CN118420054B - A method for preparing primary battery filter material using concentrated garbage leachate and its product - Google Patents

Abstract

The invention discloses a method for preparing a primary battery filter material by utilizing concentrated landfill leachate and a product thereof, wherein the method comprises the following steps: respectively weighing iron powder and concentrated landfill leachate, continuously stirring, standing for aging, placing in a vacuum drying oven for drying, taking out, grinding, and placing in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder; spraying the concentrated landfill leachate onto the iron-carbon coarse powder, drying, and placing in a low-temperature plasma reactor for irradiation to obtain the high-activity primary cell filter material. The preparation process is simple, the used raw materials are only landfill leachate and iron powder, the sources of the raw materials are wide and easy to obtain, and the high-energy battery filter material is efficiently prepared through the steps of pre-reaction, carbonization, leachate re-excitation and plasma activation. The prepared filter material can efficiently purify heavy metal pollutants and organic pollutants in waste liquid, and the used filter material has magnetism, and the recovery rate of the filter material is up to 85%.

Description

A method for preparing primary battery filter material using concentrated garbage leachate and its product

Technical Field

The invention relates to a method for preparing primary battery filter material by using concentrated garbage leachate and the product thereof, belonging to the field of polluted waste liquid disposal and resource utilization.

Background Art

As an inevitable byproduct of landfill and storage, the chemical properties and environmental impact of landfill leachate have always been the focus of research in the field of environmental protection. This high-concentration organic wastewater has a complex generation process and variable composition, which is mainly due to the multiple effects of physical compaction, chemical decomposition and biological fermentation of garbage in landfills. In the early stage of landfill, the leachate mainly comes from the moisture contained in the garbage itself and the infiltration of external precipitation; as time goes by, the organic matter in the garbage gradually decomposes under the action of microorganisms, producing more moisture and soluble substances, resulting in the concentration and toxicity of the leachate gradually increasing. There are many kinds of soluble organic matter in the leachate, including fatty acids, humus, amino acids, etc. These organic matter will further ferment under anaerobic conditions to produce odorous gases such as hydrogen sulfide and methane, which not only affect the environmental quality, but also pose an explosion risk. In addition, the leachate also contains a large amount of inorganic salts, such as chloride ions and sulfate ions, which will be further enriched during the concentration process, increasing the difficulty and cost of treatment. Natural factors such as rainfall and groundwater infiltration are also important reasons for the increase in the amount of leachate. Rainfall can cause an increase in moisture on the landfill surface, which then penetrates through the garbage layer to the underlying layer to form leachate; while groundwater infiltration may carry external pollutants into the landfill and mix with the leachate, further increasing the complexity of its composition.

At present, the treatment of leachate mainly adopts physical methods (such as adsorption, membrane separation), chemical methods (such as coagulation and sedimentation, chemical oxidation) and biological methods (such as aerobic treatment, anaerobic treatment, etc.). However, these methods often produce a large amount of concentrated landfill leachate during the treatment process, and the concentration of organic matter and inorganic salts is much higher than that of the original leachate, which is more difficult to treat. If these concentrated leachates are directly discharged without proper treatment, they will cause serious pollution and damage to the soil, water and atmospheric environment. The pollutants in the concentrated leachate will destroy the soil structure, reduce soil fertility, and affect the growth and quality of crops. At the same time, the harmful substances in the leachate may also enter the groundwater system through the soil, posing a threat to the safety of drinking water. In addition, the odorous gases and volatile organic compounds in the leachate will pollute the atmospheric environment and affect the quality of life of residents. Therefore, for the treatment and disposal of concentrated landfill leachate, scientific, reasonable and effective methods must be adopted to minimize its harm to the environment. This not only requires us to conduct in-depth research on the generation mechanism and pollution characteristics of leachate, but also requires us to develop new treatment technologies and processes to achieve the reduction, harmlessness and resource utilization of leachate.

