Method for biodegrading organic matters in underground water

Abstract

The method comprises the following steps: S1, preparing a sugar beet pulp biochar-loaded zinc oxide matrix: immersing sugar beet pulp into a zinc chloride solution, fully dipping to obtain a dipping solution, then adding a sodium hydroxide aqueous solution to completely convert zinc ions into zinc hydroxide precipitates, filtering to obtain a filter cake, washing, and drying to obtain a sugar beet pulp biochar-loaded zinc oxide matrix; and performing low-temperature drying to obtain a precursor, performing crushing and sieving, and performing high-temperature roasting treatment on the sieved material to obtain the catalyst. S2, embedding the sugar beet pulp loaded zinc oxide matrix; s3, preparing a nutrient solution; s4, domesticating indigenous microorganisms; s5, preparing a composite degradation solution; and S6, degrading organic matters in underground water. According to the invention, a modified biochar and microorganism coupled system is creatively utilized to degrade organic matters in underground water, zinc oxide modification is utilized to improve the stability and oxidation resistance of biochar, a carbon source is added to improve the activity of microorganisms, and the efficient composite degradation liquid is prepared by matching with indigenous microorganisms. The high degradation capability on organic matters in underground water is realized.

Description

Technical Field

[0001] The invention relates to the field of groundwater pollution control, and in particular to a method for biodegrading groundwater organic matter. Background Art

[0002] With the development of urbanization and industrialization, a large number of organic pollutants enter the groundwater environment due to improper treatment, exceeding the environmental carrying capacity of groundwater, thus causing serious groundwater pollution problems. These toxic and harmful substances enter the ecosystem through material circulation and pose extremely high health and ecological risks. Therefore, the issue of groundwater pollution remediation has always received widespread attention, and seeking efficient, stable, and green-friendly groundwater remediation methods has become the focus of research.

[0003] Since a large number of pollutants in the environment are oxidizing, it is an important remediation strategy to completely degrade or convert pollutants into non-toxic forms through the reduction process. At present, there are two main types of reduction technologies for in-situ remediation of groundwater pollution at home and abroad: one is chemical reduction technology, represented by oxide-mediated chemical reduction technology; the other is microbial reduction treatment technology, with biostimulation technology being the most commonly used. Both of these technologies have their own bottleneck problems when applied alone. Specifically, the anaerobic corrosion process of organic pollutants will cause the accumulation of H2. The produced H2 is a weak electron donor in the system, which can lead to the waste of oxides, accelerate surface passivation, material inactivation, and increase the cost of remediation. At the same time, gas accumulation may cause medium blockage, reduce remediation efficiency and pose safety risks. In-situ anaerobic bioremediation is often limited by the lack of available electron donors, and exogenous electron donors need to be injected into the body. Summary of the invention

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

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

[0006] S1. Preparing a beet pulp biochar-loaded zinc oxide matrix: immersing the beet pulp in a zinc chloride solution, stirring and mixing, and fully immersing to obtain an impregnation solution, then adding a sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitates, filtering to obtain a filter cake, washing, and low-temperature drying to obtain a precursor, crushing and sieving the dried precursor, and sieving the sifted material and subjecting it to high-temperature roasting to obtain a beet pulp-loaded zinc oxide matrix;

[0007] S2 embedded beet pulp loaded zinc oxide matrix: The beet pulp loaded zinc oxide matrix prepared in S1 was added to the polyamino acid solution and a calcium chloride solution was added dropwise, stirred and filtered to obtain a polyamino acid embedded beet pulp loaded zinc oxide matrix, set aside;

[0008] S3 prepare nutrient solution: The yeast extract powder and potassium dihydrogen phosphate are dissolved in an appropriate amount of water to obtain a nutrient solution and set aside;

[0009] S4. Domestication of indigenous microorganisms: Keeping anaerobic conditions, the activated sludge is put into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated with the target pollutants in the contaminated groundwater, an active bacterial liquid capable of efficiently degrading the target pollutants is obtained for standby use;

[0010] S5 preparation of composite degradation solution: the polyamino acid embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution were mixed in proportion to obtain a composite degradation solution;

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

[0012] On the basis of the above technical solutions, the present invention can also make the following further specific selections or more preferred selections.

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

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

[0015] Specifically, the washing in S1 is to use deionized water to wash the filter cake 2-3 times, the temperature of low-temperature drying is controlled to be 102-106° C., and the water content of the precursor obtained by low-temperature drying is below 5wt%.

[0016] Specifically, in S1, the precursor is crushed and sieved using a 100-mesh sieve, and high-temperature calcination refers to calcination at 490-520° C. for 6-8 hours.

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

[0018] Specifically, the concentration of yeast extract powder 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 acclimation in S4 is carried out at room temperature, and the acclimation time is 3-7 days.

