Composite filter material for antimony-containing wastewater treatment as well as preparation method and application of composite filter material

Abstract

The invention relates to the technical field of sewage treatment, and particularly discloses a composite filter material for antimony-containing wastewater treatment and a preparation method and application thereof. The composite filter material for antimony-containing wastewater treatment provided by the invention is prepared from sludge, biochar, calcium hydroxide and water in a weight ratio of 1: (0.1-0.6): (0.4-1.2): (0.5-2), wherein the sludge is obtained by carrying out alkali-adding neutralization treatment, mud-water separation and drying on iron-containing acid mine wastewater, the iron content in the sludge is 30-50wt%, the biochar is prepared by carrying out high-temperature carbonization on biomass fermentation residues, and the particle size of the biochar is 1-4mm; the invention further provides a treatment method of the antimony-containing wastewater. The composite filter material for antimony-containing wastewater treatment provided by the invention can effectively adsorb antimony in antimony-containing wastewater, so that the treated effluent meets the sewage discharge standard.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to a composite filter material for treating antimony-containing wastewater, and a preparation method and application thereof. Background Art

[0002] Antimony-containing wastewater treatment has been a focus of environmental protection in recent years. Due to the widespread use of antimony in industrial production, the discharge of antimony-containing wastewater has increased year by year, which not only causes serious pollution to the environment, but also threatens human health. In view of this, it is particularly important to research and develop efficient antimony-containing wastewater treatment technology, which not only helps environmental protection, but also reduces water resource waste, improves water quality, and promotes sustainable development.

[0003] Existing technologies for treating antimony-containing wastewater mainly include chemical precipitation, adsorption, ion exchange, etc. Among them, the chemical precipitation method is to precipitate antimony by adding chemical reagents, which has the advantages of simple operation and high efficiency, but this method is mainly used to treat wastewater with high antimony content, and the cost of the chemical reagents used is high, so the scope of use is limited. The adsorption method is to use various adsorbents to effectively remove antimony ions, but the adsorbents can usually only be used once and cannot be reused, resulting in high operating costs. The ion exchange method is to selectively exchange antimony ions through ion exchange resins, but the working time of ion exchange resins is short and needs to be replaced frequently, and the cost of ion exchange resins is high, so this method cannot be widely promoted and used. Summary of the invention

[0004] In order to overcome the defects of the existing antimony-containing wastewater treatment technology, such as high cost and inability to be widely promoted and used, the present application provides a composite filter material for antimony-containing wastewater treatment, and a preparation method and application thereof.

[0005] In a first aspect, the present application provides a composite filter material for treating antimony-containing wastewater, using the following technical solution: A composite filter material for treating antimony-containing wastewater is prepared from sludge, biochar, calcium hydroxide and water in a weight ratio of 1: (0.1-0.6): (0.4-1.2): (0.5-2).

[0006] The present application uses sludge, biochar, calcium hydroxide, etc. to prepare a composite filter material with significant adsorption performance and stability. By mixing sludge, biochar, calcium hydroxide and water according to the above-mentioned specific weight ratio, the obtained composite filter material has a good pore structure and a large specific surface area, which can effectively adsorb antimony ions in wastewater, so that the antimony content in the treated effluent can be as low as 0.3 mg / L or less. Specifically, sludge has a good specific adsorption treatment effect on antimony ions; biochar, as a precursor of activated carbon, has a high adsorption capacity and chemical stability, which can not only improve the overall adsorption efficiency of the composite filter material for antimony, but also improve the mechanical strength and durability of the filter material to a certain extent. In summary, the composite filter material provided by the present application has the advantages of low raw material cost, good adsorption, and good stability. When applied to the treatment process of antimony-containing wastewater, it can significantly reduce the antimony content in antimony-containing wastewater, so that the antimony content of the effluent can meet the national emission standards.

[0007] Optionally, the weight ratio of the sludge, biochar, calcium hydroxide and water is 1:(0.2-0.4):(0.6-1.0):(0.5-2).

