Manganese-containing sewage treatment system and method

Abstract

The invention provides a manganese-containing sewage treatment system and method, the treatment system comprises an ozone oxidation unit, a water quality monitoring unit, a water quality adjusting unit and a control unit, the water quality monitoring unit and the water quality adjusting unit are both connected with the ozone oxidation unit and the control unit; the ozone oxidation unit is configured to perform ozone oxidation treatment on the manganese-containing sewage; the water quality monitoring unit is configured to monitor the ORP value of the manganese-containing sewage in the ozone oxidation unit in real time; and the control unit is configured to control the water quality adjusting unit to adjust the ORP value of the manganese-containing sewage to be within a first preset target range according to the ORP value of the manganese-containing sewage monitored by the water quality monitoring unit. According to the manganese-containing sewage treatment system and method provided by the invention, COD (Chemical Oxygen Demand) up-to-standard discharge of the manganese-containing sewage is realized, and meanwhile, a water body can be prevented from being reddish brown or blood red, so that the attractiveness of the water body and the balance of an ecological system can be maintained.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a system and method for treating manganese-containing wastewater. Background Art

[0002] In the field of environmental protection, direct discharge of sewage is an important issue. Human activities such as industrial production, agricultural activities and daily life will inevitably produce various types of wastewater. If these sewage is discharged directly into the environment without adequate treatment, it may have a significant adverse impact on the ecosystem. The types of sewage directly discharged into the environment mainly include industrial wastewater (such as wastewater generated by industries such as papermaking, printing and dyeing, and electroplating), agricultural wastewater (such as wastewater generated by livestock and poultry breeding, aquaculture, etc.), domestic sewage (such as urban domestic sewage) and comprehensive wastewater (such as industrial park sewage and urban mixed sewage). In order to protect environmental safety, the water quality indicators of these sewage need to meet the comprehensive sewage discharge standards stipulated by the state or local authorities, such as the "Comprehensive Sewage Discharge Standard" (GB8978-1996). Only when the water quality indicators meet these standards is it allowed to discharge the wastewater directly into surface water bodies, oceans or other environments to ensure that there will be no significant adverse effects on the receiving water bodies and their surrounding environment.

[0003] In the discharged sewage, chemical oxygen demand (COD) is one of the important indicators to measure pollutants. There are many ways to remove COD from sewage. Among them, ozone treatment is widely used due to its strong oxidizing property, fast reaction speed, no secondary pollution and effective removal of various organic pollutants. In recent years, in order to meet the requirements of lower COD effluent, ozone micro-nano bubble technology with higher oxidation efficiency has emerged, which can further improve the COD removal effect and effluent quality.

[0004] However, after using ozone treatment to remove COD from certain wastewater discharged from daily industrial activities, even if the wastewater meets the standards, it may appear reddish brown or blood red when discharged, which may interfere with the balance of the ecosystem and the functional use of the water body, and easily cause public unrest and panic, which will seriously damage the image of enterprises and society. Summary of the invention

[0005] The object of the present invention is to provide a system and method for treating manganese-containing wastewater to solve one or more problems existing in the prior art, such as when ozone oxidation is used to remove COD in certain discharged wastewater, the water body appears reddish brown or blood red, which affects the balance of the ecosystem and the functional use of the water body and is likely to cause public panic.

[0006] To achieve the above-mentioned purpose, the present invention is implemented through the following technical scheme: a treatment system for manganese-containing wastewater, the treatment system comprising an ozone oxidation unit, a water quality monitoring unit, a water quality adjustment unit and a control unit, the water quality monitoring unit and the water quality adjustment unit are both connected to the ozone oxidation unit and the control unit; the ozone oxidation unit is configured to perform ozone oxidation treatment on the manganese-containing wastewater; the water quality monitoring unit is configured to monitor the ORP value of the manganese-containing wastewater in the ozone oxidation unit in real time; the control unit is configured to: according to the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit, control the water quality adjustment unit to adjust the ORP value of the manganese-containing wastewater to within a first preset target range.

[0007] Optionally, the ozone oxidation unit includes an ozone generator, a micro-nano bubble generator and an ozone contact tank which are arranged in sequence, and a sewage supply device connected to the ozone contact tank, and the water quality monitoring unit and the water quality regulating unit are both connected to the ozone contact tank.

[0008] Optionally, the ozone contact tank comprises a plug-flow ozone contact tank, wherein at least two compartments are arranged in the ozone contact tank, and the water outlet of the micro-nano bubble generator is arranged in all the compartments except the compartment closest to the water outlet of the ozone contact tank.

[0009] Optionally, the water inlet of the micro-nano bubble generator is connected to the compartment closest to the water inlet of the ozone contact tank.

[0010] Optionally, a breathing valve and an oxygen tail gas destroyer are provided on the top of the ozone contact tank.

[0011] Optionally, the water quality adjustment unit includes a hydrogen peroxide dosing device, and the control unit is configured to: when the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit is higher than the preset upper limit value of the first preset target range, control the hydrogen peroxide dosing device to turn on to add hydrogen peroxide to the ozone oxidation unit; when the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit is lower than the preset lower limit value of the first preset target range, control the hydrogen peroxide dosing device to turn off to stop adding hydrogen peroxide to the ozone oxidation unit.

[0012] Optionally, the first preset target range includes 340mV-400mV.

