Preparation method for preparing catalyst for degrading typical odorous substances by using waste zinc-carbon batteries, obtained product and application

Abstract

The invention relates to the field of solid waste resource utilization and the field of feed water treatment, in particular to a preparation method for preparing a catalyst for degrading typical odorous substances by using waste zinc-carbon batteries, an obtained product and application. The method comprises the following steps: firstly, taking a metal structure and a carbon structure of residues after crushing the waste zinc-carbon battery, grinding, mixing fine powder with a KOH solution, and drying to obtain a dry solid; the dry solid is calcined, the calcined solid is cooled and then washed, and the carbon-ZnMn2O4 catalyst is obtained. The preparation method provided by the invention is simple and low in cost, and the treated water body meets the condition that the concentration of typical smelly substances is below a smelly threshold value, and has certain commercial value. The catalyst provided by the invention can degrade a plurality of typical odorous substances, such as beta-cyclocitral, 2-MIB and the like, and is wider in application range; compared with single ozone oxidation, the removal rate of a catalytic ozonation system of the catalyst on typical odorous substances is higher, and the catalytic efficiency is remarkably improved; and through the utilization of the catalyst, the consumption of ozone is reduced, the influence on the environment is reduced, and the concept of green development is better met.

Description

Technical Field

[0001] The invention relates to the field of solid waste resource utilization and water treatment, and in particular to a method for preparing a catalyst for degrading typical odorants by using waste zinc-carbon batteries, and the obtained product and application. Background Art

[0002] With the rapid development of economy and society, water pollution is becoming more and more serious, especially the increase of nutrients such as nitrogen and phosphorus in water, which leads to eutrophication of water bodies, which in turn causes the proliferation of algae, destroys the water ecological balance, and has a serious impact on people's production and life. Among the many algae-derived organic substances, the impact of algae-derived odor substances on people is particularly prominent. These odor substances not only directly affect the sensory characteristics of water sources such as smell and taste, but may also pose a threat to human health.

[0003] The main algae-derived odor substances in water bodies include 2-methylisoborneol (2-MIB), geosmin (GSM), β-cyclocitral (β-cyclocitral), β-ionone (β-ionone), methoxypyrazine (IPMP), 2-isopropyl-3-methoxypyrazine (IBMP), isophorone (IPO), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and 2,4,6-trichloroanisole (2,4,6-TCA), etc. At present, water plants in various countries generally use sedimentation, filtration, disinfection and other processes for water treatment. These technologies have a significant effect on the removal of conventional indicators, but their ability to remove dissolved organic matter and algae-derived odor substances is limited, and deep treatment such as catalytic oxidation is still required.

[0004] Ozone (O3) is an oxidant with extremely strong oxidizing ability, and its redox potential is 2.07 V. Ozone can react with organic matter with unsaturated functional groups in water, reducing the toxicity of organic matter and improving its biodegradability. However, the oxidizing ability of ozone is limited and highly selective. When used alone, it may not be able to completely remove all pollutants, especially difficult-to-degrade substances and small-molecule organic acids. Ozone catalytic oxidation technology is to completely degrade or transform difficult-to-degrade organic components in water in a short period of time by catalyzing ozone oxidation reaction under the action of a catalyst, thereby achieving the purpose of purifying the water body. This technology uses a catalyst to coordinate ozone oxidation, which can reduce the reaction activation energy or change the reaction process, thereby achieving the purpose of deep oxidation and maximizing the removal of organic pollutants.

[0005] Zinc-carbon batteries have been widely used around the world due to their low price advantage, but they also bring a problem that cannot be ignored - the number of waste batteries generated each year is extremely large. These waste batteries contain a variety of chemical components and heavy metal elements, so they are clearly classified as hazardous wastes. Their improper treatment will pose a serious threat to the ecological environment. For a long time, waste batteries have mostly been treated by landfill or incineration. However, neither of these two methods is a long-term solution. Landfill treatment may cause soil contamination by heavy metals, affecting crop growth and groundwater quality; while incineration treatment can reduce volume, it may release harmful gases during the process, aggravating air pollution problems. Therefore, exploring ways to recycle waste batteries has become an urgent need for environmental protection and sustainable development. The resource utilization of waste batteries can not only effectively reduce the negative impact on the environment, but also embodies the core concept of circular economy and green development. Converting waste batteries into valuable resources, especially using them in environmental protection fields such as water treatment as catalysts, is a very innovative solution. This approach not only reduces the source of environmental pollution, but also promotes the recycling of resources, finding a win-win balance between environmental protection and economic development. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for preparing a catalyst for degrading typical odorants using waste zinc-carbon batteries. The method uses waste zinc-carbon batteries to prepare a manganese-zinc-carbon composite catalyst, strengthens the utilization of O3 under the activation of UV and catalyst, increases the steady-state free radical concentration in the system, and effectively degrades typical odorants in water through the combined action of OH and ozone. In subsequent practical applications, it can also be loaded on a magnetic material to improve the recovery efficiency.

