A method for biodegradation of groundwater organics

Abstract

The application relates to a method for biodegrading groundwater organics, which comprises the following steps: S1. preparing a beet pulp biochar loaded zinc oxide matrix: beet pulp is immersed in a zinc chloride solution, after sufficient impregnation, an impregnation solution is obtained, then an aqueous sodium hydroxide solution is added, so that all zinc ions are converted into zinc hydroxide precipitation, a filter cake is obtained through filtration, is washed, and is dried at low temperature to obtain a precursor, the precursor is crushed and sieved, and the sieved material is treated through high-temperature calcination, so that the zinc oxide matrix loaded beet pulp is obtained; S2. embedding the zinc oxide matrix loaded beet pulp; S3. preparing a nutrient solution; S4. domesticating indigenous microorganisms; S5. preparing a composite degradation solution; and S6. degrading groundwater organics. The application creatively utilizes a system coupling modified biochar and microorganisms to degrade groundwater organics, utilizes zinc oxide modification to improve the stability and oxidation resistance of the biochar, simultaneously adds a carbon source to improve the activity of the microorganisms, and through adaptation with indigenous microorganisms, a high-efficiency composite degradation solution is prepared, and the composite degradation solution has high degradation capacity for groundwater organics.

Description

Technical Field

[0001] This invention relates to the field of groundwater pollution control, specifically to a method for the biodegradation of organic matter in groundwater. Background Technology

[0002] With urbanization and industrialization, a large amount of organic pollutants have entered the groundwater environment due to improper treatment, exceeding the environmental carrying capacity of groundwater and causing serious groundwater pollution problems. These toxic and harmful substances enter the ecosystem through the material cycle, posing extremely high health and ecological risks. Therefore, the remediation of groundwater pollution has always been a major concern, and the search for efficient, stable, green and environmentally friendly groundwater remediation methods has become the focus of research.

[0003] Since many pollutants in the environment are oxidizing, reducing them to their full degraded or non-toxic forms is an important remediation strategy. Currently, reduction technologies for in-situ groundwater remediation both domestically and internationally fall into two main categories: chemical reduction, represented by oxide-mediated chemical reduction; and microbial reduction, with biostimulation being the most commonly used. Both technologies, when applied individually, have their own bottlenecks. Specifically, the anaerobic corrosion of organic pollutants leads to the accumulation of H2, which acts as a weak electron donor in the system, potentially wasting oxides, accelerating surface passivation and material deactivation, increasing remediation costs, and causing blockages, reducing remediation efficiency and posing safety risks. Furthermore, in-situ anaerobic bioremediation is often limited by insufficient available electron donors, requiring the injection of external electron donors. Summary of the Invention

[0004] This invention provides a method for biodegrading organic matter in groundwater, aiming to overcome the above-mentioned shortcomings of the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for biodegrading organic matter in groundwater, comprising the following steps:

[0006] S1. Preparation of beet pulp biochar-supported zinc oxide matrix: Immerse beet pulp in zinc chloride solution, stir and mix thoroughly to obtain an impregnation solution, then add sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitate, filter to obtain filter cake, wash, dry at low temperature to obtain precursor, crush the dried precursor and sieve, and calcine the sieved material at high temperature to obtain beet pulp-supported zinc oxide matrix;

[0007] S2. Beetroot-loaded zinc oxide matrix: The beetroot-loaded zinc oxide matrix obtained in S1 is added to a polyamino acid solution and calcium chloride solution is added dropwise. After thorough stirring, the mixture is filtered to obtain the polyamino acid-encapsulated beetroot-loaded zinc oxide matrix for later use.

[0008] S3. Prepare nutrient solution: Dissolve yeast extract powder and potassium dihydrogen phosphate in an appropriate amount of water to obtain nutrient solution, and set aside.

[0009] S4. Domestication of indigenous microorganisms: Under anaerobic conditions, activated sludge is introduced into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated by the target pollutants in the contaminated groundwater, an active bacterial solution that can efficiently degrade the target pollutants is obtained for later use.

[0010] S5. Preparation of composite degradation solution: Mix the polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution in a certain proportion to obtain composite degradation solution;

[0011] S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation solution is mixed with the contaminated groundwater in a certain proportion and treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

[0012] Based on the above technical solution, the present invention can also make the following further specific choices or better choices.

