A biological filler, preparation method and application thereof in sewage treatment

Abstract

The present invention provides a biological filler, a preparation method, and its application in sewage treatment. The method involves biologically treating slag produced during the beneficiation of low-grade sulfide ore, followed by drying and screening to obtain a target filler required for the sulfur autotrophic denitrification process. Since the target filler primarily comprises pyrite, pyrrhotite, and metal-deficient polysulfides, it can provide the energy required for the growth and metabolism of iron-sulfur autotrophic denitrification bacteria, thereby achieving efficient removal of ammonia nitrogen, COD, total phosphorus, and a small amount of heavy metals, effectively reducing pollutant emissions from industrial and domestic wastewater. The method also produces virtually no sludge, avoiding sludge bulking and subsequent disposal. Furthermore, the method effectively utilizes waste rock and tailings generated by mining activities as resources, reducing land use and the generation of solid waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a biological filler, a preparation method and application thereof in sewage treatment. Background Art

[0002] my country boasts abundant nonferrous metal resources across a wide variety of categories. With the rapid development of the nation's industry and technology, demand for nonferrous metals has steadily increased, leading to a corresponding increase in the discharge and storage of waste rock and tailings. These large-scale waste rock and tailings deposits not only consume significant land resources but also pose a high-energy risk of man-made debris flows, posing a risk of dam failure and potentially causing serious accidents. Therefore, the utilization of these low-grade, complex slags has long been a research priority and a technical challenge within the industry.

[0003] Currently, my country's accumulated waste rock and tailings stockpile has reached over 70 billion tons. These waste rock and tailings primarily include sulfide minerals, quartz, feldspar, and mica. These slags contain no valuable components that can be recycled, and their content of environmentally hazardous components does not exceed legal environmental standards. Therefore, they can be utilized holistically according to their strata.

[0004] In addition, in the treatment of pollutants in industrial wastewater and domestic sewage, biological filter beds are used to remove nitrogen and phosphorus. However, the source of raw materials for fillers in biological filter beds is limited and relatively single, and no new available raw materials have been found to be added to the biological filter beds as fillers. Therefore, there is an urgent need to prepare a new type of biological filler that can effectively reduce the emission of pollutants in industrial wastewater and domestic sewage, and effectively utilize the waste rock and tailings generated by mining activities, thereby reducing the generation of storage land and solid waste. Summary of the Invention

[0005] Based on this, the embodiments of the present invention provide a biological filler, a preparation method and its application in sewage treatment, aiming to use waste rock and tailings generated by mining activities as raw materials to prepare filler and apply it to sewage treatment, thereby realizing the resource utilization of waste rock and tailings and achieving the purpose of removing nitrogen and phosphorus in sewage.

[0006] A first aspect of an embodiment of the present invention provides a method for preparing a biofiller, comprising the following steps:

[0007] biologically treating slag produced during the beneficiation of low-grade sulfide ores to obtain a target slurry, wherein the biological treatment comprises mixing the slag with a culture solution at a preset mass ratio to obtain a first slurry, inoculating the first slurry with iron-sulfur oxidizing bacteria at a preset concentration, and stirring under preset conditions to obtain the target slurry;

[0008] The target slurry is filtered, dried and sieved in sequence to obtain the target filler.

[0009] Preferably, the sulfur content in the slag is not less than 10%, and the iron content is not less than 1%.

[0010] Preferably, the iron-sulfur oxidizing bacteria are one or more of Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Leptospirillum ferrooxidans, and the inoculation concentration is not less than 10 8 pcs / ml.

[0011] Preferably, the culture medium is a mixed solution of (NH4)2SO4, KCl, K2HPO4, MgSO4, and Ca(NO3)2.

[0012] Preferably, the pH of the culture solution is 1-5.

[0013] Preferably, the preset mass ratio is 1:4-20.

[0014] Preferably, the pH of the first slurry is 1-5.

[0015] Preferably, the preset conditions are a stirring speed of 30 to 200 rpm, a stirring temperature of 20 to 70° C., and a stirring time of 2 to 24 h.

[0016] A second aspect of the embodiments of the present invention provides a biological filler, which is prepared using the above-mentioned method for preparing the biological filler.

