Resource utilization method and system for manganese element in iron phosphate wastewater

Abstract

The invention provides a resource utilization method and system for a manganese element in ferric phosphate wastewater, and belongs to the technical field of wastewater treatment.The resource utilization method for the manganese element in the ferric phosphate wastewater comprises the following steps that the pH of the ferric phosphate wastewater is adjusted to 7.5-8.0, and primary wastewater is obtained through reaction, precipitation and separation; performing adsorption filtration on the primary wastewater by using an adsorption filtration medium containing activated manganese sand, and performing regular flushing to obtain manganese-containing wastewater and a washed adsorption filtration medium; adjusting the pH value of the manganese-containing wastewater to 6.5-7.0, and mixing the manganese-containing wastewater with an activating agent and a washed adsorption filtering medium to obtain primary washed sand; sequentially washing and activating the primary washed sand to obtain an adsorption filtering medium containing activated manganese sand; the adsorption filtering medium containing the activated manganese sand is used for carrying out adsorption filtering treatment on primary wastewater. According to the method, the manganese-containing wastewater obtained after adsorption and filtration and the inactivated manganese sand in the adsorption and filtration medium after washing are activated, so that resource utilization of the manganese element in the iron phosphate wastewater is realized.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a method and system for resource utilization of manganese elements in iron phosphate wastewater. Background Art

[0002] As the precursor of positive electrode materials for new energy batteries, iron phosphate will produce a large amount of manganese-containing wastewater as its production scale expands. Manganese sand is introduced into the iron phosphate wastewater manganese removal system as a filter material for groundwater manganese removal, which will produce a large amount of deactivated manganese sand every year. Therefore, the reuse of manganese elements and deactivated manganese sand in wastewater is an inevitable trend for resource utilization.

[0003] At present, the treatment methods for manganese-containing iron phosphate wastewater mainly include chemical precipitation, ion exchange, membrane separation, etc., but these methods generally have problems such as high treatment costs and difficulty in resource recovery. As for the treatment of deactivated manganese sand, it is usually landfilled or piled up as solid waste, which not only occupies land resources, but also may cause secondary pollution.

[0004] Therefore, how to realize the resource utilization of manganese in manganese-containing wastewater is an important issue that needs to be solved urgently. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a method and system for resource utilization of manganese elements in iron phosphate wastewater, aiming to solve the technical problem that traditional iron phosphate manganese-containing wastewater treatment methods cannot effectively recover manganese elements, resulting in waste of resources.

[0006] In a first aspect, the present invention provides a method for resource utilization of manganese in iron phosphate wastewater, comprising the following steps: Adjust the pH of the iron phosphate wastewater to 7.5-8.0, and obtain primary wastewater after solid-liquid separation; Using an adsorption filter medium containing activated manganese sand to perform adsorption filtration on the primary wastewater to obtain an adsorbed liquid and an adsorption filter medium containing deactivated manganese sand, and washing the adsorption filter medium containing the deactivated manganese sand to obtain manganese-containing wastewater and the washed adsorption filter medium; The pH of the manganese-containing wastewater is adjusted to 6.5-7.0 to obtain secondary wastewater; The secondary wastewater, activator and post-wash adsorption filter medium are mixed, and after solid-liquid separation, primary sand washing and tertiary wastewater are obtained; Washing the primary washed sand to obtain secondary washed sand and primary washed water; The secondary washed sand is activated by using an activator, and after solid-liquid separation, an adsorption filter medium containing activated manganese sand and secondary washed water are obtained; The adsorption filtration medium containing activated manganese sand is used for adsorption filtration treatment of primary wastewater.

[0007] In the technical scheme of the embodiment of the present application, the iron phosphate wastewater is first pretreated, and its pH is adjusted to weak alkalinity, so that the impurity metal ions such as iron, aluminum, zinc, etc. in the wastewater undergo precipitation reaction and are initially removed; then, the primary wastewater after pretreatment is adsorbed and filtered using an adsorption filter medium containing activated manganese sand, and the manganese ions in the primary wastewater are adsorbed by the activated manganese sand in the adsorption filter medium, and then the pH of the manganese-containing wastewater obtained after washing is adjusted to near neutrality to avoid oxidation and precipitation of manganese ions, and to avoid flocculation and precipitation of other metal ions in the manganese-containing wastewater; then, the secondary wastewater obtained after the pH adjustment and the washed adsorption filter medium are sequentially preactivated, sand washed, and reactivated, not only to oxidize the manganese ions in the secondary wastewater into manganese dioxide to obtain new manganese sand, but also to convert the inactivated manganese sand in the washed adsorption filter medium into manganese dioxide, thereby obtaining activated manganese sand, and realizing the resource utilization of the manganese element in the manganese-containing wastewater.

[0008] In some embodiments, in the step of adsorption filtration of primary wastewater, the adsorption filtration medium containing activated manganese sand used includes: coarse activated manganese sand, fine activated manganese sand and quartz sand; the mass ratio of coarse activated manganese sand, fine activated manganese sand and quartz sand is (1-3): (9-12): 3; the particle size of the coarse activated manganese sand is 2-4 mm, and the particle size of the fine activated manganese sand is 1-2 mm; the content of MnO2 in the activated manganese sand is ≥35%.

[0009] In this embodiment, coarse activated manganese sand, fine activated manganese sand and quartz sand are compounded as adsorption filtration media, which is beneficial to effectively adsorb manganese in primary wastewater, and reduces the number of multi-media filters set up, thereby reducing costs.

[0010] In some embodiments, after the primary wastewater is adsorbed and filtered, the ion content in the adsorbed liquid is also detected; if the manganese ion concentration in the adsorbed liquid is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, an activator is added to the adsorption filtration medium containing deactivated manganese sand; if the manganese ion concentration in the adsorbed liquid is detected to be ≤0.5 mg / L and the iron ion concentration is ≤0.3 mg / L, the adsorbed liquid is treated for effluent.