[0008] In some embodiments, the weight ratio of the sludge, biochar, calcium hydroxide and water can be 1: (0.1-0.2): 0.8: 1, 1: (0.1-0.3): 0.8: 1, 1: (0.1-0.4): 0.8: 1, 1: (0.1-0.6): 0.8: 1, 1: (0.2-0.3): 0.8: 1, (0.2-0.4): 0.8: 1, 1: (0.2-0.6): 0.8: 1, (0.3-0.4): 0.8: 1, (0.3-0.6): 0.8: 1, (0.4 -0.6):0.8:1, 1:0.3:(0.4-0.6):1, 1:0.3:(0.4-0.8):1, 1:0.3:(0.4-1.0):1, 1:0.3:(0.4-1.2):1, 1:0.3:(0.6-0.8):1, 1:0.3:(0.6-1.0):1, 1:0.3:(0.6-1.2):1, 1:0.3:(0.8-1.0):1, 1:0.3:(0.8-1.2):1 or 1:0.3:(1.0-1.2):1.

[0009] In a specific embodiment, the weight ratio of the sludge, biochar, calcium hydroxide and water can also be 1:0.1:0.8:1, 1:0.2:0.8:1, 1:0.3:0.8:1, 1:0.4:0.8:1, 1:0.6:0.8:1, 1:0.3:0.4:1, 1:0.3:0.6:1, 1:0.3:1.0:1 or 1:0.3:1.2:1.

[0010] Optionally, the sludge is obtained by neutralizing iron-containing acidic mine wastewater with alkali, separating mud and water, and drying, and the iron content in the sludge is 30-50wt%.

[0011] In this application, the high iron-containing sludge obtained by alkali neutralization treatment and mud-water separation of iron-containing acidic mine wastewater is used as one of the raw materials of the composite filter material, which can significantly improve the treatment effect of the composite filter material for antimony-containing wastewater. Specifically, the iron content in the high iron-containing sludge is controlled within the range of 30-50wt%, which not only has good adsorption properties, but also enhances the structural stability and mechanical strength of the composite filter material. In addition, the high iron-containing sludge also has good heavy metal capture ability, which can effectively remove antimony ions in the wastewater during the treatment process, thereby achieving a good purification effect and ensuring that the effluent meets environmental protection emission standards.

[0012] Optionally, the iron content in the sludge is 35-45wt%.

[0013] In this application, it was found through experimental research that by further controlling the iron content in the sludge within the above range, the obtained composite filter material has more stable adsorption performance and higher antimony removal efficiency, and can reduce the antimony content in antimony-containing wastewater to below 0.2 mg / L.

[0014] In some embodiments, the iron content in the sludge may be 30-35wt%, 30-40wt%, 30-45wt%, 30-50wt%, 35-40wt%, 35-45wt%, 35-50wt%, 40-45wt%, 40-50wt% or 45-50wt%.

[0015] In a specific embodiment, the iron content in the sludge may also be 30 wt%, 35 wt%, 40 wt%, 45 wt% or 50 wt%.

[0016] In some embodiments, the particle size of the composite filter material may be 3-6 mm, 3-8 mm, 3-10 mm, 3-12 mm, 6-8 mm, 6-10 mm, 6-12 mm, 8-10 mm, 8-12 mm, or 10-12 mm.

[0017] In a specific embodiment, the particle size of the composite filter material may also be 3 mm, 6 mm, 8 mm, 10 mm or 12 mm.

[0018] Optionally, the biochar is prepared by high-temperature carbonization of biomass fermentation residue, and the particle size of the biochar is 1-4 mm.

[0019] Optionally, the method for preparing the biochar is: heating the biomass fermentation residue to 300-700° C. at a heating rate of 5-15° C., and carbonizing at the above temperature for 1.5-3 h to obtain the biochar.

[0020] Optionally, the particle size of the composite filter material is 3-12 mm.

[0021] In a second aspect, the present application provides a method for preparing a composite filter material for treating antimony-containing wastewater.

[0022] A method for preparing a composite filter material for treating antimony-containing wastewater comprises the following steps: sludge, biochar, calcium hydroxide and water are mixed in proportion, and the mixture is granulated and dried to obtain the composite filter material.