[0013] Optionally, the treatment system also includes a water outlet unit connected to the water outlet of the ozone oxidation unit, and the water quality monitoring unit and the water quality regulating unit are both connected to the water outlet unit; the water outlet unit is configured to receive the outlet water of the ozone oxidation unit; the water quality monitoring unit is further configured to monitor the ORP value of the outlet water in the water outlet unit in real time; the control unit is further configured to: according to the ORP value of the outlet water monitored by the water quality monitoring unit, control the water quality regulating unit to adjust the ORP value of the outlet water to within a second preset target range.

[0014] Optionally, the water outlet unit includes a lifting pump, a buffer tank and a drainage pump which are arranged in sequence, the water inlet of the lifting pump is connected to the water outlet of the ozone oxidation unit through a lifting water inlet pipe, and the water quality monitoring unit and the water quality adjustment unit are both connected to the buffer tank.

[0015] To achieve the above object, the present invention further provides a method for treating manganese-containing wastewater, wherein the manganese-containing wastewater is treated by using any of the above-mentioned manganese-containing wastewater treatment systems, and the treatment method comprises:

[0016] Performing ozone oxidation treatment on the manganese-containing wastewater;

[0017] Real-time monitoring of the ORP value of the manganese-containing wastewater in the ozone oxidation unit;

[0018] According to the monitored ORP value of the manganese-containing wastewater, the water quality regulating unit is controlled to adjust the ORP value of the manganese-containing wastewater to within a first preset target range.

[0019] Compared with the prior art, the system and method for treating manganese-containing wastewater provided by the present invention have the following beneficial effects:

[0020] The treatment system of manganese-containing sewage provided by the present invention comprises an ozone oxidation unit, a water quality monitoring unit, a water quality regulating unit and a control unit, wherein the water quality monitoring unit and the water quality regulating unit are both connected to the ozone oxidation unit and the control unit; the ozone oxidation unit is configured to perform ozone oxidation treatment on the manganese-containing sewage; the water quality monitoring unit is configured to monitor the ORP value of the manganese-containing sewage in the ozone oxidation unit in real time; the control unit is configured to: according to the ORP value of the manganese-containing sewage monitored by the water quality monitoring unit, control the water quality regulating unit to adjust the ORP value of the manganese-containing sewage to within a first preset target range. Thus, the treatment system of manganese-containing sewage provided by the present invention can effectively remove COD in manganese-containing sewage by performing ozone oxidation treatment on the manganese-containing sewage through the ozone oxidation unit. Furthermore, by monitoring the ORP value of the manganese-containing sewage in the ozone oxidation unit in real time through the water quality monitoring unit, and by controlling the water quality adjustment unit through the control unit to adjust the ORP value of the manganese-containing sewage to within the first preset target range, it is possible to prevent the manganese ions in the manganese-containing sewage from being excessively oxidized to a high-valent state, causing the water body to appear reddish brown or blood red. The manganese-containing sewage treatment system provided by the present invention is used to treat manganese-containing sewage, and while achieving the COD discharge standard of the manganese-containing sewage, it is possible to prevent the water body from appearing reddish brown or blood red, thereby maintaining the aesthetics of the water body and the balance of the ecosystem.

[0021] Furthermore, the ozone oxidation unit includes an ozone generator, a micro-nano bubble generator and an ozone contact tank, which are arranged in sequence, and a sewage supply device connected to the ozone contact tank, and the water quality monitoring unit and the water quality adjustment unit are both connected to the ozone contact tank. Thus, the treatment system for manganese-containing sewage provided by the present invention can provide ozone to the micro-nano bubble generator through the ozone generator; and the manganese-containing sewage can be transported to the ozone contact tank through the sewage supply device. Furthermore, the ozone can be transported to the ozone contact tank in the form of micro-nano bubbles through the micro-nano bubble generator to produce an ozone oxidation reaction with the manganese-containing sewage, thereby improving the oxidation efficiency, and further improving the COD removal effect.

[0022] Since the method for treating manganese-containing wastewater provided by the present invention and the system for treating manganese-containing wastewater provided by the present invention belong to the same inventive concept, the method for treating manganese-containing wastewater provided by the present invention at least has all the advantages of the system for treating manganese-containing wastewater provided by the present invention. For the advantages of the method for treating manganese-containing wastewater provided by the present invention, please refer to the relevant description of the beneficial effects of the system for treating manganese-containing wastewater provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a comparison diagram of ultraviolet-visible spectra of a stream of external wastewater before and after ozone treatment and when the ORP value is controlled to be less than 480mV after ozone treatment in the prior art;

[0024] Figure 2 The UV-visible spectra of the experimental water corresponding to the external sewage before and after ozone treatment and when the ORP value is controlled to less than 480mV after ozone treatment are compared;

[0025] Figure 3 A structural block diagram of a system for treating manganese-containing wastewater provided in Example 1 of the present invention;

[0026] Figure 4 A process flow chart of a system for treating manganese-containing wastewater provided in Example 1 of the present invention;

[0027] Figure 5 A schematic flow chart of a method for treating manganese-containing wastewater provided in Example 2 of the present invention; the accompanying drawings are described as follows:

[0028] 1-ozone oxidation unit, 11-ozone generator, 12-micro-nano bubble generator, 13-ozone contact tank, 14-wastewater supply device, 2-water quality monitoring unit, 21-ORP detector, 3-water quality adjustment unit, 31-hydrogen peroxide dosing device, 4-control unit, 5-water outlet unit, 51-lifting pump, 52-buffer tank, 53-drainage pump. DETAILED DESCRIPTION

[0029] The following is a further detailed description of the treatment system and method for manganese-containing wastewater proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, which are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, in the case of the same or similar effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used to represent the same part or part with the same function between different drawings, and its repeated description is omitted.

