Modified zeolite powder-based sediment remediation agent and preparation method thereof

Abstract

The application discloses a modified zeolite powder-based sediment repairing agent, which comprises 25-35 parts of zeolite powder, 15-25 parts of yellow sand, 15-20 parts of calcium peroxide powder and 15-25 parts of a microbial agent carrier complex in terms of mass fraction; the zeolite powder contains neodymium elements; and the microbial agent carrier complex contains carbon powder, attapulgite, bacillus spores, EM bacteria, nitrifying bacteria and denitrifying bacteria. The application further discloses a method for preparing the above sediment repairing agent.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and in particular to a sediment remediation agent based on modified zeolite powder and its preparation method. Background Technology

[0002] Currently, riverbed sediment pollution is severe, and sediment pollution is the primary source of endogenous pollution. The main technologies for addressing endogenous pollution are dredging and in-situ sediment remediation. Physical dredging involves large-scale engineering projects, is costly, and easily causes secondary pollution, damaging the river's ecological environment. In-situ remediation mainly involves adding sediment remediation agents. Patent publication CN107235620A discloses a remediation agent for riverbed sediment remediation. This agent uses microorganisms and modified zeolite to remediate the sediment. However, due to the limited adsorption effect of zeolite, the remediation components disclosed in CN107235620A have relatively poor remediation effects on sediment. Summary of the Invention

[0003] To address the above-mentioned problems, this invention proposes a sediment remediation agent based on modified zeolite powder and its preparation method.

[0004] The technical solution adopted in this invention is as follows:

[0005] A sediment remediation agent based on modified zeolite powder comprises, by weight, 25-35 parts zeolite powder, 15-25 parts yellow sand, 15-20 parts calcium peroxide powder, and 15-25 parts microbial inoculant carrier complex; wherein the zeolite powder contains neodymium; and the microbial inoculant carrier complex contains charcoal powder, attapulgite clay, Bacillus, EM bacteria, nitrifying bacteria, and denitrifying bacteria.

[0006] The remediation effects of this sediment remediation agent are as follows: First, this sediment remediation agent utilizes neodymium-containing zeolite powder to adsorb pollutants in the water and sediment, exhibiting excellent adsorption effects. Simultaneously, the addition of calcium peroxide powder allows it to react with water, slowly releasing oxygen and increasing the oxygen content in the water. This enhances the activity of microorganisms in the water and accelerates the degradation of organic matter in the water and sediment. Specifically, calcium peroxide helps promote the activity of microorganisms such as Bacillus, EM bacteria, and nitrifying bacteria in the water, accelerating their degradation of organic matter. Simultaneously, the generated calcium hydroxide, yellow sand, and zeolite powder react with water to form a capping layer at the bottom of the river channel. This capping layer covers the sediment, slowing the release of pollutants from the sediment. Furthermore, the porous structure of the zeolite not only facilitates microbial attachment but also continuously adsorbs pollutants, allowing the attached microorganisms to continuously degrade the pollutants.

[0007] In summary, this type of sediment remediation agent improves the adsorption and degradation capabilities of the agent by using zeolite powder containing neodymium and adding yellow sand and calcium peroxide powder.

[0008] A method for preparing the sediment remediation agent as described above includes the following steps:

[0009] The zeolite modification process involves calcining zeolite powder at 500℃~550℃ for 60min~180min; placing the calcined zeolite in hydrochloric acid solution and then sonicating it; after sonication, placing the zeolite in neodymium nitrate solution and adjusting the pH to 10~10.5 with an alkaline solution (sodium hydroxide solution); maintaining the solution temperature at 25℃ and shaking for 3h; after shaking, rinsing with pure water until neutral; and drying at 65℃ for 8h; after drying, the modified zeolite is obtained.

[0010] The above process aims to modify zeolite powder. The principle involves prolonged impregnation of zeolite with a rare earth metal salt solution, resulting in the formation of metal oxides and hydroxides after modification. On the surface of these metal oxides, due to the unsaturated coordination of surface ions, hydroxylated surfaces are formed by coordination with water in aqueous solution. These surface hydroxyl groups can undergo proton migration in solution, exhibiting amphoteric surface characteristics and corresponding charges. After the modified zeolite surface is covered with hydroxyl groups, it readily forms surface coordination complexes with metal cations and anions, enabling the zeolite to adsorb anions and cations from water. This ensures that the zeolite powder can efficiently adsorb metal ions and pollutants such as nitrogen and phosphorus from water.

