Biodegradable composite material with microcapsules and preparation method and application thereof

Abstract

The present invention relates to the field of water treatment technology, and more specifically, to a biodegradable composite material with microcapsules, a preparation method and an application thereof. The biodegradable composite material with microcapsules includes a degradable porous material and microcapsules loaded on the degradable porous material, and the loading rate of the microcapsules on the degradable porous material is 3% to 50%; the capsule core of the microcapsule includes sewage treatment bacteria. The biodegradable composite material with microcapsules can increase the loading rate of the microcapsules on the degradable porous material and can improve the water purification efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a biodegradable composite material with microcapsules, a preparation method and application thereof. Background Art

[0002] Water pollution is one of the important environmental issues. Rivers, lakes and groundwater are all polluted by nitrogen, phosphorus, sulfur and other pollutants to varying degrees. Therefore, the degradation and removal of nitrogen, phosphorus and sulfur are important goals for ecological restoration of polluted water bodies. The removal of nitrogen, phosphorus and sulfur in water bodies can mainly be achieved by microorganisms. Microbial flocs can provide a good living environment for protozoa and micro-metazoa by adsorbing and decomposing organic matter, such as removing toxins, providing food, and increasing dissolved oxygen.

[0003] With the growth of environmental protection needs and the development of degradable materials, researchers in the field of sewage treatment have begun to try to use degradable fillers to replace traditional non-degradable fillers. For example, patent CN1562800A uses cellulose as a raw material to produce degradable microbial fillers for wastewater treatment. However, this method is complex, the foaming temperature needs to be 100℃~160℃, and alkalization treatment is required, and hazardous chemicals need to be used. In addition, during the production of the carrier, the byproduct H 2 S and CS 2 The release of harmful gases such as chlorinated carbonyl compounds complicates the fiber production process and pollutes the environment. Patent CN102603081A mainly prepares fibers through N-methylmorpholine-N-oxide, and further improves the mechanical properties of the filler through cross-linking modification technology, while treating the surface of the filler to make it positively charged, which is more conducive to the adhesion and growth of microorganisms on its surface. However, this method uses irritating drugs (N-methylmorpholine-N-oxide) and strong alkali (sodium hydroxide), which are not only dangerous in the preparation process but also have certain irritating effects on the eyes, respiratory system and skin. In addition, there are studies that use microbial immobilization technology combined with coating materials to make sewage purification fillers, but there are the following shortcomings: 1. The traditional microbial immobilization technology uses a direct coating method, that is, the microorganisms are coated with coating materials, which can easily cause the coating materials to rupture and cause the microorganisms to be lost; 2. The size of the microorganisms directly injected into the coating material is relatively large, and the contact area with the sewage is small, and even the gaps are blocked, resulting in reduced purification effects; 3. The technology for fixing microorganisms in coating materials is relatively complex, the steps are cumbersome, and it is also necessary to operate under a high-pressure environment; 4. Microorganisms have an adaptation process in the new environment. The microorganisms in this method have a low survival rate or even cannot survive under the high-concentration pollution environment conditions of black and odorous water bodies, thereby affecting the effectiveness of the microorganisms; 5. The growth environment of microorganisms changes with the flow of water, such as unstable pH values, unsatisfactory reproduction, easy to fall off, and slow degradation rate of black and odorous water bodies. Summary of the invention

[0004] Based on this, it is necessary to provide a biodegradable composite material with microcapsules that can improve the microcapsule loading rate and water purification rate, as well as a preparation method and application thereof.

[0005] An embodiment of the present invention provides a degradable composite material with microcapsules, which includes a degradable porous material and microcapsules loaded on the degradable porous material, wherein the loading rate of the microcapsules on the degradable porous material is 3% to 50%; the capsule core of the microcapsule includes sewage treatment bacteria.

[0006] Another embodiment of the present invention further provides a method for preparing the above-mentioned biodegradable composite material with microcapsules, which comprises the following steps:

[0007] The microcapsules are dissolved in water to form a first solution, the pH value of the first solution is adjusted to be 4-5, and the degradable porous material is added to carry out a complex coagulation reaction.

[0008] Another embodiment of the present invention further provides a water purifier, wherein the raw materials for preparing the water purifier include the above-mentioned biodegradable composite material with microcapsules.

