Preparation method of biozeolite for covering eutrophic water body sediment
By modifying the zeolite and loading nitrogen-detoxified microorganisms, combining modified bentonite and zero-valent iron, biological zeolites were prepared, which solved the problem of limited effect of the existing technology midsole mud covering material, and achieved nitrogen in eutrophied water bodies The effective removal of phosphorus reduces the cost of governance and has good application prospects.
Patent Information
- Application Number
- CN202411350670.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2024-12-20
AI Technical Summary
In the prior art, the bottom silt covering material that relies solely on physical barriers is limited in eutrophication water bodies and is costly, so it cannot effectively remove pollutants. A single physical barrier can only isolate pollutants in the bottom silt and cannot Completely solve the pollution problem.
By modifying the zeolite, combined with modified bentonite and zero-valent iron, and carrying nitrogen-deoxygenated microorganisms, biological zeolites with nitrogen-deoxygenated and adsorption properties were prepared for eutrophication of water bottom sludge covering to achieve nitrogen and phosphorus Remove.
It improves the ability to remove nitrogen and phosphorus, reduces the concentration of water pollutants, reduces the cost of treatment, and has simple preparation process, which has good economic value and application prospects.
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Figure CN119158538A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of eutrophic water body treatment, and in particular relates to a method for preparing biological zeolite used for covering bottom mud of eutrophic water body. Background Art
[0002] In-situ covering of eutrophic water sediments can prevent pollutants in the sediments from entering the water body, which is an important way to reduce nitrogen and phosphorus pollutants in eutrophic water bodies. The performance of sediment covering materials has an important influence on the covering effect. Choosing appropriate covering materials can not only reduce pollutants in eutrophic water bodies, but also reduce economic costs. In actual eutrophic water treatment engineering applications, the single physical barrier effect of covering materials is limited, and a large thickness is often required to work, resulting in high costs. At the same time, the physical barrier effect only isolates pollutants in the sediment and cannot remove pollutants.
[0003] Currently, the more common sediment covering materials such as gravel, ceramsite, and ordinary zeolite can inhibit the release of sediment pollutants into water bodies to a certain extent, but there are the following problems: (1) Relying solely on a single physical barrier has limited effect and often requires a large thickness to work, resulting in high costs. (2) The physical barrier effect only isolates pollutants in the sediment and cannot remove pollutants. Summary of the invention
[0004] The purpose of the present invention is to provide a method for preparing biological zeolite for covering eutrophic water body sediment, so as to solve the technical problems pointed out in the background technology.
[0005] The technical solution of the present invention to solve the above technical problems is as follows: a method for preparing biological zeolite for covering eutrophic water body sediment, comprising: Step 1, modifying zeolite to obtain modified zeolite; Step 2, loading a coupling agent onto the modified zeolite obtained in step 1 to obtain a modified zeolite with a coupling agent; the coupling agent comprises modified bentonite and zero-valent iron; Step 3, loading the denitrifying microorganisms onto the modified zeolite with coupling agent obtained in step 2 to obtain biological zeolite.
[0006] The method for preparing biological zeolite for covering the bottom mud of eutrophic water bodies as described above of the present invention, preferably, in step 1, the step of modifying the zeolite is: rinsing the zeolite and immersing it in acid, washing the zeolite with deionized water after a predetermined time, placing the washed zeolite in an oven for high-temperature drying, grinding and sieving the dried zeolite to obtain modified zeolite.
[0007] In the method for preparing biological zeolite for covering eutrophic water body sediment as described above, preferably, the modified zeolite is acid-modified zeolite, and the particle size of the acid-modified zeolite is about 3 mm to 8 mm.
[0008] The method for preparing biological zeolite for covering eutrophic water body sediment as described above of the present invention, preferably, the preparation step of the modified bentonite in step 2 is: immersing the bentonite in acid, washing the bentonite with deionized water after reaching a predetermined immersion time, placing the washed bentonite in an oven at medium temperature for drying, and grinding and sieving the dried bentonite.