[0013] Specifically, the concentration of zinc chloride solution in S1 is 1-2 mol / L, and the ratio of beet pulp to zinc oxide solution is 100g:800-1200g.

[0014] Specifically, "sufficient impregnation" in S1 refers to impregnation at room temperature for 3-5 hours, and the concentration of sodium hydroxide solution in S1 is 1.8-2.5 mol / L.

[0015] Specifically, in S1, the filter cake is washed 2-3 times with deionized water, and the temperature for low-temperature drying is controlled at 102-106℃. The water content of the precursor obtained by low-temperature drying is below 5wt%.

[0016] Specifically, when sieving the precursor in S1 after crushing, a 100-mesh sieve is used, and high-temperature calcination refers to calcination at 490-520℃ for 6-8 hours.

[0017] Specifically, the polyamino acid solution in S2 is a 3-5 wt% polyglutamic acid solution, the concentration of the added calcium chloride solution is 4-5 wt%, and the mass ratio of polyamino acid to beet pulp-supported zinc oxide matrix is ​​1:2.8-3.2.

[0018] Specifically, the concentration of yeast extract in the nutrient solution in S3 is 0.04-0.05 g / L, and the concentration of potassium dihydrogen phosphate is 0.003-0.005 g / L.

[0019] Specifically, the acclimatization in S4 is carried out at room temperature, and the acclimatization period lasts for 3-7 days.

[0020] Specifically, in S5, the beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution encapsulated with polyamino acids are mixed in a mass ratio of 0.1-0.2:0.5-0.6:1.

[0021] Specifically, the composite degradation solution in S6 is mixed with the contaminated groundwater at a mass ratio of 0.01-0.02:1.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention creatively proposes a system that couples modified biochar with microorganisms to degrade organic matter in groundwater. Zinc oxide modification is used to improve the stability and oxidation resistance of beet pulp biochar, while a carbon source is added to enhance microbial activity. After adaptation with native microorganisms, a highly efficient composite degradation solution containing specific microorganisms is prepared, exhibiting a high degradation capacity for organic pollutants in groundwater. Beet pulp biochar can promote microbial growth by altering water chemistry conditions. The H2 generated during degradation provides electron donors for the microorganisms, simultaneously alleviating the problems of H2 accumulation and blockage in the system and insufficient electron donors in the microbial system. The presence of microorganisms ensures the system maintains high reactivity by influencing the composition of zinc surface passivation products. Detailed Implementation

[0024] The principles and features of the present invention are described below with reference to specific embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0025] To avoid unnecessary details, unless otherwise specified, all pharmaceutical raw materials used in the following examples are commercially available products, and all methods used are conventional methods in the art.

[0026] It should be noted that the beet pulp-loaded zinc oxide matrix, after being encapsulated with polyamino acids, appears as small spherical particles.

[0027] Example 1

[0028] A method for biodegrading organic matter in groundwater, comprising the following steps:

[0029] S1. Preparation of beet pulp biochar-supported zinc oxide matrix: 100g of beet pulp was immersed in 800g of 1mol / L zinc chloride solution, stirred and mixed, and immersed for 5h to obtain an impregnation solution. Then, 1.8mol / L sodium hydroxide aqueous solution was added to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitate. The filter cake was obtained by filtration and washed with deionized water 2-3 times. The filter cake was dried at 105℃ until the moisture content was below 5wt% to obtain the precursor. The dried precursor was crushed and passed through a 100-mesh sieve. The sieved material was placed in a muffle furnace and calcined at 500℃ for 7h to obtain the beet pulp-supported zinc oxide matrix.

[0030] S2. Encapsulation of beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix obtained in S1 was added to a 3 wt% polyglutamic acid solution and a 4 wt% calcium chloride solution was added dropwise. The ratio of calcium chloride solution to polyglutamic acid solution was 0.1:1, and the mass ratio of polyamino acid to beet pulp-loaded zinc oxide matrix was 1:2.8. After thorough stirring, the mixture was filtered to obtain the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, which was then set aside for later use.

[0031] S3. Preparation of nutrient solution: Dissolve yeast extract powder and potassium dihydrogen phosphate in an appropriate amount of water to obtain nutrient solution for later use. The concentration of yeast extract powder in the nutrient solution is 0.04 g / L and the concentration of potassium dihydrogen phosphate is 0.003 g / L.