[0009] The above-mentioned biodegradable composite material with microcapsules adopts microcapsule technology to encapsulate the strains of microorganisms such as sewage treatment bacteria in the capsule wall of the microcapsule through the complex coagulation method, thereby providing a good living environment for the growth and reproduction of the sewage treatment bacteria strains, avoiding the loss of the sewage treatment bacteria strains, effectively improving the survival rate of microorganisms, increasing the contact area between microorganisms and sewage, and thus improving the degradation of black and odorous sewage water bodies. At the same time, the complex coagulation method is combined to prepare microcapsules and the in-situ method is used to realize the loading of microcapsules on degradable porous materials. On the one hand, the complex coagulation method is used to give the degradable wall material a certain cationic charge density, which acts on the degradable porous material with anionic charge, effectively improving the loading rate of the microcapsules. On the other hand, it will not cause secondary pollution to the microcapsules, and the operation is simple and convenient with low cost.

[0010] In summary, the use of the above-mentioned biodegradable composite materials with microcapsules in aquatic ecological restoration projects can enable sewage treatment bacteria to survive for a long time in harsh environments, with a long action time, and a large contact area between microorganisms and sewage. It is highly efficient and durable, and can effectively reduce pollutants such as COD, total phosphorus and ammonia nitrogen concentration in water bodies, and can play a positive role in long-term water ecological restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram of the structure of microcapsules in a biodegradable composite material having microcapsules prepared in one embodiment of the present invention;

[0012] Figures 2 to 4 are the COD of the biodegradable composite material with microcapsules prepared in Example 1 Mn NH 3 -N and TP indicator test results;

[0013] Figure 5 This is an imaging microscope image of the porous material prepared in Example 2;

[0014] Figure 6 This is an imaging microscope picture of microcapsules in the biodegradable composite material with microcapsules prepared in Example 2;

[0015] Figure 7 This is an imaging microscope image of the biodegradable composite material with microcapsules prepared in Example 2;

[0016] Figures 8 to 10 are the COD of the biodegradable composite material with microcapsules prepared in Example 2 Mn NH 3 -N and TP indicator test results;

[0017] Figures 11 to 13 are the COD of the biodegradable composite material with microcapsules prepared in Example 3 Mn NH 3 -N and TP indicator test results;

[0018] Figures 14 to 16 are the COD of the biodegradable composite material with microcapsules prepared in Example 4. Mn NH 3 -N and TP indicator test results;

[0019] Figures 17 to 19 are the COD of the biodegradable composite material with microcapsules prepared in Example 5 Mn NH 3 -N and TP indicator test results;

[0020] Figures 20-22 The COD of the biodegradable composite material with microcapsules prepared in Example 6 is Mn NH 3 -N and TP indicator test results;

[0021] Figures 23 to 25 The COD of the biodegradable composite material with microcapsules prepared in Comparative Example 1 is Mn NH 3 -N and TP indicator test results;

[0022] Figures 26-28The COD of the biodegradable composite material with microcapsules prepared in Comparative Example 2 is Mn NH 3 -N and TP indicator test results. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0024] Terms and Definitions:

[0025] "Loading amount" refers to the mass of microcapsules loaded on the degradable porous material, and "loading rate" refers to the mass percentage of the microcapsule loading amount to the sum of the microcapsule loading amount and the degradable porous material mass, which is calculated as follows:

[0026] Loading rate = microcapsule loading amount / (microcapsule loading amount+mass of degradable porous material)×100%.

[0027] Chemical Oxygen Demand (COD) refers to the amount of oxygen consumed when organic matter in a water sample is oxidized by a strong oxidant, which is measured by chemical methods. It is used to indicate the amount of organic matter in the water. Under certain conditions, the amount of oxidant consumed to oxidize the reducing substances in 1L of water sample is used as an indicator to convert the milligrams of oxygen required for the oxidation of the entire water sample, expressed in mg / L, which reflects the degree of water (sewage, wastewater) contamination by reducing substances. Mn It refers to the potassium permanganate index, which uses potassium permanganate as an oxidant to measure COD.

[0028] NH 3 -N refers to the ammonia nitrogen content in water (sewage, wastewater), and the unit is usually mg / L. Ammonia nitrogen refers to the free ammonia (NH 3 ) and ammonium ions (NH 4+ ) in the form of nitrogen. Ammonia nitrogen is a nutrient in water bodies, which can cause eutrophication and is the main oxygen-consuming pollutant in water bodies.

