Multi-source catalytic oxidation intelligent dosing control method and system

Abstract

The application relates to the technical field of water treatment, and provides a multi-source catalytic oxidation intelligent dosing control method and system. 2+ The amount of the reagent added into a water treatment device is controlled; the reagent comprises H2O2 and Fe 2+ The water treatment device is provided with a cathode and an anode, and can realize Fenton oxidation and electrochemical oxidation; H2O2 and Fe 2+ The reagent is calculated and intelligently dynamically controlled according to the constructed formula. The intelligent dosing control method can avoid reagent waste, reduce the operation cost of the water treatment process, and realize energy saving and consumption reduction.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a method and system for intelligent dosing control of multi-source catalytic oxidation. Background Technology

[0002] In advanced oxidation technologies for water treatment, Fenton oxidation primarily utilizes the reaction of ferrous ions and hydrogen peroxide to generate hydroxyl radicals, thereby achieving the oxidative removal of organic matter. Due to its simplicity and readily available materials, Fenton oxidation is currently the most widely used advanced oxidation technology in industrial applications. However, in practical applications, the added ferrous sulfate powder dissolves in water and reacts with H₂O₂, resulting in Fe... 2+ and the generated Fe 3+ Ferrous sulfate readily complexes with intermediate organic carboxylic acids, affecting the effective utilization of iron ions and further removal of intermediate products. This necessitates continued addition of ferrous sulfate and H₂O₂, leading to excess ferrous sulfate and H₂O₂, resulting in a large amount of iron sludge at the end of the process. Simultaneously, residual H₂O₂ negatively impacts subsequent flocculation, sedimentation, and the biological system. Electrochemical oxidation technology, due to its lack of external reagents, absence of secondary pollution, and ease of operation, has been widely studied and applied in recent years. This technology uses anode and cathode electrodes to directly oxidize (i.e., pollutants lose electrons directly at the anode) or indirectly oxidize (i.e., generate highly oxidizing intermediate products through anodic reactions), ultimately achieving the goal of oxidative degradation of pollutants.

[0003] The introduction of electrochemical oxidation technology into Fenton oxidation, particularly the breakthrough in H2O2 production at the air cathode, has significantly improved current efficiency and pollutant removal efficiency, providing a fundamental support for synergistic degradation between the anode and cathode. Existing technologies include advanced oxidation water treatment devices or reactors formed by coupling Fenton oxidation with electrochemical oxidation. For example, patent CN201610335240.6 discloses a wastewater treatment device that couples electro-Fenton oxidation with electrocatalytic oxidation, generating no solid waste. However, current related technologies do not explicitly quantify the H2O2 production at the air cathode through metering. Therefore, in practical use, this often leads to excessive H2O2, and the ferrous iron dosage cannot be adjusted according to H2O2 production. There is an urgent need for H2O2 dosage control.

[0004] Several existing technologies attempt to control and regulate the dosage of Fenton reagents. For example, some schemes use pH-indicating, staged H2O2 addition to regulate multi-stage series-connected inductive Fenton reactors. This approach starts with the relationship between pH and H2O2, determining whether to adjust the H2O2 concentration entering each stage of the inductive Fenton reactor based on pH changes, and thus determining the required H2O2 concentration for each stage. However, this approach only provides reference range values ​​for different stages and lacks a precise calculation model. Furthermore, in the actual Fenton reaction process, the concentration and valence state changes of iron ions are key factors determining iron ion utilization. From the perspective of energy saving and consumption reduction, the dynamic changes in iron ions and precise control of the dosage need to be considered. Another example is the use of the redox potential (ORP) in a sequencing batch Fenton oxidation reactor as a control variable, employing a feedback control structure to regulate the operation of the H2O2 and ferrous sulfate metering pumps. The above scheme can, to some extent, avoid the impact of excessive or insufficient Fenton reagent dosage on oxidation effect, sludge production, and subsequent treatment. However, when using the ORP detection method, if the oxidation-reduction potential is too weak, it will not be able to fully reflect the concentration of a certain oxide or reducer. In actual use, in addition to the concentration of iron ions and hydroxyl radicals, the concentration changes of other substances in wastewater all affect ORP. Therefore, determining the dosage of Fenton reagent solely based on the ORP potential has a large error.

