone.

[0053] For example, the relationship between the actual saturated dissolved oxygen value and the water temperature in the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc is shown in Formula 1 below.

[0054] C sw(T) =F3(T, E) A Formula 4 (H)

[0055] In Formula 1, C sw(T) This represents the actual saturated dissolved oxygen value, where T represents the water temperature in the aerobic zone, and E represents the actual saturated dissolved oxygen value. A The oxygen transfer efficiency of the blower, and H represents the installation depth of the aeration disc, F3(T, E A H) represents the actual saturated dissolved oxygen value C. sw(T) The aerobic zone water temperature T and the blower oxygen transfer efficiency E are... A The oxygen transfer efficiency E of the blower is a function of the installation depth H of the aeration disc. In one example, the oxygen transfer efficiency E of the blower is... A It can be taken as 0.25% or 25%. However, it should be understood that the oxygen transfer efficiency E of the blower... A It can vary depending on the blower, and even for blowers of the same model, their oxygen transfer efficiency E A They could also be different.

[0056] In one embodiment, the actual saturated dissolved oxygen (SDO) value can be determined based on the SDO value under standard atmospheric pressure conditions at the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration discs. In this embodiment, the standard atmospheric pressure can be 1.01325 × 10⁻⁶. 5 Pa.

[0057] In one example, the actual saturated dissolved oxygen value C sw(T) It can be determined by the following formula 5.

[0058]

[0059] In Formula 5, k1 represents the predetermined coefficient, C s(T) b represents the saturated dissolved oxygen in clear water at the temperature corresponding to the aerobic zone water temperature T under standard atmospheric pressure. 氧 P represents the percentage of oxygen in the air. 当地 P represents the atmospheric pressure of the aerobic zone. H P represents the water pressure corresponding to the installation depth H of the aeration disc. 标准 This represents standard atmospheric pressure. In one example, when the oxygen content in the air is b... 氧 When the volume percentage of oxygen in the air is 'b', the percentage of oxygen in the air is 'b'. 氧 It can be 0.21 or 21%. In a preferred example, the predetermined coefficient k1 can be 0.5. Furthermore, according to embodiments of this disclosure, C s(T) You can find the information in Table 1 below.

[0060] Table 1

[0061]

[0062] In step S400, the amount of compensation gas can be determined based on the compensated oxygen demand and the actual saturated dissolved oxygen value. That is, the amount of compensation gas can be determined based on the compensated oxygen demand calculated in step S200 and the actual saturated dissolved oxygen value calculated in step S300. For example, the relationship between the amount of compensation gas and the compensated oxygen demand and the actual saturated dissolved oxygen value is shown in Formula 6 below.

[0063] Q 补偿气体量 =F4(O 补偿需氧量 C sw(T) ) Formula 6

[0064] In Formula 6, Q 补偿气体量 This indicates the amount of compensation gas, and F4(O) 补偿需氧量 C sw(T) ) represents the amount of compensating gas Q 补偿气体量 It is to compensate for oxygen demand O 补偿需氧量 And the actual saturated dissolved oxygen value C sw(T) The function.

[0065] In the following text, reference will be made to Figure 2 A detailed description of the method for determining the amount of compensating gas based on the compensated oxygen demand and the actual saturated dissolved oxygen value.

[0066] Therefore, through steps S100 to S400 above, the difference between the measured ammonia nitrogen content in the aerobic zone effluent and the set value can be accurately calculated. Based on this difference, the compensation gas volume is recalculated, ensuring that the measured ammonia nitrogen content in the aerobic zone effluent meets the requirements. Furthermore, steps S100 to S400 can be automatically executed using automated control technology, thus reducing manual intervention and lowering overall energy consumption.

[0067] Figure 2 This is a flowchart of a method for determining the amount of compensating gas based on the compensated oxygen demand and the actual saturated dissolved oxygen value, according to an embodiment of the present disclosure.

