Control system for Fenton oxidation treatment process and Fenton reaction tank

Abstract

The utility model provides a Fenton oxidation treatment process control system and a Fenton reaction tank. The Fenton oxidation treatment process control system comprises an acid regulation intelligent dosing subsystem, an alkali regulation intelligent dosing subsystem, a hydrogen peroxide intelligent dosing subsystem, a ferrous sulfate intelligent dosing subsystem and a control subsystem. Data signals are transmitted to a PLC (programmable logic controller) control cabinet through online pH meters mounted at a Fenton water inlet and a Fenton water outlet, and a PLC is used for controlling the dosage of sulfuric acid and liquid caustic soda, so that the pH of inlet water and outlet water is adjusted; a flow meter and an online COD (Chemical Oxygen Demand) detection instrument are arranged at a Fenton water inlet, a data signal is transmitted to a PLC (Programmable Logic Controller), the COD concentration of effluent of a Fenton system is determined, and the chemical dosage of hydrogen peroxide and ferrous sulfate is calculated by programming, so that the effect of stably removing COD is achieved. According to the utility model, the problems of poor treatment effect of the Fenton system, untimely medicament adjustment and the like caused by frequent medicament adding amount adjustment due to the change of inlet water quality and water quantity can be avoided, and the accurate control of the Fenton process is realized by utilizing a self-control and programming system.

Description

Technical Field

[0001] The utility model relates to the technical field of mobile charging, in particular to a control system and a Fenton reaction pool for a Fenton oxidation treatment process. Background Art

[0002] Industrial wastewater, such as papermaking wastewater, printing and dyeing wastewater, and coal chemical wastewater, is characterized by complex composition, poor biodegradability, and difficulty in degradation. Currently, advanced oxidation processes are commonly used to treat difficult-to-degrade industrial wastewater. The Fenton process, a type of advanced oxidation process, utilizes a system consisting of ferrous ions and hydrogen peroxide. Under appropriate pH conditions, it generates highly oxidizing hydroxyl radicals, which react with refractory organic matter in aqueous solution, disrupting its structure and ultimately oxidizing it. The Fenton process occupies a small footprint, oxidizes organic matter rapidly, and requires a short residence time of approximately 0.5 to 2 hours. The reaction tank volume does not need to be large, saving space. The process offers operational flexibility, allowing operating conditions to be adjusted based on the quality of the incoming water to increase treatment capacity. For higher levels of contamination, increased dosages of ferrous sulfate and hydrogen peroxide and appropriate pH control are sufficient.

[0003] The Fenton method has the problem of strict reaction conditions and the treatment effect is affected by the reaction pH, reagent ratio, etc. If the appropriate reaction conditions are not met, not only will the reagents be wasted, but the expected treatment effect will not be achieved. Therefore, the reagents need to be accurately added. At the same time, the water quality and water volume of industrial influent fluctuate greatly, and the dosing needs to be adjusted in time according to the water quality and water volume. The Fenton system does not add many types of reagents, including sulfuric acid, liquid alkali, ferrous sulfate and hydrogen peroxide. The manual adjustment method has lag and is difficult to control. It cannot be adjusted in time according to changes in water quality and water volume. In addition, improper control of the Fenton effluent pH before the biochemical system will seriously affect the stable operation of the biochemical system.

[0004] Chinese Utility Model Publication No. CN219670175U discloses a precise dosing device for sewage treatment, addressing the issues of inability to adjust dosing in real time based on water quality changes and uneven dosing. The method includes a water quality sensor installed on a sewage pipe. The sewage pipe downstream of the water quality sensor is connected to a drug storage tank via a dosing pipe. A first check valve, a first flow meter, and a PID valve are sequentially installed on the dosing pipe. The upper end of the drug storage tank is connected to a vent pipe, which is mounted on a first solenoid valve. The vent pipe is connected to an air pump via an air inlet pipe. The first flow meter, pressure sensor, and water quality sensor are connected to the controller input, while the PID valve, first solenoid valve, and air pump are connected to the controller output. This method does not address the complex treatment of industrial wastewater using the Fenton oxidation process. Utility Model Content

[0005] The embodiments of the present invention provide a control system and a Fenton reaction tank for a Fenton oxidation treatment process, which solve the technical problems existing in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions.

[0007] The control system used for the Fenton oxidation treatment process includes an acid adjustment intelligent dosing subsystem, an alkali adjustment intelligent dosing subsystem, a hydrogen peroxide intelligent dosing subsystem, a ferrous sulfate intelligent dosing subsystem, and a control subsystem;

[0008] The acid adjustment intelligent dosing subsystem includes:

[0009] Two sulfuric acid dosing pumps are respectively installed on the sulfuric acid dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit;

[0010] Two sets of first pH monitors, used to obtain real-time acidic pH signals from the acid adjustment zone of the Fenton reaction tank. Each set of first pH monitors has two pH meters connected in parallel and connected to the control subsystem circuit.

