Synchronous removal of Mn 2+ and ammonia nitrogen from mine water and preparation and treatment methods of modified zeolite

Abstract

The invention discloses a preparation method and a treatment method of a modified zeolite for synchronously removing Mn<supgt;2+< / supgt; and ammonia nitrogen in mine water. First, natural clinoptilolite is impregnated in a sodium hexametaphosphate solution, and then solid-liquid separation, washing and drying are carried out to obtain a first material. After that, the first material is placed in a divalent manganese salt solution, the pH value is adjusted, and then a potassium permanganate solution is added. After water bath heating for a period of time, solid-liquid separation, washing and drying are carried out to obtain the modified zeolite for synchronously removing Mn<supgt;2+< / supgt> and ammonia nitrogen in mine water.

Description

Technical Field

[0001] The present invention relates to the technical field of mine water treatment, and particularly to a preparation method and a treatment method of a modified zeolite for synchronously removing manganese and ammonia nitrogen in mine water. Background Art

[0002] According to statistics, the mass concentrations of Mn 2+ and ammonia nitrogen ions in mine water of some coal mines in Inner Mongolia, Shaanxi, Shanxi and other regions of China are 0.2 - 2.8 and 1.2 - 3.3 mg / L respectively. At present, it is required that the coal main production areas in the above regions raise the mine water discharge standard to the Class III standard of GB3838 - 2002 "Surface Water Environmental Quality Standard" according to the regulations of the receiving water body environmental function zoning, and the effluent limits of manganese and ammonia nitrogen ions are 0.1 mg / L and 1 mg / L respectively. Excessive manganese and ammonia nitrogen have great harms to human health and industrial production. Mining areas often adopt the two-stage process of "contact oxidation for manganese removal + ion exchange resin for ammonia nitrogen removal", and there are few reports on the synchronous removal of manganese and ammonia nitrogen in mine water.

[0003] The two-stage treatment process of "contact oxidation for manganese removal + ion exchange resin for ammonia nitrogen removal" has high management and operation difficulties. The impurities in mine water are easy to wear the resin, the selectivity of special ammonia nitrogen removal is not high, and the waste liquid generated during reproduction has secondary pollution. The waste resin after use is managed as HW13 hazardous waste, which increases the project investment and maintenance costs. To meet the increasingly strict environmental management requirements, developing materials and processes for synchronously removing manganese and ammonia nitrogen in mine water can alleviate the contradiction between the sustainable development of coal mine enterprises and the shortage of water resources, which has important practical significance for greatly improving the comprehensive utilization efficiency of mine water and is also an urgent need for the implementation of the mining area ecological protection strategy.

[0004] The methods for removing low-concentration manganese ions in water generally include natural oxidation method, adsorption method, biological method, contact oxidation method, etc. The natural oxidation method is difficult to oxidize Mn 2+ to MnO2 for manganese removal only by aeration, and often alkali needs to be added to increase the pH value to achieve the purpose of manganese removal. However, the pH value of the water quality after treatment by the natural oxidation method is relatively high, and its pH value must be reduced before it can be used normally. Moreover, the process system is complex, the equipment is huge, the investment is large, and the manganese removal effect is not very ideal.

[0005] The adsorption method refers to the use of electrostatic attraction, chemical adsorption and surface ion exchange and other effects to adsorb Mn 2+。The adsorption method has problems such as difficult flow rate control, small treated water volume, and decreased regenerated adsorption capacity. Currently, the methods with great application potential and relatively mature are the biological method and the contact oxidation method. Among them, the biological activity of the biological method is relatively low under low-temperature conditions, biological inoculation is required, and the start-up period of the filter tank is long. The start-up period of the manganese-removing filter tank by the contact oxidation method is relatively fast, but it also requires a start-up period of 1-3 months. Its principle is to add potassium permanganate to the influent water to oxidize Mn 2+ to form quartz sand filter media loaded with manganese oxides, and Mn 2+ can be oxidized by the manganese oxides on the surface of the filter media to generate new active filter membrane substances. However, the time required to generate a catalytically active filter membrane by the contact oxidation method is long and the difficulty is high. Potassium permanganate needs to be frequently added to the influent water. When the dosage of potassium permanganate is large, the effluent chromaticity is high, and when the dosage is small, it is difficult to meet the effluent requirements.