[0017] The third aspect of an embodiment of the present invention provides an application of a biological filler in sewage treatment, wherein the biological filler is prepared by the above-mentioned method for preparing the biological filler, and the biological filler is filled into a filter bed, wherein the implementation temperature of the biological filler is 15°C to 45°C, and the implementation pH value is 6.5 to 8.5.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The target filler required for the sulfur autotrophic denitrification process is obtained by biologically treating the slag produced during the beneficiation of low-grade sulfide ores, followed by drying and screening. Since the target filler primarily consists of pyrite, pyrrhotite, and metal-deficient polysulfides, it provides the energy required for the growth and metabolism of iron-sulfur autotrophic denitrification bacteria, thereby efficiently removing ammonia nitrogen, COD, total phosphorus, and small amounts of heavy metals. This effectively reduces pollutant emissions from industrial and domestic wastewater, while producing virtually no sludge, thus avoiding sludge bulking and subsequent disposal. Furthermore, this method effectively utilizes waste rock and tailings generated by mining activities, reducing land use and solid waste generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a diagram showing the specific removal of sewage for 86 days provided by Comparative Example 1 and Example 1 of the present invention;

[0021] Figure 2 This is a diagram showing the specific removal of sewage over 90 days provided by Comparative Example 2 and Example 2 of the present invention;

[0022] Figure 3 This is a diagram showing the specific removal of sewage over 89 days provided by Comparative Example 3 and Example 3 of the present invention;

[0023] Figure 4 This is a diagram showing the specific removal of sewage over 92 days provided by Comparative Example 4 and Example 4 of the present invention;

[0024] Figure 5 This is a diagram showing the specific removal of sewage over 98 days provided by Comparative Example 5 and Example 5 of the present invention;

[0025] Figure 6 This is a diagram showing the specific removal of sewage over 95 days provided by Comparative Example 6 and Example 6 of the present invention;

[0026] Figure 7 This is a diagram showing the specific removal of sewage for 88 days provided by Comparative Example 7 and Example 7 of the present invention.

[0027] The following specific implementation manner will be further described in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] On the one hand, the present invention provides a method for preparing a biological filler. Figure 1 , which is a flow chart of a method for preparing a biological filler, wherein the preparation method comprises the following steps:

[0032] biologically treating slag produced during the beneficiation of low-grade sulfide ores to obtain a target slurry, wherein the biological treatment comprises mixing the slag with a culture solution at a preset mass ratio to obtain a first slurry, inoculating the first slurry with iron-sulfur oxidizing bacteria at a preset concentration, and stirring under preset conditions to obtain the target slurry;

[0033] The target slurry is filtered, dried and sieved in sequence to obtain the target filler.

[0034] In some embodiments of the present invention, the sulfur content in the slag is not less than 10%, and the iron content is not less than 1%.

[0035] In some embodiments of the present invention, the iron-sulfur oxidizing bacteria are one or more of Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Leptospirillum ferrooxidans, and the inoculation concentration is not less than 10 8 cells / ml. Specifically, Acidithiobacillus ferrooxidans ATCC81800 can be used for Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans ATCC 103932 can be used for Leptospirillum ferrioxidans, and Leptospirillum ferriphilum ATCC 03476 can be used for Leptospirillum ferriphilum.

[0036] In some embodiments of the present invention, the culture medium is a mixed solution of (NH4)2SO4, KCl, K2HPO4, MgSO4, and Ca(NO3)2.

[0037] In some embodiments of the present invention, the pH of the culture solution is 1-5.

[0038] In some embodiments of the present invention, the preset mass ratio is 1:4-20.

[0039] In some embodiments of the present invention, the pH of the first slurry is 1-5.

[0040] In some embodiments of the present invention, the preset conditions are a stirring speed of 30 to 200 rpm, a stirring temperature of 20 to 70° C., and a stirring time of 2 to 24 h.