[0011] The preparation steps of the microbial agent carrier complex are as follows: wood powder charcoal, bamboo powder charcoal, and attapulgite clay are mixed in a mass ratio of approximately 7:2:1 to obtain a microbial carrier; microbial agents are added to the microbial carrier for granulation; and the granulation is followed by drying to obtain the microbial agent carrier complex; the microbial agents include Bacillus, EM bacteria, nitrifying bacteria, denitrifying bacteria, and water.

[0012] In the mixing step, zeolite powder, yellow sand, calcium peroxide powder, and microbial inoculant carrier complex are mixed evenly.

[0013] Optionally, the microbial agent carrier complex is a particulate microbial agent carrier complex, and the particle size of the microbial agent carrier complex is 1 mm to 2 mm.

[0014] The use of microbial agent carrier complex with this particle size is to ensure that the microorganisms do not dissolve immediately after being put into the water, and to release slowly after sinking to the bottom of the river, so as to stably and efficiently attach to the cover layer.

[0015] Optionally, the particle size of the zeolite powder is 20 mesh to 40 mesh.

[0016] Optionally, 0.5 L of microbial inoculant may be added to every 1 kg of microbial carrier.

[0017] Optionally, the oscillation process in the zeolite modification step is carried out in an oscillation device, which includes a base, a first vibration motor, a second vibration motor, and a storage tank. The first vibration motor is mounted on the base, and the storage tank is inserted into and fitted with the base. The second vibration motor is located inside the storage tank, and the storage tank has an inlet and outlet (liquid enters and exits the storage tank through the inlet and outlet).

[0018] Traditional oscillation is only performed in a shaker, but when the shaker processes the solution, it only continuously shakes the liquid in a plane. This continuous shaking of the liquid cannot fully oscillate the liquid.

[0019] For the reasons mentioned above, this method provides an apparatus for preparing an oscillating liquid. First, the oscillating apparatus is equipped with a first vibration motor and a second vibration motor. The first vibration motor is mounted on a base platform, and the second vibration motor is located in a storage tank. The storage tank is used to hold an alkaline solution containing zeolite powder. When oscillation begins, the base platform is placed on a horizontal surface, and the storage tank is placed on the base platform. The storage tank is tilted relative to the base platform, and the inlet and outlet of the storage tank face upwards. The vibration directions of the first vibration motor and the second vibration motor are different. Thus, when the first vibration motor and the second vibration motor are working, they can drive the alkaline solution in the storage tank to sway in three-dimensional space. The swaying of the alkaline solution in three-dimensional space can fully oscillate the alkaline solution.

[0020] Optionally, a shell is provided inside the liquid storage tank, and there is a gap between the shell and the inner wall of the liquid storage tank. The second vibration motor is located inside the shell, and a heat-conducting jacket is provided on the shell. The heat-conducting jacket is made of metal and is located inside the liquid storage tank. A heat insulation pad is provided between the heat-conducting jacket and the shell. There is a gap between the heat-conducting jacket and the inner wall of the liquid storage tank. A semiconductor heating element is provided on the inner wall of the heat-conducting jacket and is located between the heat-conducting jacket and the shell. A heat dissipation through hole is opened at one end of the liquid storage tank and is located between the shell and the heat-conducting jacket.

[0021] Since the alkaline solution needs to be maintained at 25°C during the modification of zeolite powder, a shell and a heat-conducting jacket are further installed. The shell protects the second vibration motor and prevents the alkaline solution from contaminating the liquid. The heat-conducting jacket is fitted onto the shell, and a semiconductor heating element is installed on the inner wall of the heat-conducting jacket. The outer wall of the heat-conducting jacket is in contact with the liquid. When it is necessary to maintain a constant liquid temperature, the semiconductor heating element is turned on, and the heat generated by the semiconductor heating element is transferred to the heat-conducting jacket. The heat-conducting jacket then transfers the heat to the alkaline solution, thereby maintaining a constant temperature of the alkaline solution.

[0022] In this device, a heat insulation pad is provided between the shell and the heat-conducting jacket. The presence of the heat insulation pad can prevent the heat on the heat-conducting jacket from being transferred to the shell, causing the second vibration motor to overheat. At the same time, since a heat dissipation hole is provided at one end of the liquid storage tank, and the heat dissipation hole is located between the shell and the heat-conducting jacket, the shell and the heat-conducting jacket in the vibrating state can dissipate the heat between them by disturbing the air.