[0068] Reference Figure 2 In step S410, the total amount of supplementary oxygen required to transfer oxygen to the aerobic tank mixture at the aerobic zone water temperature can be determined based on the aerobic zone water temperature, the supplementary oxygen demand, and the actual saturated dissolved oxygen value. According to embodiments of this disclosure, the total supplementary oxygen amount can correspond to the amount of oxygen required to transfer oxygen from the supplementary oxygen demand O to the aerobic tank mixture. 补偿需氧量 The total amount of oxygen required for that much oxygen to dissolve into the aerobic zone solution.

[0069] In one example, the total compensated oxygen amount can be determined by the following formula 7.

[0070]

[0071] In Formula 5, R represents the water temperature T in the aerobic zone and the atmospheric pressure P at the location of the aerobic zone. 当地 In order to compensate for oxygen demand O 补偿需氧量 The total amount of oxygen compensation required to transfer so much oxygen to the aerobic mixed solution, C s(20) L1 represents the saturated dissolved oxygen in clean water at standard atmospheric pressure and a temperature of 20°C. k2 represents the oxygen transfer correction factor, k3 represents the oxygen solubility correction factor, k4 represents the pressure correction factor, and k5 represents the setpoint for the dissolved oxygen concentration in the aerobic tank. In one example, for municipal wastewater, the oxygen transfer correction factor k2 can be between 0.8 and 0.85, and the oxygen solubility correction factor k3 can be between 0.9 and 0.97. In a preferred example, the oxygen transfer correction factor k2 can be 0.85, the oxygen solubility correction factor k3 can be 0.95, the pressure correction factor k4 can be 1, and the setpoint for the dissolved oxygen concentration in the aerobic tank, L5, can be 2 mg / L.

[0072] In step S420, the amount of compensation gas can be determined based on the total compensation oxygen amount and the oxygen transfer efficiency of the blower. For example, the amount of compensation gas can be determined by the following formula 8.

[0073] Q 补偿气体量 =F5(R,E) A ) Formula 8

[0074] In Formula 8, Q 补偿气体量 This indicates the amount of compensation gas, and F5(R, E) A ) represents the amount of compensating gas Q 补偿气体量 It is the total compensated oxygen quantity R and the oxygen transfer efficiency E of the blower. A The function.

[0075] In one embodiment, the amount of compensating gas can be determined based on the total amount of compensated oxygen, the oxygen transfer efficiency of the blower, and the mass of oxygen per unit volume of air. In one example, the amount of compensating gas can be determined by the following formula 9.

[0076]

[0077] In Formula 6, k6 represents the mass of oxygen per unit volume of air. In one example, the mass of oxygen per unit volume of air, k6, can be expressed as the percentage of oxygen in the air, b. 氧 Obtained by multiplying the density of oxygen.

[0078] In the following text, reference will be made to Figure 3 A method for determining the amount of compensating gas based on the total compensating oxygen content and the oxygen transfer efficiency of the blower is described in detail.

[0079] Therefore, through steps S410 to S420 above, the amount of compensating gas can be accurately calculated, ensuring that the ammonia nitrogen content measurement value of the effluent from the aerobic zone meets the requirements. Furthermore, steps S410 to S420 can be automatically executed using automated control technology, thus reducing manual intervention and lowering overall energy consumption.

[0080] Figure 3 This is a flowchart of a method for determining the amount of compensating gas based on the total compensating oxygen amount and the oxygen transfer efficiency of the blower, according to embodiments of the present disclosure.

[0081] Reference Figure 3 In step S421, the transfer coefficient can be determined based on the ratio of total compensated oxygen to compensated oxygen demand. In one example, the amount of compensated gas can be determined by the following formula 10, where e represents the transfer coefficient.

[0082]

[0083] In step S422, the amount of compensation gas can be determined based on the transfer coefficient, the compensation oxygen demand, and the oxygen transfer efficiency of the blower. In one example, the amount of compensation gas can be determined by the following formula 11.

[0084]

[0085] Figure 3Steps S421 and S422, as shown, for determining the amount of compensation gas, involve a new parameter (i.e., the transfer coefficient e), which can be used in other calculations for automated wastewater treatment and / or can be obtained from calculations for other automated wastewater treatment processes. Therefore, in cases where other calculations for automated wastewater treatment are required and / or where such calculations exist, steps S421 and S422 described above can be used to more conveniently calculate the amount of compensation gas Q. 补偿气体量 .