[0005] It is evident that current water treatment technologies related to Fenton-coupled electrochemical oxidation, even when attempting to control the dosage of reagents, often involve simple control based on a specific reaction device or a single related factor or variable. There is a lack of more precise control methods for the dosage of ferrous iron and H2O2. Summary of the Invention

[0006] This invention provides a multi-source catalytic oxidation intelligent dosing control method and system to solve the problem in the prior art that there is a lack of accurate and effective calculation and control of the dosage of reagents in water treatment reaction systems using single Fenton oxidation or combined Fenton oxidation-electrochemical oxidation technologies (such as electro-Fenton, electrocatalytic Fenton, etc.).

[0007] In a first aspect, the present invention provides a method for intelligent dosing control of multi-source catalytic oxidation, which controls the amount of reagents added to a water treatment device; the reagents include H2O2 and Fe. 2+ Reagents; the water treatment device is equipped with a cathode and an anode, and the water treatment device is capable of Fenton oxidation and electrochemical oxidation;

[0008] H2O2 dosage Calculations and control are performed according to formula (1):

[0009]

[0010] In the formula, α is a proportionality coefficient, obtained based on the reaction ratio of COD and H2O2 in water; COD is the actual COD concentration in water; ξ is the cathode H2O2 production coefficient; and M is the Fe in water. 3+ The mass of the iron ions is F; F is the Faraday constant; n is the absolute value of the total change in the oxidation state of iron ions; I is the product of the current density and the working area of ​​the anode; T is the energizing time of the cathode and anode.

[0011] Optionally, α is 0.3 to 0.5.

[0012] Optionally, the ξ is 1 / 4 to 2 / 3.

[0013] Optional, Fe 2+ dosage Calculations and control are performed according to formula (2):

[0014]

[0015] In the formula: β is the molar ratio coefficient, based on the ratio of H2O2 and Fe in the Fenton oxidation reaction. 2+ The proportional relationship is obtained; δ represents the amount of H2O2 added to the water treatment device; δ represents the cathode Fe. 2+ Reduction coefficient.

[0016] Optionally, β is 1 / 15 to 1 / 10.

[0017] Optionally, the δ is 1 / 3 to 3 / 4.

[0018] A second aspect of the present invention provides a multi-source catalytic oxidation process control system for controlling a water treatment device capable of Fenton oxidation and electrochemical oxidation; the system includes a process parameter control module, which includes an H2O2 dosing module for calculating and controlling the amount of H2O2 added to the water treatment device according to formula (1).

[0019] Optionally, the process parameter control module includes Fe 2+ The dosing module, the Fe 2+ The dosing module is used to calculate and control Fe according to formula (2). 2+ dosage

[0020] In some schemes, the multi-source catalytic oxidation process control system can separately set up the H2O2 dosing module, or separately set up the Fe... 2+ The dosing module can also be set in the control system to add H2O2 and Fe. 2+ Dosing module.

[0021] A third aspect of the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the control method described above.

[0022] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the control method described above.

[0023] This invention utilizes the coupled mechanism of multi-source catalytic oxidation, including the related mechanisms of Fenton oxidation and electrochemical oxidation reactions, and constructs an intelligent dosage calculation method by identifying multiple factors affecting drug dosage, including H2O2 and Fe. 2+ The reagent dosage is precisely calculated and controlled; the dosage of water treatment equipment is dynamically and intelligently adjusted based on the calculated values, which can avoid reagent waste, reduce water treatment reagent costs and process operating costs, and achieve precise and effective reagent dosing. Detailed Implementation

[0024] This invention provides a multi-source catalytic oxidation intelligent dosing control method, which can accurately calculate and control the amount of reagent added to the water treatment device.

[0025] The multi-source catalytic oxidation described in this invention refers to the coupling of advanced oxidation technologies such as Fenton oxidation and electrochemical oxidation. The control method of this invention is applicable to water treatment devices that couple these two processes. The water treatment device is equipped with a cathode and an anode to achieve electrochemical oxidation. During operation, Fenton reagents, including H₂O₂ and ferrous sulfate, are added, with ferrous sulfate typically used for the addition of ferrous sulfate.

[0026] In other words, the control method of this invention can be applied to various existing water treatment devices using Fenton coupled electrochemical oxidation processes, enabling precise calculation and control of the Fenton dosage in the water treatment device. Based on the calculated values, dynamic intelligent regulation can be performed to reduce unnecessary waste of reagents and energy consumption, achieving synergistic energy saving and consumption reduction.

[0027] The Fenton oxidation described in this invention includes homogeneous Fenton oxidation with the addition of Fenton reagent, heterogeneous Fenton oxidation using iron-based catalysts, and Fenton-like reaction systems filled with iron crystalline oxide support materials.