[0023] Optionally, the second vibration motor is attached to the inner wall of the housing.

[0024] Because part of the outer wall of the casing is in contact with the liquid, and the inner wall of the second vibration motor is pressed tightly against the inner wall of the casing, the liquid in the storage tank can be fully vibrated.

[0025] Optionally, a handle is also included, which is disposed on the outer wall of the liquid storage tank.

[0026] Specifically, there is an insertion port on the bottom platform, and a locking post is provided on the outer wall of the liquid storage tank, which is inserted and engaged with the insertion port.

[0027] The beneficial effects of this invention are: by using zeolite powder containing neodymium and adding yellow sand and calcium peroxide powder, the adsorption and degradation capabilities of the remediation agent are improved. Attached Figure Description

[0028] Figure 1 This is a simplified schematic diagram of the oscillation device structure;

[0029] Figure 2 This is a schematic diagram showing the fit between the housing and the heat-conducting jacket.

[0030] Figure 3 This is a schematic diagram showing the positional relationship between the housing and the second vibration motor.

[0031] The attached figures are labeled as follows: 1. Base platform; 101. Insertion port; 2. First vibration motor; 3. Liquid storage tank; 301. Locking post; 302. Inlet and outlet; 303. Heat dissipation hole; 4. Second vibration motor; 5. Handle; 6. Heat insulation pad; 7. Shell; 8. Heat-conducting jacket. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] Example 1

[0034] A modified zeolite-based sediment remediation agent comprises, by weight, 25-35 parts zeolite powder, 15-25 parts yellow sand, 15-20 parts calcium peroxide powder, and 15-25 parts microbial inoculant carrier complex; wherein the zeolite powder contains neodymium; and the microbial inoculant carrier complex contains charcoal powder, attapulgite clay, Bacillus, EM bacteria, nitrifying bacteria, and denitrifying bacteria.

[0035] Example 2

[0036] A method for preparing a sediment remediation agent as described in Example 1 includes the following steps.

[0037] S1 (Zeolite Modification Step): Zeolite powder is calcined at 500℃~550℃ for 60min~180min. The calcined zeolite is then placed in a 1mol / L hydrochloric acid solution and ultrasonically modified at 450W for 120min. After ultrasonic treatment, the zeolite is placed in a 0.02mol / L neodymium nitrate solution, and the pH is adjusted to 10~10.5 with an alkaline solution (sodium hydroxide solution). The solution temperature is maintained at 25℃ and shaken for 3h. After shaking, the solution is rinsed with pure water until neutral and dried at 65℃ for 8h. After drying, the modified zeolite is obtained.

[0038] The above process aims to modify zeolite powder. The principle involves prolonged impregnation of zeolite with a rare earth metal salt solution, resulting in the formation of metal oxides and hydroxides after modification. On the surface of these metal oxides, due to the unsaturated coordination of surface ions, hydroxylated surfaces are formed by coordination with water in aqueous solution. These surface hydroxyl groups can undergo proton migration in solution, exhibiting amphoteric surface characteristics and corresponding charges. After the modified zeolite surface is covered with hydroxyl groups, it readily forms surface coordination complexes with metal cations and anions, enabling the zeolite to adsorb anions and cations from water. This ensures that the zeolite powder can efficiently adsorb metal ions and pollutants such as nitrogen and phosphorus from water.

[0039] S2 (Preparation step of microbial agent carrier complex): Wood powder charcoal, bamboo powder charcoal, and attapulgite clay are mixed in a mass ratio of approximately 7:2:1 to obtain a microbial carrier. Microbial agents are added to the microbial carrier and granulated. After granulation, the mixture is dried to obtain the microbial agent carrier complex. The microbial agents include Bacillus, EM bacteria, nitrifying bacteria, denitrifying bacteria, and water (the bacterial strain is dissolved in water).

[0040] S3 (mixing step): Mix zeolite powder, yellow sand, calcium peroxide powder and microbial inoculant carrier complex evenly.

[0041] Optionally, the microbial agent carrier complex is a particulate microbial agent carrier complex, and the particle size of the microbial agent carrier complex is 1 mm to 2 mm.

[0042] The microbial agent carrier complex with this particle size is used to ensure that microorganisms can stably and efficiently attach to the adsorption layer formed by calcium hydroxide, zeolite powder and yellow sand.

[0043] Optionally, the particle size of the zeolite powder is 20 mesh to 40 mesh.