[0023] In a third aspect, the present application provides an application of a composite filter material for treating antimony-containing wastewater in treating antimony-containing wastewater.

[0024] A method for treating antimony-containing wastewater comprises the following steps: passing the antimony-containing wastewater through a wastewater treatment tank pre-placed with the composite filter material for treating antimony-containing wastewater, maintaining the hydraulic retention time of the antimony-containing wastewater in the treatment tank at 6-12 hours, and discharging the water; the pH of the antimony-containing wastewater is ≥4, and the antimony concentration is ≤10 mg / L.

[0025] The present application proposes a simple-to-operate, low-cost treatment method for antimony-containing wastewater with the specific property of "pH ≥ 4, antimony concentration ≤ 10 mg / L". The treatment method can reduce the antimony concentration in the antimony-containing wastewater to below 0.3 mg / L by adjusting the hydraulic retention time to the above range, so that the effluent meets the environmental emission standards and has a good prospect for use.

[0026] In some embodiments, the hydraulic retention time may be 6-10 h or 10-12 h.

[0027] In a specific embodiment, the hydraulic retention time can also be 6 h, 10 h or 12 h.

[0028] In some embodiments, the antimony concentration of the antimony-containing wastewater may be 2.6-5.4 mg / L or 5.4-8.2 mg / L.

[0029] In a specific embodiment, the antimony concentration of the antimony-containing wastewater may also be 2.6 mg / L, 5.4 mg / L or 8.2 mg / L.

[0030] In summary, this application has the following beneficial effects: 1. This application uses sludge, biochar, calcium hydroxide and water in a weight ratio of 1: (0.1-0.6): (0.4-1.2): (0.5-2) to prepare a composite filter material for treating antimony-containing wastewater. The composite filter material has a good pore structure and a large specific surface area, can effectively adsorb antimony ions in the wastewater, and significantly reduce the antimony content in the antimony-containing wastewater, so that the antimony content of the effluent can be as low as 0.3 mg / L or less, thereby meeting the national emission standards.

[0031] 2. The present application further controls the weight ratio of sludge, biochar, calcium hydroxide and water within the range of 1: (0.2-0.4): (0.6-1.0): (0.5-2), the iron content in the sludge is controlled within the range of 35-45wt%, the particle size of the composite filter material is controlled within the range of 6-10mm, and the antimony content of the effluent obtained can be as low as below 0.2mg / L.

[0032] 3. The treatment method for antimony-containing wastewater provided in this application is suitable for treating antimony-containing wastewater with "pH ≥ 4, antimony concentration ≤ 10 mg / L". By controlling the hydraulic retention time in the treatment method within the range of 6-12h, it can significantly and effectively remove antimony ions in the wastewater, thereby achieving better purification effect and ensuring that the effluent meets environmental protection emission standards. DETAILED DESCRIPTION

[0033] In a first aspect, the present application provides a composite filter material for treating antimony-containing wastewater, and the preparation method thereof comprises the following steps: mixing sludge, biochar, calcium hydroxide and water in a weight ratio of 1: (0.1-0.6): (0.4-1.2): (0.5-2), granulating and drying to obtain a composite filter material with a particle size of 3-12 mm. Furthermore, the weight ratio of the sludge, biochar, calcium hydroxide and water is 1: (0.2-0.4): (0.6-1.0): (0.5-2).

[0034] The sludge preparation method comprises: adding alkali to the iron-containing acidic mine wastewater until the pH is 6-8 for full reaction, and then performing mud-water separation, collecting the dehydrated sludge for standby use. The iron content in the sludge is 30-50wt%. Furthermore, the iron content in the sludge is 35-45wt%.

[0035] The biochar preparation method comprises: heating the biomass fermentation residue to 300-700°C at a heating rate of 5-15°C, carbonizing at the above temperature for 1.5-3h to obtain biochar with a particle size of 1-4mm.