[0028] The electrochemical oxidation described in this invention mainly involves placing a plate-type or tubular electrochemical cathode and anode within a coupled reaction system. The electrodes can be placed parallel or perpendicular to the water flow direction in the water treatment device. The electrochemical anode material can be an electrode with an oxygen evolution potential greater than 1.5V, more specifically, it can be a titanium-based metal oxide coated electrode, such as lead dioxide, iridium dioxide, ruthenium dioxide, or tin dioxide coated electrodes; it can also be a BDD electrode, platinum electrode, etc. The electrochemical oxidation anode can be a high oxygen evolution potential electrode, for example, an electrode with an oxygen evolution potential of 1.9-2.2V measured by cyclic voltammetry. The electrochemical cathode material can be a modified carbon material, stainless steel, or a titanium-based electrode. In some preferred embodiments, the modified carbon material is modified graphite or carbon felt, and the modification method is doping with carbon black, impregnation with polytetrafluoroethylene, sintering, etc.

[0029] This invention fully utilizes the enhancement mechanism generated by the coupling of electrochemistry and multi-source catalytic oxidation such as Fenton oxidation to construct Fe 2+ And a method for precise control and intelligent calculation of H2O2 dosage.

[0030] (1) H2O2 dosage

[0031] Due to the coupling of electrochemical oxidation, the cathode undergoes a 2-electron oxygen reduction reaction (ORR) under O2 aeration to generate H2O2, producing an oxidant in situ and participating in the Fenton reaction, thus reducing the amount of externally added H2O2. Therefore, the amount of H2O2 added (i.e., the H2O2 concentration required by the water treatment device reaction system) can be obtained by subtracting the H2O2 generated by the cathode through aeration from the initial amount of H2O2 added to the system. The initial amount of H2O2 added to the system can be calculated based on the ratio of H2O2 to ΔCOD. In other words, the calculation formula for controlling the H2O2 dosage consists of two parts: the first part is the ratio of H2O2 to ΔCOD, and the second part is the amount of H2O2 generated through cathode reduction.

[0032] H2O2 dosage Calculations and control are performed according to formula (1):

[0033]

[0034] In the formula:

[0035] —H2O2 dosage, mg / L;

[0036] α—proportionality coefficient, obtained based on the reaction ratio of ΔCOD to H2O2 in water;

[0037] △COD—is the target COD removal concentration, which is the COD removal concentration obtained through theoretical calculation. It is generally determined based on the COD removal concentration designed for the specific project, in mg / L.

[0038] ξ—coefficient of hydrogen peroxide production at the cathode;

[0039] Fe in the M-system 3+ The mass, g; in some specific implementations, the total iron and Fe can be determined using the o-phenanthroline spectrophotometric method. 2+ Mass, subtracting gives Fe 3+ quality;

[0040] F—Faraday's constant, with a value of F = 9.65 × 10000 C / mol, is Avogadro's constant N. A =6.02214×10 23 mol -1 With elementary charge e = 1.602176 × 10 -19 The product of C;

[0041] n—the absolute value of the total change in the oxidation state of iron ions;

[0042] I—the product of current density and anode working area, in A;

[0043] T—Electrode energization time, h.

[0044] In the above formula, for the second part, since the oxygen source in the system is divided into oxygen from aeration and oxygen produced by anode oxygen evolution, the amount of oxygen cannot be measured. Therefore, this invention indirectly calculates the amount of H2O2 produced by the gain or loss of electrons generated by the current. In a preferred embodiment of this invention, ξ, as the cathode hydrogen peroxide production coefficient, can be 1 / 6 to 1 / 2, or it can also be 1 / 5 to 1 / 3, 1 / 3 to 1 / 2, 1 / 3 to 2 / 3, etc.

[0045] In a preferred embodiment of the present invention, the first part of the above formula, namely the ratio of H2O2 to ΔCOD, can preferably be a ratio that is more than 50% lower than the conventional Fenton oxidation addition ratio, that is, α is 0.3 to 0.5, and α can also be 0.3, 0.3 to 0.4, 0.4 to 0.5, 0.35 to 0.45 or 0.5, etc.