[0030] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] It should be understood that, unless otherwise stated or obvious from the context, as used herein, the term "about" is understood to be within the normal tolerance range in the art, such as within 2 standard deviations of the mean. "About" can be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the value. Unless otherwise clear from the context, all numerical values ​​provided herein are modified by the term "about".

[0032] In order to make it easier to understand and explain the present invention, before describing the specific implementation methods of the system and method for treating manganese-containing wastewater provided by the present invention, the research process for proposing the present invention is briefly described as follows.

[0033] The core idea of ​​the present invention is to solve the technical problem that the water body appears reddish brown or blood red when the COD in some wastewater is removed by ozone oxidation in the prior art. In order to solve this problem, the inventor of the present invention has conducted a lot of research and continuous in-depth practice. Figure 1 and Figure 2 , Figure 1 A schematic comparison diagram of the UV-visible spectra of a stream of wastewater in the prior art before and after ozone treatment and when the ORP value is controlled to be less than 480 mV after ozone treatment is given; Figure 2 This is a comparison chart of the UV-visible spectra of the experimental water corresponding to the discharged sewage before and after ozone treatment and when the ORP value is controlled to less than 480mV after ozone treatment.

[0034] The inventors found that in a daily industrial activity, a certain stream of discharged sewage with a COD of 32 mg / L was reduced to 18 mg / L after ozone treatment. Although the discharged sewage can meet the discharge standards, the water body will appear reddish brown, and sometimes even blood red. If it is discharged to urban wetlands, it will affect the balance of the ecosystem and the functional use of the water body, and it will easily cause public anxiety and panic, which will seriously damage the image of the company and society. In order to find out the source of the coloring substance in the discharged sewage, first, the inventors of the present invention compared the ultraviolet-visible spectra of the discharged sewage before and after ozone treatment, and found that the discharged sewage after ozone treatment had an absorption peak at 270nm~575nm; then, the inventors detected Mn in the discharged sewage. 2+ The concentration is about 0.5 mg / L. Then, the inventor used laboratory pure water to prepare Mn 2+ The experimental water with a concentration of about 0.5 mg / L was treated with the same ozone treatment method and was found to be red in color. An absorption peak also appeared at the same position after ozone treatment.

[0035] After a lot of repeated research, it was found that Mn 2+ After ozone oxidation, MnO2, MnO(OH)2 and MnO 4- , especially MnO 4- Dissolved in water, the discharged sewage will appear reddish brown. Further, based on the reaction principle of hydrogen peroxide with ozone and high-valent manganese ions, the inventors found that by controlling the ORP value of the discharged sewage or the experimental water to less than 480mV after ozone treatment, the problem of the discharged sewage or the experimental water body turning brown-red can be effectively solved, and the fine particles of MnO(OH)2 and MnO2 and the colored MnO 4- The absorption peak in the wavelength range of 270nm to 575nm disappears in the spectrum.

[0036] Based on the above research, the present invention provides a system and method for treating manganese-containing wastewater, which monitors the ORP value of the manganese-containing wastewater in the ozone oxidation unit in real time through a water quality monitoring unit, and controls the water quality adjustment unit through a control unit to adjust the ORP value of the manganese-containing wastewater to within a first preset target range, thereby solving one or more of the problems that manganese ions in the manganese-containing wastewater are excessively oxidized into a high-valent state, causing the water body to appear reddish brown or blood red, and even affecting the balance of the ecosystem and the functional use of the water body, and easily causing public panic.

[0037] Next, the specific implementation of the system and method for treating manganese-containing wastewater provided by the present invention is described in detail as follows.

[0038] Embodiment 1

[0039] This embodiment provides a treatment system for manganese-containing wastewater. Figure 3 and Figure 4 , Figure 3 A structural block diagram of a system for treating manganese-containing wastewater provided in this embodiment; Figure 4 The process flow chart of the treatment system of manganese-containing wastewater provided in this embodiment. Figure 3 and Figure 4 It can be seen that the treatment system includes an ozone oxidation unit 1, a water quality monitoring unit 2, a water quality regulating unit 3 and a control unit 4, and the water quality monitoring unit 2 and the water quality regulating unit 3 are both connected to the ozone oxidation unit 1 and the control unit 4; the ozone oxidation unit 1 is configured to perform ozone oxidation treatment on the manganese-containing wastewater; the water quality monitoring unit 2 is configured to monitor the ORP value of the manganese-containing wastewater in the ozone oxidation unit 1 in real time; the control unit 4 is configured to: according to the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit 2, control the water quality regulating unit 3 to adjust the ORP value of the manganese-containing wastewater to within the first preset target range. Therefore, the treatment system for manganese-containing wastewater provided in this embodiment can effectively remove COD in manganese-containing wastewater by performing ozone oxidation treatment on manganese-containing wastewater through the ozone oxidation unit 1. Furthermore, by real-time monitoring the ORP value of the manganese-containing wastewater in the ozone oxidation unit 1 through the water quality monitoring unit 2, and controlling the water quality adjustment unit 3 through the control unit 4 to adjust the ORP value of the manganese-containing wastewater to within the first preset target range, it is possible to prevent the manganese ions in the manganese-containing wastewater from being excessively oxidized to a high-valent state, causing the water body to appear reddish brown or blood red. The manganese-containing wastewater treatment system provided in this embodiment is used to treat manganese-containing wastewater, and while achieving the COD discharge standard of manganese-containing wastewater, it is possible to prevent the water body from appearing reddish brown or blood red, thereby maintaining the aesthetics of the water body and the balance of the ecosystem.