[0036] In a second aspect, the present application provides a method for treating antimony-containing wastewater, comprising the following steps: passing the antimony-containing wastewater through a wastewater treatment tank in which the composite filter material is pre-placed, maintaining the hydraulic retention time of the antimony-containing wastewater in the treatment tank at 6-12 hours, and discharging the water; the pH of the antimony-containing wastewater is ≥4 and the antimony concentration is ≤10 mg / L.

[0037] The raw materials, reagents, solvents, etc. used in this application can be obtained commercially.

[0038] The present application is further described in detail below in combination with preparation examples, embodiments and performance testing experiments. Preparation Example 1-9

[0039] Preparation Examples 1-9 respectively provide a composite filter material for treating antimony-containing wastewater.

[0040] The difference between the above preparation examples is that the addition amount of each raw material for preparing the composite filter material is shown in Table 1 below.

[0041] The preparation method of the composite filter material provided in Preparation Example 1-9 comprises the following steps: mixing sludge with an iron content of 40%, biochar with a particle size of 2±1 mm, calcium hydroxide and water in the weight ratio shown in Table 1, granulating and drying to obtain a composite filter material with a particle size of 8 mm.

[0042] Table 1 Weight ratio of each raw material in the composite filter material provided in Preparation Examples 1-9 Preparation Example 10-13

[0043] Preparation Examples 10-13 respectively provide a composite filter material for treating antimony-containing wastewater.

[0044] The difference between the above preparation example and preparation example 3 is that the iron content of the sludge in the composite filter material is specifically shown in Table 2 below.

[0045] Table 2 Iron content of sludge in the composite filter material provided by Preparation Examples 3 and 10-13 Preparation Examples 14-17

[0046] Preparation Examples 14-17 respectively provide a composite filter material for treating antimony-containing wastewater.

[0047] The difference between the above preparation example and preparation example 3 is that the particle size of the composite filter material is specifically shown in Table 3 below.

[0048] Table 3 Particle size of the composite filter material provided in Preparation Example 3 and Preparation Examples 14-17 Comparative Preparation Example 1

[0049] Comparative Preparation Example 1 provides a composite filter material for treating antimony-containing wastewater.

[0050] The difference between the above preparation example and preparation example 3 is that the weight ratio of sludge, biochar, calcium hydroxide and water is 1:1:0.2:1. Comparative Preparation Example 2

[0051] Comparative Preparation Example 2 provides a composite filter material for treating antimony-containing wastewater.

[0052] The difference between the above Preparation Example and Preparation Example 3 is that the weight ratio of sludge, biochar, calcium hydroxide and water is 0.5:1:1:1. Examples 1-17

[0053] Examples 1-17 each provide a method for treating antimony-containing wastewater.

[0054] The difference between the above embodiments is that the composite filter materials used in the method for treating antimony-containing wastewater are derived from Preparation Examples 1-17 respectively.

[0055] The method for treating antimony-containing wastewater provided in Examples 1-17 comprises the following steps: passing the antimony-containing wastewater with a pH of 4.7 and an antimony concentration of 8.2 mg / L through a wastewater treatment tank in which a composite filter material is pre-placed, maintaining the hydraulic retention time of the antimony-containing wastewater in the treatment tank at 10 hours, discharging the water, and obtaining treated wastewater. Embodiment 18

[0056] Example 18 provides a method for treating antimony-containing wastewater.

[0057] The difference between the above embodiment and embodiment 3 is that the hydraulic retention time in the treatment method of antimony-containing wastewater is 6 hours. Embodiment 19

[0058] Example 19 provides a method for treating antimony-containing wastewater.

[0059] The difference between the above embodiment and embodiment 3 is that the hydraulic retention time in the treatment method of antimony-containing wastewater is 12 hours. Embodiment 20

[0060] Example 20 provides a method for treating antimony-containing wastewater.

[0061] The difference between the above embodiment and embodiment 3 is that the antimony-containing wastewater is replaced by antimony-containing wastewater with a pH of 5.3 and an antimony concentration of 2.6 mg / L. Embodiment 21

[0062] Example 21 provides a method for treating antimony-containing wastewater.