[0046] (2)Fe 2+ Dosage

[0047] Fe 2+ In terms of dosage, Fenton oxidation will... 2+ Converted to Fe 3+ Fe 3+ Fe is generated during reduction at the electrochemical cathode. 2+It can be reused for Fenton oxidation, such as to produce Fe. 2+ / Fe 3+ -Organic carboxylic acid complexes can undergo complex disruption at the electrochemical anode surface, releasing iron ions and organic carboxylic acids. The iron ions can then be further reduced at the cathode, while the organic carboxylic acids can continue to degrade under the combined effects of Fenton oxidation and electrochemical anodic oxidation. Therefore, Fe... 2+ Dosage (Fe required by the system) 2+ Concentration), which can be determined based on the initial Fe in the system. 2+ Dosage minus Fe 3+ Converted to Fe via cathodic reduction 2+ The amount is obtained from the quantity. Among them, the initial Fe in the system... 2+ The dosage can be determined based on the Fenton reaction Fe 2+ The ratio between the dosage of Fe and the dosage of H2O2 is obtained. That is, the calculation formula in this invention is divided into two parts: the first part is the molar ratio with the H2O2 dosage, and the second part is the Fe reduction at the cathode. 3+ The quantity is calculated using the gain or loss of electrons generated by the current flowing through it.

[0048] Fe 2+ Dosage Calculations and control are performed according to formula (2):

[0049]

[0050] In the formula:

[0051] β—molar ratio coefficient, based on the H2O2 and Fe in the Fenton oxidation reaction 2+ The proportional relationship is obtained;

[0052] —Amount of H2O2 added to the water treatment device, mg / L;

[0053] δ—Cathode Fe 2+ Reduction coefficient;

[0054] The meanings of the other parameters in formula (2) are the same as those in formula (1).

[0055] For the first part of formula (2), the amount of H2O2 added to the water treatment device. The H2O2 dosage can be calculated using formula (1). It can also be the amount of H2O2 that has been added to the water treatment device in the early stage without using formula (1). That is, in some schemes, formula (1) and formula (2) of the present invention can be used independently, and the use of formula (2) does not necessarily depend on formula (1).

[0056] In a preferred embodiment of the present invention, for the Fenton reagent Fe in the first part 2+ The molar ratio of H2O2 added can preferably be a ratio that is more than 50% lower than that of conventional Fenton oxidation, with β being 1 / 15 to 1 / 10. Further, β can also be 1 / 15 to 1 / 13, 1 / 14 to 1 / 12, 1 / 13 to 1 / 11, 1 / 12 to 1 / 10, etc.

[0057] Preferably, for the second part of formula (2), the value of δ is 1 / 3 to 3 / 4, and can also be 1 / 3 to 1 / 2, 1 / 3 to 2 / 3, 2 / 3 to 3 / 4, etc.

[0058] Based on the above control method, the present invention also provides a multi-source catalytic oxidation process control system for controlling a water treatment device capable of Fenton oxidation and electrochemical oxidation; including a process parameter control module, wherein the process parameter control module includes an H2O2 dosing module, the H2O2 dosing module being used to calculate and control the amount of H2O2 added to the water treatment device according to formula (1). Alternatively, the process parameter control module may also include Fe 2+ The dosing module, the Fe 2+ The dosing module is used to calculate and control Fe according to formula (2). 2+ dosage

[0059] Based on the above-described control method and control system, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described control method.

[0060] Based on the above control method and control system, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the above control method.

[0061] Traditional wastewater treatment often employs non-green methods that "use energy to eliminate pollution but not reduce carbon emissions," making it difficult to achieve goals such as low-carbon treatment and resource utilization. There is an urgent need to develop advanced wastewater treatment and resource utilization technologies geared towards green and low-carbon practices. This invention, based on the premise of synergistic pollution and carbon reduction and aiming to maximize the efficiency of advanced oxidation removal, deeply analyzes and utilizes the coupling mechanism of multi-source catalytic oxidation. Through the identification of factors affecting dosage, it constructs an intelligent dosing and precise control calculation method for reagents, thus forming an intelligent dosing control technology for multi-source catalytic oxidation.

[0062] Example 1

[0063] The method of this invention was used to treat the raw water of a pesticide intermediate production enterprise. The wastewater had a COD of 8000-10000 mg / L, a pH of 6.5-7.0, a B / C ratio of 0.02, high salinity, and poor biodegradability. Therefore, advanced oxidation technology was required for pretreatment to facilitate subsequent biochemical treatment.

[0064] The technical method provided by this invention is used for preprocessing and dynamic control of various operating parameters.

[0065] S1, influent, the COD of the influent was measured to be 8600 mg / L, and the influent flow rate was 0.1 m³ / s. 3 / min;

[0066] S2, activate the process parameter control module, including the H2O2 dosing module and the Fe... 2+ The dosing module is used for Fe 2+ And the calculation of H2O2 dosage and real-time dynamic intelligent dosing.

[0067] Table 1. Comparison of technical and economic parameters of the present invention with traditional Fenton oxidation and electrochemical oxidation.