[0044] Optionally, 0.5 L of microbial inoculant may be added to every 1 kg of microbial carrier.

[0045] Example 3

[0046] An oscillation device for oscillation in the preparation method of Example 2.

[0047] See appendix Figure 1 ~Attached Figure 3 As shown in the attached document Figure 1 ~Attached Figure 3 As shown, the oscillation device includes a base 1, a first vibration motor 2, a second vibration motor 4, and a liquid storage tank 3. The first vibration motor 2 is mounted on the base 1, and the liquid storage tank 3 is inserted and fitted together with the base 1. The second vibration motor 4 is located inside the liquid storage tank 3, and the liquid storage tank 3 has an inlet and outlet 302 (the liquid enters and exits the liquid storage tank 3 through the inlet and outlet 302).

[0048] Traditional oscillation is only performed in a shaker, but when the shaker processes the solution, it only continuously shakes the liquid in a plane. This continuous shaking of the liquid cannot fully oscillate the liquid.

[0049] Based on the above reasons, this method provides an apparatus for preparing an oscillating liquid. First, the oscillating apparatus is equipped with a first oscillating motor 2 and a second oscillating motor 4. The first oscillating motor 2 is located on the base platform 1, and the second oscillating motor 4 is located in the storage tank 3. The storage tank 3 is used to hold an alkaline solution containing zeolite powder. When oscillation begins, the base platform 1 is placed on a horizontal surface, and the storage tank 3 is placed on the base platform 1. The storage tank 3 is tilted relative to the base platform 1, and the inlet and outlet 302 on the storage tank 3 faces upward. The vibration directions of the first oscillating motor 2 and the second oscillating motor 4 are different. In this way, when the first oscillating motor 2 and the second oscillating motor 4 are working, they can drive the alkaline solution in the storage tank 3 to oscillate in three-dimensional space. The oscillation of the alkaline solution in three-dimensional space can fully oscillate the alkaline solution.

[0050] As attached Figure 1 ~Attached Figure 3As shown, a housing 7 is installed inside the liquid storage tank 3, and there is a gap between the housing 7 and the inner wall of the liquid storage tank 3. The second vibration motor 4 is located inside the housing 7. A heat-conducting jacket 8 is installed on the housing 7. The heat-conducting jacket 8 is made of metal and is located inside the liquid storage tank 3. A heat insulation pad 6 is installed between the heat-conducting jacket 8 and the housing. There is a gap between the heat-conducting jacket 8 and the inner wall of the liquid storage tank 3. A semiconductor heating plate is installed on the inner wall of the heat-conducting jacket 8. The semiconductor heating plate is located between the heat-conducting jacket 8 and the housing 7. A heat dissipation through hole 303 is opened at one end of the liquid storage tank 3. The heat dissipation through hole 303 is located between the housing 7 and the heat-conducting jacket 8.

[0051] Since the alkaline solution needs to be maintained at 25°C when modifying zeolite powder, a shell 7 and a heat-conducting jacket 8 are further provided. The shell 7 is used to protect the second vibration motor 4 and prevent the alkaline solution from contaminating the liquid. At the same time, the heat-conducting jacket 8 is fitted on the shell 7, and a semiconductor heating element is set on the inner wall of the heat-conducting jacket 8. The outer wall of the heat-conducting jacket 8 is in contact with the liquid. In this way, when it is necessary to maintain a constant liquid temperature, the semiconductor heating element is turned on, and the heat generated by the semiconductor heating element is transferred to the heat-conducting jacket 8. The heat-conducting jacket 8 then transfers the heat to the alkaline solution, thereby maintaining a constant temperature of the alkaline solution.

[0052] In this device, a heat insulation pad 6 is provided between the housing 7 and the heat-conducting jacket 8. The presence of the heat insulation pad 6 can prevent the heat on the heat-conducting jacket 8 from being transferred to the housing 7, causing the second vibration motor 4 to overheat. At the same time, since a heat dissipation hole 303 is provided at one end of the liquid storage tank 3, and the heat dissipation hole 303 is located between the housing 7 and the heat-conducting jacket 8, the housing 7 and the heat-conducting jacket 8 under vibration can dissipate the heat between them by disturbing the air.

[0053] As attached Figure 1 ~Attached Figure 3 As shown, the second vibration motor 4 is attached to the inner wall of the housing 7.