[0041] Specifically, the actual process of preparing the biological filler can be to mix the slag with a sulfur content of not less than 10% and an iron content of not less than 1% produced in the beneficiation process of low-grade sulfide ore with a culture solution at a preset mass ratio of 1:4 to 20 to obtain a first slurry with a pH of 1 to 5, and then introduce a preset concentration of iron-sulfur oxidizing bacteria into the first slurry, and then stir at a stirring speed of 30 to 200 rpm, a stirring temperature of 20 to 70°C, and a stirring time of 2 to 24 hours to obtain a target slurry. Finally, the target slurry is filtered, dried and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, which are the target filler.

[0042] It should be noted that the surface of the slag treated with iron-sulfur oxidizing bacteria produces a dense biofilm and a passivation film. The biofilm includes polysaccharides, proteins, a small amount of nucleic acids and phospholipids. This biofilm provides a suitable growth and metabolic environment for bacteria, so that the bacteria can attach to the surface of the ore, shortening the adaptation period of the bacteria; the passivation film is mainly metal-deficient polysulfides, which can, on the one hand, avoid the dissolution of other impurity elements in the ore, and on the other hand, provide a source of nutrients such as reduced sulfur for iron-sulfur denitrifying bacteria, thereby enhancing their denitrification and phosphorus removal performance. This is because the precipitate (hydroxyferric sulfate) generated during the oxidation process of the sulfide ore surface has a high specific surface area and positive surface charge, which can adsorb and remove negatively charged phosphorus pollutants. The filler uses slag as raw material, has high mechanical strength, strong impact load resistance, is not prone to compaction and clogging, and enhances the life of the filter bed; at the same time, the preparation process of the filler is simple, does not require sintering, and does not produce any secondary pollution during the process. It can form a microbial community with extremely strong denitrification and phosphorus removal performance and a variety of microorganisms (nitrifying bacteria, heterotrophic denitrifying bacteria, and sulfur autotrophic denitrifying bacteria), creating a microecological environment suitable for the survival of multiple biological phases of bacteria, thereby achieving the purpose of efficiently removing organic pollutants in high-concentration organic wastewater, and almost no sludge is produced, avoiding sludge swelling and subsequent sludge disposal; more importantly, the filler is taken from the tailings pond of the mineral processing plant, which not only avoids the cost of purchasing traditional fillers, but also effectively utilizes the waste rock and tailings generated by mining activities as resources, reduces the generation of stacking land and solid waste, and greatly alleviates the space pressure of the tailings pond.

[0043] On the other hand, the present invention also provides a biological filler prepared by the above-mentioned biological filler preparation method.

[0044] On the other hand, the present invention also proposes an application of a biological filler in sewage treatment. The biological filler is prepared by the above-mentioned biological filler preparation method, and the biological filler is filled into a filter bed, wherein the implementation temperature of the biological filler is 15°C to 45°C, and the implementation pH value is 6.5 to 8.5. It can be understood that the sewage treated with the biological filler should have a temperature of 15°C to 45°C and a pH value of 6.5 to 8.5, which is a slightly alkaline environment.

[0045] To facilitate understanding of the present invention, several embodiments of the present invention are provided below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive disclosure of the present invention.

[0046] The sewage in the comparative example and the embodiment was obtained from the Wannian County Sewage Treatment Plant in Jiangxi Province. The fillers in the embodiment were taken from different production batches of mineral processing waste residues in a mining area in Tongling, Anhui Province. The toxicity test results were in accordance with the "Solid Waste Leaching Toxicity Leaching Method Sulfuric Acid and Nitric Acid Method" (HJ / T299-2007). Compared with the commonly used fillers in the filter bed, the results are as follows:

[0047] Comparative Example 1

[0048] In this comparative example, quartz and volcanic rock (mass ratio 1:1) with a filler particle size of 0.5 mm or more were selected, mixed evenly and filled into the filter bed, so that when the sewage passed through the filter bed, the organic pollutants in the sewage were treated. Among them, in the influent to be treated on the 86th day in this comparative example, COD was 170.8 mg / L, ammonia nitrogen was 26.6 mg / L, total nitrogen was 43.1 mg / L, and total phosphorus was 3.1 mg / L. The sewage was coagulated and precipitated, and the pH value was adjusted to 8.0 before being passed into the filter bed. The filter bed was operated for 6 cycles per day, with water distribution for 30 minutes per cycle, and the effluent was collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus. The specific removal of sewage on the 86th day is shown in FIG. Figure 1 As shown, specifically, in the sewage on the 86th day, COD was 89 mg / L, ammonia nitrogen was 18.1 mg / L, total nitrogen was 20.4 mg / L, and total phosphorus was 0.72 mg / L.