Although concentrated landfill leachate has serious environmental hazards, from the perspective of resource utilization, its high concentration of organic matter and inorganic salt components also provide the possibility for the preparation of highly active primary battery filter materials. Primary battery filter materials are a new type of functional material that can transform pollutants in wastewater through electrochemical processes. In theory, the organic matter in concentrated landfill leachate can be used as a carbon source in primary battery filter materials, and can be converted into materials with high conductivity and stability through specific treatment processes. These materials can not only participate in electrochemical reactions, but also improve the electrochemical properties of primary battery filter materials. At the same time, the inorganic salt components in the leachate can also be used as raw materials for electrolytes or catalysts, and catalytically active substances can be prepared through appropriate chemical reactions to accelerate the electrochemical reaction. The use of concentrated landfill leachate to prepare highly active primary battery filter materials not only provides us with a new idea for resource utilization, but also helps to promote technological innovation and industrial upgrading in the field of environmental protection.

Summary of the invention

Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing high-activity primary battery filter material using concentrated landfill leachate and its product.

Technical solution: To solve the above technical problems, the present invention provides a method for preparing a primary battery filter material by using concentrated landfill leachate, comprising the following steps:

(1) Weighing iron powder and concentrated landfill leachate respectively, stirring continuously, allowing to stand for aging, drying in a vacuum drying oven, taking out, grinding, and carbonizing in an atmosphere furnace to obtain coarse iron-carbon powder;

(2) Spraying the concentrated landfill leachate onto the iron-carbon coarse powder in step (1), drying it, and irradiating it in a low-temperature plasma reactor to obtain a high-activity primary battery filter material.

Wherein, the solid-liquid ratio of the iron powder and the concentrated landfill leachate in step (1) is 0.2-1.2:1 g/mL.

The continuous stirring time in step (1) is 0.5 to 7.5 hours.

The standing aging time in step (1) is 2 to 24 hours.

Wherein, the drying temperature in step (1) is 50-150°C.

Wherein, the working atmosphere in the atmosphere furnace in step (1) is nitrogen or argon, the working temperature of the atmosphere furnace is 350-750° C., and the working time of the atmosphere furnace is 0.5-4.5 hours.

Wherein, the liquid-to-solid ratio of the concentrated landfill leachate and the iron-carbon coarse powder in step (2) is 0.1-0.3:1 mL/g.

Wherein, the drying temperature in step (2) is 50-150°C.

The irradiation time in step (2) is 0.25 to 4.75 hours, and the voltage is 5 to 45 kV.

The invention also provides a primary battery filter material prepared by the method.

Reaction mechanism:

Mix iron powder and concentrated landfill leachate. During the stirring and aging process, organic matter, ammonia nitrogen and phosphorus pollutants in the landfill leachate concentrate are adsorbed on the surface of iron powder particles. Organic acid substances in the leachate concentrate can corrode the surface of iron powder, releasing ferrous ions and hydrogen, so that potential difference active points appear on the surface of iron powder. The released ferrous ions can combine with phosphate and ammonia nitrogen pollutants to form complex precipitates adsorbed on the surface of iron powder particles. The infiltrated powder is placed in an atmosphere furnace for carbonization treatment. Under high temperature conditions, the organic substances adsorbed on the surface of iron powder and mixed between iron powder particles in the infiltrated powder are pyrolyzed to form carbon matrix and organic small molecule gas. The carbon matrix and organic small molecule gas can promote the re-reduction of ferrous ions and combine with iron to form iron-carbon primary battery substances. The inorganic salts introduced by the landfill leachate in the infiltrated powder can not only accelerate the corrosion of iron ions under high temperature conditions, thereby releasing more ferrous ions to participate in reduction and complex reactions, but also penetrate into the iron-carbon primary battery structure to form electrolyte substances, thereby stimulating the activity of the primary battery substances. The concentrated landfill leachate is sprayed onto the iron-carbon coarse powder. During the drying process, organic matter, ammonia nitrogen, phosphorus pollutants and other inorganic salts in the landfill leachate are adsorbed on the surface of the iron-carbon coarse powder particles or penetrate into the iron-carbon coarse powder particles. The iron-carbon percolation powder is placed in a low-temperature plasma reactor for irradiation. The oxygen free radicals and hydroxyl free radicals released in the discharge channel can oxidize the organic matter, ammonia nitrogen, and phosphorus pollutants adsorbed on the surface of the iron-carbon coarse powder particles, and promote the further migration of inorganic salts into the particles. Under the strong oxidation of free radicals and local heat release, the carbon chain of macromolecular organic matter or oily organic matter is broken, forming a variety of organic functional groups loaded on the surface of the iron-carbon coarse powder particles, and some phosphorus pollutants are hydrolyzed and polymerized with hydrogen free radicals, water and electrons to form a polyphosphate structure loaded on the surface of the iron-carbon coarse powder particles or in the iron-carbon structure. At the same time, under the bombardment of free radicals and high-energy electron beams, part of the iron on the iron-carbon surface is oxidized to form ferrite substances in which iron, ferrous iron and trivalent iron coexist. The inorganic salt accelerates its migration into the iron-carbon source battery structure through catalytic oxidation and ion exchange, thereby further activating the iron-carbon coarse powder material and ultimately forming a highly active source battery filter material.

Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the preparation process is simple, the raw materials used are only garbage leachate and iron powder, the raw materials are widely available and easily available, and the high-performance source battery filter material is efficiently prepared through pre-reaction, carbonization, leachate re-excitation and plasma activation steps. The prepared filter material can efficiently purify heavy metal pollutants and organic pollutants in waste liquid, and the filter material used has magnetism, and the filter material recovery rate is as high as 85%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of the preparation method of the present invention.

DETAILED DESCRIPTION

The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

Sampling and basic properties of domestic waste leachate: The test leachate was taken from the domestic waste landfill in Shanghu Town, Changshu. The COD mass concentration of this batch of urban domestic waste leachate was 4615 mg/L, the total phosphorus concentration was 493 mg/L, and the ammonia nitrogen concentration was 986 mg/L.

Preparation of test wastewater: Dissolve 200 mg of mercury and 200 mg of lead in 1 L of test landfill leachate and stir evenly to obtain test wastewater.

Preparation of concentrated landfill leachate: The test landfill leachate was concentrated to 20% of its original volume through a membrane to obtain concentrated landfill leachate.

Example 1 Effect of the solid-liquid ratio of iron powder and concentrated landfill leachate on the performance of the prepared high-activity primary battery filter material

According to the solid-liquid ratio of 0.05:1g/mL, 0.1:1g/mL, 0.15:1g/mL, 0.2:1g/mL, 0.7:1g/mL, 1.2:1g/mL, 1.4:1g/mL, 1.6:1g/mL, and 1.8:1g/mL, the iron powder and concentrated landfill leachate were weighed respectively, stirred continuously for 0.5 hours, and then allowed to stand for aging for 2 hours to obtain iron powder infiltration slurry. The iron powder infiltration slurry was placed in a vacuum drying oven for drying, taken out, and ground to obtain iron infiltration powder, wherein the drying temperature was 50°C. The iron infiltration powder was placed in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace was nitrogen, the atmosphere furnace temperature was 350°C, and the atmosphere furnace action time was 0.5 hours. According to the liquid-solid ratio of 0.1:1mL/g, the concentrated landfill leachate was sprayed on the iron-carbon coarse powder, dried, and iron-carbon infiltration powder was obtained, wherein the drying temperature was 50°C. The iron-carbon infiltration powder was placed in a low-temperature plasma reactor and irradiated for 0.25 hours to obtain a high-activity primary battery filter material, wherein the low-temperature plasma action voltage was 5 kV.