[0006] The treatment methods for low-concentration ammonia nitrogen in water generally adopt the adsorption method and the ion exchange method, etc. The ion exchange method refers to the process in which materials with ion exchange ability perform ion exchange on target ions with high selectivity in water. The removal of ammonia by the ion exchange method usually refers to using ion exchange resins to treat ammonia nitrogen sewage or wastewater. The resin has a relatively large specific surface area, a large adsorption capacity, relatively simple regeneration and a high regeneration rate. However, the engineering investment cost is high, the impurities in mine water have a relatively high wear rate on the resin, affecting the reuse of the resin, and the waste liquid generated during resin regeneration has secondary pollution. The used and discarded resin is managed as hazardous waste of HW13 category. The adsorption method for ammonia nitrogen removal is to use an adsorption material to adsorb ammonia nitrogen. Its adsorption occurs at the interface between two phases and is an interfacial reaction. By using the unsaturated molecular force or chemical bond force on the surface of the adsorption material, the polluting components in the mixture are adsorbed from the liquid phase to the surface of the solid-phase adsorption material, so as to achieve the purpose of separating and removing ammonia nitrogen.

[0007] Zeolite is a natural mineral of porous silicon aluminates with good environmental properties, formed by the staggered arrangement of [SiO2] and [AlO4] tetrahedral units to form a three-dimensional framework structure. It has good adsorption and ion exchange capabilities for ammonia nitrogen and heavy metals. Cationic pollutants can perform ion exchange with alkali metals or alkaline earth metals at its sites, making zeolite a natural adsorbent. Moreover, natural zeolite has a rich storage, a good stable structure, and has a wide range of applications in the field of water treatment. The advantages of zeolite for removing manganese and ammonia nitrogen are simple operation, high efficiency and rapidity, no need to add a large amount of chemical reagents, less energy consumption, the adsorbent can be regenerated, no secondary pollution, relatively environmentally friendly, etc. However, its adsorption capacity is often limited, its selectivity for ammonia nitrogen is not high, and it does not have catalytic oxidation ability. The deep treatment of manganese is not satisfactory and cannot achieve the expected effect.

[0008] At present, for the "contact oxidation for manganese removal + resin for ammonia nitrogen removal" two-stage process used in mining areas, there are problems such as high management and operation difficulties, cumbersome process, and inability to synchronously remove manganese and ammonia nitrogen. Therefore, there is an urgent need to develop a new material that can synchronously remove manganese and ammonia nitrogen in mine water through multiple mechanisms, achieve synchronous removal of manganese and ammonia nitrogen ions to meet increasingly strict environmental management requirements, reduce engineering investment and operation management difficulties, and improve the comprehensive utilization rate of mine water resources. Summary of the Invention

[0009] To solve the problems of high management and operation difficulties, cumbersome process, and inability to synchronously remove manganese and ammonia nitrogen in the "contact oxidation for manganese removal + resin for ammonia nitrogen removal" two-stage treatment process adopted by coal mining enterprises,

[0010] According to one aspect of the present invention, there is provided a method for preparing a modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in mine water. The modified zeolite is prepared by a method of impregnating zeolite with sodium hexametaphosphate and loading birnessite-type manganese dioxide by hydrothermal method. The preparation method includes the following steps:

[0011] (1) Immerse natural clinoptilolite in a sodium hexametaphosphate solution, then perform solid-liquid separation, washing, and drying to obtain a first material;

[0012] (2) Place the first material in a divalent manganese salt solution, adjust the pH value, add a potassium permanganate solution, heat in a water bath for a period of time, and then perform solid-liquid separation, washing, and drying to obtain a modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in mine water.

[0013] In some embodiments, the modified zeolite is used for synchronously removing Mn 2+ and ammonia nitrogen in mine water,

[0014] The modified zeolite uses natural clinoptilolite as the base material.

[0015] In some embodiments, the particle size of the natural clinoptilolite is 100 - 300 mesh,

[0016] The divalent manganese salts include manganese sulfate and manganese chloride.

[0017] In some embodiments, in step (1), the concentration of the sodium hexametaphosphate solution is 0.02 - 0.3 mol / L; the pH value of the sodium hexametaphosphate solution is 4.0 - 8.0; the impregnation time is 2 - 24 h.

[0018] In some embodiments, the solid-liquid ratio (g / mL) of natural clinoptilolite to the sodium hexametaphosphate solution is 1:10 - 1:100.