[0029] TP refers to the total phosphorus content in water (sewage, wastewater), which is the result of converting various forms of phosphorus into orthophosphate after digestion of the water sample.

[0030] One aspect of the present invention relates to a biodegradable composite material with microcapsules, which includes a degradable porous material and microcapsules loaded on the degradable porous material, wherein the loading rate of the microcapsules on the degradable porous material is 3% to 50%; the capsule core of the microcapsule includes sewage treatment bacteria. It can be understood that the microcapsule usually includes a capsule wall and a capsule core embedded or enclosed in the capsule wall.

[0031] In some embodiments, the loading rate of microcapsules on the degradable porous material can be any value between 3% and 50%, or can be 5%, 7%, 10%, 12%, 13%, 15%, 18%, 20%, 22%, 25%, 27%, 30%, 32%, 35%, or 40%.

[0032] It is understandable that microcapsules generally include capsule walls and capsule cores embedded or enclosed in the capsule walls. In order to improve the viability, stability and sustained release of sewage treatment bacteria, in one embodiment of the present invention, the sewage treatment bacteria are placed in the capsule core and coated with the capsule wall.

[0033] In some embodiments, the particle size of the microcapsule can be any value between 10 μm and 500 μm, preferably any value between 10 μm and 100 μm, for example, it can also be 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 70 μm, 80 μm, or 90 μm.

[0034] It is understandable that degradable materials refer to materials that can be degraded in a certain period of time in both thermodynamic and kinetic senses. The degradable porous material in the present invention is a material with a network structure consisting of interconnected or closed holes, and can be degraded under natural environmental conditions such as light, heat, water, pollutants, microorganisms, insects, mechanical forces, etc. In some embodiments, the raw materials for preparing the degradable porous material include the following components in parts by weight:

[0035] 80-100 parts of floating algae, 20-20 parts of sugars, 12-28 parts of binders, 5-10 parts of foaming agents and 3-5 parts of cross-linking agents.

[0036] In some embodiments, the floating algae may be one or more of Chlorella, Scenedesmus obliquus and Hylocereus fasciatus, preferably Chlorella.

[0037] In some embodiments, the binder may be one or more of starch, polylactic acid and sodium alginate, preferably starch and polylactic acid, starch and sodium alginate, or starch, polylactic acid and sodium alginate.

[0038] In some embodiments, the foaming agent may be a carbonate and / or a bicarbonate, for example, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, etc., preferably sodium bicarbonate.

[0039] In some embodiments, the crosslinking agent is an inorganic salt and a weak acid, wherein the acidity coefficient pKa of the weak acid is greater than 4, wherein the inorganic salt may be calcium chloride, and the weak acid may be acetic acid. Preferably, the mass ratio of calcium chloride to acetic acid is (1-10): (10-1).

[0040] In some embodiments, the pore size of the degradable porous material may be 500 μm to 10 4 μm, the specific surface area can be 350m 2 / g~550m 2 / g.

[0041] In some embodiments, the sewage treatment bacteria can be selected from one or more of Bacillus subtilis, EM bacteria and composite bacteria.

[0042] The Bacillus subtilis is a simple Gram-positive aerobic bacterium with excellent acid resistance, salt resistance, high temperature resistance and extrusion resistance. Bacillus subtillus is a simple bacterium and a dominant population in the soil, with rich proteases, lipases, amylases, cellulases, etc. Bacillus subtilis can strongly decompose carbon, nitrogen, phosphorus and sulfur pollutants. Bacillus subtilis can also decompose complex polysaccharides, proteins and water-soluble organic matter, and can form a dominant bacterial community in a water environment.

[0043] The EM bacteria is a composite microbial strain formed by single strains such as bifidobacteria, lactic acid bacteria, bacillus (Bacillus licheniformis, Bacillus subtilis, Bacillus mucilaginosus, Bacillus thuringiensis, etc.), photosynthetic bacteria, yeast, actinomycetes, acetic acid bacteria, etc., through a special process of separate expansion, fermentation, and spray drying. EM bacteria can effectively degrade harmful substances such as ammonia nitrogen, biogas, nitrite, hydrogen sulfide, etc. in water bodies, and can also decompose residual bait and organic matter in water, playing a role in stabilizing the pH of water bodies, removing chemical residual toxins in water, purifying water quality, maintaining the balance of beneficial bacteria and plankton in water, and inhibiting the growth of harmful algae.

