Phosphorus and nitrogen removal material from pyrite modified glass lightweight aggregate, preparation method and application thereof

Abstract

The present application relates to the field of sewage treatment materials, in particular to a pyrite modified glass lightweight denitrification and dephosphorization material, a preparation method and application thereof. The material is prepared from waste glass, pyrite and calcium-magnesium carbonate as raw materials. The material prepared by the present application has the functions of denitrification and dephosphorization in addition to the filtration and adsorption functions due to the addition of pyrite and sulfur, and has a wider application in the field of water treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sewage treatment materials, in particular to a preparation method and application of a pyrite modified glass lightweight stone denitrification and phosphorus removal material. BACKGROUND

[0002] Glass lightweight stone using waste glass as raw material is widely used, which is light in quality, porous, high in strength, non-toxic and harmless, and has the functions of "infiltration, lag, storage, purification, use and discharge", and is an ideal sponge city construction material. Such glass lightweight stone using waste glass as raw material is mainly used in the form of filter material in the field of water treatment, mainly through filtration and adsorption to reduce suspended solids and other impurities in water. The glass lightweight stone filter for water treatment (CN213221100) uses glass lightweight stone as filter material, and after adsorption and filtration of the glass lightweight stone, the suspended solids and ammonia nitrogen in the water are effectively reduced. In addition, the patent "Glass lightweight stone with phosphorus removal function and preparation method thereof" (CN114105473A) proposes a glass lightweight stone with phosphorus removal function made of glass powder and ferric oxide as raw materials, which has a faster phosphorus removal effect than ordinary glass lightweight stone. It can be seen that the glass lightweight stone material using waste glass as raw material has great application potential in the field of water treatment.

[0003] Autotrophic denitrification is increasingly valued due to its low operating cost, simple operation and no need for external carbon source. Pyrite is a natural mineral resource that is abundant in nature. Studies have shown that a biological filter constructed with pyrite as filler can effectively remove nitrogen and phosphorus from wastewater. However, due to the small number of active sites on the surface of natural pyrite, small specific surface area, and high density, more and more studies have been conducted on the preparation of modified fillers based on pyrite. Practice has shown that pyrite modified fillers have higher nitrogen and phosphorus removal efficiency than natural pyrite.

[0004] In summary, the present application aims to prepare a modified glass lightweight stone denitrification and phosphorus removal material using waste glass and pyrite as raw materials. On the one hand, waste glass is reused to fully utilize the advantages of lightweight and porosity of glass lightweight stone, and on the other hand, the shortcomings of natural pyrite such as high density and small specific surface area are improved to produce a material with denitrification and phosphorus removal function, thereby expanding the application of glass lightweight stone in water treatment.

[0005] Currently, research on modified glass lightweight stone materials mainly focuses on producing lightweight and porous glass lightweight stone materials for use as filter material in sponge city water storage and municipal sewage treatment, mainly to remove suspended solids and adsorb impurities in wastewater, which has low treatment efficiency and limited application approach. SUMMARY

[0006] The present application is directed to the above-mentioned technical problems and provides a pyrite modified glass lightweight stone denitrification and phosphorus removal material, a preparation method and application thereof.

[0007] The object of the present application can be realized by the following technical solutions.

[0008] A preparation method of a pyrite modified glass lightweight stone denitrification and dephosphorization material, the steps of the method are as follows:

[0009] Step one: grind and screen separate the waste glass, pyrite and calcium magnesium carbonate according to the particle size of 100-150 mu m;

[0010] Step two: after the raw materials in step one are uniformly mixed, they are sent into a heating furnace for sintering; wherein: the mass ratio of waste glass, pyrite and calcium magnesium carbonate is 80-90:2-10:2-10;

[0011] Step three: add 1%-5% of pyrite powder to the sintered material in step two and put them into a tube furnace together for calcination, and then cool to room temperature after calcination is completed;

[0012] Step four: uniformly disperse sodium thiosulfate powder in water by ultrasonic dispersion to obtain a sodium thiosulfate solution;

[0013] Step five: place the material obtained in step three in the sodium thiosulfate solution, ultrasonically treat again, and then filter for use;

[0014] Step six: place the material obtained in step five in an oven for drying, then put it into a tube furnace for calcination, and finally cool to room temperature to obtain the target product.

[0015] In the technical scheme of the present application: the sintering process in step two is as follows:

[0016] ① The raw materials enter the preheating zone at a temperature of 550-650 DEG C, and the preheating time is 5-10 minutes;

[0017] ② The preheated raw materials enter the temperature rising zone at 700-800 DEG C, and the temperature rising time is 15-25 minutes;

[0018] ③ The heated raw materials enter the melting zone at 850-900 DEG C, and the melting time is 15-30 minutes;

[0019] ④ The raw materials in the molten state enter the sintering zone at 950-1200 DEG C, and the sintering time is 5-10 minutes;

[0020] ⑤ Cooling, the glass lightweight stone formed by sintering in ④ is cooled to room temperature.