[0009] The method for preparing biological zeolite for covering eutrophic water body sediment as described above of the present invention, preferably, in step 2, the step of loading the coupling agent onto the modified zeolite obtained in step 1 is: uniformly mixing the modified bentonite powder and the zero-valent iron powder, adding ultrapure water into an ultrasonic cleaner, placing the modified zeolite, ultrasonically oscillating for 12h to 36h under uniform stirring, and discarding the supernatant after precipitation.
[0010] In the method for preparing biological zeolite for covering eutrophic water body sediment as described above, preferably, the particle size of the zero-valent iron is 50 nm to 100 μm.
[0011] In the method for preparing biological zeolite for covering eutrophic water sediment as described above, preferably, the mass ratio of modified zeolite to modified bentonite is 100:10; and the mass ratio of modified zeolite to zero-valent iron is 100:1.
[0012] The method for preparing biological zeolite for covering bottom sediment of eutrophic water body as described above of the present invention, preferably, step 3, the step of loading the denitrifying microorganisms onto the modified zeolite with coupling agent obtained in step 2 is: placing the modified zeolite with coupling agent in a container, adding denitrifying microorganisms, adding nutrient elements for growth of denitrifying microorganisms and ultrapure water, and culturing at 28°C to 30°C in a mixed state for 3 to 5 days to obtain the biological zeolite for covering bottom sediment of eutrophic water body.
[0013] In the method for preparing biological zeolite for covering bottom mud of eutrophic water bodies as described above, preferably, the denitrifying microorganisms are denitrifying bacteria and / or nitrifying bacteria in the logarithmic growth phase.
[0014] In the method for preparing biological zeolite for covering eutrophic water body sediment as described above, preferably, the nutrient elements for growth of denitrifying microorganisms are nutrient elements for bacterial culture medium, and the nutrient elements for bacterial culture medium include sodium chloride, potassium chloride, ammonium chloride, sodium nitrate and glucose.
[0015] The beneficial effects of the present invention are: (1) The present invention uses a cultured highly active bacterial suspension as an inoculating strain to load a denitrifying bacterial community on the modified zeolite, thereby increasing the biomass of the denitrifying bacterial community on the zeolite, making the modified zeolite have a stronger denitrification performance, and can be used to degrade nitrogen pollutants in water bodies, thereby giving the modified zeolite the function of denitrification in the process of sediment covering of eutrophic water bodies.
[0016] (2) The present invention uses modified bentonite and zero-valent iron powder as modified zeolite coupling agents, which increases the specific surface area and adsorption capacity of the modified zeolite, and improves the adsorption performance of the modified zeolite on phosphorus. In the process of sediment covering, the barrier effect on phosphorus in eutrophic water bodies is enhanced, achieving the purpose of reducing phosphorus in water bodies.
[0017] (3) The biological zeolite prepared by the present invention has a stable structure and high strength and can be used for a long time; the zeolite preparation steps are simple and the cost is low. The method is easy to promote and apply on a large scale and has great economic value and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a flow chart of a method for preparing biological zeolite for covering bottom mud of eutrophic water bodies according to an embodiment of the present invention.
[0019] Figure 2 These are the experimental results of the effect of bacteria loading on zeolite on the degradation of nitrate nitrogen.
[0020] Figure 3 These are the experimental results of the adsorption of phosphorus by loaded bentonite and iron powder on zeolite. DETAILED DESCRIPTION
[0021] The embodiments described herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention, are illustrative and exemplary, and should not be construed as limiting the embodiments of the present invention and the scope of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the claims and the contents disclosed in the specification of this application, including technical solutions that adopt any obvious replacement and modification of the embodiments described herein.