[0032] S4. Acclimation of indigenous microorganisms: Under anaerobic conditions, activated sludge is introduced into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are acclimated to the target pollutants in the contaminated groundwater, an active bacterial solution capable of efficiently degrading the target pollutants is obtained. Acclimation is carried out at room temperature and lasts for 3-7 days.

[0033] S5. Preparation of composite degradation solution: Mix the polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution in a certain proportion to obtain composite degradation solution. The polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution are mixed in a mass ratio of 0.1:0.6:1.

[0034] S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation solution is mixed with the contaminated groundwater in a ratio of 0.02:1 by mass. The mixture is then treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

[0035] Example 2

[0036] A method for biodegrading organic matter in groundwater, comprising the following steps:

[0037] S1. Preparation of beet pulp biochar-supported zinc oxide matrix: 100g of beet pulp was immersed in 1000g of 2mol / L zinc chloride solution, stirred and mixed, and immersed for 3-5h to obtain an impregnation solution. Then, 2.5mol / L sodium hydroxide aqueous solution was added to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitate. The filter cake was obtained by filtration and washed with deionized water 2-3 times. The filter cake was dried at 102℃ until the moisture content was below 5wt% to obtain the precursor. The dried precursor was crushed and passed through a 100-mesh sieve. The sieved material was placed in a muffle furnace and calcined at 490℃ for 8h to obtain the beet pulp-supported zinc oxide matrix.

[0038] S2. Encapsulation of beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix obtained in S1 was added to a 5 wt% polyglutamic acid solution and a 5 wt% calcium chloride solution was added dropwise. The ratio of calcium chloride solution to polyglutamic acid solution was 0.05:1, and the mass ratio of polyamino acid to beet pulp-loaded zinc oxide matrix was 1:3. After thorough stirring, the mixture was filtered to obtain the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix for later use.

[0039] S3. Preparation of nutrient solution: Dissolve yeast extract powder and potassium dihydrogen phosphate in an appropriate amount of water to obtain nutrient solution for later use. The concentration of yeast extract powder in the nutrient solution is 0.05 g / L and the concentration of potassium dihydrogen phosphate is 0.005 g / L.

[0040] S4. Acclimation of indigenous microorganisms: Under anaerobic conditions, activated sludge is introduced into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are acclimated to the target pollutants in the contaminated groundwater, an active bacterial solution capable of efficiently degrading the target pollutants is obtained. Acclimation is carried out at room temperature and lasts for 3-7 days.

[0041] S5. Preparation of composite degradation solution: Mix the polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution in a certain proportion to obtain composite degradation solution. The polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution are mixed in a mass ratio of 0.2:0.5:1.

[0042] S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation solution is mixed with the contaminated groundwater in a ratio of 0.01:1 by mass. The mixture is then treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

[0043] Example 3

[0044] A method for biodegrading organic matter in groundwater, comprising the following steps:

[0045] S1. Preparation of beet pulp biochar-supported zinc oxide matrix: 100g of beet pulp was immersed in 1200g of 1mol / L zinc chloride solution, stirred and mixed, and immersed for 3h to obtain an impregnation solution. Then, 2mol / L sodium hydroxide aqueous solution was added to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitate. The filter cake was obtained by filtration and washed with deionized water 2-3 times. The filter cake was dried at 104℃ until the moisture content was below 5wt% to obtain the precursor. The dried precursor was crushed and passed through a 100-mesh sieve. The sieved material was placed in a muffle furnace and calcined at 520℃ for 6h to obtain the beet pulp-supported zinc oxide matrix.

[0046] S2. Encapsulation of beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix obtained in S1 was added to a 4 wt% polyglutamic acid solution and a 5 wt% calcium chloride solution was added dropwise. The ratio of calcium chloride solution to polyglutamic acid solution was 0.08:1, and the mass ratio of polyamino acid to beet pulp-loaded zinc oxide matrix was 1:3.2. After thorough stirring, the mixture was filtered to obtain the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, which was then set aside for later use.

[0047] S3. Preparation of nutrient solution: Dissolve yeast extract powder and potassium dihydrogen phosphate in an appropriate amount of water to obtain nutrient solution for later use. The concentration of yeast extract powder in the nutrient solution is 0.05 g / L and the concentration of potassium dihydrogen phosphate is 0.004 g / L.