[0019] In some embodiments, in step (2), the solid-liquid ratio (g / mL) of natural clinoptilolite to the mixed solution of divalent manganese salt and potassium permanganate is 1:40; the concentration of divalent manganese ions in the divalent manganese salt solution is 1.5 - 2.2 mmol / L.

[0020] In some embodiments, the divalent manganese salt is manganese sulfate.

[0021] The molar ratio of divalent manganese ions to permanganate ions in the mixed solution of manganese sulfate and potassium permanganate is 1:2.5 - 2.5:1; the pH value of the mixed solution is 6.0 - 12.0; it is heated in a water bath at 40 - 90 °C.

[0022] According to another aspect of the present invention, there is provided a treatment method for synchronously removing Mn 2+ and ammonia nitrogen from mine water, wherein the modified zeolite is prepared by the method for preparing the modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen from mine water as described above.

[0023] The treatment method includes the following steps:

[0024] Adjust the pH value of the mine water containing Mn 2+ and ammonia nitrogen to 6.0 - 8.0;

[0025] Add the modified zeolite to the mine water containing Mn 2+ and ammonia nitrogen to be treated, and oscillate it using a constant temperature water bath oscillator at a certain temperature, oscillation rate and oscillation time.

[0026] In some embodiments, the pH value of the mine water containing Mn 2+ and ammonia nitrogen is adjusted using an acid or base solution with a mass concentration of 5 - 15%;

[0027] Add 1 - 5 g / L of the modified zeolite to the mine water containing Mn 2+ and ammonia nitrogen;

[0028] The temperature of the constant temperature water bath oscillator is 20 - 35 °C, the oscillation rate is 150 - 300 r / min, and the oscillation time is 2 h - 12 h.

[0029] In some embodiments, the acid solution includes hydrochloric acid, sulfuric acid or nitric acid, and the base solution includes sodium hydroxide, potassium hydroxide or calcium hydroxide;

[0030] The pH value range of the mine water containing Mn 2+ and ammonia nitrogen to be treated is 6.0 - 8.0;

[0031] The Mn 2+ in the mine water containing Mn 2+The initial mass concentrations of manganese and ammonia nitrogen are less than 0.5 - 20 and 1 - 20 mg / L respectively. After shaking for 2 h, the mass concentrations of manganese and ammonia nitrogen in water are less than 0.1 mg / L and 1 mg / L respectively.

[0032] The preparation method and treatment method of the modified zeolite for synchronously removing manganese and ammonia nitrogen in mine water according to the present invention have at least one of the following advantages:

[0033] Using the material according to the present invention to synchronously treat Mn in mine water 2+ and ammonia nitrogen has the advantages of simple preparation process, low price of natural clinoptilolite and the modified zeolite of the present invention, and low cost of treating wastewater. For Mn in mine water 2+ and ammonia nitrogen, the removal effect is high, the effluent water quality is stable, and the treatment process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of the preferred embodiments in conjunction with the accompanying drawings, wherein:

[0035] Figure 1A 、 Figure 1B and Figure 1C are the scanning electron microscope images of natural clinoptilolite, the first material and the modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in mine water according to an embodiment of the present invention;

[0036] Figure 2 is the flow chart of the preparation method of the modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in mine water according to an embodiment of the present invention;

[0037] Figure 3 is the flow chart of the treatment method using the modified zeolite to synchronously remove Mn 2+ and ammonia nitrogen in mine water according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following further elaborates the characteristics of the present invention through specific embodiments. The description of the embodiments of the present invention below with reference to the accompanying drawings aims to explain the overall concept of the present invention and should not be construed as a limitation to the present invention.

[0039] The present invention provides a modified zeolite for synchronously removing manganese and ammonia nitrogen ions in mine water, a preparation method of a modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen (ions) in mine water, and a treatment method using the modified zeolite to synchronously remove Mn 2+ and ammonia nitrogen (ions) in mine water.

[0040] In one aspect of the present invention, a modified zeolite for synchronously removing manganese and ammonia nitrogen ions from mine water is provided. The modified zeolite uses natural clinoptilolite as the base material.

[0041] Preferably, the modified zeolite is used for synchronously removing manganese and ammonia nitrogen ions from mine water, and the particle size of the zeolite particles is 100 - 300 mesh.