[0068]

[0069] Note: The energy consumption of this invention is compared with that of electrochemical oxidation under the same COD removal rate (50%). The dosage of the reagent in this invention is compared with that of traditional Fenton under the same COD removal rate.

[0070] Example 2

[0071] The wastewater is being treated as concentrated RO membrane filtration wastewater from a dyeing and printing wastewater enterprise. The wastewater has a COD of 100-120 mg / L, a pH of 6.5-7.0, a B / C ratio of 0.02, high salinity, and poor biodegradability. Therefore, advanced oxidation technology is required for pretreatment to facilitate subsequent biological treatment.

[0072] The technical method provided by this invention is used for preprocessing and dynamic control of various operating parameters.

[0073] S1, influent, the COD of the influent was measured to be 108 mg / L, and the influent flow rate was 0.1 m³ / L. 3 / min;

[0074] S2, activate the process parameter control module, including the H2O2 dosing module and the Fe... 2+ The dosing module is used for Fe 2+ And the calculation of H2O2 dosage and real-time dynamic intelligent dosing.

[0075] Table 2. Comparison of technical and economic parameters of the present invention with traditional Fenton oxidation and electrochemical oxidation.

[0076]

[0077] Note: The energy consumption of this invention is compared with that of electrochemical oxidation under the same COD removal rate (50%). The dosage of the reagent in this invention is compared with that of traditional Fenton under the same COD removal rate.

[0078] The above results show that traditional Fenton oxidation has the lowest iron utilization rate because iron ions cannot further react with hydrogen peroxide after forming a complex with organic acids. In the combined approach of traditional Fenton oxidation and electrochemical oxidation, the ferrous ions reduced by electrochemical oxidation and the H2O2 generated at the cathode are not quantified and therefore not utilized. The only advantage is that electrochemical oxidation contributes to COD removal, thus allowing for a reduction in the dosage of ferrous ions and H2O2.

[0079] This invention introduces an intelligent dosing control system to dynamically adjust the dosage of ferrous ions and H2O2, effectively utilizing the H2O2 generated by the electrochemical cathode and the ferrous ions generated by cathode reduction. By calculating the amount of electron transfer, the amount of generated H2O2 and reduced ferrous ions is calculated and fed back to the change in the dosage, thereby improving the utilization rate of ferrous ions and H2O2.

[0080] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the present invention, and all such modifications and improvements fall within the scope of the present invention.

Claims

1. A method for intelligent dosing control of multi-source catalytic oxidation, characterized in that, The amount of reagents added to the water treatment device is controlled; the reagents include H2O2 and Fe. 2+ Reagents; the water treatment device is equipped with a cathode and an anode, and the water treatment device is capable of Fenton oxidation and electrochemical oxidation; H2O2 dosage Calculations and control are performed according to formula (1): （1） In the formula, α is a proportionality coefficient, obtained based on the reaction ratio of ΔCOD to H2O2 in water; ΔCOD is the target COD removal concentration; ξ is the cathode H2O2 production coefficient; and M is the Fe in water. 3+ The mass of the iron ions; F is the Faraday constant; n is the absolute value of the total change in the oxidation state of iron ions; I is the product of the current density and the working area of ​​the anode; T is the energizing time of the cathode and anode; α is 0.3~0.5; ξ is 1 / 6~1 / 2; Fe 2+ dosage Calculations and control are performed according to formula (2): （2） In the formula: β is the molar ratio coefficient, based on the ratio of H2O2 and Fe in the Fenton oxidation reaction. 2+ The proportional relationship is obtained; δ represents the amount of H2O2 added to the water treatment device; δ represents the cathode Fe. 2+ The reduction coefficient; β is 1 / 15 to 1 / 10; δ is 1 / 3 to 3 / 4.

2. A multi-source catalytic oxidation process control system capable of implementing the intelligent dosing control method for multi-source catalytic oxidation as described in claim 1, characterized in that, This device is used to control a water treatment system capable of performing Fenton oxidation and electrochemical oxidation; it includes a process parameter control module, which comprises an H2O2 dosing module and a Fe... 2+ Dosing module; The H2O2 dosing module is used to calculate and control the amount of H2O2 added to the water treatment device according to formula (1). ; The Fe 2+ The dosing module is used to calculate and control Fe according to formula (2). 2+ dosage .

3. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the intelligent dosing control method for multi-source catalytic oxidation as described in claim 1.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the intelligent dosing control method for multi-source catalytic oxidation as described in claim 1.

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