[0044] The composite bacteria is a composite bacterial species composed of molds, yeasts, flocculent bacteria, nitrogen-fixing bacteria, cocci, bacilli, nitrifying bacteria, etc. Among them, yeasts have the function of decomposing fat and degrading phenol; molds have strong oxidation ability and can oxidize nitrogen-containing substances such as proteins and nucleic acids in water; flocculent bacteria can form flocs, such as filamentous bacteria, Escherichia coli, Pseudomonas rod-shaped bacteria, fungi, etc., and have strong ability to oxidize and decompose organic matter and good sedimentation; nitrogen-fixing bacteria are some species that can survive by using nitrogen in air and wastewater, such as nitrogen-fixing cyanobacteria.

[0045] In some embodiments, the raw materials for preparing the capsule wall of the microcapsule include: a first polymer material with a positive charge and a second polymer material with a negative charge within a pH range of 4 to 5, wherein the mass ratio of the first polymer material to the second polymer material can be any value between (1 to 4): (4 to 1). The capsule wall of the microcapsule is formed by electrostatic interaction between the first polymer material with a positive charge and the second polymer material with a negative charge under specific pH conditions.

[0046] In some embodiments, the first polymer material can be one or more of type A gelatin, peach gum, xanthan gum and gum arabic. Selecting polymers from natural sources to form the microcapsule wall has the advantages of being degradable and not polluting the environment.

[0047] In some embodiments, the second polymer material may be one or more of maltodextrin, sodium carboxymethyl cellulose, sodium alginate, and sodium caseinate.

[0048] Another aspect of the present invention also relates to a method for preparing the above-mentioned biodegradable composite material with microcapsules, which may specifically include the following steps S10 to S30:

[0049] Step S10: placing the phytoplankton in a plant nutrient solution to allow the algae cells to enter an exponential growth phase and to concentrate the algae cells; and

[0050] The concentrated algae cells, binder, foaming agent and cross-linking agent are dissolved in water for cross-linking and curing to prepare a degradable porous material. It is understandable that in some embodiments, step S10 can be omitted. Using algae cells as a matrix, the degradable porous material is formed by foaming and curing, which can make the degradable porous material have good adsorption properties, can adsorb gases, microorganisms, etc., and is conducive to the adsorption of sewage treatment bacteria in microcapsules.

[0051] In some embodiments, the binder is selected from one or more of starch, polylactic acid and sodium alginate, which not only has a gelling effect but is also degradable and will not pollute the environment.

[0052] In some embodiments, the method of placing phytoplankton in a plant nutrient solution to allow algal cells to enter an exponential growth phase may specifically include the following steps:

[0053] S100: placing phytoplankton in a plant nutrient solution, irradiating with light, and taking out the algae after the algae cells enter an exponential growth phase to prepare a test algae; and

[0054] S200: adjusting the volume concentration of the tested algae to 0.5% to 5% and placing the tested algae in a plant nutrient solution, and concentrating and drying the algae cells after the algae cells enter an exponential growth phase.

[0055] In some embodiments, the plant nutrient solution may be any plant nutrient solution commonly used in the art, and illustratively, may be Hoagland's nutrient solution, wherein the mass concentration of the Hoagland's nutrient solution may be 5% to 20%.

[0056] In some embodiments, the method of concentrating algal cells can be performed using a No. 25 plankton net.

[0057] In some embodiments, the steps of dissolving the concentrated algal cells, the binder, the foaming agent and the cross-linking agent in water for cross-linking and curing may be as follows:

[0058] Adding a first binder into water, heating and dissolving it, and then adding concentrated algae cells to form a first flocculent body, wherein the first binder is starch and polylactic acid;

[0059] The second binder is dissolved in water and heated to form a second flocculent body, and then cooled, and a foaming agent, a first flocculent body and a cross-linking agent are added, wherein the second binder is sodium alginate.

[0060] In some embodiments, the time for cross-linking and curing is not limited, and illustratively, it can be 10 min to 60 min.

[0061] In some embodiments, the volume ratio of phytoplankton to plant nutrient solution may be 0.1% to 1%.