[0042] In another aspect of the present invention, a preparation method of a modified zeolite for synchronously removing manganese and ammonia nitrogen ions from water is provided. The preparation method includes the following steps: First, immerse natural clinoptilolite in a sodium hexametaphosphate solution, then perform solid - liquid separation, washing, and drying to obtain a first material; place the first material in a manganese sulfate solution, adjust the pH value, add a potassium permanganate solution, heat in a water bath for a period of time, and then perform solid - liquid separation, washing, and drying to obtain the modified zeolite for synchronously removing manganese and ammonia nitrogen from mine water.

[0043] After natural clinoptilolite is modified by sodium hexametaphosphate, it can chelate a large amount of metal cations such as calcium and magnesium in the zeolite, enabling sodium ions to occupy the active sites of the zeolite in large quantities and efficiently, significantly increasing the cation adsorption capacity of the zeolite, and improving the pore structure, making its adsorption capacity for Mn 2+ and ammonia nitrogen in water enhanced; then the first material is further loaded with birnessite - type manganese dioxide by hydrothermal method, which has high - efficiency catalytic oxidation ability and specific adsorption ability for Mn 2+ and ammonia nitrogen in water, and increases the specific surface area of the zeolite, thus achieving the effect of synchronously removing Mn 2+ and ammonia nitrogen from mine water.

[0044] Generally, inorganic sodium salt modifiers such as sodium chloride and sodium nitrate, the modified zeolites prepared by the modification method relying on the priority of Na + and the concentration gradient between the exchangeable ions of the zeolite have general ammonia nitrogen removal effects. The fundamental reason is that the inhibitory effects of metal cations such as calcium and magnesium cannot be removed during the modification process, and it is difficult for Na + to occupy the active sites of the zeolite. The modification mechanism of the first material described in the present invention is very different from the inorganic sodium salt modification mechanism. Sodium hexametaphosphate is an inorganic metal chelating sodium salt. During the process of impregnating and modifying natural clinoptilolite, the metaphosphate radical can chelate metal cations such as calcium and magnesium in the zeolite, effectively reducing the concentration of free metal ions during the modification process, enabling sodium ions to occupy the active sites of the zeolite in large quantities and efficiently, significantly increasing the cation adsorption capacity of the zeolite, and dredging the zeolite pores. The micropore volume of the zeolite decreases, and the mesopores, macropores, and average pore diameter increase, which is beneficial to the migration and diffusion of Mn 2+ and ammonia nitrogen ions.

[0045] Afterwards, the first material is further loaded with birnessite-type manganese dioxide through a hydrothermal method. This process makes the surface of the first material rich in hydroxyl groups, increases the content of surface-adsorbed oxygen, lattice oxygen, trivalent manganese, and tetravalent manganese with catalytic oxidation ability, and further increases the specific surface area of the material, which can improve the catalytic oxidation ability and specific adsorption ability for Mn 2+ and ammonium ions, so as to achieve the synchronous removal of Mn 2+ and ammonia nitrogen in mine water.

[0046] The key to the preparation of the zeolite material of the present invention lies in:

[0047] (1) First, natural clinoptilolite is impregnated and modified with sodium hexametaphosphate. After solid-liquid separation and drying, the first material is obtained.

[0048] Preferably, the concentration of the sodium hexametaphosphate solution is 0.02 - 0.3 mol / L

[0049] Preferably, the pH value of the sodium hexametaphosphate solution is 4.0 - 8.0;

[0050] Preferably, the impregnation time is 2 - 24 h.

[0051] Preferably, the solid-liquid ratio (g / mL) of the natural clinoptilolite to the sodium hexametaphosphate solution is 1:10 - 1:100.

[0052] (2) The birnessite-type manganese dioxide is loaded onto the first material through a hydrothermal method, thus achieving the synchronous removal of manganese (II) and ammonia nitrogen in water. The solid-liquid ratio (g / mL) of the first material to the mixed solution of manganese sulfate and potassium permanganate is 1:40.

[0053] Preferably, the concentration of the manganese sulfate solution is 1.5 - 2.2 mmol / L;

[0054] Preferably, the molar ratio of divalent manganese ions to permanganate ions is 1:2.5 - 2.5:1;

[0055] Preferably, the pH value of the mixed solution is 6.0 - 12.0;

[0056] Preferably, the water bath temperature is 40 - 90 °C.