[0011] In this embodiment, by detecting the iron and manganese content in the liquid after adsorption, it is convenient to determine whether the manganese sand in the adsorption filter medium is inactivated and the degree of inactivation. If the manganese ion concentration in the liquid after adsorption is detected to be greater than 0.5 mg / L and the iron ion concentration is greater than 0.3 mg / L, it indicates that a large amount of manganese sand in the adsorption filter medium has been inactivated, and the water quality cannot be guaranteed. In addition, when it is determined that the manganese sand is inactivated, an activator is promptly added to the adsorption filter medium containing the inactivated manganese sand to oxidize the inactivated manganese sand (manganese compounds in other valence states adsorbed on the surface of the manganese sand) into activated manganese sand (manganese is tetravalent manganese dioxide), thereby improving the manganese removal capacity of the adsorption filter medium.

[0012] In some embodiments, if the manganese ion concentration in the liquid after adsorption is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, in the step of adding an activator to the adsorption filter medium containing deactivated manganese sand, the volume ratio of the total solid-liquid volume of the system to the activator is (10~25):1; the concentration of the activator is 0.01~0.1 mol / L; and / or the activator includes one or more of hydrogen peroxide and sodium hypochlorite.

[0013] In this embodiment, by setting the volume ratio of the total solid-liquid volume to the volume of the activator to (10-25):1 and the concentration of the activator to 0.01-0.1 mol / L, it can ensure that the deactivated manganese sand is fully activated while avoiding waste of resources due to excessive use of the activator.

[0014] In some embodiments, the step of washing the adsorption filter medium containing deactivated manganese sand comprises: sequentially performing forward washing, air blowing and backwashing on the adsorption filter medium containing deactivated manganese sand; the water inlet flow rate of the forward washing is 190-210 m 3 / h, the positive washing time is 2~3min; and / or, the gas flux of the air blowing is 20~25m 3 / min, the air blowing time is 5~10min; and / or the backwash water flow rate is 350~400m 3 / h, backwash until the effluent is clear.

[0015] In this embodiment, by combining forward washing, air blowing and backwashing and controlling the conditions of each process, it is possible to ensure that the manganese ions on the adsorption filter medium are fully eluted to obtain manganese-containing wastewater, thereby avoiding waste of manganese elements due to residue.

[0016] In some embodiments, in the step of mixing secondary wastewater, an activator and a washed adsorption filter medium, the volume ratio of the secondary wastewater, the activator and the washed adsorption filter medium is (10~50):1:0.6; wherein the concentration of the activator is 0.01~0.1 mol / L; and / or the activator includes one or more of hydrogen peroxide and sodium hypochlorite.

[0017] In this embodiment, when a large amount of manganese sand in the adsorption filter medium is deactivated, which seriously affects its adsorption effect, the washed adsorption filter medium and the activator are added to the secondary wastewater, and the amount of the activator is appropriately increased, so that the manganese ions in the secondary wastewater are oxidized and converted into manganese dioxide, and the deactivated manganese sand in the adsorption filter medium is pre-activated. If the deactivated manganese sand does not need to be activated, it is only necessary to mix the secondary wastewater with the activator, oxidize the manganese ions in the secondary wastewater into manganese dioxide, and use it as activated manganese sand.

[0018] In some embodiments, the step of activating the secondary sand washing using an activator includes: using the activator solution to rinse, soak, and re-rinse the secondary sand washing in sequence; the rinsing and re-rinsing are both cyclic rinses for 10 to 30 minutes; and / or the soaking time is 1 to 2 hours.

[0019] In this embodiment, a combined process of flushing, soaking and re-flushing is adopted and the processing time of each step is controlled. This ensures that the deactivated manganese sand in the secondary sand washing is fully activated and the resource utilization efficiency of the manganese element is improved without causing the manganese dioxide to be converted into high-valent manganese due to excessive oxidation.

[0020] In some embodiments, the activator includes one or more of hydrogen peroxide and sodium hypochlorite; if the activator is hydrogen peroxide, the pH of the hydrogen peroxide is adjusted to 6.0-6.5; if the activator is sodium hypochlorite, the pH of the sodium hypochlorite is adjusted to 9.0-12.

[0021] In this embodiment, when hydrogen peroxide is used as an activator, its pH is adjusted to 6.0-6.5, under which condition the oxidizing effect of hydrogen peroxide can be fully exerted. When sodium hypochlorite is used as an activator, it is prepared as an alkaline solution, and this alkalinity environment is close to the manganese removal environment of the deactivated manganese sand, which is conducive to more manganese adsorbed on the surface of the manganese sand being oxidized to manganese dioxide.

[0022] In some embodiments, the above process steps also include: mixing the tertiary wastewater with the iron phosphate wastewater and circulating the mixture; and recycling the primary wash water and the secondary wash water to adjust the pH of the manganese-containing wastewater.

[0023] In this embodiment, the tertiary wastewater is returned to the front end of the process for recycling treatment to avoid the loss of unoxidized manganese ions and ensure that the manganese ions in the iron phosphate wastewater are fully utilized. The primary wash water and the secondary wash water are reused to avoid the waste of water resources caused by directly discharging the wash water.

[0024] In a second aspect, an embodiment of the present application provides a system for resource utilization of manganese in iron phosphate wastewater, which is used to execute the resource utilization method of manganese in iron phosphate wastewater as described in the first aspect, including: Pre-processing unit; The adsorption and filtration unit, the water outlet of the pretreatment unit is connected to the water inlet of the adsorption and filtration unit; A pH adjusting unit, wherein the water inlet of the pH adjusting unit is connected to the washing water outlet of the adsorption and filtration unit; An ion conversion unit, wherein a water inlet of the ion conversion unit is connected to a water outlet of the pH adjustment unit; A washing unit, wherein a sand inlet of the washing unit is connected to a sand outlet of the ion conversion unit; A manganese sand activation unit, wherein a sand inlet of the manganese sand activation unit is connected to a sand outlet of the washing unit.