[0062] In some embodiments, the intensity of the illumination may be 2000 lx to 6000 lx, the temperature may be 15° C. to 40° C., and the light-to-dark ratio may be (6h to 18h): (18h to 6h).

[0063] Step S20: dissolving the capsule wall of the microcapsule in water to form a second solution, and adding bacterial sludge of sewage treatment bacteria to form a first solution.

[0064] In some embodiments, the method for obtaining bacterial sludge of sewage treatment bacteria can be any method commonly used in the art, such as centrifugation.

[0065] In some embodiments, the mass concentration of the second solution may be any value between 0.5% and 5%, for example, 1%, 1.5%, 2%, 3%, or 4%.

[0066] In some embodiments, the step of heating the second solution is further included, wherein the heating temperature can be 20°C to 50°C.

[0067] In some embodiments, the amount of bacterial sludge of sewage treatment bacteria added can be calculated based on the capsule wall content of the microcapsule, for example, 10 8 cfu~10 12 cfu of bacterial sludge.

[0068] Step S30: adjusting the pH value of the first solution to 4-5 and adding a degradable porous material to perform a complex coagulation reaction, and drying.

[0069] In some embodiments, the pH value may be any value between 4 and 5, for example, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, or 4.9.

[0070] In some embodiments, the time of the complex coacervation reaction can be any value between 10 min and 90 min.

[0071] The present invention also relates to a water purifier, the raw materials for preparing the water purifier include the above-mentioned biodegradable composite material with microcapsules.

[0072] The present invention is further described in detail below with reference to specific embodiments and comparative examples.

[0073] Example 1

[0074] (1) Preparation of degradable porous materials

[0075] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 5% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0076] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 5%, and is placed in 5% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 20° C. for drying;

[0077] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0078] 4) mixing sodium alginate and water, heating to 60° C. to form flocs, cooling, adding sodium bicarbonate and stirring evenly to obtain a second mixture;

[0079] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 1:1 to form a cross-linking reagent;

[0080] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 10 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0081] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0082] 1) Take 10 g of frozen EM strain, dilute it with water at a mass ratio of 1:25, culture it in an incubator at 25°C for 48 h, centrifuge it, discard the supernatant, and prepare bacterial sludge;

[0083] 2) Weigh 10 g of type A gelatin and 10 g of sodium caseinate and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 10% and a sodium caseinate solution with a mass concentration of 10%, and keep them warm at 35° C.;

[0084] 3) At 35° C., 5 g of the bacterial sludge in step 1), 50 g of the type A gelatin solution in step 2) and 50 g of the sodium caseinate solution were mixed evenly, the pH value was adjusted to 4.3 and then the porous material prepared in step (1) was immediately added to induce a complex coacervation reaction for 20 min, and freeze-dried to obtain a biodegradable composite material with microcapsules, wherein the structural schematic diagram of the microcapsules is as shown in FIG. Figure 1 As shown, it includes a capsule core and a capsule wall. The size D50 of the microcapsules in the biodegradable composite material of the microcapsules was measured to be 12.426 μm, and the loading rate of the microcapsules on the porous material was 28.5%. The following related performance tests were performed on it:

[0085] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Figure 2 , 3 and 4. The results show that the prepared biodegradable composite material with microcapsules can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers was reduced by 35% to 45%. After 7 days, the concentration of various pollutants can be reduced to 79% to 81%, which has a significant sewage purification effect.

[0086] Example 2

[0087] (1) Preparation of degradable porous materials

[0088] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 10% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0089] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 3%, and is placed in 10% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 35° C. for drying;

[0090] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0091] 4) mixing sodium alginate and water, heating to 75° C. to form flocs, cooling, adding sodium bicarbonate and stirring evenly to obtain a second mixture;

[0092] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 1:3 to form a cross-linking reagent;

[0093] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 30 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material. The imaging microscope image of the porous material is as follows: Figure 5 As shown, the objective lens magnification is 10×;

[0094] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0095] 1) Take 5 g of frozen EM strain and 5 g of Bacillus subtilis, dilute the EM strain and Bacillus subtilis with water at a mass ratio of 1:25, culture in an incubator at 25° C. for 48 h, centrifuge, discard the supernatant, and prepare bacterial sludge;