[0040] Preferably, the ozone oxidation unit 1 comprises an ozone generator 11, a micro-nano bubble generator 12, an ozone contact tank 13, and a sewage supply device 14 connected to the ozone contact tank 13, which are arranged in sequence, and the water quality monitoring unit 2 and the water quality adjustment unit 3 are both connected to the ozone contact tank 13. Thus, the ozone generator 11 can provide ozone for the micro-nano bubble generator 12; and the manganese-containing sewage can be transported to the ozone contact tank 13 through the sewage supply device 14. Furthermore, the ozone can be transported to the ozone contact tank 13 in the form of micro-nano bubbles through the micro-nano bubble generator 12 to produce an ozone oxidation reaction with the manganese-containing sewage, thereby improving the oxidation efficiency and further improving the COD removal effect.

[0041] It should be noted that the ozone generator 11 uses oxygen as a gas source, and the ozone generated by the ozone generator 11 enters the micro-nano bubble generator 12. For example, the conversion efficiency of the ozone generator 11 is about 5%wt-13%wt, the working environment temperature is not higher than 45°C, and the relative humidity is not higher than 85%. The water circulation volume of the micro-nano bubble generator 12 is not less than 25m 3 / h, stable air intake volume not less than 4m 3 / h. In one preferred embodiment, the micro-nano bubble generator 12 adopts a pump-back air intake form, a gas-liquid ratio of 1:15 to 1:6, a water inlet pressure of 0.25Mpa-0.45Mpa, and a water outlet pressure of 0.12Mpa-0.2Mpa. Thus, it can ensure that the gas and liquid are fully mixed under a high pressure environment to form micro-nano bubbles; and the size, quantity and distribution of the bubbles in the liquid can be adjusted to meet the corresponding application requirements.

[0042] For example, in one exemplary embodiment, the water quality characteristics of the manganese-containing wastewater are: pH 6-9, COD 20 mg / L-150 mg / L, Mn 2+ The concentration is 0.1 mg / L-10 mg / L. The sewage supply device 14 includes a water inlet pump (not shown in the figure), through which the manganese-containing sewage is transported to the ozone contact tank 13.

[0043] It should be noted that the present invention does not impose too many restrictions on the number of the micro-nano bubble generators 12. For example, in some embodiments, the micro-nano bubble generator 12 can be provided with one; in other embodiments, the micro-nano bubble generator 12 can also be provided with multiple units, and the multiple micro-nano bubble generators 12 are connected in parallel.

[0044] It should be noted that the cumulative ozone concentration added by the micro-nano bubble generator 12 to the ozone contact tank 13 is calculated according to the following formula (1).

[0045] Cumulative ozone concentration = ozone output of the ozone generator 11 ÷ flow rate of the water inlet pump (1)

[0046] Preferably, the ozone contact tank 13 comprises a plug-flow ozone contact tank, at least two compartments are arranged in the ozone contact tank 13, and the water outlet of the micro-nano bubble generator 12 is arranged in all the compartments except the compartment closest to the water outlet of the ozone contact tank 13. Thus, it is possible to ensure that ozone is evenly distributed in the ozone contact tank 13, thereby improving the treatment efficiency of manganese-containing wastewater. In addition, the water outlet of the micro-nano bubble generator 12 is not arranged in the compartment closest to the water outlet of the ozone contact tank 13, which can prevent incompletely reacted ozone and micro-nano bubbles from being directly discharged with the effluent, thereby laying a good foundation for ensuring that the ORP value of the effluent of the ozone contact tank 13 can be controlled within the first preset target range.

[0047] Exemplarily, three compartments are arranged in the ozone contact tank 13, the water outlet of the micro-nano bubble generator 12 is arranged in two compartments except the compartment closest to the water outlet of the ozone contact tank 13, and the water quality monitoring unit 2 and the water quality adjustment unit 3 are both connected in the second compartment.

[0048] It should be noted that, as can be understood by those skilled in the art, the present invention does not impose too many restrictions on the number of compartments in the ozone contact tank 13, the location of the water outlet of the micro-nano bubble generator 12, and the connection location of the water quality monitoring unit 2 and the water quality adjustment unit 3. For example, in some other embodiments, 5 compartments are arranged in the ozone contact tank 13, the water outlet of the micro-nano bubble generator 12 is arranged in 3 compartments other than the 2 compartments close to the water outlet of the ozone contact tank 13, and the water quality monitoring unit 2 and the water quality adjustment unit 3 are both connected to the 3rd compartment. In addition, the present invention does not impose too many restrictions on the type of the ozone contact tank 13. For example, in some other embodiments, the ozone contact tank 13 can also be a bubble type ozone contact tank, a water film type ozone contact tank, etc.

[0049] Exemplarily, each water outlet of the micro-nano bubble generator 12 is connected to a water distributor (not shown in the figure), and the water produced by the micro-nano bubble generator 12 is evenly distributed to all the compartments except the compartment closest to the water outlet of the ozone contact tank 13 through the water distributor, and the nozzle outlet pressure of the water distributor is not less than 0.1Mpa. For another example, the water produced by the micro-nano bubble generator 12 is tested by using the nanoparticle tracking analysis technology (NTA). The test results show that the bubble particle size distribution range is 70nm-380nm, the median particle size is between 90nm-220nm, and the nanobubble concentration is not less than 4.5×10 7 num / mL.