[0086] Figure 4 This is a flowchart of a dissolved oxygen control method for wastewater treatment according to an embodiment of the present disclosure.

[0087] Reference Figure 4 In step S500, the dissolved oxygen measurement value at the end of the aerobic zone can be obtained. According to an embodiment of this disclosure, the dissolved oxygen measurement value at the end of the aerobic zone can be obtained by periodically detecting the solution at the end of the aerobic zone in real time using a dissolved oxygen measuring instrument installed at the end of the aerobic zone.

[0088] In step S600, the blower's airflow can be selectively controlled based on the difference between the measured dissolved oxygen value at the end of the aerobic zone and the dissolved oxygen setpoint. In one example, the dissolved oxygen setpoint can be in the range of 2.0 ± 0.5 mg / L. However, it should be understood that this disclosure is not limited thereto. Referring below... Figure 5 Describe in detail a method for selectively controlling the air volume of a blower.

[0089] Figure 5 This is a flowchart of a method for selectively controlling the air volume of a blower according to embodiments of the present disclosure.

[0090] Reference Figure 5 In step S610, the blower's airflow may not be controlled if the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is within a predetermined range. In one example, the predetermined range may be 1.5-2.2 mg / L. In this case, according to an embodiment of the present disclosure, the blower's airflow is not controlled when the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is within the predetermined range of 1.5-2.2 mg / L.

[0091] In step S620, in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being outside a predetermined range, the blower's airflow can be controlled based on the amount of compensating gas. According to embodiments of this disclosure, when the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is less than 1.5 mg / L, the blower can be controlled to increase the airflow; when the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is greater than 2.2 mg / L, the blower can be controlled to decrease the airflow.

[0092] Therefore, through steps S610 and S620 above, the air volume of the blower can be controlled when needed, achieving precise control. Furthermore, steps S610 and S620 can be executed automatically through automation control technology, thus reducing manual intervention and lowering overall energy consumption.

[0093] Figure 6 This is a flowchart of a dissolved oxygen control device for wastewater treatment according to an embodiment of the present disclosure.

[0094] Reference Figure 6 The dissolved oxygen control device 100 may include an ammonia nitrogen content measuring instrument 110, a compensation oxygen demand determination module 120, a dissolved oxygen determination module 130, and a compensation gas quantity determination module 140.

[0095] The ammonia nitrogen content measuring instrument 110 can be configured to obtain the ammonia nitrogen content measurement value of the effluent from the aerobic zone.

[0096] The compensated oxygen demand (COD) determination module 120 can be configured to determine the compensated COD based on the measured ammonia nitrogen content of the effluent from the aerobic zone and the set ammonia nitrogen content of the effluent from the aerobic zone. In one embodiment, the compensated COD determination module 120 can be configured to determine the compensated COD based on the difference between the measured ammonia nitrogen content of the effluent from the aerobic zone and the set ammonia nitrogen content of the effluent from the aerobic zone, the influent flow rate of the aerobic zone, and the COD required to oxidize one unit of ammonia nitrogen.

[0097] The dissolved oxygen determination module 130 can be configured to determine the actual saturated dissolved oxygen value based on the water temperature in the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc. In one embodiment, the dissolved oxygen determination module 130 can be configured to determine the actual saturated dissolved oxygen value based on the saturated dissolved oxygen value under standard atmospheric pressure conditions at the water temperature in the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc.

[0098] For example, in one example, the compensation gas quantity determination module 140 may be configured to: determine the total compensation oxygen quantity required to transfer oxygen to the aerobic tank mixture at the aerobic zone water temperature, the compensation oxygen demand, and the actual saturated dissolved oxygen value; and determine the compensation gas quantity based on the total compensation oxygen quantity and the oxygen transfer efficiency of the blower.