[0048] S4. Acclimation of indigenous microorganisms: Under anaerobic conditions, activated sludge is introduced into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are acclimated to the target pollutants in the contaminated groundwater, an active bacterial solution capable of efficiently degrading the target pollutants is obtained. Acclimation is carried out at room temperature and lasts for 3-7 days.

[0049] S5. Preparation of composite degradation solution: Mix the polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution in a certain proportion to obtain composite degradation solution. The polyamino acid-embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution are mixed in a mass ratio of 0.1:0.6:1.

[0050] S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation solution is mixed with the contaminated groundwater in a ratio of 0.02:1 by mass. The mixture is then treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

[0051] It should be noted that after each degradation of organic matter in the groundwater is completed, the purified groundwater is tested and found to meet the standards, and then reinjected into the ground through a recharge well. When the purified groundwater is discharged, it passes through a filter screen, which can intercept the polyamino acid-encapsulated beet pulp loaded with zinc oxide matrix. The polyamino acid-encapsulated beet pulp loaded with zinc oxide matrix can be reused.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for biodegrading organic matter in groundwater, characterized in that, Includes the following steps: S1. Preparation of beet pulp biochar supported on zinc oxide matrix: Beet pulp is immersed in zinc chloride solution, stirred and mixed thoroughly to obtain an impregnation solution. Then, sodium hydroxide aqueous solution is added to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitate. The filter cake is obtained by filtration, washing, and low-temperature drying to obtain the precursor. The dried precursor is pulverized and sieved. The sieved material is then subjected to high-temperature calcination to obtain beet pulp biochar supported on zinc oxide matrix. The concentration of zinc chloride solution is 1-2 mol / L, and the ratio of beet pulp to zinc chloride solution is 100g:800-1200g. S2. Encapsulation of beet pulp biochar-supported zinc oxide matrix: The beet pulp biochar-supported zinc oxide matrix obtained in S1 was added to a polyamino acid solution, and calcium chloride solution was added dropwise. After thorough stirring, the mixture was filtered to obtain the polyamino acid-encapsulated beet pulp biochar-supported zinc oxide matrix, which was set aside for later use. The polyamino acid solution was a 3-5 wt% polyglutamic acid solution, and the concentration of the added calcium chloride solution was 4-5 wt%. The mass ratio of polyamino acid to beet pulp biochar-supported zinc oxide matrix was 1:2.8-3.

2. S3. Prepare nutrient solution: Dissolve yeast extract powder and potassium dihydrogen phosphate in an appropriate amount of water to obtain nutrient solution, and set aside. S4. Domestication of indigenous microorganisms: Under anaerobic conditions, activated sludge is introduced into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated by the target pollutants in the contaminated groundwater, an active bacterial solution that can efficiently degrade the target pollutants is obtained for later use. S5. Preparation of composite degradation solution: Mix the polyamino acid-embedded beet residue biochar-supported zinc oxide matrix, nutrient solution and active bacterial solution in a certain proportion to obtain the composite degradation solution; S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation solution is mixed with the contaminated groundwater in a certain proportion and treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

2. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, Sufficient immersion in S1 refers to immersion at room temperature for 3-5 hours, and the concentration of sodium hydroxide solution in S1 is 1.8-2.5 mol / L.

3. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, The washing process in S1 involves rinsing the filter cake 2-3 times with deionized water. The temperature for low-temperature drying is controlled at 102-106℃, and the water content of the precursor obtained from low-temperature drying is below 5wt%.

4. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, When sieving the precursor in S1 after crushing, a 100-mesh sieve is used. High-temperature calcination refers to calcination at 490-520℃ for 6-8 hours.

5. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, The concentration of yeast extract in the nutrient solution in S3 is 0.04-0.05 g / L, and the concentration of potassium dihydrogen phosphate is 0.003-0.005 g / L.

6. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, The acclimatization process in S4 is carried out at room temperature and lasts for 3-7 days.

7. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that, S5 was prepared by mixing beet pulp biochar-supported zinc oxide matrix encapsulated with polyamino acids, nutrient solution and active bacterial solution in a mass ratio of 0.1-0.2:0.5-0.6:

1.

8. A method for biodegrading organic matter in groundwater according to any one of claims 1 to 7, characterized in that, The S6 composite degradation solution is mixed with the contaminated groundwater at a mass ratio of 0.01-0.02:1.