[0007] The present invention also provides a typical odor-degrading catalyst prepared by the preparation method.

[0008] The present invention further provides application of the above catalyst.

[0009] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: The present invention provides a method for preparing a catalyst for degrading typical odorants by using waste zinc-carbon batteries, comprising the following steps: ① Mechanically crush the waste zinc-carbon batteries to remove the battery shell, and rinse the remaining metal structure and carbon structure with deionized water until they are neutral; ② The residue after washing is filtered through quantitative filter paper, the filtered residue is dried, and then fully ground to obtain fine powder; ③ The obtained fine powder is mixed with KOH solution and dried to obtain a dry solid; the dry solid is calcined, and the calcined solid is cooled and then washed to obtain a carbon-ZnMn2O4 catalyst.

[0010] Preferably, in step ②, the quantitative filter paper is 4-12 μm.

[0011] Preferably, in step ②, the drying is performed at 105° C. for 10 h.

[0012] Preferably, in step ③, the mass ratio of the fine powder to KOH is 1:1; and the concentration of the KOH solution is 10 M.

[0013] Preferably, in step ③, the drying is performed at 105° C. for 2 days; the calcination is performed at 900° C. for 5 hours under an argon atmosphere; and the washing is performed by first washing with 10% H 2 SO 4 and then repeatedly rinsing with deionized water until the pH is 7.

[0014] The present invention also provides a typical odor-degrading catalyst prepared by the preparation method.

[0015] The present invention further provides the use of the above catalyst in degrading typical odorants, wherein the catalyst catalyzes ozone to degrade typical odorants.

[0016] Preferably, UV irradiation can also be used in the process of degrading typical odorants.

[0017] The waste zinc-carbon battery used in the present invention has a battery metal component of Mn-Zn and a carbon column at the center of the battery.

[0018] The specific process of the catalyst system provided by the present invention, the ozone catalytic oxidation is: (1) The catalyst prepared by the present invention was used to introduce O3 to degrade the odorous substances in the water body. The dosage of the reaction catalyst and whether to increase UV irradiation were controlled to achieve different reaction systems of O3, C-ZM / O3, and C-ZM / UV / O3. The reaction was carried out for 30 minutes. During the reaction, samples were taken at different time intervals and 0.1 M sodium thiosulfate was added to terminate the reaction. The degradation effect of the odorous substances was detected by gas chromatography-mass spectrometry.

[0019] The catalyst provided by the invention can be reused after being filtered and rinsed with deionized water after the reaction.

[0020] The catalyst provided by the present invention degrades typical odorants including, but not limited to, 2-methylisoborneol (2-MIB), geosmin (GSM), β-cyclocitral (β-cyclocitral), β-ionone (β-ionone), methoxypyrazine (IPMP), 2-isopropyl-3-methoxypyrazine (IBMP), isophorone (IPO), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and 2,4,6-trichloroanisole (2,4,6-TCA).

[0021] The beneficial effects of the present invention are: (1) The present invention utilizes waste zinc-carbon batteries to make catalysts, thereby solving the problem of waste battery disposal, realizing resource utilization, and reducing environmental pollution; (2) The catalyst prepared by the present invention has a significant degradation effect on odor substances (typical odorants) under the combined action of UV and ozone. For example, the degradation effect of β-cyclocitral can reach more than 90%. Moreover, the catalyst can be filtered and rinsed after the reaction and then reused, thereby reducing the processing cost.

[0022] (3) The preparation method provided by the present invention is simple and low-cost, and the concentration of odorous substances in the treated water is below the odor threshold, which has certain commercial value.

[0023] (4) The catalyst provided by the present invention can degrade a variety of typical odorants, such as β-cyclocitral, 2-MIB, etc., and has a wider range of applications. Compared with ozone oxidation alone, the catalyst catalyzed ozonation system has a higher removal rate for odorous substances and significantly improved catalytic efficiency. In addition, through the use of the catalyst, the amount of ozone used is reduced, the impact on the environment is reduced, and it is more in line with the concept of green development. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the preparation process of the composite catalyst in the present invention; Figure 2 This is a diagram of an ozone catalytic reaction device; Figure 3 This is a comparison chart of the degradation effects of different systems on β-cyclocitral. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further explained and illustrated by means of specific embodiments below.

[0026] The schematic diagram of the preparation process of the carbon-ZnMn2O4 catalyst provided by the present invention is as follows Figure 1 shown.