[0099] For example, in another example, the compensation gas quantity determination module 140 may be configured to: determine a transfer coefficient based on the ratio of total compensation oxygen quantity to compensation oxygen demand; and determine the compensation gas quantity based on the transfer coefficient, compensation oxygen demand, and the oxygen transfer efficiency of the blower. In this case, the compensation gas quantity determination module 140 may also be configured to: determine the compensation gas quantity based on compensation oxygen demand and the actual saturated dissolved oxygen value.

[0100] Optionally, refer to Figure 6The dissolved oxygen control device 100 may also include a dissolved oxygen meter 150 (as shown by the dashed line) and a blower controller 160 (as shown by the dashed line).

[0101] The dissolved oxygen meter 150 can be configured to obtain a dissolved oxygen measurement value at the end of the aerobic zone. The blower controller 160 can be configured to selectively control the blower's airflow based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen setpoint. In this case, the blower controller 160 can be configured to: not control the blower's airflow in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen setpoint being within a predetermined range; and control the blower's airflow based on the amount of compensating gas in response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen setpoint being outside the predetermined range.

[0102] Therefore, the dissolved oxygen control device 100 can accurately calculate the difference between the measured value and the set value of the ammonia nitrogen content in the aerobic zone effluent, and then recalculate the compensation gas volume based on this difference to ensure that the measured value of the ammonia nitrogen content in the aerobic zone effluent meets the requirements. Furthermore, the dissolved oxygen control device 100 can control the blower's airflow when needed, achieving precise control. In addition, the dissolved oxygen control device 100 can be automatically executed through automation control technology, thus reducing manual intervention and lowering overall energy consumption.

[0103] Figure 7 This is a block diagram illustrating a control device for wastewater treatment according to an embodiment of the present invention.

[0104] Reference Figure 7 The control device 200 for wastewater treatment according to embodiments of this disclosure may be (but is not limited to) a programmable logic controller (PLC) industrial computer. The control device 200 for chemical phosphorus removal dosing according to embodiments of this disclosure may include a processor 210 and a memory 220. The processor 210 may include (but is not limited to) a central processing unit (CPU), a digital signal processor (DSP), a microcomputer, a field-programmable gate array (FPGA), a system-on-a-chip (SoC), a microprocessor, an application-specific integrated circuit (ASIC), etc. The memory 720 stores computer programs to be executed by the processor 210. The memory 220 includes high-speed random access memory and / or a non-volatile computer-readable storage medium. When the processor 210 executes the computer program stored in the memory 220, the dissolved oxygen control method for wastewater treatment as described above can be implemented.

[0105] Alternatively, the control device 200 can communicate with other components in the water treatment system via wired / wireless communication, and can also communicate with other devices in the water treatment system via wired / wireless communication. Furthermore, the control device 200 can communicate with devices external to the water treatment system via wired / wireless communication. Additionally, the control device 200 may have timer and encoder functions.

[0106] The dissolved oxygen control method for wastewater treatment according to embodiments of this disclosure can be programmed into a computer program and stored on a computer-readable storage medium. When the computer program is executed by a processor, the dissolved oxygen control method for wastewater treatment as described above can be implemented. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and to provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0107] The dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can accurately calculate the difference between the measured value and the set value of the ammonia nitrogen content in the effluent from the aerobic zone, and then recalculate the amount of compensation gas based on this difference, so that the measured value of the ammonia nitrogen content in the effluent from the aerobic zone meets the requirements. Furthermore, the dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can control the airflow of the blower when needed, achieving refined control. In addition, the dissolved oxygen control method and equipment for wastewater treatment according to embodiments of this disclosure can be automatically executed through automation control technology, thus reducing manual intervention and lowering overall energy consumption.