[0057] According to another aspect of the present invention, a treatment method for synchronously removing Mn 2+ and ammonia nitrogen in water using modified zeolite is provided. The treatment method includes the following steps: adjusting the pH value of mine water containing Mn 2+ and ammonia nitrogen to 6.0 - 8.0, and then adding modified zeolite to the water to be treated and oscillating it with a constant temperature water bath oscillator at a certain temperature, oscillation rate, and oscillation time.

[0058] Preferably, the oscillation temperature is 20 - 35°C.

[0059] Preferably, the oscillation rate is 150 - 300 r / min.

[0060] Preferably, the oscillation time is 2 - 12 h.

[0061] In some embodiments, a hydrochloric acid or sodium hydroxide solution with a mass concentration of 10% is used to adjust the pH value of the mine water containing Mn 2+ and ammonia nitrogen.

[0062] In some embodiments, the pH value range of the mine water containing Mn 2+ and ammonia nitrogen to be treated is 6.0 - 8.0; in the mine water containing Mn 2+ and ammonia nitrogen to be treated, the initial mass concentrations of Mn 2+ and ammonia nitrogen are 0.5 - 20 and 2 - 20 mg / L respectively. When 1 - 10 g / L of the modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in water is added and oscillated for 2 h, the mass concentrations of manganese and ammonia nitrogen in water are less than 0.1 mg / L and 1 mg / L respectively.

[0063] Example 1:

[0064] Refer to Figure 1A 、 Figure 1B 、 Figure 1C and Figure 2 The steps of the preparation method of the modified zeolite for synchronously removing Mn 2+ and ammonia nitrogen in mine water described in the embodiments of the present invention are as follows:

[0065] Step (1): Immerse natural clinoptilolite with a mesh size of 100 - 300 in a sodium hexametaphosphate solution with a solid - liquid ratio (g / mL) of 1:10 - 1:100 and a concentration of 0.02 - 0.3 mol / L. The pH value of the sodium hexametaphosphate solution is 4.0 - 8.0. After impregnation for 2 - 24 h, solid - liquid separation, washing and drying are carried out to obtain the first material.

[0066] Preferably, the natural clinoptilolite is 200 - mesh, the concentration of the sodium hexametaphosphate solution is 0.1 mol / L, the pH value of the sodium hexametaphosphate solution is 5.6, the solid - liquid ratio (g / mL) of the zeolite to the sodium hexametaphosphate solution is 1:20, and the impregnation time is 3 h.

[0067] Step (2): Add the first material prepared in step (1) into a manganese sulfate solution with a concentration of 1.5 - 2.2 mmol / L, adjust the pH value to 6 - 12, raise the temperature in a water bath to 40 - 90 °C, then add a potassium permanganate solution, so that the solid-liquid ratio (g / mL) of the first material to the mixed solution is 1:40, and the molar ratio of divalent manganese ions to permanganate ions is 1:2.5 - 2.5:1. Finally, after reacting for 2 hours, perform solid-liquid separation, washing, and drying to obtain modified zeolite for simultaneously removing Mn 2+ and ammonia nitrogen in mine water.

[0068] Preferably, the concentration of the manganese sulfate solution is 2 mmol / L, the pH value is 10.0, the water bath temperature is 70 °C, and the molar ratio of divalent manganese ions to permanganate ions is 1.5:1.

[0069] Thus, the modified zeolite material for simultaneously removing Mn 2+ and ammonia nitrogen in mine water is prepared.

[0070] See Figure 3 , which shows a treatment method for treating mine water containing Mn 2+ and ammonia nitrogen using the above-mentioned modified zeolite material. The treatment method includes the following steps:

[0071] (a) Adjust the pH value of the mine water containing Mn 2+ and ammonia nitrogen to be treated to 6.0 - 8.0. Preferably, use a hydrochloric acid or sodium hydroxide solution with a mass concentration of 10% to adjust the pH value to 7.0.

[0072] (b) Add the modified zeolite material to the mine water containing Mn 2+ and ammonia nitrogen to be treated. Preferably, use a constant temperature water bath oscillator to oscillate at an oscillation rate of 200 r / min at 25 °C for 2 hours.

[0073] The modified zeolite for simultaneously removing manganese and ammonia nitrogen in mine water in this embodiment is used to treat mine water containing Mn 2+ and ammonia nitrogen. The initial concentrations of Mn 2+ and ammonia nitrogen, the dosage of the modified zeolite, and the concentrations of manganese and ammonia nitrogen in the effluent are shown in Table 1.