[0027] Example 1 (1) Completely discharge the collected used disposable zinc-carbon batteries and mechanically disassemble the batteries; (2) placing the disassembled metal structure and carbon structure in a magnetic stirrer and repeatedly washing with deionized water until the pH reaches 7 to obtain a mixture; (3) The mixture after repeated washing was filtered using quantitative filter paper (10 μm), and the filter residue was dried at 105 °C for 10 h; the dried product was then ground in a grinder to obtain a fine powder; (4) The fine powder obtained in (3) was mixed with 10 M KOH (1:1 ratio) in a ceramic dish and dried at 105 °C for 2 days to obtain a dry solid; (5) Calcine the dry solid in a tube furnace at 900 °C for 5 h, and introduce argon (Ar) to isolate oxygen and prevent solid oxidation; (6) The calcined solid was naturally cooled and then washed twice with 10% H2SO4 and then repeatedly rinsed with deionized water until the pH reached 7 to obtain a carbon-ZnMn2O4 catalyst (C-ZM catalyst).

[0028] Example 2 (1) Using the C-ZM catalyst prepared in Example 1, catalyze ozone to degrade odorous substances in water under UV irradiation for 30 min. During this period, samples were taken for detection at 0, 3 min, 5 min, 10 min, 15 min, 20 min, and 30 min.

[0029] (2) Ozone is produced by an ozone generator, and the ozone concentration is adjusted between 1.0 and 2.0 mg / L by controlling the ozone flow meter and air pump of the ozone generator.

[0030] (3) The dosage of C-ZM catalyst is 10~20 mg / L; (4) The UV lamp is a 15 W low-pressure mercury lamp with a wavelength of 254 nm. The reaction system is adjusted by controlling the UV lamp switch.

[0031] Example 3 The experiment was carried out in a 2 L reactor, which was connected to an ozone generator and an online ozone concentration detector. A 15 W low-pressure mercury lamp with an emission wavelength of 254 nm was placed vertically in the center of the reactor to irradiate ultraviolet light in all directions. The reaction device is shown in the figure below. Figure 2 shown.

[0032] The experiment used the filtered water of Jinan Quehua Water Plant as the background, spiked with 500 ng / L β-cyclocitral, preheated the UV lamp for 30 min, controlled the ozone concentration at 1.5 mg / L by controlling the air pump flowmeter valve, and the C-ZM dosage was 10 mg / L. Single ozone, C-ZM / O3, and C-ZM / UV / O3 reactions were carried out respectively. 50 mL of sample was taken at 0, 3 min, 5 min, 10 min, 15 min, 20 min, and 30 min, and excess Na2S2O3 solution was added to quench the reaction. Then the sample was filtered with a 0.45 μm PTFE filter membrane. Finally, 40 mL of the filtered sample was taken in a 60 mL brown sample bottle and 10 g NaCl was added to shake well and detected by SPME-GC-MS method. β-cyclocitral detection method: solid phase microextraction at 65℃ for 30 min, magnetic stirrer speed 500 r / min. GC-MS analysis conditions: gas chromatography column HP-5MS (30 m×250 μm×0.25 μm), injection port temperature 240℃, ion source 230℃, quadrupole temperature 150℃; initial temperature 50℃, maintained for 2 min, heated to 120℃ at 10℃ / min, heated to 130℃ at 5℃ / min, heated to 200℃ at 15℃ / min, maintained for 2 min, selected ion scanning mode, quantitative ions 137, 152.

[0033] Within 30 minutes of reaction, the degradation effects of the three systems on β-cyclocitral were C-ZM / UV / O3>C-ZM / O3>ozone alone. The comparison of degradation effects is shown in the figure below. Figure 3 As shown, C-ZM catalyzed UV / O3 significantly improved the removal efficiency of β-cyclocitral (94.33%).

Claims

1. A method for preparing a catalyst for degrading typical odorants using waste zinc-carbon batteries, characterized in that: The following steps are involved: ① Mechanically crush the waste zinc-carbon batteries to remove the battery shell, and rinse the remaining metal structure and carbon structure with deionized water until they are neutral; ② The residue after washing is filtered through quantitative filter paper, the filtered residue is dried, and then fully ground to obtain fine powder; ③ Mix the obtained fine powder with KOH solution and dry to obtain dry solid; The dry solid is calcined, and the calcined solid is cooled and washed to obtain a carbon-ZnMn2O4 catalyst.

2. The preparation method according to claim 1, characterized in that: In step ②, the quantitative filter paper is 4-12 μm.

3. The preparation method according to claim 1 or 2, characterized in that: In step ②, the drying is carried out at 105° C. for 10 hours.

4. The preparation method according to claim 1, characterized in that: In step ③, the mass ratio of the fine powder to KOH is 1:1; the concentration of the KOH solution is 10 M.

5. The preparation method according to claim 1 or 4, characterized in that: In step ③, the drying is performed at 105° C. for 2 days; the calcination is performed at 900° C. for 5 hours under an argon atmosphere; and the washing is performed by first washing with 10% H 2 SO 4 and then repeatedly rinsing with deionized water until the pH is 7.

6. A catalyst for degrading typical odorants prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the catalyst as claimed in claim 6 in degrading typical odorants, characterized in that: The catalyst catalyzes ozone degradation of typical odorants.

8. The use according to claim 7, characterized in that: UV irradiation can also be used in the process of degrading typical odorants.

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