[0096] 2) Weigh 5 g of type A gelatin and 5 g of sodium alginate and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 5% and a sodium alginate solution with a mass concentration of 5%, and keep them warm at 35°C;

[0097] 3) At 20°C, 3 g of bacterial sludge from step 1), 50 g of type A gelatin solution from step 2) and 50 g of sodium alginate solution were mixed evenly, the pH value was adjusted to 4.5 and then immediately added to the porous material prepared in step (1), and a complex coacervation reaction was induced for 60 min, followed by freeze drying to obtain a biodegradable composite material with microcapsules. The imaging microscope image of the microcapsules in the biodegradable composite material with microcapsules is shown in FIG. Figure 6As shown in Figure 2, the imaging microscope images of the biodegradable composite material with microcapsules are shown in Figure 2. Figure 7 As shown. The size D50 of the microcapsules in the biodegradable composite material with microcapsules was measured to be 31.572 μm, and the loading rate of the microcapsules on the porous material was 15.2%. The following related performance tests were performed on it:

[0098] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Figure 8 , 9 and 10. The results show that the prepared biodegradable composite material with microcapsules can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers was reduced by about 23% to 27%. After 7 days, the concentration of various pollutants can be reduced to about 47% to 55%, which has a significant sewage purification effect.

[0099] Example 3

[0100] (1) Preparation of degradable porous materials

[0101] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 20% ​​Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0102] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 0.5%, and placed in 20% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 50° C. for drying;

[0103] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0104] 4) mixing sodium alginate and water, heating to 90° C. to form flocs, adding sodium bicarbonate after cooling and stirring evenly to obtain a second mixture;

[0105] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 2:1 to form a cross-linking reagent;

[0106] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 60 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0107] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0108] 1) Take 2 g of frozen EM strain and 1 g of Bacillus subtilis, dilute the EM strain with water at a mass ratio of 1:25, culture in an incubator at 25°C for 48 h, centrifuge, discard the supernatant, and prepare bacterial sludge;

[0109] 2) Weigh 1 g of type A gelatin and 4 g of sodium carboxymethyl cellulose and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 1% and a sodium carboxymethyl cellulose solution with a mass concentration of 1%, and keep them warm at 35° C.

[0110] 3) At 20°C, take 2g of the bacterial mud in step 1), take 100g of the type A gelatin solution in step 2) and 50g of the sodium carboxymethyl cellulose solution, mix them evenly, adjust the pH value to 4.6 and immediately add the porous material prepared in step (1), induce a complex coacervation reaction for 90 minutes, freeze-dry, and obtain a composite material with biodegradable microcapsules. The size D50 of the microcapsules in the composite material with biodegradable microcapsules was measured to be 21.384μm, and the loading rate of the microcapsules on the porous material was 8.4%. The following related performance tests were performed on it:

[0111] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3The test results of -N and TP indicators are as follows Fig.11 , 12 The results show that the biodegradable composite material with microcapsules can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers decreased by about 13% to 15%. After 7 days, the concentration of various pollutants can be reduced to about 25% to 28%, which has a significant sewage purification effect.

[0112] Example 4

[0113] (1) Preparation of degradable porous materials

[0114] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 12% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0115] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 1.0%, and is placed in 12% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 40° C. for drying;

[0116] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0117] 4) mixing sodium alginate and water, heating to 70° C. to form flocs, cooling, adding sodium bicarbonate and stirring evenly to obtain a second mixture;

[0118] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 5:1 to form a cross-linking reagent;

[0119] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 30 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0120] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0121] 1) Take 3 g of frozen EM strain, dilute it with water at a mass ratio of 1:25, culture it in an incubator at 25°C for 48 h, centrifuge it, discard the supernatant, and prepare bacterial sludge;

[0122] 2) Weigh 3 g of type A gelatin, 3 g of sodium alginate and 3 g of gum arabic and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 3%, a sodium alginate solution with a mass concentration of 1% and a gum arabic solution with a mass concentration of 1%, and keep them warm at 35°C;

[0123] 3) At 20°C, 5g of bacterial mud in step 1), 100g of type A gelatin solution, 100g of sodium alginate solution and 100g of gum arabic solution in step 2) were mixed evenly, and the pH value was adjusted to 4.8 and then immediately added to the porous material prepared in step (1), and a complex coagulation reaction was induced for 60 minutes, and freeze-dried to obtain a composite material with biodegradable microcapsules. The size D50 of the microcapsules in the composite material with biodegradable microcapsules was measured to be 39.452μm, and the loading rate of the microcapsules on the porous material was 27.4%. The following related performance tests were performed on it:

[0124] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Fig.14 , 15 The results show that the biodegradable composite material with microcapsules can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers was reduced by about 40% to 50%. After 7 days, the concentration of various pollutants can be reduced to about 80% to 85%, which has a significant sewage purification effect.