[0049] Example 1

[0050] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 35.2% sulfur, 2.5% iron, 18% silicon, 2.3% sodium, 1.7% potassium, and 5.8% aluminum in its main elements. The slag and the culture solution are prepared in a mass ratio of 1:4 to obtain a first slurry with a pH of 1, wherein the culture solution components are (NH4)2SO4 3g / L, Ca(NO3)2 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O0.5g / L, and KCl 0.1g / L, and 0.5% of acidithiobacillus ferrooxidans, specifically Acidithiobacillus ferrooxidans ATCC 81800, are inoculated into the first slurry. The stirring speed is set to 200 rpm, the stirring temperature is set to 30°C, and the stirring time is 12 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, which are the target filler.

[0051] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, the COD of the influent to be treated on the 86th day in this embodiment is 170.8 mg / L, the ammonia nitrogen is 26.6 mg / L, the total nitrogen is 43.1 mg / L, and the total phosphorus is 3.1 mg / L, which is consistent with that in the comparative example 1. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.8 before being passed into the filter bed. The filter bed runs 6 cycles a day, and the water distribution is 30 minutes in each cycle. The effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 86th day is shown in FIG. Figure 1 As shown, specifically, in the sewage on the 86th day, COD was 21 mg / L, ammonia nitrogen was 1.7 mg / L, total nitrogen was 4 mg / L, and total phosphorus was 0.25 mg / L.

[0052] Comparative Example 2

[0053] In this comparative example, manganese sand with a filler particle size of 0.5 mm or more was selected and evenly filled into the filter bed to treat the organic pollutants in the sewage when it passed through the filter bed. Among them, in the influent to be treated on the 90th day in this comparative example, COD was 243.5 mg / L, ammonia nitrogen was 36.8 mg / L, total nitrogen was 43.9 mg / L, and total phosphorus was 3.65 mg / L. The sewage was coagulated and precipitated, and the pH value was adjusted to 7.6 before being passed into the filter bed. The filter bed was operated for 6 cycles per day, with water distribution for 30 minutes per cycle, and the effluent was collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage after 90 days is shown in FIG. Figure 2As shown, specifically, in the sewage on the 90th day, COD was 38.2 mg / L, ammonia nitrogen was 18.3 mg / L, total nitrogen was 22.6 mg / L, and total phosphorus was 1.19 mg / L.

[0054] Example 2

[0055] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 29.8% sulfur, 1.6% iron, 21% silicon, 2.8% sodium, 1.1% potassium, and 4.2% aluminum in its main elements. The slag and the culture solution are prepared in a mass ratio of 1:20 to obtain a first slurry with a pH of 5, wherein the culture solution components are (NH4)2SO4 1g / L, Ca(NO3)2 0.5g / L, K2HPO4 1.0g / L, MgSO4·7H2O1g / L, and KCl 0.5g / L, and 0.5% of acidithiobacillus ferrooxidans, specifically Acidithiobacillus ferrooxidans ATCC 81800, are inoculated into the first slurry. The stirring speed is set to 50rpm, the stirring temperature is set to 30°C, and the stirring time is set to 18 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5mm or more, which are the target filler.

[0056] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, in the influent to be treated on the 90th day in this embodiment, COD is 243.5 mg / L, ammonia nitrogen is 36.8 mg / L, total nitrogen is 43.9 mg / L, and total phosphorus is 3.65 mg / L, which is consistent with that in Comparative Example 2. The sewage is coagulated and precipitated, and the pH value is adjusted to 7 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage after 90 days is shown in FIG. Figure 2 As shown, specifically, in the sewage on the 90th day, COD was 16.5 mg / L, ammonia nitrogen was 1.75 mg / L, total nitrogen was 2.7 mg / L, and total phosphorus was 0.25 mg / L.