[0025] In the technical scheme of the embodiment of the present application, the pretreatment unit is used to adjust the pH value of the iron phosphate wastewater so that the impurity metal ions therein undergo a precipitation reaction and are initially removed; the adsorption and filtration unit is used to perform adsorption and filtration treatment on the primary wastewater to remove the manganese and iron ions therein, thereby obtaining purified water; the pH adjustment unit is used to adjust the pH of the manganese-containing wastewater to ensure that other elements in the primary wastewater do not flocculate and precipitate without changing the valence state of the manganese ions; the ion conversion unit is used to oxidize the divalent manganese ions in the secondary wastewater to convert them into manganese dioxide, the main component of manganese sand, to achieve resource utilization of manganese ions in the wastewater, and at the same time, convert other manganese compounds in other valence states on the surface of the inactivated manganese sand in the washed adsorption and filtration medium into manganese dioxide to achieve pre-activation of the inactivated manganese sand; the washing unit is used to wash the primary washed sand to remove the attachments adsorbed on the surface of the manganese sand; the manganese sand activation unit is used to activate the washed secondary washed sand to obtain activated manganese sand; the resource utilization of the manganese element in the iron phosphate wastewater is achieved through this system.

[0026] The beneficial effects of this application are: The present application activates the manganese-containing wastewater obtained after adsorption filtration and the inactivated manganese sand in the adsorption filtration medium after washing, and converts the manganese ions in the wastewater and the manganese compounds attached to the surface of the inactivated manganese sand into manganese dioxide, an effective component for removing manganese in the adsorption filtration medium, thereby realizing the resource utilization of the manganese element in the ferric phosphate wastewater, as well as the activation and reuse of the inactivated manganese sand in the wastewater treatment process, and the reuse rate of manganese in the ferric phosphate wastewater is increased to more than 99%.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 This is a schematic diagram of a method for resource utilization of manganese in iron phosphate wastewater in an embodiment of the present application; Figure 2 This is a schematic diagram of a method for resource utilization of manganese in iron phosphate wastewater in an embodiment of the present application; Explanation of the accompanying drawings: 1. Pretreatment unit; 2. Adsorption and filtration unit; 3. pH adjustment unit; 4. Ion conversion unit; 5. Washing unit; 6. Manganese sand activation unit. DETAILED DESCRIPTION

[0030] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0032] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0035] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0036] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] Existing treatment methods for manganese-containing iron phosphate wastewater mainly include chemical precipitation, ion exchange, membrane separation, etc., but these methods generally have problems such as high treatment costs and difficulty in resource recovery. As for the treatment of deactivated manganese sand, it is usually landfilled or piled up as solid waste, which not only occupies land resources, but also may cause secondary pollution.

[0039] In order to solve the technical problem that the traditional method for treating manganese-containing wastewater in iron phosphate cannot effectively recover manganese elements, resulting in waste of resources. The present application provides a method and system for resource utilization of manganese elements in iron phosphate wastewater, wherein the manganese-containing wastewater and deactivated manganese sand obtained in the adsorption and filtration stage are activated, so that manganese ions are continuously converted into MnO2, a catalyst for manganese removal, and the activity of manganese sand attached by a large number of other valence manganese compounds in the adsorption and filtration medium is stimulated, thereby improving the recovery efficiency of manganese elements.

[0040] Please refer to Figure 1 In a first aspect, the present application provides a method for resource utilization of manganese in iron phosphate wastewater, comprising the following steps: The pH of the iron phosphate wastewater is adjusted to 7.5-8.0, and after solid-liquid separation, primary wastewater is obtained; Using an adsorption filter medium containing activated manganese sand to perform adsorption filtration on the primary wastewater to obtain an adsorbed liquid and an adsorption filter medium containing deactivated manganese sand, and washing the adsorption filter medium containing the deactivated manganese sand to obtain manganese-containing wastewater and the washed adsorption filter medium; The pH of the manganese-containing wastewater is adjusted to 6.5-7.0 to obtain secondary wastewater; The secondary wastewater, activator and post-wash adsorption filter medium are mixed, and after solid-liquid separation, primary sand washing and tertiary wastewater are obtained; Washing the primary washed sand to obtain secondary washed sand and primary washed water; The secondary washed sand is activated by using an activator, and after solid-liquid separation, an adsorption filter medium containing activated manganese sand and secondary washed water are obtained; The adsorption filtration medium containing activated manganese sand is used for adsorption filtration treatment of primary wastewater.

[0041] In the technical scheme of the embodiment of the present application, the iron phosphate wastewater is first pretreated, and its pH is adjusted to weak alkalinity, so that the impurity metal ions such as iron, aluminum, zinc, etc. in the wastewater undergo precipitation reaction and are initially removed; then, the primary wastewater after pretreatment is adsorbed and filtered using an adsorption filter medium containing activated manganese sand, and the manganese ions in the primary wastewater are adsorbed by the activated manganese sand in the adsorption filter medium, and then the pH of the manganese-containing wastewater obtained after washing is adjusted to near neutrality to avoid oxidation and precipitation of manganese ions, and to avoid flocculation and precipitation of other metal ions in the manganese-containing wastewater; then, the secondary wastewater obtained after the pH adjustment and the washed adsorption filter medium are sequentially preactivated, sand washed, and reactivated, not only to oxidize the manganese ions in the secondary wastewater into manganese dioxide to obtain new manganese sand, but also to convert the inactivated manganese sand in the washed adsorption filter medium into manganese dioxide, thereby obtaining activated manganese sand, and realizing the resource utilization of the manganese element in the manganese-containing wastewater.

[0042] Furthermore, in some embodiments, in the step of performing adsorption filtration on primary wastewater, the adsorption filtration medium containing activated manganese sand used includes: coarse activated manganese sand, fine activated manganese sand and quartz sand; the mass ratio of coarse activated manganese sand, fine activated manganese sand and quartz sand is (1-3): (9-12): 3; the particle size of the coarse activated manganese sand is 2-4 mm, and the particle size of the fine activated manganese sand is 1-2 mm; the content of MnO2 in the activated manganese sand is ≥35%.

[0043] In the technical solution of the embodiment of the present application, coarse activated manganese sand, fine activated manganese sand and quartz sand are compounded as adsorption filtration media, and their filling ratio is controlled, which is beneficial to the effective adsorption of iron and manganese in primary wastewater to obtain higher purity water production. At the same time, it can extend the adsorption cycle of manganese sand, reduce the number of multi-media filters set, and reduce costs.