[0108] Although the invention has been specifically shown and described with reference to exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A method for dissolved oxygen control for wastewater treatment, characterized by, The dissolved oxygen control method includes: Obtain the ammonia nitrogen content measurement value of the effluent from the aerobic zone; The ammonia nitrogen content in the effluent from the aerobic zone is measured and the set value of ammonia nitrogen content in the effluent from the aerobic zone is used to determine the compensation oxygen demand. The actual saturated dissolved oxygen value is determined based on the water temperature in the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc. The amount of compensating gas is determined based on the compensated oxygen demand and the actual saturated dissolved oxygen value. The compensation oxygen demand is determined using the following formula, based on the difference between the measured ammonia nitrogen content in the aerobic zone effluent and the set ammonia nitrogen content in the aerobic zone effluent, the influent flow rate in the aerobic zone, and the oxygen demand per unit ammonia nitrogen oxidation: in, This indicates the measured value of ammonia nitrogen content. This indicates the set value for the ammonia nitrogen content. This indicates the influent flow rate to the aerobic zone. This indicates the oxygen demand; The actual saturated dissolved oxygen value is determined using the following formula, based on the saturated dissolved oxygen value under standard atmospheric pressure conditions at the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc. in, This indicates the actual saturated dissolved oxygen value. Indicates the predetermined coefficient. This represents the saturated dissolved oxygen in clear water at a temperature corresponding to the water temperature in the aerobic zone under standard atmospheric pressure. It indicates the percentage of oxygen in the air. This indicates the atmospheric pressure of the aerobic zone. This indicates the water pressure corresponding to the installation depth H of the aeration disc. Indicates standard atmospheric pressure. This indicates the oxygen transfer efficiency; The total amount of compensated oxygen required to transfer oxygen to the mixed liquor in the aerobic tank at the aerobic zone water temperature is determined using the following formula, based on the aerobic zone water temperature, compensated oxygen demand, and actual saturated dissolved oxygen value: in, Indicates the water temperature in the aerobic zone Atmospheric pressure in the aerobic zone The following is the total amount of oxygen required to transfer the oxygen from the oxygen demand compensation zone to the aerobic mixed solution. This represents the saturated dissolved oxygen in clean water at standard atmospheric pressure and a temperature of 20°C. Indicates the oxygen transfer correction factor. This represents the oxygen solubility correction factor. This represents the pressure correction factor. This indicates the set value of dissolved oxygen concentration in the aerobic tank; The amount of compensating gas is determined using the following formula, based on the total compensated oxygen amount and the oxygen transfer efficiency of the blower: wherein, represents the mass of oxygen in a unit volume of air.

2. The dissolved oxygen control method as claimed in claim 1, characterized by, The steps for determining the amount of compensating gas based on the total compensated oxygen content and the oxygen transfer efficiency of the blower include: The transfer coefficient is determined based on the ratio of total compensated oxygen to compensated oxygen demand; The amount of compensating gas is determined based on the transfer coefficient, the oxygen demand for compensation, and the oxygen transfer efficiency of the blower.

3. The dissolved oxygen control method as claimed in claim 1, wherein, The steps for determining the amount of compensating gas based on the total compensated oxygen content and the oxygen transfer efficiency of the blower include: The amount of compensating gas is determined based on the total compensated oxygen amount, the oxygen transfer efficiency of the blower, and the mass of oxygen per unit volume of air.

4. The dissolved oxygen control method as claimed in claim 1, wherein, The dissolved oxygen control method further includes: Obtain dissolved oxygen measurements at the end of the aerobic zone; Based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value, the air volume of the blower is selectively controlled.

5. The dissolved oxygen control method as claimed in claim 4, characterized by, The steps for selectively controlling the blower's airflow based on the difference between the measured dissolved oxygen value at the end of the aerobic zone and the set dissolved oxygen value include: If the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is within a predetermined range, the blower airflow will not be controlled. In response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being outside the predetermined range, the blower's air volume is controlled based on the amount of compensating gas.