[0074] It can be seen that the concentrations of Mn and NH4 + -N in the effluent are respectively lower than 0.1 and 1 mg / L, meeting the requirements of Class III limit values in the "Surface Water Environmental Quality Standard".

[0075] In Table 1, the pH value of the mine water containing manganese (II) and ammonia nitrogen is 6 - 8, the oscillation temperature of the constant temperature water bath oscillator is 25 °C, the oscillation rate is 200 r / min, and the oscillation time is 2 hours.

[0076] Table 1 Effect of Modified Zeolite on Simultaneous Removal of Manganese and Ammonia Nitrogen in Mine Water

[0077]

[0078] Comparative Example 1:

[0079] Use unmodified natural clinoptilolite to treat the mine water containing Mn 2+ and ammonia nitrogen in Sample 2 of Table 1. The mass concentrations of manganese and ammonia nitrogen in the effluent are 0.67 - 1.69 mg / L and 1.5 - 2.1 mg / L, respectively.

[0080] Example 2:

[0081] The difference from Example 1 is only that the solid-liquid ratio of natural clinoptilolite to sodium hexametaphosphate solution is 1:10.

[0082] Example 3:

[0083] The difference from Example 1 is only that the solid-liquid ratio of natural clinoptilolite to sodium hexametaphosphate solution is 1:100.

[0084] Example 4:

[0085] The difference from Example 1 is only that the concentration of sodium hexametaphosphate solution is 0.3 mol / L.

[0086] Example 5:

[0087] The difference from Example 1 is only that the pH value of sodium hexametaphosphate solution is 4.

[0088] Example 6:

[0089] The difference from Example 1 is only that the pH value of sodium hexametaphosphate solution is 8.

[0090] Example 7:

[0091] The difference from Example 1 is only that the impregnation time is 24 h.

[0092] Example 8:

[0093] The difference from Example 1 is only that the concentration of manganese sulfate solution is 1.5 mmol / L.

[0094] Example 9:

[0095] The difference from Example 1 is only that the concentration of manganese sulfate solution is 2.2 mmol / L.

[0096] Example 10:

[0097] The difference from Example 1 is only that the molar ratio of manganese sulfate to permanganate is 1:2.5.

[0098] Example 11:

[0099] The difference from Example 1 is only that the molar ratio of manganese sulfate to permanganate is 2.5:1.

[0100] Example 12:

[0101] The difference from Example 1 is only that the pH value of the mixed solution is 7.

[0102] Example 13:

[0103] The difference from Example 1 is only that the pH value of the mixed solution is 12.

[0104] Example 15:

[0105] The difference from Example 1 is only that the hydrothermal temperature is 40 °C.

[0106] Example 16:

[0107] The difference from Example 1 is only that the hydrothermal temperature is 90 °C.

[0108] Comparative Example 2:

[0109] The difference from Example 1 is only that the solid-liquid ratio of the natural clinoptilolite sodium hexametaphosphate solution is 1:5. Comparative Example 3:

[0110] The difference from Example 1 is only that the concentration of the sodium hexametaphosphate solution is 0.01 mol / L.

[0111] Comparative Example 4:

[0112] The difference from Example 1 is only that the impregnation time is 1 h.

[0113] Comparative Example 5:

[0114] The difference from Example 1 is only that the concentration of the manganese sulfate solution is 1 mmol / L.

[0115] Comparative Example 6:

[0116] The difference from Example 1 is only that the hydrothermal temperature is 30 °C.

[0117] The modified zeolite materials obtained from Examples 2-16 and Comparative Examples 1-6 are used to treat mine water containing Mn 2+ and ammonia nitrogen. The difference from Example 1 is only that the solid-liquid ratio of the modified zeolite to the mine water to be treated is (2 g: 1000 mL). The effluent quality of the mine water containing manganese (II) and ammonia nitrogen is shown in Table 2.

[0118] In Table 2, the initial mass concentrations of manganese and ammonia nitrogen in the mine water containing manganese (II) and ammonia nitrogen are 3 and 5 mg / L, respectively.