[0057] Comparative Example 3

[0058] In this comparative example, manganese sand with a filler particle size of 0.5 mm or more was selected and evenly filled into the filter bed to treat the organic pollutants in the sewage when it passed through the filter bed. Among them, in the influent to be treated on the 89th day in this comparative example, COD was 179.9 mg / L, ammonia nitrogen was 27 mg / L, total nitrogen was 35.8 mg / L, and total phosphorus was 3.59 mg / L. The sewage was coagulated and precipitated, and the pH value was adjusted to 8.1 before being passed into the filter bed. The filter bed was operated for 6 cycles per day, with water distribution for 30 minutes per cycle, and the effluent was collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 89th day is shown in FIG. Figure 3 As shown, specifically, in the sewage on the 89th day, COD was 30.2 mg / L, ammonia nitrogen was 16.2 mg / L, total nitrogen was 20 mg / L, and total phosphorus was 1.2 mg / L.

[0059] Example 3

[0060] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 45.2% sulfur, 1.5% iron, 11.6% silicon, 2.3% sodium, 2.5% potassium, and 3.3% aluminum in its main elements. The slag and the culture solution are prepared in a mass ratio of 1:10 to obtain a first slurry with a pH of 2, wherein the culture solution components are (NH4)2SO4 2.5g / L, Ca(NO3)2 1g / L, K2HPO4 2g / L, MgSO4·7H2O1g / L, and KCl 0.5g / L, and 0.5% of acidithiobacillus ferrooxidans, specifically Acidithiobacillus ferrooxidans ATCC 81800, are inoculated into the first slurry. The stirring speed is set to 150rpm, the stirring temperature is set to 30°C, and the stirring time is set to 10 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5mm or more, which are the target filler.

[0061] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, in the influent to be treated on the 89th day in this embodiment, COD is 179.9 mg / L, ammonia nitrogen is 27 mg / L, total nitrogen is 35.8 mg / L, and total phosphorus is 3.59 mg / L, which is consistent with that in Comparative Example 3. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.2 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 89th day is shown in FIG. Figure 3 As shown, specifically, in the sewage on the 89th day, COD was 15 mg / L, ammonia nitrogen was 2.46 mg / L, total nitrogen was 2.5 mg / L, and total phosphorus was 0.08 mg / L.

[0062] Comparative Example 4

[0063] In this comparative example, the vermiculite with a filler particle size of more than 0.5 mm is selected and evenly filled into the filter bed. When the sewage passes through the filter bed, the organic pollutants in the sewage are processed. Among them, in the 92nd day in the to-be-treated water among this comparative example, COD is 263.1 mg / L, ammonia nitrogen is 31 mg / L, total nitrogen is 32.3 mg / L, and total phosphorus is 1.83 mg / L. After the sewage is subjected to coagulation and precipitation, it is regulated that the pH value is 6.7 and is passed into the filter bed. The filter bed runs 6 cycles every day, and each cycle is 30 min for water distribution. The effluent is collected every day, and COD, ammonia nitrogen, total nitrogen and total phosphorus are measured therein. The specific removal of sewage for 92 days is shown in FIG. Figure 4 As shown, specifically, in the sewage on the 92nd day, COD was 30.2 mg / L, ammonia nitrogen was 17.6 mg / L, total nitrogen was 22 mg / L, and total phosphorus was 0.71 mg / L.

[0064] Example 4

[0065] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 25.6% sulfur, 1.8% iron, 22.3% silicon, 5.2% sodium, 1.3% potassium, and 2.1% aluminum in its main elements. The slag and culture solution are prepared in a mass ratio of 1:10 to obtain a first slurry with a pH of 1.5, wherein the culture solution comprises 1 g / L (NH4)2SO4, 2 g / L Ca(NO3)2, 1 g / L K2HPO4, 0.5 g / L MgSO4·7H2O, and 1 g / L KCl, and 0.5% of ferrophilic Leptospirillum ferriphilum ATCC 03476 is inoculated into the first slurry. The stirring speed is set to 200 rpm, the stirring temperature is set to 45°C, and the stirring time is set to 6 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, namely the target filler.