[0044] Furthermore, in some embodiments, after the primary wastewater is adsorbed and filtered, the ion content in the adsorbed liquid is detected; if the manganese ion concentration in the adsorbed liquid is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, an activator is added to the adsorption filtration medium containing deactivated manganese sand; if the manganese ion concentration in the adsorbed liquid is detected to be ≤0.5 mg / L and the iron ion concentration is ≤0.3 mg / L, the adsorbed liquid is subjected to effluent treatment.

[0045] In the technical solution of the embodiment of the present application, by detecting the iron and manganese content in the liquid after adsorption, it is convenient to determine whether the manganese sand in the adsorption filter medium is inactivated. If the manganese ion concentration in the liquid after adsorption is detected to be greater than 0.5 mg / L and the iron ion concentration is greater than 0.3 mg / L, it indicates that a large amount of manganese sand in the adsorption filter medium has been inactivated, and the water quality cannot be guaranteed. In addition, when it is determined that the manganese sand is inactivated, an activator is promptly added to the adsorption filter medium containing the inactivated manganese sand. While removing impurities on the surface of the manganese sand, the inactivated manganese sand (manganese compounds in other valence states adsorbed on the surface of the manganese sand) is oxidized into activated manganese sand (manganese is tetravalent manganese dioxide), thereby improving the manganese removal capacity of the adsorption filter medium.

[0046] Furthermore, in some embodiments, if the manganese ion concentration in the liquid after adsorption is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, in the step of adding an activator to the adsorption filtration medium containing deactivated manganese sand, the volume ratio of the total solid-liquid volume of the system to the activator is (10~25):1; the concentration of the activator is 0.01~0.1 mol / L; and / or the activator includes one or more of hydrogen peroxide and sodium hypochlorite.

[0047] In the technical solution of the embodiment of the present application, the total solid-liquid volume refers to the total volume of the adsorption filtration medium and the primary wastewater. By setting the volume ratio of the total solid-liquid volume to the activator to (10~25):1 and the concentration of the activator to 0.01~0.1 mol / L, it can ensure that the deactivated manganese sand is completely activated while avoiding waste of resources due to excessive use of the activator.

[0048] Furthermore, in some embodiments, the step of washing the adsorption filter medium containing the deactivated manganese sand comprises: sequentially performing forward washing, air blowing and backwashing on the adsorption filter medium containing the deactivated manganese sand; the water inlet flow rate of the forward washing is 190-210 m 3 / h, the positive washing time is 2~3min; and / or, the gas flux of the air blowing is 20~25m 3 / min, the air blowing time is 5~10min; and / or the backwash water flow rate is 350~400m 3 / h, backwash until the effluent is clear.

[0049] In the technical solution of the embodiment of the present application, by using a combined process of forward washing, air blowing and backwashing and controlling the conditions of each process, it is possible to ensure that the manganese ions on the adsorption filter medium are fully eluted to obtain manganese-containing wastewater, thereby avoiding the waste of manganese elements due to residues, and at the same time greatly extending the adsorption period of manganese sand in the adsorption filter medium.

[0050] Furthermore, in some embodiments, in the step of mixing the secondary wastewater, the activator and the washed adsorption filter medium, the volume ratio of the secondary wastewater, the activator and the washed adsorption filter medium is (10~50):1:0.6; wherein the concentration of the activator is 0.01~0.1 mol / L; and / or the activator includes one or more of hydrogen peroxide and sodium hypochlorite.

[0051] In the technical solution of the embodiment of the present application, when a large amount of manganese sand in the adsorption filter medium is deactivated, which seriously affects its adsorption effect, the washed adsorption filter medium and the activator are added to the secondary wastewater, and the amount of the activator is appropriately increased, so that the manganese ions in the secondary wastewater are oxidized and converted into manganese dioxide, and the deactivated manganese sand in the adsorption filter medium is pre-activated. If the deactivated manganese sand does not need to be activated, it is only necessary to mix the secondary wastewater with the activator, oxidize the manganese ions in the secondary wastewater into manganese dioxide, and use it as activated manganese sand.

[0052] Further, in some embodiments, the step of activating the secondary washed sand with an activator includes: using an activator solution to sequentially rinse, soak, and re-rinse the secondary washed sand; both the rinsing and re-rinsing are cyclic rinses for 10 to 30 minutes; and / or the soaking time is 1 to 2 hours.

[0053] In the technical solution of the embodiment of the present application, a combined process of flushing, soaking and re-flushing is adopted and the processing time of each step is controlled. This can ensure that the deactivated manganese sand in the secondary sand washing is fully activated and the resource utilization efficiency of the manganese element is improved without causing manganese dioxide to be converted into high-valent manganese due to excessive oxidation.

[0054] Furthermore, in some embodiments, the activator includes one or more of hydrogen peroxide and sodium hypochlorite; if the activator is hydrogen peroxide, the pH of the hydrogen peroxide is adjusted to 6.0-6.5; if the activator is sodium hypochlorite, the pH of the sodium hypochlorite is adjusted to 9.0-12.

[0055] In the technical solution of the embodiment of the present application, when hydrogen peroxide is used as an activator, its pH is adjusted to 6.0-6.5, under which condition the oxidizing effect of hydrogen peroxide can be fully exerted. When sodium hypochlorite is used as an activator, it is prepared as an alkaline solution. This alkalinity environment is close to the manganese removal environment of the deactivated manganese sand, which is conducive to the oxidation of other valence manganese ions adsorbed on the surface of the manganese sand to manganese dioxide, thereby improving the activation efficiency of the deactivated manganese sand.

[0056] Furthermore, in some embodiments, the above process steps also include: mixing the tertiary wastewater with the iron phosphate wastewater and circulating the mixture; and recycling the primary wash water and the secondary wash water to adjust the pH of the manganese-containing wastewater.

[0057] In the technical solution of the embodiment of the present application, the tertiary wastewater is returned to the front end of the process for circulation treatment to avoid the loss of unoxidized manganese ions and ensure that the manganese ions in the iron phosphate wastewater are fully utilized. The primary wash water and the secondary wash water are reused to avoid the waste of water resources caused by directly discharging the wash water.