Adsorption test: 1g of each of the 9 groups of high-activity primary battery filter materials was put into 1L of experimental sewage, stirred at 120 rpm for 30 minutes, and then centrifuged at 5000 rpm for solid-liquid separation. The concentrations of different pollutants in the separated liquid were tested and the adsorption capacity was calculated. The specific test and calculation are as follows.

COD concentration detection: The COD concentration in sewage is determined in accordance with the national standard "Water quality - Determination of chemical oxygen demand - Dichromate method" (HJ 828-2017).

Total phosphorus concentration detection: The total phosphorus concentration in sewage is determined in accordance with the standard "Water quality-Determination of phosphate and total phosphorus-Continuous flow-ammonium molybdate spectrophotometry" (HJ 670-2013).

Ammonia nitrogen concentration detection: The concentration of ammonia nitrogen in sewage is determined in accordance with "Water quality - Determination of ammonia nitrogen - Salicylic acid spectrophotometry" (HJ 536-2009).

Heavy metal concentration detection: The lead concentration in sewage is measured in accordance with the standard "Water quality - Determination of 32 elements - Inductively coupled plasma emission spectrometry" (HJ 776-2015). The mercury concentration in sewage is measured in accordance with the standard "Water quality - Determination of mercury, arsenic, selenium, bismuth and antimony - Atomic fluorescence method" (HJ 695-2014).

The adsorption performance of high-activity primary battery filter material is calculated according to formula (1), where: is the adsorption capacity of the high-activity galvanic filter material for specific pollutants in mg/g, _c0 and _ct are the concentrations of specific pollutants in the solution before and after the adsorption experiment in mg/L, V is the solution volume in L (1L), and m is the dosage of the high-activity galvanic filter material (1g).

After the test, the high-activity galvanic cell filter material is recovered from the liquid by a magnet and dried, and the mass ratio of the high-activity galvanic cell filter material to the original high-activity galvanic cell filter material is the filter material recovery rate.

The test results of the adsorption capacity of the high-activity primary battery filter material for COD, total phosphorus, ammonia nitrogen and heavy metals and the filter material recovery rate in this embodiment are shown in Table 1.

Table 1 Effect of the solid-liquid ratio of iron powder and concentrated landfill leachate on the performance of the prepared high-activity galvanic cell filter material

It can be seen from Table 1 that when the solid-liquid ratio of iron powder to concentrated landfill leachate is less than 0.2:1 g/mL (such as in Table 1, the solid-liquid ratio of iron powder to concentrated landfill leachate = 0.15:1 g/mL, 0.1:1 g/mL, 0.05:1 g/mL and lower ratios not listed in Table 1), less iron powder is added, the reaction between iron powder and concentrated landfill leachate is not sufficient, and the carbonization and later plasma activation effects are reduced, resulting in a decrease in the performance of the prepared high-activity primary battery filter material, and the adsorption capacity of COD, total phosphorus, ammonia nitrogen, lead, and mercury and the recovery rate of the filter material are significantly reduced with the decrease of the solid-liquid ratio of iron powder to concentrated landfill leachate. When the solid-liquid ratio of iron powder to concentrated landfill leachate is equal to 0.2~1.2:1g/mL (as in Table 1, the solid-liquid ratio of iron powder to concentrated landfill leachate = 0.2:1g/mL, 0.7:1g/mL, 1.2:1g/mL), the iron powder and concentrated landfill leachate are mixed. During the stirring and aging process, the organic matter, ammonia nitrogen and phosphorus pollutants in the landfill leachate concentrate are adsorbed on the surface of the iron powder particles, and the organic acid substances in the leachate concentrate can corrode the surface of the iron powder, releasing ferrous ions and hydrogen, so that potential difference active points appear on the surface of the iron powder. The released ferrous ions can combine with phosphate and ammonia nitrogen pollutants to form complex precipitates adsorbed on the surface of the iron powder particles. The prepared high-activity galvanic filter materials have COD adsorption capacity greater than 1046 mg/g, total phosphorus adsorption capacity greater than 204 mg/g, ammonia nitrogen adsorption capacity greater than 376 mg/g, lead adsorption capacity greater than 97 mg/g, mercury adsorption capacity greater than 68 mg/g, and filter material recovery rate greater than 76%. When the solid-liquid ratio of iron powder to concentrated landfill leachate is greater than 1.2:1 g/mL (such as in Table 1, the solid-liquid ratio of iron powder to concentrated landfill leachate = 1.4:1 g/mL, 1.6:1 g/mL, 1.8:1 g/mL and higher ratios not listed in Table 1), excessive addition of iron powder will cause an imbalance in the reaction between iron powder and concentrated landfill leachate, and the carbonization and later plasma activation effects will decrease, resulting in a decrease in the performance of the prepared high-activity galvanic filter materials. The adsorption capacity of COD, total phosphorus, ammonia nitrogen, lead, and mercury and the filter material recovery rate will all decrease significantly with the further increase of the solid-liquid ratio of iron powder to concentrated landfill leachate. In summary, considering the benefits and costs, when the solid-liquid ratio of iron powder and concentrated landfill leachate is equal to 0.2~1.2:1g/mL, it is most conducive to improving the performance of the prepared high-activity primary battery filter material.