[0066] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, in the influent to be treated on the 92nd day in this embodiment, COD is 263.1 mg / L, ammonia nitrogen is 31 mg / L, total nitrogen is 32.3 mg / L, and total phosphorus is 1.83 mg / L, which is consistent with that in Comparative Example 4. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.5 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage after 92 days is shown in FIG. Figure 4As shown, specifically, in the sewage on the 92nd day, COD was 10.2 mg / L, ammonia nitrogen was 0.9 mg / L, total nitrogen was 0.8 mg / L, and total phosphorus was 0.08 mg / L.

[0067] Comparative Example 5

[0068] In this comparative example, diatomaceous earth with a filler particle size of 0.5 mm or more was selected and evenly filled into the filter bed to treat the organic pollutants in the sewage when it passed through the filter bed. Among them, in the influent to be treated on the 98th day in this comparative example, COD was 193.1 mg / L, ammonia nitrogen was 30 mg / L, total nitrogen was 37.5 mg / L, and total phosphorus was 4.16 mg / L. The sewage was coagulated and precipitated, and the pH value was adjusted to 6.7 before being passed into the filter bed. The filter bed was operated for 6 cycles per day, with water distribution for 30 minutes per cycle, and the effluent was collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 98th day is shown in FIG. Figure 5 As shown, specifically, in the sewage on the 98th day, COD was 77.3 mg / L, ammonia nitrogen was 17.5 mg / L, total nitrogen was 21 mg / L, and total phosphorus was 0.72 mg / L.

[0069] Example 5

[0070] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 28.5% sulfur, 3.2% iron, 21.6% silicon, 2.2% sodium, 1.9% potassium, and 0.5% aluminum in its main elements. The slag and culture solution are prepared in a mass ratio of 1:5 to obtain a first slurry with a pH of 1.2, wherein the culture solution components are (NH4)2SO4 2g / L, Ca(NO3)2 1g / L, K2HPO4 1g / L, MgSO4·7H2O0.5g / L, and KCl 1g / L, and 0.5% of ferrophilic Leptospirillum ferriphilum ATCC 03476 is inoculated into the first slurry. The stirring speed is set to 180 rpm, the stirring temperature is set to 45°C, and the stirring time is set to 8 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, namely the target filler.

[0071] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, the COD of the influent to be treated on the 98th day in this embodiment is 193.1 mg / L, the ammonia nitrogen is 30 mg / L, the total nitrogen is 37.5 mg / L, and the total phosphorus is 4.16 mg / L, which is consistent with that in Comparative Example 5. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.6 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage after 98 days is shown in FIG. Figure 5 As shown, specifically, in the sewage on the 98th day, COD was 17.8 mg / L, ammonia nitrogen was 0.9 mg / L, total nitrogen was 2.41 mg / L, and total phosphorus was 0.21 mg / L.

[0072] Comparative Example 6

[0073] In this comparative example, pine bark with a filler particle size of 0.5 mm or more was selected and evenly filled into the filter bed to treat the organic pollutants in the sewage as it passed through the filter bed. Among them, in the influent to be treated on the 95th day in this comparative example, COD was 210 mg / L, ammonia nitrogen was 28.6 mg / L, total nitrogen was 33.8 mg / L, and total phosphorus was 4.17 mg / L. The sewage was coagulated and precipitated, and the pH value was adjusted to 7.8 before being passed into the filter bed. The filter bed was operated for 6 cycles per day, with water distribution for 30 minutes per cycle, and the effluent was collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 95th day is shown in FIG. Figure 6 As shown, specifically, in the sewage on the 95th day, COD was 60 mg / L, ammonia nitrogen was 16.7 mg / L, total nitrogen was 17.3 mg / L, and total phosphorus was 0.88 mg / L.

[0074] Example 6

[0075] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 36.9% sulfur, 1.7% iron, 20.3% silicon, 0.8% sodium, 3% potassium, and 1.7% aluminum in its main elements. The slag and culture solution are prepared in a mass ratio of 1:8 to obtain a first slurry with a pH of 2.3, wherein the culture solution comprises 2 g / L (NH4)2SO4, 1 g / L Ca(NO3)2, 0.5 g / L K2HPO4, 1 g / L MgSO4·7H2O, and 1 g / L KCl, and 0.5% of ferrophilic Leptospirillum ferriphilum ATCC 03476 is inoculated into the first slurry. The stirring speed is set to 145 rpm, the stirring temperature is set to 45°C, and the stirring time is set to 8 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, namely the target filler.