[0058] Furthermore, the adsorbed liquid in the present application enters subsequent ultrafiltration and multi-stage reverse osmosis membrane treatment to produce industrial pure water that can be directly reused and concentrated liquid to be separated from the salt. The concentrated liquid undergoes multi-stage evaporation and separation to produce different by-product salts, and the pure water can be used to clean the first-stage sand washing.

[0059] Furthermore, the iron phosphate wastewater of the present application includes, but is not limited to, rinse water and mother liquor in the iron phosphate production process, and may also include other manganese-containing wastewater with similar pH conditions.

[0060] Second, please refer to Figure 2 The embodiment of the present application provides a resource utilization system for manganese element in iron phosphate wastewater, which includes a pretreatment unit 1, an adsorption filtration unit 2, a pH adjustment unit 3, an ion conversion unit 4, a washing unit 5, and a manganese sand activation unit 6 connected in sequence. Among them, the pretreatment unit 1 is used to adjust the pH value of the iron phosphate wastewater so that the impurity metal ions therein undergo a precipitation reaction and are initially removed; the adsorption and filtration unit 2 is used to perform adsorption and filtration treatment on the primary wastewater to remove the manganese and iron ions therein, thereby obtaining purified water; the pH adjustment unit 3 is used to adjust the pH of the manganese-containing wastewater to ensure that other elements in the primary wastewater do not flocculate and precipitate without changing the valence state of the manganese ions; the ion conversion unit 4 is used to oxidize the divalent manganese ions in the secondary wastewater to convert them into manganese dioxide, the main component of manganese sand, to achieve resource utilization of manganese ions in the wastewater, and at the same time, convert other valence states of manganese compounds on the surface of the inactivated manganese sand in the washed adsorption and filtration medium into manganese dioxide to achieve pre-activation of the inactivated manganese sand; the washing unit 5 is used to wash the primary washed sand to remove the attached matter adsorbed on the surface of the manganese sand; the manganese sand activation unit 6 is used to activate the washed secondary washed sand to obtain activated manganese sand; the resource utilization of manganese elements in the iron phosphate wastewater is achieved through this system.

[0061] Further, in some embodiments, the water outlet of the ion conversion unit 4 is connected to the water inlet of the pretreatment unit 1; the water outlet of the washing unit 5 is connected to the water inlet of the pH adjustment unit 3; and the water outlet of the manganese sand activation unit 6 is connected to the water inlet of the pH adjustment unit 3.

[0062] In the technical solution of the embodiment of the present application, the tertiary wastewater can be returned to the front end of the process for circulation treatment, avoiding the loss of unoxidized manganese ions and ensuring that the manganese ions in the iron phosphate wastewater are fully utilized. At the same time, the primary wash water and the secondary wash water are reused, avoiding the waste of water resources caused by directly discharging the wash water.

[0063] Further, in some embodiments, the method for resource utilization of manganese in iron phosphate wastewater of the present application is implemented based on the above system, and specifically includes the following steps: 1) The iron phosphate wastewater is passed into the sedimentation tank of the pretreatment unit 1, and alkali solution is added to adjust the pH of the iron phosphate wastewater to 7.5-8.0. After solid-liquid separation, primary wastewater is obtained.

[0064] 2) The primary wastewater is passed into the multi-media filter in the adsorption filtration unit 2, and the primary wastewater is adsorbed and filtered by the adsorption filtration medium containing activated manganese sand filled therein to obtain the adsorption liquid and the adsorption filtration medium containing inactivated manganese sand, and the ion content in the adsorption liquid is detected; if the manganese ion concentration in the adsorption liquid is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, an activator is added to the adsorption filtration medium containing inactivated manganese sand to activate the inactivated manganese sand; if the manganese ion concentration in the adsorption liquid is detected to be ≤0.5 mg / L and the iron ion concentration is ≤0.3 mg / L, the adsorption liquid is treated for effluent, and then the adsorption liquid is subjected to ultrafiltration, multi-stage reverse osmosis and multi-stage evaporation filtration concentration, and finally industrial pure water and a variety of by-product salts are produced. The adsorption filtration medium containing inactivated manganese sand is forward washed, air blown and backwashed to obtain manganese-containing wastewater and washed adsorption filtration medium.

[0065] 3) In the pH adjustment unit 3, the pH of the manganese-containing wastewater is adjusted to 6.5-7.0 to obtain secondary wastewater.

[0066] 4) When it is not necessary to activate the inactivated manganese sand in the adsorption filter medium, the secondary wastewater is passed into the ion conversion unit 4, and an activator is added to convert the manganese ions in the secondary wastewater into manganese dioxide. After solid-liquid separation, primary sand washing and tertiary wastewater are obtained; when it is necessary to activate the inactivated manganese sand in the adsorption filter medium, the secondary wastewater is passed into the ion conversion unit 4, and an activator and an adsorption filter medium containing inactivated manganese sand are added to convert the manganese ions in the secondary wastewater into manganese dioxide. At the same time, the inactivated manganese sand is pre-activated. After solid-liquid separation, primary sand washing and tertiary wastewater are obtained; the tertiary wastewater is passed into the pretreatment unit 1 for circulation treatment.

[0067] 5) The primary washed sand is passed into the washing unit 5 for washing to obtain secondary washed sand and primary washed water, and the primary washed water is passed into the pH adjustment unit 3 for reuse.

[0068] 6) The secondary washed sand is passed into the manganese sand activation unit 6, and an activator is added to activate the secondary washed sand. After solid-liquid separation, an adsorption filter medium containing activated manganese sand and secondary washing water are obtained; the secondary washing water is passed into the pH adjustment unit 3 for reuse.

[0069] 7) The adsorption filtration medium containing activated manganese sand is put into the adsorption filtration unit 2 for adsorption filtration treatment of the primary wastewater.

[0070] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0071] The iron phosphate wastewater in the following embodiments uses the iron phosphate mother liquor with the highest manganese content and the fastest deactivation of manganese sand. The impurities in the wastewater are composed of calcium, magnesium, manganese, iron and other ions, and the original pH of the wastewater is 2.2-2.5.