Example 2 Effect of atmosphere furnace action time on the performance of the prepared high-activity primary battery filter material

According to the solid-liquid ratio of 1.2:1g/mL, iron powder and concentrated landfill leachate were weighed respectively, stirred continuously for 4 hours, and then allowed to stand for aging for 13 hours to obtain iron powder infiltration slurry. The iron powder infiltration slurry was placed in a vacuum drying oven for drying, taken out, and ground to obtain iron infiltration powder, wherein the drying temperature was 100°C. The iron infiltration powder was placed in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace was argon, the atmosphere furnace temperature was 550°C, and the atmosphere furnace action time was 0.25 hours, 0.3 hours, 0.4 hours, 0.5 hours, 2.5 hours, 4.5 hours, 4.75 hours, 5 hours, and 5.25 hours. According to the liquid-solid ratio of 0.2:1mL/g, the concentrated landfill leachate was sprayed on the iron-carbon coarse powder and dried to obtain iron-carbon infiltration powder, wherein the drying temperature was 100°C. The iron-carbon infiltration powder was placed in a low-temperature plasma reactor and irradiated for 2.5 hours to obtain a high-activity primary battery filter material, wherein the low-temperature plasma action voltage was 25 kV.

The adsorption test, COD concentration detection, total phosphorus concentration detection, ammonia nitrogen concentration detection, heavy metal concentration detection, high-activity primary battery filter material adsorption performance calculation, and filter material recovery rate calculation are all the same as in Example 1.

The results of the adsorption capacity of the high-activity primary battery filter material for COD, total phosphorus, ammonia nitrogen and heavy metals and the filter material recovery rate in this embodiment are shown in Table 2.

Table 2 Effect of atmosphere furnace action time on the performance of the prepared high-activity primary battery filter material