[0063] The difference between the above embodiment and embodiment 3 is that the antimony-containing wastewater is replaced by antimony-containing wastewater with a pH of 6.3 and an antimony concentration of 5.4 mg / L. Comparative Example 1-2

[0064] Comparative Examples 1-2 respectively provide a method for treating antimony-containing wastewater.

[0065] The difference between the above comparative example and Example 3 is that the composite filter materials used in the method for treating antimony-containing wastewater are derived from comparative preparation examples 1-2 respectively. Comparative Example 3

[0066] Comparative Example 3 provides a method for treating antimony-containing wastewater.

[0067] The difference between the comparative example and Example 3 is that the hydraulic retention time in the treatment method of antimony-containing wastewater is 4h. Comparative Example 4

[0068] Comparative Example 4 provides a method for treating antimony-containing wastewater.

[0069] The difference between the comparative example and Example 3 is that the antimony-containing wastewater is replaced by antimony-containing wastewater with a pH of 5.8 and an antimony concentration of 12.5 mg / L. Performance testing

[0070] The antimony content in the treated wastewater obtained in Examples 1-21 and Comparative Examples 1-4 was tested, and the results are shown in Table 4 below.

[0071] The detection method of antimony content is: use the atomic fluorescence method of "Determination of Mercury, Arsenic, Selenium, Bismuth and Antimony in Water Quality" HJ 694-2014 to detect the antimony content in water quality. Note: The emission limit of the enterprise water pollutant "Tin" stipulated in the "Tin, Antimony and Mercury Industrial Pollutant Emission Standard" GB30770-2014 is 0.3mg / L.

[0072] Table 4 Antimony content in treated wastewater obtained from Examples 1-21 and Comparative Examples 1-4

[0073] The test results in Table 4 show that after treating the antimony-containing wastewater using the treatment method for antimony-containing wastewater provided in Example 1-21, the antimony concentration of the effluent is 0.14-0.28 mg / L (<0.3 mg / L), which meets the water pollutant discharge standard; while after treating the antimony-containing wastewater using the treatment method for antimony-containing wastewater provided in Comparative Example 1-4, the antimony concentration of the effluent is still as high as 0.66-1.64 mg / L (>0.3 mg / L), which does not meet the water pollutant discharge standard. Therefore, it is explained that the present application uses sludge, biochar, calcium hydroxide and water to prepare a composite filter material, and controls the weight ratio of the four within the range of 1: (0.1-0.6): (0.4-1.2): (0.5-2), and the prepared composite material has a good treatment effect on antimony-containing wastewater with "antimony concentration ≤ 10 mg / L", and can reduce the antimony concentration of antimony-containing wastewater to below 0.3 mg / L, so that the antimony content of the effluent can meet the national emission standards.

[0074] The test results of Examples 1-9 show that after treating the antimony-containing wastewater using the treatment methods of Examples 1, 5-6, and 9, the antimony concentration of the effluent is 0.21-0.26 mg / L; while after treating the antimony-containing wastewater using the treatment methods of Examples 2-4 and 7-8, the antimony concentration of the effluent is 0.15-0.19 mg / L (<0.2 mg / L). Therefore, it is explained that the present application further controls the weight ratio of sludge, biochar, calcium hydroxide, and water within the range of 1: (0.2-0.4): (0.6-1.0): (0.5-2), and the obtained composite filter material has a better treatment effect on antimony-containing wastewater.

[0075] From the test results of Example 3 and Examples 10-13, it can be seen that with the increase of the iron content in the sludge of the composite filter material, the antimony concentration of the effluent after treating the antimony-containing wastewater shows a trend of first decreasing and then increasing; further comparison shows that Example 3 and Examples 11-12 control the iron content in the sludge within the range of 35-45wt%, and the obtained composite filter material has a more stable adsorption performance and a higher antimony removal efficiency, which can reduce the antimony content in the antimony-containing wastewater to below 0.2mg / L.