[0011] The intelligent dosing subsystem for alkali adjustment includes:

[0012] Two alkali solution dosing pumps are respectively installed on the alkali solution dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit;

[0013] Two sets of second pH monitors, used to obtain the alkaline pH value signal of the alkaline adjustment zone of the Fenton reaction tank in real time. Each set of second pH monitors has two pH meters connected in parallel and connected to the control subsystem circuit;

[0014] The hydrogen peroxide intelligent dosing subsystem includes:

[0015] Two hydrogen peroxide dosing pumps are respectively installed on the hydrogen peroxide dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit;

[0016] A COD detector for real-time detection of COD concentration signals on the inlet side of the Fenton reactor;

[0017] Ferrous sulfate intelligent dosing subsystem includes:

[0018] Two ferrous sulfate dosing pumps are respectively installed on the ferrous sulfate dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit;

[0019] The control subsystem includes a PLC and a PID loop that are interconnected; the PLC is respectively connected to a first pH monitor, a second pH monitor and a COD detector; the PID loop is respectively connected to a sulfuric acid dosing pump, an alkali dosing pump, a hydrogen peroxide dosing pump and a ferrous sulfate dosing pump; the PLC is used to generate a sulfuric acid dosing control signal, an alkali dosing control signal, a hydrogen peroxide dosing control signal and a ferrous sulfate dosing control signal according to the received acidic pH value signal, the alkaline pH value signal and the COD concentration signal, so that the PID loop can control the sulfuric acid dosing pump, the alkali dosing pump, the hydrogen peroxide dosing pump and the ferrous sulfate dosing pump.

[0020] Preferably, the control subsystem also includes a first frequency converter, a second frequency converter, a third frequency converter and a fourth frequency converter; the first frequency converter is respectively connected to the PID loop and the sulfuric acid dosing pump; the second frequency converter is respectively connected to the PID loop and the alkali solution dosing pump, the third frequency converter is respectively connected to the PID loop and the hydrogen peroxide dosing pump; the fourth frequency converter is respectively connected to the PID loop and the ferrous sulfate dosing pump.

[0021] Preferably, the acid adjustment intelligent dosing subsystem further includes a sulfuric acid tank, the sulfuric acid tank is connected to a sulfuric acid dosing pipeline, and the sulfuric acid dosing pipeline is provided with a first ball valve, a first Y-type filter, a sulfuric acid dosing pump, a first pulse damper, a first blowdown valve, a first back pressure valve and a sulfuric acid dosing end which are sequentially arranged in series along the liquid flow direction; the sulfuric acid dosing end is connected to a Fenton reaction tank; a first branch is further connected between the first pulse damper and the sulfuric acid dosing pump, the other end of the first branch is connected to the sulfuric acid tank, and the first branch is also provided with a first safety valve;

[0022] The alkali adjustment intelligent dosing subsystem also includes an alkali solution tank, which is connected to an alkali solution dosing pipeline. The dosing pipeline includes a second ball valve, a second Y-type filter, an alkali solution dosing pump, a second pulse damper, a second blowdown valve, a second back pressure valve, and an alkali solution dosing end, which are arranged in series along the liquid flow direction. The alkali solution dosing end is connected to the Fenton reaction tank. A second branch is also connected between the second pulse damper and the alkali solution dosing pump. The other end of the second branch is connected to the alkali solution tank. The second branch also has a second safety valve.

[0023] The hydrogen peroxide intelligent dosing subsystem also includes a hydrogen peroxide tank connected to a hydrogen peroxide dosing pipeline. The dosing pipeline includes a third ball valve, a third Y-type filter, a hydrogen peroxide dosing pump, a third pulse damper, a third blowdown valve, a third back pressure valve, and a hydrogen peroxide dosing end, which are arranged in series along the liquid flow direction. The hydrogen peroxide dosing end is connected to the Fenton reaction tank. A third branch is connected between the third pulse damper and the hydrogen peroxide dosing pump. The other end of the third branch is connected to the hydrogen peroxide tank. The third branch also has a third safety valve.

[0024] The intelligent ferrous sulfate dosing subsystem also includes a ferrous sulfate tank, which is connected to a ferrous sulfate dosing pipeline. The dosing pipeline includes a fourth ball valve, a fourth Y-type filter, a ferrous sulfate dosing pump, a fourth pulse damper, a fourth drain valve, a fourth back pressure valve and a ferrous sulfate dosing end arranged in series along the liquid flow direction; the ferrous sulfate dosing end is connected to the Fenton reaction tank; a fourth branch is also connected between the fourth pulse damper and the ferrous sulfate dosing pump, the other end of the fourth branch is connected to the ferrous sulfate tank, and the fourth branch is also provided with a fourth safety valve.

[0025] Preferably, the sulfuric acid dosing pump, the alkali solution dosing pump, the hydrogen peroxide dosing pump and the ferrous sulfate dosing pump are metering pumps.