[0072] Example 1 A method for resource utilization of manganese element in ferric phosphate wastewater, comprising the following steps: (1) The iron phosphate wastewater is passed into the sedimentation tank of the pretreatment unit 1, and sodium hydroxide is added to adjust the pH of the iron phosphate wastewater to 7.5-7.7, and the supernatant is separated to obtain primary wastewater.

[0073] (2) The primary wastewater is passed through the multi-media filter of the adsorption filtration unit 2 at 60 t / H for adsorption filtration treatment to obtain an adsorbed liquid and an adsorption filtration medium containing inactivated manganese sand; wherein the adsorption filtration medium in the multi-media filter is composed of coarse manganese sand (particle size 2~4 mm), fine manganese sand (particle size 1~2 mm) and quartz sand (particle size 1~2 mm) in a mass ratio of 1:11:3, and the average manganese ion content in the primary wastewater is 135.47 mg / L, and the average iron ion content is 5.25 mg / L. The manganese ion concentration in the adsorbed liquid is detected to be 0.4 mg / L, and the iron ion concentration is 0.1 mg / L. The adsorbed liquid is subjected to ultrafiltration, multi-stage reverse osmosis and multi-stage evaporation filtration and concentration, and finally industrial pure water and a variety of by-product salts are produced. The adsorption filtration medium containing inactivated manganese sand is subjected to a water flow rate of 200m 3 / h, forward washing 2min; gas flux 25m 3 / min, air blowing for 10min; water inlet flow rate is 400m 3 / h, backwash until the effluent is clear, and wash once every 4 hours to obtain manganese-containing wastewater and washed adsorption filter medium.

[0074] (3) Sulfuric acid was added to the manganese-containing wastewater collection pool of the pH adjustment unit 3 to adjust the pH of the manganese-containing wastewater to 6.5, thereby obtaining secondary wastewater. At this time, the average manganese ion content in the secondary wastewater was 55.68 mg / L, and the average iron ion content was 5.87 mg / L.

[0075] (4) The secondary wastewater is passed into the reaction tank of the ion conversion unit 4, and an activator and deactivated manganese sand are added to convert the manganese ions in the secondary wastewater into manganese dioxide to obtain primary sand washing and tertiary wastewater; wherein the activator is hydrogen peroxide with a concentration of 0.03 mol / L, and the volume ratio of secondary wastewater: activator: deactivated manganese sand is 15:1:0.6. It is measured that the manganese content in the tertiary wastewater is stable at less than 0.25 mg / L, and the iron ion content is stable at less than 0.05 mg / L, indicating that the manganese ions are oxidized to manganese dioxide, the main component of manganese sand.

[0076] (5) The primary washed sand is passed into the washing unit 5 for water washing to obtain secondary washed sand and primary washed water, and the primary washed water is passed into the pH adjustment unit 3 for reuse.

[0077] (6) 5 tons of secondary washed sand were put into the manganese sand activation unit 6, and an activator was added to activate the secondary washed sand. After solid-liquid separation, activated manganese sand and secondary washed water were obtained; the secondary washed water was passed into the pH adjustment unit 3 for reuse. Among them, the activator was hydrogen peroxide with a pH of 6.4, and the amount of hydrogen peroxide used was 21L. The activator solution was used to activate the secondary washed sand by circulating and flushing for 20 minutes, soaking for 1 hour, and recirculating and flushing for 15 minutes. It was measured that the single manganese ion adsorption of the activated manganese sand could reach 13835 mg / kg. Compared with the new manganese sand of 15343 mg / kg obtained in the experiment, the activation rate could reach 90.17%.

[0078] (7) The activated manganese sand is rinsed to neutrality and then air-dried, and is put into the adsorption filtration unit 2 as an adsorption filtration medium for adsorption filtration treatment of the primary wastewater.

[0079] Example 2 A method for resource utilization of manganese element in ferric phosphate wastewater, comprising the following steps: (1) The ferric phosphate wastewater is passed into the sedimentation tank of the pretreatment unit 1, and ammonia water is added to adjust the pH of the ferric phosphate wastewater to 7.6-7.8, and the supernatant is separated to obtain primary wastewater.

[0080] (2) The primary wastewater is passed through the multi-media filter of the adsorption filtration unit 2 at a rate of 30 t / H for adsorption filtration treatment to obtain an adsorbed liquid and an adsorption filtration medium containing inactivated manganese sand; wherein the adsorption filtration medium in the multi-media filter is composed of coarse manganese sand (particle size 2~4 mm), fine manganese sand (particle size 1~2 mm) and quartz sand (particle size 1~2 mm) in a mass ratio of 1:10:3, and the primary wastewater contains 131.58 mg / L of manganese ions and an average iron ion content of 4.96 mg / L. The manganese ion concentration in the adsorbed liquid was detected to be 0.36 mg / L, and the iron ion concentration was 0.17 mg / L. The adsorbed liquid was subjected to ultrafiltration, multi-stage reverse osmosis and multi-stage evaporation filtration concentration to finally produce industrial pure water and a variety of by-product salts. The adsorption filtration medium containing inactivated manganese sand was subjected to a water flow rate of 200m 3 / h, forward washing 2min; gas flux 25m 3 / min, air blowing time is 10min; water inlet flow rate is 400m 3 / h, backwash until the effluent is clear, and wash once every 4 hours to obtain manganese-containing wastewater and washed adsorption filter medium.

[0081] (3) Sulfuric acid was added to the manganese-containing wastewater collection pool of the pH adjustment unit 3 to adjust the pH of the manganese-containing wastewater to 6.6, thereby obtaining secondary wastewater. At this time, the manganese ion content in the secondary wastewater was 52.21 mg / L, and the average iron ion content was 4.83 mg / L.

[0082] (4) The secondary wastewater is passed into the reaction tank of the ion conversion unit 4, and an activator and deactivated manganese sand are added to convert the manganese ions in the secondary wastewater into manganese dioxide to obtain primary sand washing and tertiary wastewater; wherein the activator is hydrogen peroxide with a concentration of 0.03 mol / L, and the volume ratio of secondary wastewater: activator: deactivated manganese sand is 25:1:0.6. It is measured that the manganese content in the produced water is stable at less than 0.32 mg / L, and the iron ion content is stable at less than 0.12 mg / L, indicating that the manganese ions are oxidized to manganese dioxide, the main component of manganese sand.