[0050] Furthermore, the water inlet of the micro-nano bubble generator 12 is connected to the compartment closest to the water inlet of the ozone contact tank 13. Thus, the manganese-containing wastewater in the ozone contact tank 13 can quickly enter the micro-nano bubble generator 12, so that the water quality entering the micro-nano bubble generator 12 can be relatively fresh and has not been treated for a long time, thereby improving the working efficiency and treatment effect of the micro-nano bubble generator 12.

[0051] It should be noted that the present invention does not impose too many restrictions on the connection position between the water inlet of the micro-nano bubble generator 12 and the ozone contact tank 13. For example, in some other embodiments, four compartments are provided in the ozone contact tank 13, and the water inlet of the micro-nano bubble generator 12 can be connected to the second compartment.

[0052] Preferably, a breathing valve (not shown in the figure) and an oxygen tail gas destroyer (not shown in the figure) are provided on the top of the ozone contact tank 13. Thus, the breathing valve can maintain the pressure balance in the tank, thereby improving the safety of sewage treatment; the oxygen tail gas destroyer can treat the tail gas generated during the reaction, thereby better protecting the environment.

[0053] Further, the water quality adjustment unit 3 includes a hydrogen peroxide dosing device 31, and the control unit 4 is configured to: when the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit 2 is higher than the preset upper limit value of the first preset target range, control the hydrogen peroxide dosing device 31 to open to add hydrogen peroxide to the ozone oxidation unit 1; when the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit 2 is lower than the preset lower limit value of the first preset target range, control the hydrogen peroxide dosing device 31 to close to stop adding hydrogen peroxide to the ozone oxidation unit 1. Thus, the control unit 4 controls the opening and closing of the hydrogen peroxide dosing device 31 according to the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit 2, and can control the ORP value of the manganese-containing wastewater in the ozone contact tank 13 within the first preset target range, thereby preventing the manganese ions in the manganese-containing wastewater from being excessively oxidized to a high-valent state, causing the water body to appear reddish brown or blood red.

[0054] Exemplarily, the hydrogen peroxide dosing device 31 includes a hydrogen peroxide storage tank (not shown in the figure) for storing hydrogen peroxide and a hydrogen peroxide dosing pump (not shown in the figure) for conveying hydrogen peroxide, the water quality monitoring unit 2 includes an ORP detector 21, and the control unit 4 is connected to both the hydrogen peroxide dosing pump and the ORP detector 21. The control unit 4 includes computer instructions stored on a non-transient storage medium, which is used to monitor the ORP value of the manganese-containing wastewater in the ozone contact tank 13 in real time, and automatically adjust the dosage of the hydrogen peroxide dosing pump according to the real-time monitored ORP value.

[0055] Preferably, the first preset target range includes 340mV-400mV. Thus, the ORP value of the manganese-containing wastewater after ozone oxidation treatment is lower than 480mV, which can ensure that the manganese-containing wastewater discharged after treatment will not appear reddish brown or blood red.

[0056] Furthermore, the treatment system further includes a water outlet unit 5 connected to the water outlet of the ozone oxidation unit 1, the water quality monitoring unit 2 and the water quality regulating unit 3 are both connected to the water outlet unit 5; the water outlet unit 5 is configured to receive the water outlet of the ozone oxidation unit 1; the water quality monitoring unit 2 is also configured to monitor the ORP value of the water outlet in the water outlet unit 5 in real time; the control unit 4 is also configured to: according to the ORP value of the water outlet monitored by the water quality monitoring unit 2, control the water quality regulating unit 3 to adjust the ORP value of the water outlet to within the second preset target range. Thus, by setting the water outlet unit 5 at the water outlet of the ozone oxidation unit 1, and connecting the water quality monitoring unit 2 and the water quality regulating unit 3 to the water outlet unit 5, the control unit 4 can control the water quality regulating unit 3 to adjust the ORP value of the water outlet to within the second preset target range according to the ORP value of the water outlet monitored by the water quality monitoring unit 2, thereby further ensuring that the manganese-containing wastewater discharged will not appear reddish brown or blood red.

[0057] Preferably, the second preset target range includes 340mV-450mV.

[0058] For example, in one exemplary embodiment, the water outlet unit 5 includes a lift pump 51, a buffer tank 52 and a drainage pump 53, which are sequentially arranged. The water inlet of the lift pump 51 is connected to the water outlet of the ozone oxidation unit 1 through a lift water inlet pipe (not shown in the figure), and the water quality monitoring unit 2 and the water quality adjustment unit 3 are both connected to the buffer tank 52. Thus, the effluent of the ozone contact tank 13 is transported to the buffer tank 52 through the lift pump 51, and after the effluent stays in the buffer tank 52 for a period of time, the residual ozone in the effluent can be removed, and then the effluent can be discharged through the drainage pump 53.

[0059] Embodiment 2

[0060] This embodiment provides a method for treating manganese-containing wastewater, wherein the manganese-containing wastewater treatment system described in any of the above embodiments is used to treat the manganese-containing wastewater. Figure 5 , Figure 5 The following is a schematic diagram of the process for treating manganese-containing wastewater provided in this embodiment. Figure 5 It can be seen that the processing method includes:

[0061] S100: performing ozone oxidation treatment on the manganese-containing wastewater;

[0062] S200: real-time monitoring of the ORP value of the manganese-containing wastewater in the ozone oxidation unit 1;

[0063] S300: According to the monitored ORP value of the manganese-containing wastewater, controlling the water quality adjustment unit 3 to adjust the ORP value of the manganese-containing wastewater to within a first preset target range.