[0026] In a second aspect, the utility model provides a Fenton reaction tank for a Fenton oxidation treatment process, comprising a reaction tank, the reaction tank comprising an inlet side, an acid adjustment zone, a Fenton reagent input zone, an aeration reaction zone, an alkali adjustment zone and an outlet side arranged in sequence along the water flow direction, the inlet side being used to connect a sewage input device, and the outlet side being used to output treated water; a sulfuric acid dosing pipeline, an alkali dosing pipeline, a hydrogen peroxide dosing pipeline and a hydrogen peroxide dosing pipeline are respectively provided on both sides of the reaction tank, the sulfuric acid dosing pipeline is connected to the acid adjustment zone, the alkali dosing pipeline is connected to the alkali adjustment zone, and the hydrogen peroxide dosing pipeline and the hydrogen peroxide dosing pipeline are connected to the Fenton reagent input zone; mixing agitators are respectively provided in the Fenton reagent input zone and the alkali adjustment zone; the Fenton reaction tank also includes the above-mentioned control system.

[0027] It can be seen from the technical solutions provided by the embodiments of the present invention that the present invention provides a control system for a Fenton oxidation treatment process, including an intelligent dosing subsystem for acid adjustment, an intelligent dosing subsystem for alkali adjustment, an intelligent dosing subsystem for hydrogen peroxide, an intelligent dosing subsystem for ferrous sulfate, and a control subsystem. The online pH meter installed at the Fenton water inlet and outlet transmits the data signal to the PLC control cabinet, and the PLC is used to control the dosage of sulfuric acid and liquid alkali to adjust the pH of the inlet and outlet water; a flow meter and an online COD detection instrument are installed at the Fenton water inlet, and the data signal is transmitted to the PLC to determine the COD concentration to be achieved in the outlet water of the Fenton system, and the dosage of hydrogen peroxide and ferrous sulfate is calculated by programming to achieve the effect of stable COD removal. The present invention can avoid the frequent adjustment of the dosage of the reagent due to changes in the water quality and water volume of the inlet water, which leads to problems such as poor treatment effect of the Fenton system and untimely adjustment of the reagent, and uses the automatic control and programming system to achieve precise control of the Fenton process.

[0028] Additional aspects and advantages of the present invention will be partially given in the following description, which will become apparent from the following description or be understood through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of the structure of a control system for a Fenton oxidation treatment process provided by the present invention;

[0031] Figure 2 This is a flow chart of the intelligent dosing of hydrogen peroxide and ferrous sulfate reagents for the control system of the Fenton oxidation treatment process provided by the utility model;

[0032] Figure 3 This is a flow chart of the pH intelligent control of the control system for the Fenton oxidation treatment process provided by the utility model;

[0033] Figure 4 A schematic structural diagram of a sulfuric acid dosing subsystem of a Fenton reaction tank for a Fenton oxidation treatment process provided by the present invention;

[0034] Figure 5 This is a schematic structural diagram of a Fenton reaction tank for a Fenton oxidation treatment process provided by the present invention.

[0035] In the picture:

[0036] 11. Sulfuric acid dosing pump 12. First pH monitor 13. Sulfuric acid tank 14. Sulfuric acid dosing line 141. First ball valve 142. First Y-type filter 143. First pulse dampener 144. First blowdown valve 145. First back pressure valve 146. Sulfuric acid dosing port 15. First branch line 151. First safety valve 16. First mixer 17. First flow calibration column;

[0037] 21. Alkali dosing pump 22. Second pH monitor 31. Hydrogen peroxide dosing pump 32. COD detector 41. Ferrous sulfate dosing pump 51. PLC 52. PID loop 6. Fenton reactor 7. Control cabinet DETAILED DESCRIPTION

[0038] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0039] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or couplings. The term "and / or" as used herein includes any unit and all combinations of one or more associated listed items.

[0040] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such herein.

[0041] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each embodiment does not constitute a limitation on the embodiments of the present invention.

[0042] See also Figure 1 The utility model provides a control system for a Fenton oxidation treatment process, including an acid adjustment intelligent dosing subsystem, an alkali adjustment intelligent dosing subsystem, a hydrogen peroxide intelligent dosing subsystem, a ferrous sulfate intelligent dosing subsystem and a control subsystem.

[0043] The specific settings of each subsystem are as follows.

[0044] Acid adjustment intelligent dosing subsystem, which includes:

[0045] Two sulfuric acid dosing pumps 11 are respectively arranged on the sulfuric acid dosing pipelines 14 on both sides of the Fenton reaction tank 6 and are connected to the ferrous sulfate control subsystem circuit;

[0046] Two groups of first pH monitors 12 are used to obtain the acidic pH value signals of the sulfuric acid dosing pipelines 14 on both sides of the Fenton reaction tank 6 in real time. Each group of ferrous sulfate first pH monitors 12 has two pH meters connected in parallel and is connected to the ferrous sulfate control subsystem circuit.

[0047] In one feasible embodiment, two metering pumps (two in use and one in standby) are used to independently add sulfuric acid to the Fenton reaction tanks 6 on both sides. pH meters are installed in the Fenton acid adjustment zone and the mixing and stirring zone. After measuring the pH of the influent, the data signal is transmitted to the PLC 51 control cabinet. The metering pumps and the two online pH meters in the Fenton reaction tank 6 are interlocked, using the lower value of the two as the effective condition. When the pH value is higher than 4.0 (which can be set), it is turned on and when it is lower than 3.0 (which can be set), it is turned off. On the basis of the interlocking, a PID loop 52 is added to control the frequency of the frequency converter to adjust the dosage of the sulfuric acid dosing pumps 11 on both sides so that the pH value reaches the specified target value of 3.5 (which can be set). Each meter provides run, stop, and fault signals, which are remotely transmitted to the central control room.