[0083] (5) The primary washed sand is passed into the washing unit 5 for water washing to obtain secondary washed sand and primary washed water, and the primary washed water is passed into the pH adjustment unit 3 for reuse.

[0084] (6) 3 tons of secondary washed sand were put into the manganese sand activation unit 6, and an activator was added to activate the secondary washed sand. After solid-liquid separation, activated manganese sand and secondary washed water were obtained; the secondary washed water was passed into the pH adjustment unit 3 for reuse. Among them, the activator was hydrogen peroxide with a pH of 6.5, and the amount of hydrogen peroxide used was 13.24L. The activator solution was used to activate the secondary washed sand by circulating and flushing for 15 minutes, soaking for 1.5 hours, and recirculating and flushing for 15 minutes. It was measured that the single manganese ion adsorption of the activated manganese sand could reach 12969 mg / kg. Compared with the new manganese sand 15343 mg / kg obtained in the experiment, the activation rate could reach 84.53%.

[0085] (7) The activated manganese sand is rinsed to neutrality and then air-dried, and is put into the adsorption filtration unit 2 as an adsorption filtration medium for adsorption filtration treatment of the primary wastewater.

[0086] Example 3 A method for resource utilization of manganese element in ferric phosphate wastewater, comprising the following steps: (1) The ferric phosphate wastewater is passed into the sedimentation tank of the pretreatment unit 1, and sodium hydroxide is added to adjust the pH of the ferric phosphate wastewater to 7.7-7.9, and the supernatant is separated to obtain primary wastewater.

[0087] (2) The primary wastewater is passed through the multi-media filter of the adsorption filtration unit 2 at 45t / H for adsorption filtration treatment to obtain an adsorbed liquid and an adsorption filtration medium containing inactivated manganese sand; wherein the adsorption filtration medium in the multi-media filter is composed of coarse manganese sand (particle size 2~4mm), fine manganese sand (particle size 1~2mm) and quartz sand (particle size 1~2mm) in a mass ratio of 1:9:3, and the primary wastewater contains 137.23mg / L of manganese ions and an average iron ion content of 5.11mg / L. The manganese ion concentration in the adsorbed liquid was detected to be 0.42mg / L, and the iron ion concentration was 0.22mg / L. The adsorbed liquid was subjected to ultrafiltration, multi-stage reverse osmosis and multi-stage evaporation filtration concentration, and finally industrial pure water and a variety of by-product salts were produced. The adsorption filtration medium containing inactivated manganese sand was subjected to a water flow rate of 200m 3 / h, forward washing 2min; gas flux 25m 3 / min, air blowing time is 10min; water inlet flow rate is 400m 3 / h, backwash until the effluent is clear, and wash once every 4 hours to obtain manganese-containing wastewater and washed adsorption filter medium.

[0088] (3) Sulfuric acid was added to the manganese-containing wastewater collection pool of the pH adjustment unit 3 to adjust the pH of the manganese-containing wastewater to 6.7 to obtain secondary wastewater. At this time, the manganese ion content in the secondary wastewater was 53.36 mg / L, and the average iron ion content was 5.05 mg / L.

[0089] (4) The secondary wastewater is passed into the reaction tank of the ion conversion unit 4, and an activator and deactivated manganese sand are added to convert the manganese ions in the secondary wastewater into manganese dioxide to obtain primary sand washing and tertiary wastewater; wherein the activator is hydrogen peroxide with a concentration of 0.03 mol / L, and the volume ratio of secondary wastewater: activator: deactivated manganese sand is 25:1:0.6. It is measured that the manganese content in the tertiary wastewater is stable at less than 0.48 mg / L, and the iron ion content is stable at less than 0.27 mg / L, indicating that the manganese ions are oxidized to manganese dioxide, the main component of manganese sand.

[0090] (5) The primary washed sand is passed into the washing unit 5 for water washing to obtain secondary washed sand and primary washed water, and the primary washed water is passed into the pH adjustment unit 3 for reuse.

[0091] (6) 6 tons of secondary washed sand were put into the manganese sand activation unit 6, and an activator was added to activate the secondary washed sand. After solid-liquid separation, activated manganese sand and secondary washed water were obtained; the secondary washed water was passed into the pH adjustment unit 3 for reuse. Among them, the activator was hydrogen peroxide with a pH of 6.6, and the amount of hydrogen peroxide used was 26.48L. The activator solution was used to activate the secondary washed sand by circulating and flushing for 20 minutes, soaking for 1 hour, and recirculating and flushing for 30 minutes. It was measured that the single manganese ion adsorption capacity of the activated manganese sand could reach 12367 mg / kg. Compared with the new manganese sand of 15343 mg / kg obtained in the experiment, the activation rate could reach 80.60%.

[0092] (7) The activated manganese sand is rinsed to neutrality and then air-dried, and is put into the adsorption filtration unit 2 as an adsorption filtration medium for adsorption filtration treatment of the primary wastewater.

[0093] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in step (3), sulfuric acid is added to the manganese-containing wastewater collection tank of the pH adjustment unit 3 to adjust the pH of the manganese-containing wastewater to 8.0 to obtain secondary wastewater. In step (4), the secondary wastewater, the activator and the deactivated manganese sand are mixed and reacted to obtain primary sand washing and tertiary wastewater, and the manganese ion content in the obtained tertiary wastewater is 0.42 mg / L and the iron ion content is 0.25 mg / L. In step (6), after the secondary sand washing is activated by hydrogen peroxide, the single manganese ion adsorption amount of the activated manganese sand is measured to be 9094 mg / kg, which is 59.27% ​​compared with the new manganese sand 15343 mg / kg obtained in the experiment. The activation rate is 59.27%.

[0094] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in step (3), sulfuric acid is added to the manganese-containing wastewater collection tank of the pH adjustment unit 3 to adjust the pH of the manganese-containing wastewater to 5.0 to obtain secondary wastewater. In step (4), the secondary wastewater, the activator and the deactivated manganese sand are mixed and reacted to obtain primary sand washing and tertiary wastewater, and the manganese ion content in the obtained tertiary wastewater is 42.16 mg / L and the iron ion content is 4.19 mg / L. In step (6), after the secondary sand washing is activated by hydrogen peroxide, the single manganese ion adsorption amount of the activated manganese sand is measured to be 5436 mg / kg, which is 35.43% compared with the new manganese sand 15343 mg / kg obtained in the experiment. The activation rate is 35.43%.