[0064] Since the method for treating manganese-containing wastewater provided in this embodiment and the system for treating manganese-containing wastewater provided in any of the above-mentioned embodiments belong to the same inventive concept, the method for treating manganese-containing wastewater provided in this embodiment has at least all the advantages of the system for treating manganese-containing wastewater provided in the above-mentioned embodiments. For the advantages of the method for treating manganese-containing wastewater provided in this embodiment, please refer to the relevant description of the beneficial effects of the system for treating manganese-containing wastewater provided in the above-mentioned embodiments, which will not be repeated here.

[0065] Preferably, the processing method further comprises:

[0066] S400: transporting the outlet water of the ozone oxidation unit 1 to the outlet water unit 5;

[0067] S500: real-time monitoring of the ORP value of the outlet water in the outlet water unit 5;

[0068] S600: According to the monitored ORP value of the outlet water, the water quality adjustment unit 3 is controlled to adjust the ORP value of the outlet water to within a second preset target range.

[0069] In this way, it can be further ensured that the water body will not appear reddish brown or blood red when manganese-containing wastewater is discharged.

[0070] In order to facilitate the understanding of the present invention, the present invention is described below with two specific examples of wastewater treatment using the method for treating manganese-containing wastewater provided by the present invention.

[0071] Example 1: In a comprehensive wastewater treatment project of a steel enterprise, the comprehensive wastewater is required to meet the Class III surface water index in Table 1 of the Surface Water Environmental Quality Standard (GB3838-2002) and be discharged into urban wetlands. The water quality characteristics of the comprehensive wastewater are: pH 7.2-7.9, COD 30mg / L-50mg / L, Mn 2+ The concentration is 0.1mg / L-0.4mg / L. Therefore, the comprehensive wastewater is judged to be manganese-containing wastewater. According to the external discharge index requirements, the COD must be no higher than 20mg / L to stably meet the discharge standards. The following is an explanation of the process of treating the comprehensive wastewater using the method for treating manganese-containing wastewater provided by the present invention.

[0072] First, the treated water volume of the manganese-containing wastewater is 4,900 m 3 / d, the manganese-containing wastewater is transported to the ozone contact tank 13 through the water inlet pump. The ozone contact tank 13 is provided with 5 compartments, the pool depth is 4.5 meters, and the residence time of the manganese-containing wastewater in the pool is 2 hours. At the same time, the ozone produced by the ozone generator 11 is transported to the micro-nano bubble generator 12, so that the ozone enters the ozone contact tank 13 in the form of micro-nano bubbles to carry out ozone oxidation reaction with the manganese-containing wastewater. Among them, there are two micro-nano bubble generators 12, and the water circulation volume of each micro-nano bubble generator 12 is 450m 3 / h, stable air intake volume not less than 58m 3 / h, the micro-nano bubble generator 12 adopts the pump-back air intake form, the gas-liquid ratio is 1:7.8, the water inlet pressure is 0.45Mpa, and the water outlet pressure is 0.12Mpa. The ozone dosage of the micro-nano bubble generator 12 to the ozone contact tank 13 is 19kg / h. The nanoparticle tracking analysis technology is used to detect the water outlet generated by the micro-nano bubble generator 12. The test results show that the bubble particle size distribution range is 70nm-380nm, the median particle size is between 90nm-220nm, and the nano bubble concentration is not less than 4.5×10 7 The water distributor of the water outlet of the micro-nano bubble generator 12 is distributed in the first four compartments of the ozone contact tank 13, and the nozzle outlet pressure of the water distributor is 0.1Mpa. The water inlet of the micro-nano bubble generator 12 comes from the ozone contact tank 13.

[0073] Then, the ORP value of the manganese-containing wastewater in the ozone contact tank 13 is monitored in real time by the ORP detector 21 connected to the penultimate compartment of the ozone contact tank 13 , and the hydrogen peroxide dosing device 31 is also connected to the penultimate compartment of the ozone contact tank 13 .

[0074] Next, the control unit 4 controls the hydrogen peroxide dosing device 31 to add 27.5%wt industrial-grade hydrogen peroxide to adjust the ORP value of the manganese-containing wastewater to 340mV-400mV according to the ORP value of the manganese-containing wastewater monitored by the ORP detector 21, with an average cumulative dosing of 1.5t / d of hydrogen peroxide.

[0075] Subsequently, the effluent from the ozone contact tank 13 is transported to the buffer tank 52 by the lifting pump 51 and stays there for 45 minutes. At the same time, the ORP detector 21 is also connected to the buffer tank 52 to monitor the ORP value of the effluent from the buffer tank 52 in real time, and the hydrogen peroxide dosing device 31 is also connected to the buffer tank 52. The control unit 4 controls the hydrogen peroxide dosing device 31 to add hydrogen peroxide to the buffer tank 52 according to the ORP value of the effluent from the buffer tank 52 monitored by the ORP detector 21 to adjust the ORP value of the effluent from the buffer tank 52 to not higher than 450mV, so that the effluent from the buffer tank 52 is clear, transparent and colorless, and the COD of the effluent is 12mg / L-20mg / L.