[0048] Alkali adjustment intelligent dosing subsystem, which includes:

[0049] Two alkali solution dosing pumps 21 are respectively arranged on the alkali solution dosing pipelines on both sides of the Fenton reaction tank 6 and are connected to the ferrous sulfate control subsystem circuit;

[0050] Two sets of second pH monitors 22 are used to obtain the alkaline pH value signals of the sulfuric acid dosing pipelines 14 on both sides of the Fenton reaction tank 6 in real time. Each set of ferrous sulfate second pH monitors 22 has two pH meters connected in parallel and is connected to the ferrous sulfate control subsystem circuit.

[0051] In one feasible embodiment, two metering pumps (two in use and one in standby) are used to independently feed sulfuric acid to the Fenton reaction tanks 6 on both sides. pH meters are installed in the Fenton alkali adjustment zone and the mixing and stirring zone. After measuring the pH of the influent, the data signal is transmitted to the PLC 51 control cabinet. The metering pumps and the two online pH meters in the Fenton reaction tanks 6 are interlocked, using the lower of the two values as the effective condition. When the pH value is lower than 6.8 (which can be set), it is turned on and off when it is higher than 7.8 (which can be set). Based on this interlocking, a PID loop 52 is added to control the frequency of the inverter to adjust the dosage of the liquid alkali metering pumps on both sides of the Fenton tank to ensure that the pH value reaches the specified target range of 6.8-7.8 (which can be set). Each meter provides run, stop, and fault signals, which are remotely transmitted to the central control room.

[0052] The hydrogen peroxide intelligent dosing subsystem includes:

[0053] Two hydrogen peroxide dosing pumps 31 are respectively arranged on the hydrogen peroxide dosing pipelines on both sides of the Fenton reaction tank 6 and are connected to the ferrous sulfate control subsystem circuit;

[0054] The two COD detectors 32 are respectively used to detect the COD concentration signals of the hydrogen peroxide dosing pipelines on both sides of the Fenton reaction tank 6 in real time.

[0055] In a feasible embodiment, two metering pumps (two in use and one in standby) are used to add hydrogen peroxide to the Fenton reaction pools 6 on both sides. A COD detector 32 is installed at the water inlet of the Fenton pool. At the same time, water inlet flow meters are installed on both sides of the parallel operation. The detected COD concentration C1 and flow rate Q are transmitted to the PLC51 control cabinet. The effluent COD concentration is set to C2 in the program, and the COD reduction amount can be calculated as C 削减 =(C2-C1)*Q, assuming the ratio of hydrogen peroxide dosage to COD reduction is m:n, then the calculation formula for hydrogen peroxide dosage is M H2O2 =(n*C 削减 ) / m. PID loop 52 controls the inverter frequency to adjust the dosage of hydrogen peroxide metering pumps on both sides. Each pump provides run, stop, and fault signals, which are transmitted remotely to the central control room.

[0056] Ferrous sulfate intelligent dosing subsystem, which includes:

[0057] Two ferrous sulfate dosing pumps 41 are respectively arranged on the ferrous sulfate dosing pipelines on both sides of the Fenton reaction tank 6 and are connected to the ferrous sulfate control subsystem circuit.

[0058] It consists of two metering pumps (two in use and one in standby), which separately add ferrous sulfate to the Fenton reaction pools 6 on both sides. The amount of ferrous sulfate added is controlled according to the amount of hydrogen peroxide. The dosing ratio of ferrous sulfate to hydrogen peroxide is set to u:v. When the amount of hydrogen peroxide added is M H2O2 Calculate the dosage of ferrous sulfate M FeSO4 =(u*M H2O2 ) / v, and the frequency converter frequency is controlled by PID loop 52 to adjust the dosage of the ferrous sulfate metering pumps on both sides. Each pump provides run, stop, and fault signals, which are transmitted remotely to the central control room.

[0059] It should be understood that the Fenton reaction tank 6 is configured with corresponding treatment zones according to the Fenton oxidation process flow, specifically: water intake → acid adjustment → addition of Fenton reagents (hydrogen peroxide and ferrous sulfate) → mixing and stirring → aeration reaction → alkali adjustment, and finally, water discharge after mixing on both sides. The aforementioned subsystems are arranged on "both sides" of the reaction tank, referring to the two sides perpendicular to the direction of water flow, i.e., the direction of the process flow.