6. A dissolved oxygen control apparatus for sewage treatment, characterized by comprising: The dissolved oxygen control device includes: The ammonia nitrogen content measuring instrument is configured to: obtain the ammonia nitrogen content measurement value of the effluent from the aerobic zone; The compensated oxygen demand determination module is configured to determine the compensated oxygen demand based on the measured ammonia nitrogen content of the effluent from the aerobic zone and the set ammonia nitrogen content of the effluent from the aerobic zone. The dissolved oxygen determination module is configured to determine the actual saturated dissolved oxygen value based on the water temperature in the aerobic zone, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc. The compensation gas quantity determination module is configured to determine the compensation gas quantity based on the compensation oxygen demand and the actual saturated dissolved oxygen value. The compensated oxygen demand determination module is configured to determine the compensated oxygen demand using the following formula: based on the difference between the measured ammonia nitrogen content of the effluent from the aerobic zone and the set ammonia nitrogen content of the effluent from the aerobic zone, the influent flow rate of the aerobic zone, and the oxygen demand per unit of ammonia nitrogen oxidation. in, This indicates the measured value of ammonia nitrogen content. This indicates the set value for the ammonia nitrogen content. This indicates the influent flow rate to the aerobic zone. This indicates the oxygen demand; The dissolved oxygen determination module is configured to determine the actual saturated dissolved oxygen value based on the saturated dissolved oxygen value under standard atmospheric pressure conditions at the aerobic zone water temperature, the oxygen transfer efficiency of the blower, and the installation depth of the aeration disc using the following formula. in, This indicates the actual saturated dissolved oxygen value. Indicates the predetermined coefficient. This represents the saturated dissolved oxygen in clear water at a temperature corresponding to the water temperature in the aerobic zone under standard atmospheric pressure. It indicates the percentage of oxygen in the air. This indicates the atmospheric pressure of the aerobic zone. This indicates the water pressure corresponding to the installation depth H of the aeration disc. Indicates standard atmospheric pressure. This indicates the oxygen transfer efficiency; The compensation gas quantity determination module is configured to determine the total compensation oxygen quantity required to transfer oxygen to the aerobic tank mixture at the aerobic zone water temperature, based on the aerobic zone water temperature, compensation oxygen demand, and actual saturated dissolved oxygen value, using the following formula: in, Indicates the water temperature in the aerobic zone Atmospheric pressure in the aerobic zone The following is the total amount of oxygen required to transfer the oxygen from the oxygen demand compensation zone to the aerobic mixed solution. This represents the saturated dissolved oxygen in clean water at standard atmospheric pressure and a temperature of 20°C. Indicates the oxygen transfer correction factor. This represents the oxygen solubility correction factor. This represents the pressure correction factor. This indicates the set value of dissolved oxygen concentration in the aerobic tank; The compensation gas quantity determination module is configured to determine the compensation gas quantity based on the total compensation oxygen quantity and the oxygen transfer efficiency of the blower using the following formula: wherein, represents the mass of oxygen in a unit volume of air.

7. The dissolved oxygen control device as described in claim 6, characterized in that, The compensation gas quantity determination module is configured as follows: The transfer coefficient is determined based on the ratio of total compensated oxygen to compensated oxygen demand; The amount of compensating gas is determined based on the transfer coefficient, the oxygen demand for compensation, and the oxygen transfer efficiency of the blower.

8. The dissolved oxygen control device as described in claim 6, characterized in that, The compensation gas quantity determination module is configured as follows: The amount of compensating gas is determined based on the total compensated oxygen amount, the oxygen transfer efficiency of the blower, and the mass of oxygen per unit volume of air.

9. The dissolved oxygen control device as described in claim 6, characterized in that, Dissolved oxygen control equipment also includes: The dissolved oxygen meter is configured to obtain the dissolved oxygen measurement value at the end of the aerobic zone; The blower controller is configured to selectively control the blower's airflow based on the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value.

10. The dissolved oxygen control device as described in claim 9, characterized in that, The blower controller is configured as follows: If the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value is within a predetermined range, the blower airflow will not be controlled. In response to the difference between the dissolved oxygen measurement value at the end of the aerobic zone and the dissolved oxygen set value being outside the predetermined range, the blower's air volume is controlled based on the amount of compensating gas.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the dissolved oxygen control method as described in any one of claims 1 to 5.

12. A control device, characterized in that, The control device includes: processor; A memory storing a computer program that, when executed by a processor, implements the dissolved oxygen control method as described in any one of claims 1 to 5.

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