[0076] Finally, the effluent in the buffer tank 52 is discharged to the urban wetland through the drainage pump 53.

[0077] Example 2: In a comprehensive wastewater treatment project in a chemical park, the comprehensive wastewater is required to meet the surface water Class V index in Table 1 of the "Surface Water Environmental Quality Standard" (GB3838-2002) and be discharged into the urban sewage network. The water quality characteristics of the comprehensive wastewater are: pH 7.0-8.2, COD 60mg / L-90mg / L, Mn 2+ The concentration is 0.25mg / L-0.6mg / L. Therefore, the comprehensive wastewater is judged to be manganese-containing wastewater. According to the external discharge index requirements, the COD must be no higher than 30mg / L to stably meet the discharge standards. The following is an explanation of the process of treating the comprehensive wastewater using the method for treating manganese-containing wastewater provided by the present invention.

[0078] First, the treated water volume of the manganese-containing wastewater is 85m 3 / d, the manganese-containing wastewater is transported to the ozone contact tank 13 through the water inlet pump. The ozone contact tank 13 is provided with 3 compartments, the pool depth is 4 meters, and the residence time of the manganese-containing wastewater in the pool is 2.5 hours. At the same time, the ozone produced by the ozone generator 11 is transported to the micro-nano bubble generator 12, so that the ozone enters the ozone contact tank 13 in the form of micro-nano bubbles to carry out ozone oxidation reaction with the manganese-containing wastewater. Among them, there are two micro-nano bubble generators 12, and the water circulation volume of each micro-nano bubble generator 12 is 250m 3 / h, stable air intake volume not less than 35m 3 / h, the micro-nano bubble generator 12 adopts the pump-back air intake form, the gas-liquid ratio is 1:7.1, the water inlet pressure is 0.42Mpa, and the water outlet pressure is 0.12Mpa. The ozone dosage of the micro-nano bubble generator 12 to the ozone contact tank 13 is 20.5kg / h. The nanoparticle tracking analysis technology is used to detect the water outlet generated by the micro-nano bubble generator 12. The test results show that the bubble particle size distribution range is 70nm-380nm, the median particle size is between 90nm-220nm, and the nano bubble concentration is not less than 4.5×10 7The water distributor of the water outlet of the micro-nano bubble generator 12 is distributed in the first two compartments of the ozone contact tank 13, and the nozzle outlet pressure of the water distributor is 0.1Mpa. The water inlet of the micro-nano bubble generator 12 comes from the ozone contact tank 13.

[0079] Then, the ORP value of the manganese-containing wastewater in the ozone contact tank 13 is monitored in real time by the ORP detector 21 connected to the second compartment of the ozone contact tank 13 , and the hydrogen peroxide dosing device 31 is also connected to the second compartment of the ozone contact tank 13 .

[0080] Next, the control unit 4 controls the hydrogen peroxide dosing device 31 to add 27.5%wt industrial-grade hydrogen peroxide to adjust the ORP value of the manganese-containing wastewater to 340mV-400mV according to the ORP value of the manganese-containing wastewater monitored by the ORP detector 21, with an average cumulative dosing of 0.6t / d-1.1t / d of hydrogen peroxide.

[0081] Subsequently, the effluent from the ozone contact tank 13 is transported to the buffer tank 52 by the lifting pump 51 and stays there for 60 minutes. At the same time, the ORP detector 21 is also connected to the buffer tank 52 to monitor the ORP value of the effluent from the buffer tank 52 in real time, and the hydrogen peroxide dosing device 31 is also connected to the buffer tank 52. The control unit 4 controls the hydrogen peroxide dosing device 31 to add hydrogen peroxide to the buffer tank 52 according to the ORP value of the effluent from the buffer tank 52 monitored by the ORP detector 21 to adjust the ORP value of the effluent from the buffer tank 52 to not higher than 450mV, so that the effluent from the buffer tank 52 is clear, transparent and colorless, and the COD of the effluent is 15mg / L-30mg / L.

[0082] Finally, the effluent in the buffer tank 52 is discharged to the urban sewage network through the drainage pump 53.

[0083] In summary, the treatment system and method for manganese-containing sewage provided by the present invention have the following advantages: the treatment system for manganese-containing sewage provided by the present invention, the treatment system includes an ozone oxidation unit, a water quality monitoring unit, a water quality regulating unit and a control unit, the water quality monitoring unit and the water quality regulating unit are both connected to the ozone oxidation unit and the control unit; the ozone oxidation unit is configured to perform ozone oxidation treatment on the manganese-containing sewage; the water quality monitoring unit is configured to monitor the ORP value of the manganese-containing sewage in the ozone oxidation unit in real time; the control unit is configured to: according to the ORP value of the manganese-containing sewage monitored by the water quality monitoring unit, control the water quality regulating unit to adjust the ORP value of the manganese-containing sewage to within the first preset target range. Therefore, the treatment system for manganese-containing sewage provided by the present invention can effectively remove COD in manganese-containing sewage by performing ozone oxidation treatment on manganese-containing sewage through the ozone oxidation unit. Furthermore, by monitoring the ORP value of the manganese-containing sewage in the ozone oxidation unit in real time through the water quality monitoring unit, and by controlling the water quality adjustment unit through the control unit to adjust the ORP value of the manganese-containing sewage to within the first preset target range, it is possible to prevent the manganese ions in the manganese-containing sewage from being excessively oxidized to a high-valent state, causing the water body to appear reddish brown or blood red. The manganese-containing sewage treatment system provided by the present invention is used to treat manganese-containing sewage, and while achieving the COD discharge standard of the manganese-containing sewage, it is possible to prevent the water body from appearing reddish brown or blood red, thereby maintaining the aesthetics of the water body and the balance of the ecosystem.