It can be seen from Table 2 that when the atmosphere furnace action time is less than 0.5 hours (such as in Table 2, the atmosphere furnace action time = 0.4 hours, 0.3 hours, 0.25 hours and lower values not listed in Table 2), the atmosphere furnace action time is short, the carbonization reaction and the iron-carbon primary battery formation efficiency are reduced, resulting in the performance of the prepared high-activity primary battery filter material decreased, COD, total phosphorus, ammonia nitrogen, lead, mercury adsorption capacity and filter material recovery rate are significantly reduced with the decrease of the atmosphere furnace action time. When the atmosphere furnace action time is equal to 0.5~4.5 hours (such as in Table 2, the atmosphere furnace action time = 0.5 hours, 2.5 hours, 4.5 hours), the infiltration powder is placed in the atmosphere furnace for carbonization treatment. Under high temperature environment, the organic matter adsorbed on the surface of the iron powder and mixed between the iron powder particles in the infiltration powder is pyrolyzed to form a carbon matrix and organic small molecule gas. The carbon matrix and organic small molecule gas can promote the reduction of ferrous ions and combine with iron to form iron-carbon primary battery substances. The inorganic salts introduced by the landfill leachate in the infiltration powder can not only accelerate the corrosion of iron ions under high temperature environment, thereby releasing more ferrous ions to participate in reduction and complexation reactions, but also penetrate into the iron-carbon galvanic cell structure to form electrolyte substances, thereby stimulating the activity of the galvanic cell substances. The prepared high-activity galvanic cell filter materials have COD adsorption capacity greater than 1159 mg/g, total phosphorus adsorption capacity greater than 239 mg/g, ammonia nitrogen adsorption capacity greater than 394 mg/g, lead adsorption capacity greater than 109 mg/g, mercury adsorption capacity greater than 74 mg/g, and filter material recovery rate greater than 80%. When the atmosphere furnace action time is greater than 4.5 hours (such as in Table 2, the atmosphere furnace action time = 4.75 hours, 5 hours, 5.25 hours and higher values not listed in Table 2), the atmosphere furnace action time is too long, the material is coked, resulting in the performance of the prepared high-activity galvanic cell filter material being reduced, and the COD, total phosphorus, ammonia nitrogen, lead, mercury adsorption capacity and filter material recovery rate are significantly reduced as the atmosphere furnace action time increases further. In summary, considering the benefits and costs, when the atmosphere furnace action time is equal to 0.5~4.5 hours, it is most conducive to improving the performance of the prepared high-activity primary battery filter material.

Example 3 Effect of low temperature plasma irradiation time on the performance of the prepared high-activity primary battery filter material

According to the solid-liquid ratio of 1.2:1g/mL, iron powder and concentrated landfill leachate were weighed respectively, stirred continuously for 7.5 hours, and then allowed to stand for aging for 24 hours to obtain iron powder infiltration slurry. The iron powder infiltration slurry was placed in a vacuum drying oven for drying, taken out, and ground to obtain iron infiltration powder, wherein the drying temperature was 150°C. The iron infiltration powder was placed in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace was nitrogen, the atmosphere furnace temperature was 750°C, and the atmosphere furnace action time was 4.5 hours. According to the liquid-solid ratio of 0.3:1mL/g, the concentrated landfill leachate was sprayed on the iron-carbon coarse powder, dried, and iron-carbon infiltration powder was obtained, wherein the drying temperature was 150°C. The iron-carbon infiltration powder was placed in a low-temperature plasma reactor and irradiated for 0.1 hour, 0.15 hour, 0.2 hour, 0.25 hour, 2.5 hour, 4.75 hour, 5 hour, 5.25 hour and 5.5 hour to obtain a high-activity primary battery filter material, wherein the low-temperature plasma action voltage was 45 kV.

The adsorption test, COD concentration detection, total phosphorus concentration detection, ammonia nitrogen concentration detection, heavy metal concentration detection, high-activity primary battery filter material adsorption performance calculation, and filter material recovery rate calculation are all the same as in Example 1.

The results of the adsorption capacity of the high-activity primary battery filter material for COD, total phosphorus, ammonia nitrogen and heavy metals and the filter material recovery rate in this embodiment are shown in Table 3.

Table 3 Effect of low temperature plasma irradiation time on the performance of the prepared high activity primary battery filter material