[0021] In the technical scheme of the present application: the particle size of the pyrite powder in step three is 100-150 mu m.

[0022] In the technical scheme of the present application: the calcination atmosphere in step three is nitrogen, the N2 flow rate is 30-40 mL / min; the calcination temperature is 80-100 DEG C, and the calcination time is 30-50 min.

[0023] In the technical scheme of the present application: in step four, the mass concentration of the sodium thiosulfate solution is 1-2%, the ultrasonic frequency is 20-40 kHz, and the ultrasonic time is 15-30 min.

[0024] In the technical scheme of the present application: in step five, the ultrasonic treatment condition is that the ultrasonic frequency is 40-50 kHz, and the ultrasonic time is 4-6 h.

[0025] In the technical scheme of the present application: in step six, the drying temperature is 95-105 DEG C, the time is 1-2 h, the atmosphere of the calcination is nitrogen, the N2 flow is 30-40 mL / min, the calcination temperature is 140-150 DEG C, and the calcination time is 30-50 min.

[0026] A pyrite modified glass lightweight stone denitrification and dephosphorization material is prepared by the method.

[0027] In the technical scheme of the present application: the application of the above-mentioned pyrite modified glass lightweight stone denitrification and dephosphorization material in water treatment. Further, the application is a filter, an adsorbent or a denitrification and dephosphorization agent.

[0028] The beneficial effects of the present application are as follows:

[0029] 1. The porous glass lightweight stone is used as a skeleton material to improve the denitrification and dephosphorization effect, compared with the traditional porous material, which is more beneficial to the reaction mass transfer and the enrichment of pollutants.

[0030] 2. The material prepared by the present application has the functions of denitrification and dephosphorization in addition to the filtration and adsorption functions due to the addition of pyrite and sulfur, and the application in the field of water treatment is more extensive.

[0031] 3. The material prepared by the present application has a simple preparation method, the raw materials are cheap and easy to obtain, is not easy to be cemented, can be reused, effectively reduces the cost of pollutant treatment, does not contain toxic and harmful substances, and does not cause potential environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a total nitrogen effect diagram of the material prepared in Example 1. Fig. 1 FIG. 2 is a total phosphorus effect diagram of the material prepared in Example 1.

[0033] FIG. 3 is a total nitrogen effect diagram of the material prepared in Example 2. Fig. 2 FIG. 4 is a total phosphorus effect diagram of the material prepared in Example 2. DETAILED DESCRIPTION

[0034] The present application will be further described in conjunction with the examples, but the protection scope of the present application is not limited thereto:

[0035] Example 1

[0036] Step one: the waste glass, pyrite, calcium magnesium carbonate are ground and screened according to the particle size of 100-150 μm and separated;

[0037] Step two: the waste glass, pyrite, calcium magnesium carbonate are mixed uniformly according to the mass ratio of 90:8:2 and then sent into a heating furnace for sintering. First, the raw materials enter the preheating zone at a temperature of 580℃, and the preheating time is 7 minutes. The preheated raw materials enter the temperature rising zone at 750℃, and the temperature rising time is 20 minutes. The temperature-risen raw materials enter the melting zone at 860℃, and the melting time is 20 minutes. The melted raw materials enter the sintering zone at 1000℃, and the sintering time is 8 minutes. Finally, the sintered glass pumice is cooled to room temperature.

[0038] Step three: the sintered material in step two is added with pyrite powder (100-150 μm) at a mass ratio of 4%, and the tube furnace is set to be baked at 100℃ under N2 flow of 40 mL / min for 30 min.

[0039] Step four: a sodium thiosulfate solution is configured, and the mass concentration of the sodium thiosulfate solution is 1%. The ultrasonic frequency is set to be 30 kHz, and the ultrasonic mixing time is 15 min.

[0040] Step five: the ultrasonic frequency is set to be 50 kHz, and after ultrasonic immersion for 4 h, the material is taken out, filtered, and drained for standby use.

[0041] Step six: the material obtained in step five is placed in an oven and dried at a temperature of 101℃ for 2 h, and then placed in a tube furnace and baked at 145℃ under N2 flow of 40 mL / min for 50 min, and then taken out and cooled to room temperature.