[0022] Example 1 This embodiment provides a method for preparing biological zeolite for covering eutrophic water sediments. The prepared biological zeolite is laid on top of the water sediments to treat the eutrophic water bodies. Figure 1 As shown, the above method includes: Step 1, modifying zeolite to obtain modified zeolite; In a preferred embodiment, in step 1, the step of modifying the zeolite is: rinsing the zeolite and immersing it in acid, washing the clean zeolite with deionized water after a predetermined time, placing the washed zeolite in an oven at high temperature for drying, grinding and sieving the dried zeolite to obtain modified zeolite. In a specific embodiment, the step of modifying the zeolite is: rinsing the zeolite and immersing it in 1 mol / L hydrochloric acid for 24 hours, washing it with deionized water, placing it in an oven at high temperature for drying for 24 hours, grinding and sieving.
[0023] In a preferred embodiment, the modified zeolite is an acid-modified zeolite, the particle size of the acid-modified zeolite is about 3 mm to 8 mm, and the main chemical component is silicon dioxide.
[0024] Step 2, loading a coupling agent onto the modified zeolite obtained in step 1 to obtain a modified zeolite with a coupling agent; the coupling agent comprises modified bentonite and zero-valent iron; In a preferred embodiment, the preparation steps of the modified bentonite described in step 2 are: immersing the bentonite in acid, washing the bentonite with deionized water after reaching a predetermined immersion time, placing the washed bentonite in an oven at medium temperature for drying, grinding and sieving the dried bentonite, and the main chemical component of the modified bentonite is silicon dioxide. In a specific embodiment, the bentonite modification step is: immersing the bentonite in a 1 mol / L sodium carbonate solution for 24 hours, washing with deionized water, placing it in an oven at medium temperature for drying, grinding and sieving.
[0025] In a preferred embodiment, in step 2, the step of loading the coupling agent onto the modified zeolite obtained in step 1 is: uniformly mixing the modified bentonite powder and the zero-valent iron powder, adding ultrapure water into an ultrasonic cleaner, placing the modified zeolite, and ultrasonically oscillating for 12 h to 36 h under uniform stirring, and discarding the supernatant after settling for 0.5 h to 3 h.
[0026] In a preferred embodiment, the particle size of the zero-valent iron is 50 nm to 100 μm, and the main chemical component is iron.
[0027] In a preferred embodiment, the mass ratio of the modified zeolite to the modified bentonite is 100:10; the mass ratio of the modified zeolite to the zero-valent iron is 100:1.
[0028] Step 3, loading the denitrifying microorganisms onto the modified zeolite with coupling agent obtained in step 2 to obtain biological zeolite.
[0029] In a preferred embodiment, step 3, the step of loading the denitrifying microorganisms onto the modified zeolite with a coupling agent obtained in step 2 is: placing the modified zeolite with a coupling agent in a container, adding denitrifying microorganisms, adding nutrients for the growth of denitrifying microorganisms and ultrapure water, and culturing at 28°C to 30°C for 3 to 5 days in a mixed state to obtain the biological zeolite for covering the bottom mud of eutrophic water bodies. In a preferred embodiment, the volume ratio of the inoculated bacteria (the total weight of the denitrifying microorganisms, nutrients for the growth of denitrifying microorganisms and ultrapure water) to the mass ratio of the zeolite is 1:1.
[0030] In a preferred embodiment, the denitrifying microorganisms are denitrifying bacteria and / or nitrifying bacteria in the logarithmic growth phase.
[0031] In a preferred embodiment, the denitrifying microorganism growth nutrient elements are bacterial culture medium nutrient elements, and the bacterial culture medium nutrient elements include sodium chloride, potassium chloride, ammonium chloride, sodium nitrate and glucose.
[0032] Modified bentonite powder and zero-valent iron powder are coupled to the modified zeolite to increase the specific surface area and phosphorus adsorption of the zeolite, and at the same time, the zeolite has a denitrification function by loading a highly active denitrifying bacterial community. The biological zeolite prepared by the present invention can be used for covering the bottom sediment of eutrophic water bodies, achieving the purpose of blocking the release of bottom sediment pollutants into the water body while removing some pollutants.