[0095] Comparative Examples 1-2 Compared with Example 1, it can be seen that if the pH of the secondary wastewater is too high, part of the manganese ions in the solution are prone to generate manganese oxide or hydroxide precipitation, resulting in a decrease in the dissolved manganese content in the solution, and catalytic decomposition of the subsequently added hydrogen peroxide, thereby reducing the recovery rate of manganese ions converted into manganese dioxide and the activation rate of inactivated manganese sand. If the pH of the secondary wastewater is too low, it is not conducive to the adsorption of manganese ions by inactivated manganese sand. At the same time, the optimal pH of the activator hydrogen peroxide is 6.0-6.5. Too low a pH environment is prone to decomposition of hydrogen peroxide, reducing its oxidation effect, thereby causing a decrease in the recovery rate of activated manganese sand.

[0096] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for resource utilization of manganese in iron phosphate wastewater, characterized in that: The following steps are involved: The pH of the iron phosphate wastewater is adjusted to 7.5-8.0, and after solid-liquid separation, primary wastewater is obtained; Using an adsorption filter medium containing activated manganese sand to perform adsorption filtration on the primary wastewater to obtain an adsorbed liquid and an adsorption filter medium containing deactivated manganese sand, and washing the adsorption filter medium containing the deactivated manganese sand to obtain manganese-containing wastewater and a washed adsorption filter medium; Adjusting the pH of the manganese-containing wastewater to 6.5-7.0 to obtain secondary wastewater; The secondary wastewater, the activator and the post-washing adsorption filter medium are mixed, and after solid-liquid separation, primary sand washing and tertiary wastewater are obtained; Washing the primary washed sand to obtain secondary washed sand and primary washed water; The secondary washed sand is activated by an activator, and after solid-liquid separation, an adsorption filter medium containing activated manganese sand and secondary washed water are obtained; The adsorption and filtration medium containing activated manganese sand is used to carry out adsorption and filtration treatment on the primary wastewater.

2. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: In the step of adsorption filtration of the primary wastewater, the adsorption filtration medium containing activated manganese sand used includes: coarse activated manganese sand, fine activated manganese sand and quartz sand; the mass ratio of the coarse activated manganese sand, fine activated manganese sand and quartz sand is (1-3): (9-12): 3; the particle size of the coarse activated manganese sand is 2-4 mm, and the particle size of the fine activated manganese sand is 1-2 mm; the content of MnO2 in the activated manganese sand is ≥35%.

3. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: It also includes detecting the ion content in the liquid after the adsorption; If the manganese ion concentration in the adsorption liquid is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, an activator is added to the adsorption filtration medium containing the deactivated manganese sand; If the manganese ion concentration in the adsorbed liquid is detected to be ≤0.5 mg / L and the iron ion concentration is ≤0.3 mg / L, the adsorbed liquid is subjected to water treatment.

4. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 3, characterized in that: If the manganese ion concentration in the adsorbed liquid is detected to be greater than 0.5 mg / L, and / or the iron ion concentration is greater than 0.3 mg / L, in the step of adding an activator to the adsorption filter medium containing deactivated manganese sand, the volume ratio of the total solid-liquid volume of the system to the volume of the activator is (10-25):1; The concentration of the activator is 0.01-0.1 mol / L; and / or The activator includes one or more of hydrogen peroxide and sodium hypochlorite.

5. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: The step of washing the adsorption filter medium containing the deactivated manganese sand comprises: sequentially performing forward washing, air blowing and backwashing on the adsorption filter medium containing the deactivated manganese sand; The water flow rate of the positive wash is 190~210m 3 / h, the washing time is 2~3min; and / or The gas flux of the air blowing is 20~25m 3 / min, air blowing time is 5~10min; and / or The backwash water flow rate is 350~400m 3 / h, backwash until the effluent is clear.

6. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: In the step of mixing the secondary wastewater, the activator and the washed adsorption filter medium, the volume ratio of the secondary wastewater, the activator and the washed adsorption filter medium is (10-50): 1: 0.6; Wherein, the concentration of the activator is 0.01-0.1 mol / L; and / or The activator includes one or more of hydrogen peroxide and sodium hypochlorite.

7. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: The step of activating the secondary washed sand with an activator comprises: using an activator solution to sequentially rinse, soak, and rinse the secondary washed sand; The flushing and re-flushing are both cyclic flushing for 10 to 30 minutes; and / or The soaking time is 1 to 2 hours.

8. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 7, characterized in that: The activator includes one or more of hydrogen peroxide and sodium hypochlorite; If the activator is hydrogen peroxide, the pH of the hydrogen peroxide is adjusted to 6.0-6.5; if the activator is sodium hypochlorite, the pH of the sodium hypochlorite is adjusted to 9.0-12.

9. The method for resource utilization of manganese in ferric phosphate wastewater according to claim 1, characterized in that: The method also includes the following steps: mixing the tertiary wastewater with the iron phosphate wastewater and performing a circulation treatment; and recycling the primary wash water and the secondary wash water in the step of adjusting the pH of the manganese-containing wastewater.

10. A resource utilization system for manganese in ferric phosphate wastewater, used for executing the resource utilization method for manganese in ferric phosphate wastewater according to any one of claims 1 to 9, characterized in that: include: Pre-processing unit; An adsorption and filtration unit, wherein the water outlet of the pretreatment unit is connected to the water inlet of the adsorption and filtration unit; A pH adjusting unit, wherein the water inlet of the pH adjusting unit is connected to the washing water outlet of the adsorption and filtration unit; an ion conversion unit, wherein the water inlet of the ion conversion unit is connected to the water outlet of the pH adjustment unit; A washing unit, wherein a sand inlet of the washing unit is connected to a sand outlet of the ion conversion unit; A manganese sand activation unit, wherein the sand inlet of the manganese sand activation unit is connected to the sand outlet of the washing unit.

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