[0060] The control subsystem includes:

[0061] The PLC51 and PID loop 52 are interconnected; the PLC51 is respectively connected to the first pH monitor 12, the second pH monitor 22 and the COD detector 32; the PID loop 52 is respectively connected to the sulfuric acid dosing pump 11, the alkali dosing pump 21, the hydrogen peroxide dosing pump 31 and the ferrous sulfate dosing pump 41; the PLC51 is used to generate a sulfuric acid dosing control signal, an alkali dosing control signal, a hydrogen peroxide dosing control signal and a ferrous sulfate dosing control signal according to the received acidic pH value signal, the alkaline pH value signal and the COD concentration signal, so that the PID loop 52 can control the sulfuric acid dosing pump 11, the alkali dosing pump 21, the hydrogen peroxide dosing pump 31 and the ferrous sulfate dosing pump 41. For example, according to the above-mentioned process parameters, a preset threshold value for judging whether to start dosing and a preset threshold value for judging whether to close dosing can be preset in the PLC51, and then the PLC51 generates and outputs a corresponding control signal according to the judgment result. Figure 1 As shown, the above elements can be provided in two sets, corresponding to the aforementioned subsystems, that is, located on both sides of the reaction tank.

[0062] In some preferred embodiments, the system further includes a first frequency converter, a second frequency converter, a third frequency converter and a fourth frequency converter; the first frequency converter is respectively connected to the PID loop 52 and the sulfuric acid dosing pump 11; the second frequency converter is respectively connected to the PID loop 52 and the alkali solution dosing pump 21; the third frequency converter is respectively connected to the PID loop 52 and the hydrogen peroxide dosing pump 31; and the fourth frequency converter is respectively connected to the PID loop 52 and the ferrous sulfate dosing pump 41.

[0063] It consists of a metering pump, electrical control cabinet, safety valve, back pressure valve, flow calibration column, pulse damper, Y-type filter, online pH meter, ball valve, drain valve, pressure gauge, pipelines and accessories, cables installed inside the equipment, equipment base and support platform, automatic monitoring system, power control system, programmable logic controller (PLC), intelligent PID controller, etc., which are assembled on a common platform according to the process flow to form a module, the so-called skid-mounted combined unit (referred to as "skid").

[0064] Centralized monitoring is employed to centralize all equipment status, key process parameters, perimeter alarms, and other information throughout the water plant in a permanently manned control room. Simultaneously, all equipment is remotely controlled and interlocked based on alarms and process requirements. Key monitoring functions include: collection of key process parameters during the production process; measurement and accumulation of energy and material consumption, as well as inlet and outlet water flow; monitoring of equipment operating conditions and process flow during the production process; control switching between the automation system and the electrical system; data regression and trend analysis; data storage and historical backtracking of production parameters; automatic generation and printing of production reports; and accident alarms and printing.

[0065] The equipment is controlled in the following ways: 1) On-site manual mode: When the "local / remote" switch on the equipment's on-site control box or MCC control cabinet is in "local" mode, the equipment can be started / stopped and turned on / off using the buttons on the on-site control box or MCC control cabinet. 2) Remote control mode: This is remote manual control mode. When the "local / remote" switch on the on-site control box or MCC control cabinet is in "remote" mode, the operator selects "remote" mode via the soft button on the on-site PLC51 substation touch screen or the central monitoring station screen, and starts / stops and turns on / off the individual equipment through the PLC51 internal program control. 3) Automatic mode: When the "local / remote" switch on the on-site control box or MCC control cabinet is in "remote" mode, and the operator selects "automatic" mode via the soft button on the on-site PLC51 substation touch screen, the equipment's operation or on / off control is completely completed by each on-site control station according to the sewage treatment plant's operating conditions and production requirements, reducing manual intervention.

[0066] After the water enters the Fenton tank, it is split into two sides and operated in parallel. The process flow on each side is acid adjustment → addition of Fenton reagent (hydrogen peroxide and ferrous sulfate) → mixing and stirring → aeration reaction → alkali adjustment. Finally, the water on both sides is mixed and discharged. A COD detector 32 is installed at the water inlet; both acid adjustment areas have sulfuric acid dosing pipes, and are equipped with water inlet flow meters and pH meters; the mixing and stirring areas are equipped with pH meters and Fenton reagent (hydrogen peroxide and ferrous sulfate) dosing pipes; and the alkali adjustment area is equipped with pH meters and liquid alkali dosing pipes. The signals from all detection instruments are transmitted to the PLC51 controller, and the dosing pump is controlled by the frequency converter controlled by the PID loop 52. The amount of dosing can be freely adjusted to meet the needs of different dosing locations through the metering pump to the dosing point.

[0067] The utility model provides a test example for exemplarily displaying the control process of the control system.

[0068] Industrial wastewater was collected for Fenton testing. Acid adjustment: sulfuric acid was added to adjust the pH to 3.5 ± 0.1. Fenton reaction: hydrogen peroxide and ferrous sulfate were added in ratios of H₂O₂:COD = 1:1 and H₂O₂:FeSO₄ of 10:1, 6:1, 3:1, 2:1, 1:1, and 1:2, respectively, and aeration was performed for 1 hour. Alkali adjustment: liquid caustic soda was added to adjust the pH to between 7 and 7.5. COD values were measured before and after the reaction, and the COD reduction was calculated. The results are shown in Table 1.

[0069] Table 1

[0070]

[0071] As shown in Table 1, under the condition of H2O2:COD = 1:1, as the H2O2:FeSO4 ratio decreases, the COD reduction gradually increases, from 13.4 mg / L to 121.1 mg / L, showing a significant removal effect. In practice, the ratio can be set to H2O2:FeSO4 = 1:2.