[0033] Example 2 Taking the loading of denitrifying bacteria on acid-modified zeolite as an example, the strain used is preferably but not limited to denitrifying bacteria, and the steps are as follows: a certain amount of zeolite is weighed and immersed in 1mol / L hydrochloric acid for 24 hours, then washed with ultrapure water, placed in an oven at 50 degrees for 24 hours for drying, placed in a mortar and ground into 5mm particles, and sieved to obtain modified zeolite. A certain amount of bentonite is weighed and immersed in 1mol / L sodium carbonate solution for 24 hours, then washed with ultrapure water, placed in an oven at 50 degrees for 48 hours for drying, placed in a mortar and ground, and sieved to obtain modified bentonite.
[0034] Put 100g of the above-mentioned modified zeolite into a 1L ultrasonic cleaner, add 1.0L of ultrapure water, add 10g of modified bentonite powder and 1g of zero-valent iron powder and mix evenly, and perform ultrasonic vibration for 24h under slow stirring (20-30r / min). After settling for 1h, discard the supernatant to obtain the modified zeolite with coupling agent.
[0035] Take 100g of the modified zeolite with coupling agent obtained above and place it in a 1.0L glass container, add 100mL of denitrifying bacteria suspension in the logarithmic growth phase, add appropriate amount of ultrapure water and nutrients including sodium chloride, potassium chloride, ammonium chloride, sodium nitrate, glucose to maintain the normal growth of the bacterial flora, seal the container to maintain anoxic environment, and culture for 5 days at 28-30°C with slow stirring (10-15r / min) to obtain biological zeolite that can be used for denitrification and phosphorus absorption in eutrophic water bodies.
[0036] Effect example Among the materials used in the following effect examples, (1), (3) and (4) are obtained from the intermediate step or the final step of the above Example 2. Zeolite A loaded with denitrifying bacteria was prepared separately according to the following method. Zeolite A was used as a control group.
[0037] (1) Zeolite A: acid-modified zeolite, marked as zeolite in the statistical results; (2) Zeolite A loaded with denitrifying bacteria, marked as: zeolite + denitrifying bacteria; 100 g of zeolite A was placed in a 1.0 L glass container, 100 mL of a suspension of denitrifying bacteria in the logarithmic growth phase was added, an appropriate amount of ultrapure water and nutrients such as sodium chloride, potassium chloride, ammonium chloride, sodium nitrate, glucose, etc. that maintain the normal growth of the bacterial flora were added, the container was sealed to maintain an anaerobic environment, and cultured at 28-30 °C with slow stirring (10-15 r / min) for 5 days to obtain zeolite A loaded with denitrifying bacteria.
[0038] (3) Zeolite A loaded with modified bentonite powder and zero-valent iron powder, labeled as: zeolite + bentonite and iron powder; (4) Zeolite A loaded with denitrifying bacteria, modified bentonite powder, and zero-valent iron powder, labeled as: zeolite + bentonite and iron powder + denitrifying bacteria.
[0039] Four groups of experiments were set up. 500 ml of sludge from the river bottom (this sludge does not contain denitrifying bacteria and has no adsorption effect on phosphorus) was placed in four 2L beakers respectively. Then 100 ml of a solution containing 50 mg / L phosphorus (prepared with potassium dihydrogen phosphate) was added, and the sludge was stirred evenly. After standing and settling, the supernatant was discarded. Four kinds of covering materials were added to the four beakers respectively, so that the covering materials covered the mud-water interface with a thickness of 1 cm. 1000 ml of 100 mg / L nitrate nitrogen solution was added to the four beakers respectively, and appropriate amounts of glucose and other nutrients necessary for the growth of denitrifying bacteria were added to the beakers at the same time, and the concentrations of nitrate nitrogen and phosphorus in the water overlying the beakers were measured according to the detection method recorded in the "Water and Wastewater Monitoring and Analysis Methods (Fourth Edition)".