It can be seen from Table 3 that when the low-temperature plasma irradiation time is less than 0.25 hours (such as in Table 3, the low-temperature plasma irradiation time = 0.2 hours, 0.15 hours, 0.1 hours and lower values not listed in Table 3), the low-temperature plasma irradiation time is short, the surface activation efficiency is reduced, resulting in a decrease in the performance of the prepared high-activity primary battery filter material, COD, total phosphorus, ammonia nitrogen, lead, mercury adsorption capacity and filter material recovery rate are significantly reduced as the low-temperature plasma irradiation time decreases. When the low-temperature plasma irradiation time is equal to 0.25~4.75 hours (such as in Table 3, the low-temperature plasma irradiation time = 0.25 hours, 2.5 hours, 4.75 hours), the iron-carbon percolation powder is placed in a low-temperature plasma reactor for irradiation, and the oxygen free radicals and hydroxyl free radicals released in the discharge channel can oxidize the organic matter, ammonia nitrogen, and phosphorus pollutants adsorbed on the surface of the iron-carbon coarse powder particles, and promote the further migration of inorganic salts into the particles. Under the strong oxidation of free radicals and the action of local heat release, the carbon chains of macromolecular organic matter or oily organic matter are broken, forming a variety of organic functional groups loaded on the surface of iron-carbon coarse powder particles, and some phosphorus pollutants are hydrolyzed and polymerized with hydrogen free radicals, water and electrons to form polyphosphate structures loaded on the surface of iron-carbon coarse powder particles or in the iron-carbon structure. At the same time, under the bombardment of free radicals and high-energy electron beams, part of the iron on the iron-carbon surface is oxidized to form ferrite substances in which iron, ferrous iron and trivalent iron coexist. Inorganic salts accelerate the migration into the iron-carbon source battery structure through catalytic oxidation and ion exchange, thereby further activating the iron-carbon coarse powder substances and finally forming a highly active source battery filter material. The prepared high-activity primary battery filter material has a COD adsorption capacity greater than 1272 mg/g, a total phosphorus adsorption capacity greater than 257 mg/g, an ammonia nitrogen adsorption capacity greater than 430 mg/g, a lead adsorption capacity greater than 115 mg/g, a mercury adsorption capacity greater than 83 mg/g, and a filter material recovery rate greater than 83%. When the low-temperature plasma irradiation time is greater than 4.5 hours (such as in Table 3, when the low-temperature plasma irradiation time = 5 hours, 5.25 hours, 5.5 hours and higher values not listed in Table 3), the low-temperature plasma irradiation time is too long, iron is overoxidized, and the iron-carbon combination efficiency is reduced, resulting in a decrease in the performance of the prepared high-activity galvanic cell filter material. The COD, total phosphorus, ammonia nitrogen, lead, mercury adsorption capacity and filter material recovery rate are significantly reduced as the low-temperature plasma irradiation time further increases. In general, combining benefits and costs, when the low-temperature plasma irradiation time is equal to 0.25~4.75 hours, it is most conducive to improving the performance of the prepared high-activity galvanic cell filter material.

Comparative Example Effects of different processes on the performance of high-activity primary battery filter materials prepared

The process of the present invention: the iron powder and concentrated landfill leachate are weighed respectively according to the solid-liquid ratio of 1.2:1g/mL, stirred continuously for 7.5 hours, and then allowed to stand for aging for 24 hours to obtain an iron powder infiltration slurry. The iron powder infiltration slurry is placed in a vacuum drying oven for drying, taken out, and ground to obtain an iron infiltration powder, wherein the drying temperature is 150°C. The iron infiltration powder is placed in an atmosphere furnace for carbonization treatment to obtain an iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace is nitrogen, the atmosphere furnace action temperature is 750°C, and the atmosphere furnace action time is 4.5 hours. The concentrated landfill leachate is sprayed onto the iron-carbon coarse powder according to the liquid-solid ratio of 0.3:1mL/g, dried, and an iron-carbon infiltration powder is obtained, wherein the drying temperature is 150°C. The iron-carbon infiltration powder is placed in a low-temperature plasma reactor for irradiation for 4.75 hours to obtain a high-activity primary battery filter material, wherein the low-temperature plasma action voltage is 45kV.