[0076] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, in the influent to be treated on the 95th day in this embodiment, COD is 210 mg / L, ammonia nitrogen is 28.6 mg / L, total nitrogen is 33.8 mg / L, and total phosphorus is 4.17 mg / L, which is consistent with that in Comparative Example 6. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.5 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage after 95 days is shown in FIG. Figure 6 As shown, specifically, in the sewage on the 95th day, COD was 7.6 mg / L, ammonia nitrogen was 2.47 mg / L, total nitrogen was 3.92 mg / L, and total phosphorus was 1.73 mg / L.

[0077] Comparative Example 7

[0078] In this comparative example, a slag containing 5.2% sulfur, 0.6% iron, 40.8% silicon, 3.2% sodium, 1% potassium, and 0.5% aluminum was selected, and the slag and culture solution were configured in a mass ratio of 1:6 to obtain a first slurry with a pH of 2.0, wherein the culture solution components were (NH4)2SO4 2g / L, Ca(NO3)2 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O 1g / L, and KCl 1g / L, and 0.5% of ferrophilic Leptospirillum ferriphilum ATCC03476 was inoculated into the first slurry. The stirring speed was set to 175 rpm, the stirring temperature was set to 33°C, and the stirring time was set to 8 hours to obtain the target slurry, which was then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, which were the target filler.

[0079] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, the COD of the influent to be treated on the 88th day in this embodiment is 241 mg / L, the ammonia nitrogen is 32.5 mg / L, the total nitrogen is 35.2 mg / L, and the total phosphorus is 3.51 mg / L. The sewage is adjusted to a pH value of 7.6 after coagulation and sedimentation and then passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 88th day is shown in FIG. Figure 7 As shown, specifically, in the sewage on the 88th day, COD was 41.5 mg / L, ammonia nitrogen was 7.1 mg / L, total nitrogen was 14.5 mg / L, and total phosphorus was 0.49 mg / L.

[0080] Example 7

[0081] In this embodiment, slag produced in the beneficiation process of low-grade sulfide ore is selected. XRF testing shows that the slag contains 40.1% sulfur, 8.3% iron, 17.8% silicon, 2.2% sodium, 3.1% potassium, and 3.2% aluminum in its main elements. The slag and culture solution are prepared in a mass ratio of 1:6 to obtain a first slurry with a pH of 2.0, wherein the culture solution composition is (NH4)2SO4 2g / L, Ca(NO3)2 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O1g / L, and KCl 1g / L, and 0.5% of ferrophilic Leptospirillum ferriphilum ATCC 03476 is inoculated into the first slurry. The stirring speed is set to 175 rpm, the stirring temperature is set to 33°C, and the stirring time is set to 8 hours to obtain the target slurry, which is then filtered, dried, and sieved in sequence to obtain particles with a particle size of 0.5 mm or more, namely the target filler.

[0082] The target filler is filled into the filter bed to treat the organic pollutants in the sewage when it passes through the filter bed. Among them, the COD of the influent to be treated on the 88th day in this embodiment is 241 mg / L, the ammonia nitrogen is 32.5 mg / L, the total nitrogen is 35.2 mg / L, and the total phosphorus is 3.51 mg / L, which is consistent with that in Comparative Example 7. The sewage is coagulated and precipitated, and the pH value is adjusted to 7.6 before being passed into the filter bed. The filter bed runs 6 cycles a day, with water distribution for 30 minutes in each cycle, and the effluent is collected every day to measure the COD, ammonia nitrogen, total nitrogen and total phosphorus therein. The specific removal of sewage on the 88th day is shown in FIG. Figure 7 As shown, specifically, in the sewage on the 88th day, the COD was 30.2 mg / L, the ammonia nitrogen was 2.51 mg / L, the total nitrogen was 1.76 mg / L, and the total phosphorus was 0.25 mg / L.