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

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

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention creatively proposes to utilize a system of modified biochar coupled with microorganisms to degrade organic matter in groundwater. The stability and oxidation resistance of beet pulp biochar are improved by zinc oxide modification, and a carbon source is added to improve microbial activity. After adaptation with indigenous microorganisms, the most suitable high-efficiency composite degradation liquid containing specific microorganisms is prepared, which has a high degradation ability for organic pollutants in groundwater. Beet pulp biochar can promote the growth of microorganisms by changing water chemical conditions, and the H2 produced during the degradation process can provide electron donors for 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 affects the composition of zinc surface passivation products and thus ensures the system's continued high reaction activity. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

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

[0026] It should be noted that the beet pulp-loaded zinc oxide matrix is ​​spherical fine particles after being embedded by polyamino acids.

[0027] Example 1

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

[0029] S1. Preparation of beet pulp biochar loaded with zinc oxide matrix: immerse 100g of beet pulp in 800g of 1mol / L zinc chloride solution, stir and mix, and immerse for 5h to obtain an impregnation solution, then add a 1.8mol / L sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitates, filter to obtain a filter cake, rinse the filter cake with deionized water 2-3 times, dry at 105°C to a moisture content of less than 5wt% to obtain a precursor, crush the dried precursor and pass it through a 100-mesh sieve, place the sieved material in a muffle furnace, and calcine at 500°C for 7h to obtain a beet pulp loaded with zinc oxide matrix;

[0030] S2. Embedding beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix prepared in S1 was added to a 3wt% polyglutamic acid solution and a 4wt% calcium chloride solution was added dropwise, the amount ratio of the calcium chloride solution to the polyglutamic acid solution was 0.1:1, the mass ratio of the polyamino acid to the beet pulp-loaded zinc oxide matrix was 1:2.8, and the mixture was stirred thoroughly and filtered to obtain a polyamino acid-embedded beet pulp-loaded zinc oxide matrix for later use;

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

[0032] S4. Domestication of indigenous microorganisms: Keeping anaerobic conditions, the activated sludge is put into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated with the target pollutants in the contaminated groundwater, an active bacterial liquid capable of efficiently degrading the target pollutants is obtained. The domestication is carried out at room temperature for 3-7 days for standby use;

[0033] S5. Prepare a composite degradation solution: mix the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, nutrient solution and active bacterial solution in proportion to obtain a composite degradation solution. The polyamino acid-encapsulated beet pulp-loaded 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 liquid is mixed with contaminated groundwater in a mass ratio of 0.02:1. The mixture is 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 loaded with zinc oxide matrix: immerse 100g of beet pulp in 1000g of 2mol / L zinc chloride solution, stir and mix, and immerse for 3-5h to obtain an impregnation solution, then add a 2.5mol / L sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitates, filter to obtain a filter cake, rinse the filter cake with deionized water 2-3 times, and dry at 102°C to a moisture content of less than 5wt% to obtain a precursor, crush the dried precursor and pass it through a 100-mesh sieve, place the sieved material in a muffle furnace, and calcine it at 490°C for 8h to obtain a beet pulp loaded with zinc oxide matrix;

[0038] S2. Embedding beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix prepared in S1 was added to a 5wt% polyglutamic acid solution and a 5wt% calcium chloride solution was added dropwise, the amount ratio of the calcium chloride solution to the polyglutamic acid solution was 0.05:1, the mass ratio of the polyamino acid to the beet pulp-loaded zinc oxide matrix was 1:3, and the mixture was stirred and filtered to obtain a polyamino acid-embedded beet pulp-loaded zinc oxide matrix for standby use;

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

[0040] S4. Domestication of indigenous microorganisms: Keeping anaerobic conditions, the activated sludge is put into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated with the target pollutants in the contaminated groundwater, an active bacterial liquid capable of efficiently degrading the target pollutants is obtained. The domestication is carried out at room temperature for 3-7 days for standby use;

[0041] S5. Prepare a composite degradation solution: mix the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, nutrient solution and active bacterial solution in proportion to obtain a composite degradation solution. The polyamino acid-encapsulated beet pulp-loaded 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 liquid is mixed with contaminated groundwater in a mass ratio of 0.01:1. The mixture is 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 loaded with zinc oxide matrix: immerse 100g of beet pulp in 1200g of 1mol / L zinc chloride solution, stir and mix, and immerse for 3h to obtain an impregnation solution, then add a 2mol / L sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitates, filter to obtain a filter cake, rinse the filter cake with deionized water 2-3 times, dry at 104°C to a moisture content of less than 5wt% to obtain a precursor, crush the dried precursor and pass it through a 100-mesh sieve, place the sieved material in a muffle furnace, and calcine at 520°C for 6h to obtain a beet pulp loaded with zinc oxide matrix;