[0125] Example 5

[0126] (1) Preparation of degradable porous materials

[0127] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 15% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0128] 2) preparing the test algae prepared in step 1) into a solution with a volume concentration of 1.2%, placing it in 15% Hoagland's nutrient solution for amplification and culture, and when the algae cells enter the exponential growth phase, concentrating the algae cells with a No. 25 plankton net, and placing them in an oven at 30° C. to dry;

[0129] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0130] 4) mixing sodium alginate and water, heating to 80° C. to form flocs, adding sodium bicarbonate after cooling and stirring evenly to obtain a second mixture;

[0131] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 1:2 to form a cross-linking reagent;

[0132] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 70 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0133] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0134] 1) Take 1 g of frozen EM strain, 3 g of Bacillus subtilis and 1 g of composite bacteria, dilute the EM strain with water at a mass ratio of 1:25, culture in an incubator at 25°C for 48 h, centrifuge, discard the supernatant, and prepare bacterial slurry;

[0135] 2) Weigh 2 g of type A gelatin and 2 g of sodium alginate and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 2% and a sodium alginate solution with a mass concentration of 2%, and keep them warm at 35°C;

[0136] 3) At 20°C, 1g of bacterial mud in step 1), 100g of type A gelatin solution in step 2) and 100g of sodium alginate solution were mixed evenly, the pH value was adjusted to 4.8 and then immediately added to the porous material prepared in step (1), and a complex coagulation reaction was induced for 60 minutes, and freeze-dried to obtain a composite material with biodegradable microcapsules. The size D50 of the microcapsules in the composite material with biodegradable microcapsules was measured to be 18.542μm, and the loading rate of the microcapsules on the porous material was 7.1%. The following related performance tests were performed on it:

[0137] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Fig.17 , 18 and 19. The results show that the biodegradable composite material with microcapsules prepared above can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers and streams was reduced by about 11% to 15%. After 7 days, the concentration of various pollutants can be reduced to about 22% to 27%, which has a significant sewage purification effect.

[0138] Example 6

[0139] (1) Preparation of degradable porous materials

[0140] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 10% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0141] 2) preparing the test algae prepared in step 1) into a solution with a volume concentration of 1.0%, placing it in 10% Hoagland's nutrient solution for amplification and culture, and when the algae cells enter the exponential growth phase, concentrating the algae cells with a No. 25 plankton net, and placing it in a 40° C. oven to dry;

[0142] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0143] 4) mixing sodium alginate and water, heating to 60° C. to form flocs, cooling, adding sodium bicarbonate and stirring evenly to obtain a second mixture;

[0144] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 1:1 to form a cross-linking reagent;

[0145] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 30 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0146] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0147] 1) Take 5 g of frozen EM strain, dilute it with water at a mass ratio of 1:25, culture it in an incubator at 25°C for 48 h, centrifuge it, discard the supernatant, and prepare bacterial sludge;

[0148] 2) Weigh 1 g of type A gelatin and 4 g of sodium alginate and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 1% and a sodium alginate solution with a mass concentration of 1%, and keep them warm at 35°C;

[0149] 3) At 20°C, 1g of bacterial mud in step 1), 100g of type A gelatin solution in step 2) and 50g of sodium alginate solution were mixed evenly, the pH value was adjusted to 4.8 and then immediately added to the porous material prepared in step (1), and a complex coagulation reaction was induced for 90 minutes, and freeze-dried to obtain a composite material with biodegradable microcapsules. The size D50 of the microcapsules in the composite material with biodegradable microcapsules was measured to be 13.534μm, and the loading rate of the microcapsules on the porous material was 21.9%. The following relevant performance tests were performed on it:

[0150] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Fig. 20 , 21 and 22. The results show that the prepared biodegradable composite material with microcapsules can effectively remove phosphorus, ammonia nitrogen and COD in wastewater. After 3 days of reaction, the concentration of various pollutants in the two rivers was reduced by about 31% to 34%. After 7 days, the concentration of various pollutants can be reduced to about 64% to 66%, which has a significant sewage purification effect.