[0072] Comparative Example 2

[0073] Different from Example 1, the H2O2:COD ratio in this comparative example is 1.5:1.

[0074] Comparative Example 2

[0075] Different from Example 1, the H2O2:COD ratio in this comparative example is 2:1.

[0076] Test Example 2

[0077] Following the method in Experimental Example 1, industrial wastewater was collected and subjected to a Fenton test. Following the methods in Comparative Examples 1 and 2, the H₂O₂:COD ratio and the dosage of hydrogen peroxide and ferrous sulfate were adjusted. COD values before and after the reaction were measured, and the COD reduction was calculated. The results are shown in Tables 2 and 3.

[0078] Table 2

[0079]

[0080]

[0081] Table 3

[0082]

[0083] It can be seen from Tables 2 and 3 that after increasing the ratio of H2O2 to COD, the COD reduction amount is improved, but the treatment effect is not obvious. The ratio of H2O2 to COD increases from 1:1 to 2:1, but the COD reduction amount only increases from 121.1 to 133.7 mg / L. The treatment effect is not proportional to the cost. Therefore, the most appropriate H2O2 to COD ratio is determined to be 1:1.

[0084] In some preferred embodiments, the four subsystems of the control system are specifically configured as follows:

[0085] like Figure 4As shown, the acid adjustment intelligent dosing subsystem includes a sulfuric acid tank 13, which is connected to a sulfuric acid dosing pipeline 14. The dosing pipeline includes a first ball valve 141, a first Y-type filter 142, a sulfuric acid dosing pump 11, a first pulse damper 143, a first blowdown valve 144, a first back pressure valve 145, and a sulfuric acid dosing port 146, which are sequentially arranged in series along the liquid flow direction; the sulfuric acid dosing port 146 is connected to the Fenton reaction tank 6; a first branch 15 is also connected between the first pulse damper 143 and the sulfuric acid dosing pump 11, and the other end of the first branch 15 is connected to the sulfuric acid tank 13. The first branch 15 is also provided with a first safety valve 151; a first stirrer 16 is provided on the sulfuric acid tank 13 for stirring the liquid; and a first flow calibration column 17 is also provided in the sulfuric acid tank 13.

[0086] In one feasible embodiment, metering pumps, (electrical) control cabinets, safety valves, back pressure valves, flow calibration columns, pulse dampers, Y-type filters, online pH meters, ball valves, drain valves, pressure gauges, pipelines and accessories, cables installed in the equipment, equipment bases and support platforms, automatic monitoring systems, power control systems, programmable logic controllers (PLCs), intelligent PID controllers (PID loops), etc. are assembled on a common platform according to the process flow to form a module, namely the so-called skid-mounted modular unit (referred to as "skid body"). All of the above-mentioned valves, sensors, etc. can be connected to the PLC and controlled by the PLC. Figure 4 As shown, control components such as the PLC, PID loop, and first frequency converter can be installed in a control cabinet 7. The control cabinet can also integrate frequency converters for controlling other subsystems. The control cabinet can be equipped with a visual display and an operating console according to existing technologies, and can also be equipped with communication devices for remote control.

[0087] The alkali adjustment intelligent dosing subsystem includes an alkali solution tank, which is connected to an alkali solution dosing pipeline. The dosing pipeline includes a second ball valve, a second Y-type filter, an alkali solution dosing pump 21, a second pulse damper, a second drain valve, a second back pressure valve, and an alkali solution dosing end, which are arranged in series along the liquid flow direction; the alkali solution dosing end is connected to the Fenton reaction tank 6; a second branch is also connected between the second pulse damper and the alkali solution dosing pump 21, the other end of which is connected to the alkali solution tank, and the second branch also has a second safety valve;

[0088] The hydrogen peroxide intelligent dosing subsystem includes a hydrogen peroxide tank, which is connected to a hydrogen peroxide dosing pipeline. The dosing pipeline includes a third ball valve, a third Y-type filter, a hydrogen peroxide dosing pump 31, a third pulse damper, a third drain valve, a third back pressure valve, and a hydrogen peroxide dosing terminal, which are arranged in series along the liquid flow direction. The hydrogen peroxide dosing terminal is connected to the Fenton reaction tank 6. A third branch is also connected between the third pulse damper and the hydrogen peroxide dosing pump 31. The other end of the third branch is connected to the hydrogen peroxide tank. The third branch also has a third safety valve.

[0089] The intelligent ferrous sulfate dosing subsystem includes a ferrous sulfate tank, which is connected to a ferrous sulfate dosing pipeline. The dosing pipeline includes a fourth ball valve, a fourth Y-type filter, a ferrous sulfate dosing pump 41, a fourth pulse damper, a fourth drain valve, a fourth back pressure valve and a ferrous sulfate dosing end arranged in series along the liquid flow direction; the ferrous sulfate dosing end is connected to the Fenton reaction tank 6; a fourth branch is also connected between the fourth pulse damper and the ferrous sulfate dosing pump 41, the other end of the fourth branch is connected to the ferrous sulfate tank, and the fourth branch is also provided with a fourth safety valve.