[0084] Furthermore, the ozone oxidation unit includes an ozone generator, a micro-nano bubble generator and an ozone contact tank, which are arranged in sequence, and a sewage supply device connected to the ozone contact tank, and the water quality monitoring unit and the water quality adjustment unit are both connected to the ozone contact tank. Thus, the treatment system for manganese-containing sewage provided by the present invention can provide ozone to the micro-nano bubble generator through the ozone generator; and the manganese-containing sewage can be transported to the ozone contact tank through the sewage supply device. Furthermore, the ozone can be transported to the ozone contact tank in the form of micro-nano bubbles through the micro-nano bubble generator to produce an ozone oxidation reaction with the manganese-containing sewage, thereby improving the oxidation efficiency, and further improving the COD removal effect.

[0085] Since the method for treating manganese-containing wastewater provided by the present invention and the system for treating manganese-containing wastewater provided by the present invention belong to the same inventive concept, the method for treating manganese-containing wastewater provided by the present invention at least has all the advantages of the system for treating manganese-containing wastewater provided by the present invention. For the advantages of the method for treating manganese-containing wastewater provided by the present invention, please refer to the relevant description of the beneficial effects of the system for treating manganese-containing wastewater provided by the present invention, which will not be repeated here.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A treatment system for manganese-containing wastewater, characterized in that: The treatment system comprises an ozone oxidation unit, a water quality monitoring unit, a water quality regulating unit and a control unit, wherein the water quality monitoring unit and the water quality regulating unit are both connected to the ozone oxidation unit and the control unit; The ozone oxidation unit is configured to perform ozone oxidation treatment on the manganese-containing wastewater; The water quality monitoring unit is configured to monitor the ORP value of the manganese-containing wastewater in the ozone oxidation unit in real time; The control unit is configured to: control the water quality adjustment unit to adjust the ORP value of the manganese-containing wastewater to within a first preset target range according to the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit.

2. The treatment system for manganese-containing wastewater according to claim 1, characterized in that: The ozone oxidation unit comprises an ozone generator, a micro-nano bubble generator and an ozone contact tank which are arranged in sequence, and a sewage supply device connected to the ozone contact tank. The water quality monitoring unit and the water quality regulating unit are both connected to the ozone contact tank.

3. The treatment system for manganese-containing wastewater according to claim 2, characterized in that: The ozone contact tank comprises a plug-flow ozone contact tank, in which at least two compartments are arranged, and the water outlet of the micro-nano bubble generator is arranged in all the compartments except the compartment closest to the water outlet of the ozone contact tank.

4. The treatment system for manganese-containing wastewater according to claim 3, characterized in that: The water inlet of the micro-nano bubble generator is connected to the compartment closest to the water inlet of the ozone contact tank.

5. The treatment system for manganese-containing wastewater according to claim 2, characterized in that: A breathing valve and an oxygen tail gas destroyer are arranged on the top of the ozone contact tank.

6. The treatment system for manganese-containing wastewater according to claim 1, characterized in that: The water quality adjustment unit includes a hydrogen peroxide dosing device, and the control unit is configured to: when the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit is higher than the preset upper limit value of the first preset target range, control the hydrogen peroxide dosing device to start so as to add hydrogen peroxide to the ozone oxidation unit; When the ORP value of the manganese-containing wastewater monitored by the water quality monitoring unit is lower than the preset lower limit of the first preset target range, the hydrogen peroxide dosing device is controlled to be closed to stop adding hydrogen peroxide to the ozone oxidation unit.

7. The treatment system for manganese-containing wastewater according to claim 1, characterized in that: The first preset target range includes 340mV-400mV.

8. The treatment system for manganese-containing wastewater according to claim 1, characterized in that: The treatment system further comprises a water outlet unit connected to the water outlet of the ozone oxidation unit, and the water quality monitoring unit and the water quality regulating unit are both connected to the water outlet unit; The water outlet unit is configured to receive the water outlet of the ozone oxidation unit; The water quality monitoring unit is further configured to monitor the ORP value of the outlet water in the outlet water unit in real time; The control unit is further configured to: control the water quality regulating unit to regulate the ORP value of the outlet water to within a second preset target range according to the ORP value of the outlet water monitored by the water quality monitoring unit.

9. The system for treating manganese-containing wastewater according to claim 8, characterized in that: The water outlet unit includes a lift pump, a buffer tank and a drainage pump which are arranged in sequence. The water inlet of the lift pump is connected to the water outlet of the ozone oxidation unit through a lift water inlet pipe. The water quality monitoring unit and the water quality regulating unit are both connected to the buffer tank.

10. A method for treating manganese-containing wastewater, characterized in that: The manganese-containing wastewater is treated using the manganese-containing wastewater treatment system according to any one of claims 1 to 9, wherein the treatment method comprises: Performing ozone oxidation treatment on the manganese-containing wastewater; Real-time monitoring of the ORP value of the manganese-containing wastewater in the ozone oxidation unit; According to the monitored ORP value of the manganese-containing wastewater, the water quality regulating unit is controlled to adjust the ORP value of the manganese-containing wastewater to within a first preset target range.

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