[0119] Table 2 Implementation effect of modified wastewater for synchronous treatment of mine water containing Mn 2+ and ammonia nitrogen

[0120]

[0121]

[0122] From the effluent quality results shown in Examples 1-16, it can be seen that the synchronous removal of Mn 2+ and ammonia nitrogen by the modified zeolite of the present invention can stably and synchronously remove Mn 2+ and ammonia nitrogen in water, making the concentrations of manganese and ammonia nitrogen in the treated water less than the 0.1 and 1.0 mg / L limits required by the water body.

[0123] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. Those of ordinary skill in the art will understand that these embodiments can be changed without departing from the principles and spirit of the general concept of the present invention, and these changes should also be regarded as falling within the protection scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for simultaneous removal of Mn from mine water 2+ A method for preparing a modified zeolite containing 1% sodium hexametaphosphate and 1% ammonia nitrogen, wherein the modified zeolite is prepared by impregnating zeolite with sodium hexametaphosphate and then loading birnessite-type manganese dioxide with a hydrothermal method, and the preparation method comprises the following steps: (1) impregnating natural clinoptilolite in a sodium hexametaphosphate solution, followed by solid-liquid separation, washing, and drying to obtain a first material; The concentration of the sodium hexametaphosphate solution is 0.02-0.3 mol / L; the pH value of the sodium hexametaphosphate solution is 4.0-8.0; and the immersion time is 2-24 h; The solid-to-liquid ratio of natural clinoptilolite to sodium hexametaphosphate solution is 1:10-1:100 g / mL; (2) The first material is placed in a divalent manganese salt solution, and potassium permanganate solution is added after adjusting the pH value. After heating in a water bath for a period of time, solid-liquid separation, washing, and drying are performed to obtain a solution for the simultaneous removal of Mn from the mine water. 2+ and ammonia nitrogen modified zeolite; The solid-to-liquid ratio of the mixed solution of natural clinoptilolite, divalent manganese salt and potassium permanganate is 1:40 g / mL; The concentration of divalent manganese ions in the divalent manganese salt solution is 1.5-2.2 mmol / L; The divalent manganese salt solution is a manganese sulfate solution, The molar ratio of divalent manganese ions to permanganate ions in the mixed solution of manganese sulfate and potassium permanganate is 1:2.5-2.5:1; the pH value of the mixed solution is 6.0-12.0; and the solution is heated in a water bath at 40-90°C.

2. The method for synchronously removing Mn from mine water according to claim 1 2+ and ammonia nitrogen modified zeolite preparation method, characterized in that, The particle size of the natural clinoptilolite is 100-300 meshes.

3. A method for simultaneous removal of Mn from mine water using modified zeolite 2+ and ammonia nitrogen treatment method, the modified zeolite is according to any one of claims 1-2 to simultaneously remove Mn in mine water 2+ and ammonia nitrogen modified zeolite prepared by the preparation method, characterized in that, The processing method comprises the following steps: Mn 2+ and ammonia nitrogen in the mine water to adjust the pH value to 6.0-8.0; To the Mn-containing 2+ Modified zeolite was added to the mine water containing nitrogen and ammonia and the water was oscillated at a certain temperature, oscillation rate and oscillation time using a constant temperature water bath oscillator.

4. The method for synchronously removing Mn from mine water using modified zeolite according to claim 3 2+ and ammonia nitrogen treatment method, characterized in that, Use acid or alkali solution with a mass concentration of 5-15% to adjust the Mn content. 2+ and pH value of mine water containing ammonia and nitrogen; Towards Mn 2+ Add 1-5 g / L modified zeolite to the mine water containing nitrogen and ammonia; The temperature of the constant temperature water bath oscillator is 20-35 °C, the oscillation rate is 150-300 r / min, and the oscillation time is 2 h-12 h.

5. Synchronous removal of Mn from mine water using modified zeolite according to claim 4 2+ and ammonia nitrogen treatment method, characterized in that, The acid solution includes hydrochloric acid, sulfuric acid or nitric acid, and the alkaline solution includes sodium hydroxide, potassium hydroxide or calcium hydroxide; Mn-containing 2+ and ammonia nitrogen mine water pH range is 6.0-8.0; Mn-containing 2+ and ammonia nitrogen Mn in mine water 2+ The initial mass concentrations of manganese and ammonia nitrogen were 0.5-20 and 1-20 mg / L, respectively. After oscillation for 2 h, the mass concentrations of manganese and ammonia nitrogen in the water were less than 0.1 mg / L and 1 mg / L, respectively.

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