Comparative process 1: Weigh iron powder and concentrated landfill leachate according to the solid-liquid ratio of 1.2:1g/mL, stir continuously for 7.5 hours, and then stand for aging for 24 hours to obtain iron powder infiltration slurry. The iron powder infiltration slurry is placed in a vacuum drying oven for drying, taken out, and ground to obtain iron infiltration powder, wherein the drying temperature is 150°C. The iron infiltration powder is placed in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace is nitrogen, the atmosphere furnace action temperature is 750°C, and the atmosphere furnace action time is 4.5 hours. The iron-carbon coarse powder is placed in a low-temperature plasma reactor for irradiation for 4.75 hours to obtain a high-activity primary battery filter material, wherein the low-temperature plasma action voltage is 45kV.

Comparative process 2: Weigh iron powder and concentrated landfill leachate at a solid-liquid ratio of 1.2:1 g/mL, stir continuously for 7.5 hours, and then stand for aging for 24 hours to obtain iron powder leachate slurry. The iron powder leachate slurry is placed in a vacuum drying oven for drying, taken out, and ground to obtain iron infiltration powder, wherein the drying temperature is 150°C. The iron infiltration powder is placed in an atmosphere furnace for carbonization treatment to obtain iron-carbon coarse powder, wherein the atmosphere in the atmosphere furnace is nitrogen, the atmosphere furnace temperature is 750°C, and the atmosphere furnace action time is 4.5 hours. Spray the concentrated landfill leachate onto the iron-carbon coarse powder at a liquid-solid ratio of 0.3:1 mL/g, dry it, and obtain a high-activity primary battery filter material, wherein the drying temperature is 150°C.

The adsorption test, COD concentration detection, total phosphorus concentration detection, ammonia nitrogen concentration detection, heavy metal concentration detection, high-activity primary battery filter material adsorption performance calculation, and filter material recovery rate calculation are all the same as in Example 1.

The results of the adsorption capacity of the high-activity primary battery filter material for COD, total phosphorus, ammonia nitrogen and heavy metals and the filter material recovery rate in this embodiment are shown in Table 4.

Table 4 Effects of different processes on the performance of the prepared high-activity primary battery filter material

It can be seen from Table 4 that the COD, total phosphorus, ammonia nitrogen, lead, mercury adsorption capacity and filter material recovery rate achieved by the high-activity primary battery filter material prepared by the process of the present invention are significantly higher than those of comparative process 1 and comparative process 2, and higher than the sum of the two.

Claims (10)

1. A method for preparing high-activity primary battery filter material using concentrated landfill leachate, characterized in that it comprises the following steps: (1) Weighing iron powder and concentrated landfill leachate respectively, stirring continuously, allowing to stand for aging, drying in a vacuum drying oven, taking out, grinding, and carbonizing in an atmosphere furnace to obtain coarse iron-carbon powder; (2) Spraying the concentrated landfill leachate onto the iron-carbon coarse powder in step (1), drying it, and irradiating it in a low-temperature plasma reactor to obtain a high-activity primary battery filter material. 2. The method according to claim 1, characterized in that the solid-liquid ratio of the iron powder and the concentrated landfill leachate in step (1) is 0.2~1.2:1 g/mL. 3. The method according to claim 1, characterized in that the continuous stirring time in step (1) is 0.5 to 7.5 hours. 4. The method according to claim 1, characterized in that the time of standing and aging in step (1) is 2 to 24 hours. 5. The method according to claim 1, characterized in that the drying temperature in step (1) is 50-150°C. 6. The method according to claim 1, characterized in that the working atmosphere in the atmosphere furnace in step (1) is nitrogen or argon, the working temperature of the atmosphere furnace is 350-750°C, and the working time of the atmosphere furnace is 0.5-4.5 hours. 7. The method according to claim 1, characterized in that the liquid-to-solid ratio of the concentrated landfill leachate and the iron-carbon coarse powder in step (2) is 0.1-0.3:1 mL/g. 8. The method according to claim 1, characterized in that the drying temperature in step (2) is 50-150°C. 9. The method according to claim 1, characterized in that the irradiation time in step (2) is 0.25 to 4.75 hours and the voltage is 5 to 45 kV. 10. A high-activity primary battery filter material prepared by the method according to any one of claims 1 to 9.