[0076] From the test results of Example 3 and Examples 14-17, it can be seen that with the increase of the particle size of the composite filter material, the antimony concentration of the effluent after treating the antimony-containing wastewater shows a trend of first decreasing and then increasing; further comparison shows that in Example 3 and Examples 15-16, the particle size of the composite filter material is controlled within the range of 6-10 mm, and the obtained composite filter material has a more stable adsorption performance and a higher antimony removal efficiency, which can reduce the antimony content in the antimony-containing wastewater to below 0.2 mg / L.

[0077] From the test results of Example 3, Examples 18-19, and Comparative Example 3, it can be seen that after the antimony-containing wastewater is treated by the treatment methods of Example 3 and Examples 18-19, the antimony concentration of the effluent is 0.14-0.25 mg / L; and after the antimony-containing wastewater is treated by the treatment method of Comparative Example 3, the antimony concentration of the effluent is 1.17 mg / L, indicating that in the method for treating antimony-containing wastewater in this application, the hydraulic retention time is controlled within the range of 6-12h, which can reduce the antimony concentration in the antimony-containing wastewater to below 0.3 mg / L.

[0078] The test results of Example 3, Example 20-21, and Comparative Example 4 show that in Example 3 and Example 20-21, when the antimony content of the antimony-containing wastewater is ≤10 mg / L, the antimony concentration of the treated effluent can be less than 0.3 mg / L; and when the antimony content of the antimony-containing wastewater is greater than 10 mg / L (the antimony content of Comparative Example 4 is as high as 12.5 mg / L), the antimony concentration of the treated effluent is 1.64 mg / L (>0.3 mg / L), which does not meet the water pollutant discharge standard. Therefore, it is shown that the treatment method of antimony-containing wastewater provided in this application is suitable for treating antimony-containing wastewater with the specific property of "antimony concentration ≤10 mg / L", and has a good treatment effect on the above antimony-containing wastewater.

[0079] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A composite filter material for treating antimony-containing wastewater, characterized in that: It is prepared by using sludge, biochar, calcium hydroxide and water in a weight ratio of 1: (0.1-0.6): (0.4-1.2): (0.5-2).

2. The composite filter material for treating antimony-containing wastewater according to claim 1, characterized in that: The weight ratio of the sludge, biochar, calcium hydroxide and water is 1: (0.2-0.4): (0.6-1.0): (0.5-2).

3. The composite filter material for treating antimony-containing wastewater according to claim 1, characterized in that: The sludge is obtained by neutralizing iron-containing acidic mine wastewater with alkali, separating mud and water, and drying. The iron content in the sludge is 30-50wt%.

4. The composite filter material for treating antimony-containing wastewater according to claim 3, characterized in that: The iron content in the sludge is 35-45wt%.

5. The composite filter material for treating antimony-containing wastewater according to claim 1, characterized in that: The biochar is prepared by high-temperature carbonization of biomass fermentation residues, and the particle size of the biochar is 1-4 mm.

6. The composite filter material for treating antimony-containing wastewater according to claim 5, characterized in that: The method for preparing the biochar comprises: heating the biomass fermentation residue to 300-700° C. at a heating rate of 5-15° C., and carbonizing at the above temperature for 1.5-3 hours to obtain the biochar.

7. The composite filter material for treating antimony-containing wastewater according to any one of claims 1 to 6, characterized in that: The particle size of the composite filter material is 3-12 mm.

8. The method for preparing a composite filter material for treating antimony-containing wastewater according to any one of claims 1 to 7, characterized in that: The following steps are involved: The sludge, biochar, calcium hydroxide and water are mixed in proportion, granulated and dried to obtain a composite filter material.

9. Use of the composite filter material for treating antimony-containing wastewater according to any one of claims 1 to 7 in treating antimony-containing wastewater.

10. A method for treating antimony-containing wastewater, characterized in that: The following steps are involved: Passing the antimony-containing wastewater through a wastewater treatment tank pre-placed with a composite filter material for treating antimony-containing wastewater according to any one of claims 1 to 7, maintaining the hydraulic retention time of the antimony-containing wastewater in the treatment tank at 6 to 12 hours, and discharging the water; The pH of the antimony-containing wastewater is ≥4 and the antimony concentration is ≤10 mg / L.

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