[0083] Please refer to Table 1 below, which shows the parameters corresponding to the above-mentioned Examples 1 to 7 and Comparative Example 7 of the present invention.

[0084] Table 1:

[0085]

[0086] In actual application, the corresponding target fillers were prepared using the preparation methods and parameters corresponding to Examples 1 to 7 and Comparative Examples 1 to 7 of the present invention, and filled into the filter bed. Sewage was passed through the filter bed, and the pollutant concentration in the sewage was regularly detected. The detected pollutants included COD, ammonia nitrogen, total nitrogen, and total phosphorus. The test data are shown in Tables 2 and 3 below.

[0087] Table 2:

[0088]

[0089]

[0090] Table 3:

[0091]

[0092]

[0093] Combining the data in Tables 1, 2 and 3 above, it can be clearly seen that the target fillers prepared in Examples 1 to 7 of the present invention significantly improve the decontamination efficiency of high-concentration organic wastewater. Among them, the target filler prepared in Example 4 of the present invention is better than that in other embodiments. Specifically, the decontamination efficiency of COD in sewage is 96%, the decontamination efficiency of ammonia nitrogen is 97%, the decontamination efficiency of total nitrogen is 98%, and the decontamination efficiency of total phosphorus is 96%. In addition, in Comparative Example 7, although the preparation method used is consistent with that of Examples 1 to 7 of the present invention, the sulfur content in the slag is less than 10% and the iron content is less than 1%, resulting in poor effect, but the decontamination efficiency of organic wastewater is improved compared with the traditional method.

[0094] In summary, the present invention relates to a biological filler, a preparation method and its application in sewage treatment. The method obtains the target filler required for the sulfur autotrophic denitrification process by biologically treating the slag produced in the beneficiation process of low-grade sulfide ore, drying and screening it. Since the main components of the target filler are pyrite, pyrrhotite and metal-deficient polysulfides, it can provide the energy required for the growth and metabolism of iron-sulfur autotrophic denitrification bacteria, thereby achieving efficient removal of ammonia nitrogen, COD, total phosphorus and a small amount of heavy metals, effectively reducing the emission of pollutants in industrial and domestic sewage, and almost no sludge is generated, avoiding sludge swelling and subsequent disposal of sludge. At the same time, the method effectively utilizes the waste rock and tailings generated by mining activities as resources, reducing the generation of storage land and solid waste.

[0095] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0096] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a biological filler, characterized in that: The following steps are involved: The slag produced during the beneficiation of low-grade sulfide ore is subjected to biological treatment to obtain a target slurry, wherein the biological treatment process comprises mixing the slag with a culture solution at a preset mass ratio to obtain a first slurry, inoculating the first slurry with iron-sulfur oxidizing bacteria at a preset concentration, and then stirring under preset conditions to obtain the target slurry, wherein the preset mass ratio is 1:4 to 20; The target slurry is filtered, dried and sieved in sequence to obtain a target filler; The sulfur content of the slag is not less than 10%, and the iron content is not less than 1%; The iron-sulfur oxidizing bacteria are one or more of Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Leptospirillum ferrophilum, and the inoculation concentration is not less than 10 8 pcs / ml; The culture solution is a mixed solution of (NH4)2SO4, KCl, K2HPO4, MgSO4, and Ca(NO3)2.

2. The method for preparing the biological filler according to claim 1, characterized in that: The pH of the culture solution is 1-5.

3. The method for preparing the biological filler according to claim 1, characterized in that: The pH of the first slurry is 1-5.

4. The method for preparing the biological filler according to claim 1, characterized in that: The preset conditions are as follows: a stirring speed of 30 to 200 rpm, a stirring temperature of 20 to 70° C., and a stirring time of 2 to 24 hours.

5. A biological filler, characterized in that: The biofiller is prepared according to the preparation method of any one of claims 1 to 4.

6. Application of a biological filler in sewage treatment, characterized in that: The biological filler is prepared by the preparation method of the biological filler according to any one of claims 1 to 4, and the biological filler is filled into the filter bed, wherein the implementation temperature of the biological filler is 15° C. to 45° C., and the implementation pH value is 6.5 to 8.5.

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