[0090] The structures of the remaining three subsystems are the same as that of the acid adjustment intelligent dosing subsystem, and therefore are not shown in the figure.

[0091] The four dosing pumps of the above four subsystems are preferably metering pumps.

[0092] In the embodiments provided by the present invention, PLC51, PID loop 52, frequency converter and the above-mentioned various valves, filters, mixers and flow calibration columns and other instruments can all be commercially available products, and the specific settings and installation methods are not repeated here.

[0093] In a second aspect, the present invention provides a Fenton reaction tank for a Fenton oxidation treatment process, such as Figure 5 As shown, it includes a reaction tank, which includes an inlet side, an acid adjustment zone, a Fenton reagent input zone, an aeration reaction zone (i.e., the Fenton reaction zone in the figure), an alkali adjustment zone, and an outlet side, which are arranged in sequence along the water flow direction. The inlet side is used to connect the sewage input device, and the outlet side is used to output treated water. The reaction tank is respectively provided with a sulfuric acid dosing pipeline, an alkali dosing pipeline, a hydrogen peroxide dosing pipeline, and a hydrogen peroxide dosing pipeline on both sides. The sulfuric acid dosing pipeline is connected to the acid adjustment zone, the alkali dosing pipeline is connected to the alkali adjustment zone, and the hydrogen peroxide dosing pipeline and the hydrogen peroxide dosing pipeline are connected to the Fenton reagent input zone. Mixing agitators are also respectively provided in the Fenton reagent input zone and the alkali adjustment zone. The aeration reaction zone is an area for aeration and Fenton reaction. The Fenton reaction tank also includes the above-mentioned control system.

[0094] In summary, the utility model provides a control system for a Fenton oxidation treatment process, including an intelligent dosing subsystem for acid adjustment, an intelligent dosing subsystem for alkali adjustment, an intelligent dosing subsystem for hydrogen peroxide, an intelligent dosing subsystem for ferrous sulfate, and a control subsystem. The online pH meter installed at the Fenton water inlet and outlet transmits the data signal to the PLC control cabinet, and the PLC is used to control the dosage of sulfuric acid and liquid alkali to adjust the pH of the inlet and outlet water; a flow meter and an online COD detection instrument are installed at the Fenton water inlet, and the data signal is transmitted to the PLC to determine the COD concentration to be achieved in the outlet water of the Fenton system, and the dosage of hydrogen peroxide and ferrous sulfate is calculated by programming to achieve the effect of stable COD removal. The utility model can avoid frequent adjustments to the dosage of reagents due to changes in the quality and amount of influent water, which lead to problems such as poor treatment effect of the Fenton system and untimely adjustment of reagents, and uses automatic control and programming systems to achieve precise control of the Fenton process. It also has the following advantages:

[0095] The dosing system of the utility model has the advantages of compact structure, small size, low noise, stable operation, simple installation, and convenient operation and use.

[0096] The utility model can completely replace the manual dosing method, realize automatic operation and is easy to maintain.

[0097] The utility model has high economic benefits, reduces labor costs, and greatly reduces medicine costs.

[0098] The utility model can dynamically adjust the dosage according to the fluctuation of the water quality and quantity of the inlet and outlet water, the system has strong impact resistance and the outlet water quality is stable.

[0099] The dosing system of the utility model is highly flexible, intelligent and convenient, and has a complete set of program algorithms, and parameter settings can be changed in time according to actual needs.

[0100] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, refer to the partial description of the method embodiments. The device and system embodiments described above are merely schematic. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without making any creative efforts.

[0101] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A control system for a Fenton oxidation treatment process, characterized in that: It includes the intelligent dosing subsystem for acid adjustment, the intelligent dosing subsystem for alkali adjustment, the intelligent dosing subsystem for hydrogen peroxide, the intelligent dosing subsystem for ferrous sulfate and the control subsystem; The acid adjustment intelligent dosing subsystem includes: Two sulfuric acid dosing pumps are respectively arranged on the sulfuric acid dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit; Two sets of first pH monitors, used to obtain real-time acidic pH value signals of the acid adjustment zone of the Fenton reaction tank, each set of first pH monitors having two pH meters connected in parallel and connected to the control subsystem circuit; The alkali adjustment intelligent dosing subsystem includes: Two alkali solution dosing pumps are respectively arranged on the alkali solution dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit; Two sets of second pH monitors, used to obtain the alkaline pH value signal of the alkaline adjustment zone of the Fenton reaction tank in real time, each set of the second pH monitors having two pH meters connected in parallel and connected to the control subsystem circuit; The hydrogen peroxide intelligent dosing subsystem includes: Two hydrogen peroxide dosing pumps are respectively arranged on the hydrogen peroxide dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit; A COD detector for real-time detection of COD concentration signals on the inlet side of the Fenton reactor; The ferrous sulfate intelligent dosing subsystem includes: Two ferrous sulfate dosing pumps are respectively arranged on the ferrous sulfate dosing pipelines on both sides of the Fenton reaction tank and connected to the control subsystem circuit; The control subsystem includes a PLC and a PID loop that are interconnected; the PLC is respectively connected to the first pH monitor, the second pH monitor and the COD detector; the PID loop is respectively connected to the sulfuric acid dosing pump, the alkali dosing pump, the hydrogen peroxide dosing pump and the ferrous sulfate dosing pump; the PLC is used to generate a sulfuric acid dosing control signal, an alkali dosing control signal, a hydrogen peroxide dosing control signal and a ferrous sulfate dosing control signal according to the received acidic pH value signal, the alkaline pH value signal and the COD concentration signal, so that the PID loop can control the sulfuric acid dosing pump, the alkali dosing pump, the hydrogen peroxide dosing pump and the ferrous sulfate dosing pump.