[0040] Experimental result 1: From Figure 2It can be seen that after the zeolite is loaded with bacteria, the degradation rate of nitrate nitrogen is significantly accelerated, and 100 mg / L of nitrate nitrogen can be completely degraded within 48 hours. Zeolite without bacteria only has an adsorption effect on nitrate nitrogen, and the adsorption effect is limited. This shows that after loading denitrifying bacteria on acid-modified zeolite, it has a good degradation effect on nitrate nitrogen.
[0041] Experimental results 2: From Figure 3 It can be seen that in the experimental group with bentonite and iron powder loaded on zeolite, the phosphorus concentration in the overlying water was significantly lower than that in the control group without bentonite and iron powder loaded, indicating that loading bentonite and iron powder on zeolite can improve the adsorption of zeolite on phosphorus or block the release of phosphorus from the sediment to the water body.
[0042] The technical features disclosed above are not limited to the disclosed combinations with other features. Those skilled in the art may also make other combinations between the technical features according to the purpose of the invention to achieve the purpose of the invention.
Claims
1. A method for preparing biological zeolite for covering eutrophic water sediment, characterized in that: include: Step 1, modifying zeolite to obtain modified zeolite; Step 2, loading a coupling agent onto the modified zeolite obtained in step 1 to obtain a modified zeolite with a coupling agent; the coupling agent comprises modified bentonite and zero-valent iron; Step 3, loading the denitrifying microorganisms onto the modified zeolite with coupling agent obtained in step 2 to obtain biological zeolite.
2. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 1, characterized in that: In step 1, the zeolite is modified by: rinsing the zeolite and immersing it in acid, washing the zeolite with deionized water after a predetermined time, drying the washed zeolite in an oven at high temperature, grinding and sieving the dried zeolite to obtain modified zeolite.
3. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 2, characterized in that: The modified zeolite is an acid-modified zeolite, and the particle size of the acid-modified zeolite is about 3 mm to 8 mm.
4. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 3, characterized in that: The preparation steps of the modified bentonite in step 2 are: immersing the bentonite in acid, washing the bentonite with deionized water after a predetermined immersion time, drying the washed bentonite in an oven at medium temperature, and grinding and sieving the dried bentonite.
5. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 4, characterized in that: In step 2, the step of loading the coupling agent onto the modified zeolite obtained in step 1 is as follows: the modified bentonite powder and the zero-valent iron powder are mixed evenly, ultrapure water is added into an ultrasonic cleaner, the modified zeolite is put in, ultrasonic vibration is performed for 12 hours to 36 hours under uniform stirring, and the supernatant is discarded after precipitation.
6. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 5, characterized in that: The particle size of the zero-valent iron is 50 nm to 100 μm.
7. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 5, characterized in that: The mass ratio of the modified zeolite to the modified bentonite is 100:10; the mass ratio of the modified zeolite to the zero-valent iron is 100:
1.
8. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 7, characterized in that: Step 3, the step of loading the denitrifying microorganisms onto the modified zeolite with a coupling agent obtained in step 2 is as follows: placing the modified zeolite with a coupling agent in a container, adding denitrifying microorganisms, adding nutrient elements for the growth of denitrifying microorganisms and ultrapure water, and culturing at 28°C to 30°C in a mixed state for 3 to 5 days to obtain the biological zeolite for covering the bottom mud of eutrophic water bodies.
9. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 8, characterized in that: The denitrifying microorganisms are denitrifying bacteria and / or nitrifying bacteria in the logarithmic growth phase.
10. The method for preparing biological zeolite for covering eutrophic water sediment according to claim 8, characterized in that: The denitrifying microorganism growth nutrient elements are bacterial culture medium nutrient elements, and the bacterial culture medium nutrient elements include sodium chloride, potassium chloride, ammonium chloride, sodium nitrate and glucose.