[0046] S2. Embedding beet pulp-loaded zinc oxide matrix: The beet pulp-loaded zinc oxide matrix prepared in S1 was added to a 4wt% polyglutamic acid solution and a 5wt% calcium chloride solution was added dropwise, the amount ratio of the calcium chloride solution to the polyglutamic acid solution was 0.08:1, the mass ratio of the polyamino acid to the beet pulp-loaded zinc oxide matrix was 1:3.2, and the mixture was stirred thoroughly and filtered to obtain a polyamino acid-embedded beet pulp-loaded zinc oxide matrix for standby use;

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

[0048] S4. Domestication of indigenous microorganisms: Keeping anaerobic conditions, the activated sludge is put into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated with the target pollutants in the contaminated groundwater, an active bacterial liquid capable of efficiently degrading the target pollutants is obtained. The domestication is carried out at room temperature for 3-7 days for standby use;

[0049] S5. Prepare a composite degradation solution: mix the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, nutrient solution and active bacterial solution in proportion to obtain a composite degradation solution. The polyamino acid-encapsulated beet pulp-loaded 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 liquid is mixed with contaminated groundwater in a mass ratio of 0.02:1. The mixture is 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 groundwater organic matter is completed, the purified groundwater is reinjected into the ground through the reinjection well after being tested and meeting the standards. The purified groundwater is discharged through a filter that can intercept the polyamino acid-embedded beet pulp-loaded zinc oxide matrix, and the polyamino acid-embedded beet pulp-loaded 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for biodegrading organic matter in groundwater, characterized in that: The steps include: S1. Preparing a beet pulp biochar-loaded zinc oxide matrix: immersing the beet pulp in a zinc chloride solution, stirring and mixing, and fully immersing to obtain an impregnation solution, then adding a sodium hydroxide aqueous solution to the impregnation solution to convert all zinc ions in the impregnation solution into zinc hydroxide precipitates, filtering to obtain a filter cake, washing, and low-temperature drying to obtain a precursor, crushing and sieving the dried precursor, and sieving the sifted material and subjecting it to high-temperature roasting to obtain a beet pulp-loaded zinc oxide matrix; S2 embedded beet pulp loaded zinc oxide matrix: The beet pulp loaded zinc oxide matrix prepared in S1 was added to the polyamino acid solution and a calcium chloride solution was added dropwise, stirred and filtered to obtain a polyamino acid embedded beet pulp loaded zinc oxide matrix, set aside; S3 prepare nutrient solution: The yeast extract powder and potassium dihydrogen phosphate are dissolved in an appropriate amount of water to obtain a nutrient solution and set aside; S4. Domestication of indigenous microorganisms: Keeping anaerobic conditions, the activated sludge is put into the extracted contaminated groundwater. After the mixed bacteria in the activated sludge are domesticated with the target pollutants in the contaminated groundwater, an active bacterial liquid capable of efficiently degrading the target pollutants is obtained for standby use; S5 preparation of composite degradation solution: the polyamino acid embedded beet pulp loaded with zinc oxide matrix, nutrient solution and active bacterial solution were mixed in proportion to obtain a composite degradation solution; S6. Degradation of organic matter in groundwater: Under anaerobic conditions, the composite degradation liquid is mixed with the contaminated groundwater in proportion and treated at room temperature for 2-3 days to complete the degradation of organic matter in the groundwater.

2. A method for biodegrading organic matter in groundwater according to claim 1, characterized in that: The concentration of the zinc chloride solution in S1 is 1-2 mol / L, and the dosage ratio of beet pulp to zinc oxide solution is 100 g:800-1200 g.

3. 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 the sodium hydroxide solution in S1 is 1.8-2.5 mol / L.

4. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that: The washing in S1 is to use deionized water to wash the filter cake 2-3 times, the temperature of low-temperature drying is controlled to be 102-106° C., and the water content of the precursor obtained by low-temperature drying is below 5wt%.

5. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that: In S1, the precursor is sieved through a 100-mesh sieve after being crushed, and high-temperature calcination refers to calcination at 490-520° C. for 6-8 hours.

6. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that: The polyamino acid solution in S2 is a 3-5wt% polyglutamic acid solution, the concentration of the added calcium chloride solution is 4-5wt%, and the mass ratio of the polyamino acid to the beet pulp-loaded zinc oxide matrix is ​​1:2.8-3.

2.

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

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

9. The method for biodegrading organic matter in groundwater according to claim 1, characterized in that: In S5, the polyamino acid-encapsulated beet pulp-loaded zinc oxide matrix, nutrient solution and active bacterial solution are mixed in a mass ratio of 0.1-0.2:0.5-0.6:

1.

10. A method for biodegrading organic matter in groundwater according to any one of claims 1 to 9, characterized in that: The composite degradation liquid in S6 is mixed with the contaminated groundwater in a mass ratio of 0.01-0.02:1.