2. The control system according to claim 1, characterized in that: The control subsystem also includes a first frequency converter, a second frequency converter, a third frequency converter and a fourth frequency converter; the first frequency converter is respectively connected to the PID loop and the sulfuric acid dosing pump; the second frequency converter is respectively connected to the PID loop and the alkali solution dosing pump, the third frequency converter is respectively connected to the PID loop and the hydrogen peroxide dosing pump; the fourth frequency converter is respectively connected to the PID loop and the ferrous sulfate dosing pump.

3. The control system according to claim 1 or 2, characterized in that: The acid adjustment intelligent dosing subsystem also includes a sulfuric acid tank, which is connected to the sulfuric acid dosing pipeline. The sulfuric acid dosing pipeline is provided with a first ball valve, a first Y-type filter, the sulfuric acid dosing pump, a first pulse damper, a first blowdown valve, a first back pressure valve, and a sulfuric acid dosing end, which are arranged in series along the liquid flow direction; the sulfuric acid dosing end is connected to the Fenton reaction tank; a first branch is also connected between the first pulse damper and the sulfuric acid dosing pump, the other end of the first branch is connected to the sulfuric acid tank, and the first branch is also provided with a first safety valve; The alkali adjustment intelligent dosing subsystem also includes an alkali solution tank, which is connected to the alkali solution dosing pipeline. The dosing pipeline includes a second ball valve, a second Y-type filter, the alkali solution dosing pump, a second pulse damper, a second drain valve, a second back pressure valve, and an alkali solution dosing end, which are sequentially arranged in series along the liquid flow direction; the alkali solution dosing end is connected to the Fenton reaction tank; a second branch is also connected between the second pulse damper and the alkali solution dosing pump, the other end of the second branch is connected to the alkali solution tank, and the second branch is also provided with a second safety valve; The hydrogen peroxide intelligent dosing subsystem also includes a hydrogen peroxide tank, which is connected to the hydrogen peroxide dosing pipeline. The dosing pipeline includes a third ball valve, a third Y-type filter, the hydrogen peroxide dosing pump, a third pulse damper, a third blowdown valve, a third back pressure valve, and a hydrogen peroxide dosing end, which are sequentially arranged in series along the liquid flow direction; the hydrogen peroxide dosing end is connected to the Fenton reaction tank; a third branch is connected between the third pulse damper and the hydrogen peroxide dosing pump, the other end of which is connected to the hydrogen peroxide tank, and the third branch is also provided with a third safety valve; The ferrous sulfate intelligent dosing subsystem also includes a ferrous sulfate pool, which is connected to the ferrous sulfate dosing pipeline. The dosing pipeline includes a fourth ball valve, a fourth Y-type filter, the ferrous sulfate dosing pump, a fourth pulse damper, a fourth drain valve, a fourth back pressure valve and a ferrous sulfate dosing end arranged in series along the liquid flow direction; the ferrous sulfate dosing end is connected to the Fenton reaction pool; a fourth branch is also connected between the fourth pulse damper and the ferrous sulfate dosing pump, the other end of the fourth branch is connected to the ferrous sulfate pool, and the fourth branch also has a fourth safety valve.

4. The control system according to claim 3, characterized in that: The sulfuric acid dosing pump, the alkali solution dosing pump, the hydrogen peroxide dosing pump and the ferrous sulfate dosing pump are metering pumps.

5. A Fenton reaction tank for a Fenton oxidation treatment process, characterized in that: The reaction tank includes a water inlet side, an acid adjustment zone, a Fenton reagent input zone, an aeration reaction zone, an alkali adjustment zone, and a water outlet side, which are sequentially arranged along the water flow direction. The water inlet side is used to connect to a sewage input device, and the water outlet side is used to output treated water. The reaction tank is provided with a sulfuric acid dosing pipeline, an alkali dosing pipeline, a hydrogen peroxide dosing pipeline, and a hydrogen peroxide dosing pipeline on both sides, respectively. The sulfuric acid dosing pipeline is connected to the acid adjustment zone, the alkali dosing pipeline is connected to the alkali adjustment zone, and the hydrogen peroxide dosing pipeline and the hydrogen peroxide dosing pipeline are connected to the Fenton reagent input zone. Mixing agitators are respectively provided in the Fenton reagent input area and the alkali adjustment area; the Fenton reaction tank also includes a control system as described in any one of claims 1 to 4.

Images