[0042] Example 2

[0043] Step one: the waste glass, pyrite, calcium magnesium carbonate are ground and screened according to the particle size of 100-150 μm and separated;

[0044] Step two: the waste glass, pyrite, calcium magnesium carbonate are mixed uniformly according to the mass ratio of 80:10:10 and then sent into a heating furnace for sintering. First, the raw materials enter the preheating zone at a temperature of 560℃, and the preheating time is 5 minutes. The preheated raw materials enter the temperature rising zone at 720℃, and the temperature rising time is 15 minutes. The temperature-risen raw materials enter the melting zone at 850℃, and the melting time is 15 minutes. The melted raw materials enter the sintering zone at 960℃, and the sintering time is 5 minutes. Finally, the sintered glass pumice is cooled to room temperature.

[0045] Step three: the sintered material in step two is added with 5% pyrite powder (100-150 μm) by mass, and the tube furnace is set to 80°C and N2 flow rate of 30 mL / min for roasting for 50 min;

[0046] Step four: a sodium thiosulfate solution is prepared with a mass concentration of 2%, and the ultrasonic frequency is set to 30 kHz for ultrasonic mixing for 30 min.

[0047] Step five: the ultrasonic frequency is set to 50 kHz, and after ultrasonic immersion for 6 h, the material is taken out, filtered, and drained for standby use.

[0048] Step six: the material obtained in step five is placed in an oven and dried at 101°C for 2 h, and then placed in a tube furnace and roasted at 140°C and N2 flow rate of 40 mL / min for 50 min, and then taken out and cooled to room temperature.

[0049] Application example 1

[0050] The pyrite modified glass lightweight denitrification and dephosphorization material prepared in example 1 is used to treat laboratory simulated wastewater, and the hydraulic retention time is set to 2 h, and the TN and TP of the effluent water quality are monitored. After 30 days of monitoring, the total nitrogen concentration of the effluent water is <5 mg / L, and the removal rate is more than 65%; the total phosphorus concentration of the effluent water is <0.2 mg / L, and the removal rate is more than 60%, and the specific data are shown in Table 1. Figs. 1-2 Table 1

Claims

1. A method for preparing a nitrogen and phosphorus removal material from pyrite-modified glass pumice, characterized in that: The steps of this method are as follows: Step 1: Grind and screen the waste glass, pyrite, and calcium magnesium carbonate according to a particle size of 100~150μm; Step 2: After the raw materials in Step 1 are mixed evenly, they are sent to the heating furnace for sintering. The mass ratio of waste glass, pyrite, and calcium magnesium carbonate is 80~90:2~10:2~10. Step 3: Add 1% to 5% by mass of pyrite powder to the sintered material from Step 2 and place it together in a tube furnace for roasting. After roasting, cool to room temperature. Step 4: Add sodium thiosulfate powder to water and disperse it evenly by ultrasonication to obtain sodium thiosulfate solution; Step 5: Place the material obtained in Step 3 in a sodium thiosulfate solution, sonicate it again, and then filter it for later use; Step Six: Place the material obtained in Step Five in an oven to dry, then place it in a tube furnace for calcination, and finally cool it to room temperature to obtain the target product; The sintering process in step two is as follows: ①The raw materials enter the preheating zone at a temperature of 550-650℃, and the preheating time is 5-10 minutes; ②The preheated raw materials are placed in a heating zone of 700-800℃, and the heating time is 15-25 minutes; ③The heated raw material enters the melting zone at 850-900℃, and the melting time is 15-30 minutes; ④ The molten raw material enters the sintering zone at 950-1200℃ and the sintering time is 5-10 minutes; ⑤ Cooling: Cool the glass pumice formed by sintering in ④ to room temperature; The roasting atmosphere in step three is nitrogen, with an N2 flow rate of 30–40 mL / min; the roasting temperature is 80–100℃, and the roasting time is 30–50 min. In step six, the drying temperature is 95~105℃ and the time is 1~2h; the calcination atmosphere is nitrogen, the N2 flow rate is 30~40mL / min; the calcination temperature is 140~150℃ and the calcination time is 30~50min.

2. The preparation method according to claim 1, characterized in that: In step three, the particle size of the pyrite powder is 100~150μm.

3. The preparation method according to claim 1, characterized in that: In step four, the mass concentration of the sodium thiosulfate solution is 1-2%, and the ultrasonic conditions are: ultrasonic frequency 20-40 kHz, ultrasonic time 15-30 min.

4. The preparation method according to claim 1, characterized in that: In step five, the conditions for ultrasonic treatment are: ultrasonic frequency of 40–50 kHz and ultrasonic time of 4–6 h.

5. A denitrification and dephosphorization material made from pyrite-modified glass pumice, characterized in that: The material is prepared by the method described in any one of claims 1 to 4.

6. The application of the material obtained by the method according to any one of claims 1 to 4 in water treatment.

7. The application according to claim 6, characterized in that: The application is as a filter, adsorbent, or denitrification and phosphorus removal agent.

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