[0054] Because part of the outer wall of the housing 7 is in contact with the liquid, and the inner wall of the second vibration motor 4 is in close contact with the inner wall of the housing 7, the liquid in the storage tank 3 can be fully vibrated.

[0055] As attached Figure 1 ~Attached Figure 3 As shown, it also includes a handle 5, which is disposed on the outer wall of the liquid storage tank 3.

[0056] Specifically, the base 1 has an insertion port 101, and the outer wall of the liquid storage tank 3 is provided with a locking post 301, which is inserted and engaged with the insertion port 101.

[0057] Testing and verification

[0058] After collecting sediment from a polluted riverbed, it was placed in a 30×30×50cm glass container, with a sediment layer 15cm high, and then filled with 25cm of polluted river water. Two sets of glass containers were set up: one as a blank control group and the other as an experimental group. The sediment remediation agent prepared in Example 2 was sprinkled on the sediment of the experimental group, ensuring it was evenly covered, with a layer thickness of approximately 3-5mm. No sediment remediation agent was applied to the control group.

[0059] After treatment with the remediation agent for a certain period of time, the bottom mud and overlying water of the two groups were taken for testing. The test results are shown in Table 1 and Table 2.

[0060] Table 1

[0061]

[0062] Table 2

[0063]

[0064] According to the experimental data in Tables 1 and 2 above, after the addition of the sediment remediation agent, the pollutants in the sediment and water body showed a significant decrease over time, indicating that the sediment remediation agent can indeed effectively remediate river sediment.

[0065] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent modifications made based on the content of the present invention specification, whether directly or indirectly applied to other related technical fields, are similarly included within the scope of protection of the present invention.

Claims

1. A method for preparing a sediment remediation agent, characterized in that, Includes the following steps, The zeolite modification process involves calcining zeolite powder at 500℃~550℃ for 60 min~180 min; placing the calcined zeolite in hydrochloric acid solution and then sonicating it; after sonication, placing the zeolite in neodymium nitrate solution and adjusting the pH to 10~10.5 with an alkaline solution; maintaining the solution temperature at 25℃ and vibrating for 3 h; after vibration, rinsing with pure water until neutral; and drying at 65℃ for 8 h; after drying, the modified zeolite is obtained. The preparation steps of the microbial agent carrier complex are as follows: wood powder charcoal, bamboo powder charcoal, and attapulgite clay are mixed in a mass ratio of 7:2:1 to obtain a microbial carrier; microbial agents are added to the microbial carrier and granulated; after granulation, the mixture is dried to obtain the microbial agent carrier complex; the microbial agents include Bacillus, EM bacteria, nitrifying bacteria, and denitrifying bacteria. In the mixing step, 25 to 35 parts of modified zeolite, 15 to 25 parts of yellow sand, 15 to 20 parts of calcium peroxide powder and 15 to 25 parts of microbial agent carrier complex are mixed evenly by mass. The oscillation process in the zeolite modification step is carried out in an oscillation device, which includes a base, a first vibration motor, a second vibration motor, and a storage tank. The first vibration motor is mounted on the base, and the storage tank is inserted into the base. The second vibration motor is located inside the storage tank, and the storage tank has an inlet and outlet. The liquid storage tank is equipped with a shell, and there is a gap between the shell and the inner wall of the liquid storage tank. The second vibration motor is located inside the shell. A heat-conducting jacket is provided on the shell. The heat-conducting jacket is made of metal and is located inside the liquid storage tank. A heat insulation pad is provided between the heat-conducting jacket and the shell. There is a gap between the heat-conducting jacket and the inner wall of the liquid storage tank. A semiconductor heating element is provided on the inner wall of the heat-conducting jacket and is located between the heat-conducting jacket and the shell. A heat dissipation through hole is opened at one end of the liquid storage tank and is located between the shell and the heat-conducting jacket.

2. The preparation method according to claim 1, characterized in that, The microbial agent carrier complex is a particulate microbial agent carrier complex, and the particle size of the microbial agent carrier complex is 1 mm to 2 mm.

3. The preparation method according to claim 1, characterized in that, The particle size of the zeolite powder is 20 mesh to 40 mesh.

4. The preparation method according to claim 1, characterized in that, Add 0.5L of microbial inoculant to every 1kg of microbial carrier.

5. The preparation method according to claim 1, characterized in that, The second vibration motor is pressed tightly against the inner wall of the housing.

6. The preparation method according to claim 1, characterized in that, It also includes a handle, which is provided on the outer wall of the liquid storage tank.

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