[0151] Comparative Example 1

[0152] (1) Preparation of degradable porous materials

[0153] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 1% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0154] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 0.2%, and is placed in 1% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 50° C. for drying;

[0155] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0156] 4) mixing sodium alginate and water, heating to 90° C. to form flocs, adding sodium bicarbonate after cooling and stirring evenly to obtain a second mixture;

[0157] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 1:1 to form a cross-linking reagent;

[0158] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 60 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0159] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0160] 1) Take 2 g of frozen EM strain and 1 g of Bacillus subtilis, dilute the EM strain with water at a mass ratio of 1:25, culture in an incubator at 25°C for 48 h, centrifuge, discard the supernatant, and prepare bacterial sludge;

[0161] 2) Weigh 2 g of type A gelatin and 2 g of sodium alginate and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 2% and a sodium alginate solution with a mass concentration of 2%, and keep them warm at 35°C;

[0162] 3) At 20°C, take 2g of the bacterial mud in step 1), take 100g of the type A gelatin solution in step 2) and 100g of the sodium alginate solution and mix them evenly, adjust the pH value to 5.1 and immediately add the porous material prepared in step (1), induce a complex coagulation reaction for 60 minutes, freeze-dry, and obtain a biodegradable composite material with microcapsules. The average particle size cannot be measured by the Malvern particle size analyzer, and a multi-peak distribution appears. The loading rate of the microcapsules on the porous material is 1.5%. The following related performance tests are performed on it:

[0163] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3 The test results of -N and TP indicators are as follows Fig.23 , 24 and 25. The results show that the biodegradable composite material with microcapsules prepared above cannot effectively remove phosphorus, ammonia nitrogen and COD in wastewater. Whether the reaction time is 3 days or 7 days, the concentrations of various pollutants in the two rivers are not significantly purified.

[0164] Comparative Example 2

[0165] (1) Preparation of degradable porous materials

[0166] 1) Under sterile conditions, the Chlorella solution was transferred into a conical flask containing 10% Hoagland's nutrient solution, and then the conical flask was placed in a light incubator for amplification culture. When the algal cells entered the exponential growth phase, the algae were taken out for the culture experiment;

[0167] 2) The test algae prepared in step 1) is prepared into a solution with a volume concentration of 3%, and is placed in 10% Hoagland's nutrient solution for amplification and culture. When the algae cells enter the exponential growth phase, the algae cells are concentrated using a No. 25 plankton net and placed in an oven at 40° C. for drying;

[0168] 3) adding starch and polylactic acid into water and heating to dissolve, then adding the dried algae cells and stirring to form flocs, thereby obtaining a first mixture;

[0169] 4) mixing sodium alginate and water, heating to 70° C. to form flocs, cooling, adding sodium bicarbonate and stirring evenly to obtain a second mixture;

[0170] 5) dissolving calcium chloride in water, and mixing the calcium chloride solution and acetic acid in a volume ratio of 15:1 to form a cross-linking reagent;

[0171] 6) Mix the first mixture and the second mixture and stir them evenly, then pour them into a mold. Then add the cross-linking reagent in step 5) and react for 60 minutes. After the cross-linking and curing is completed, rinse with water to obtain a porous material;

[0172] (2) Preparation of biomicrocapsules and their loading on degradable porous materials

[0173] 1) Take 2 g of frozen EM strain, dilute it with water at a mass ratio of 1:25, culture it in an incubator at 25°C for 48 h, centrifuge it, discard the supernatant, and prepare bacterial sludge;

[0174] 2) Weigh 1 g of type A gelatin and 1 g of gum arabic and dissolve them in water to prepare a type A gelatin solution with a mass concentration of 0.1% and a gum arabic solution with a mass concentration of 0.1%, and keep them warm at 35°C;

[0175] 3) At 20°C, 0.1g of bacterial mud in step 1), 100g of type A gelatin solution in step 2) and 100g of gum arabic solution were mixed evenly, and the pH value was adjusted to 4.6 and then immediately added to the porous material prepared in step (1), and a complex coacervation reaction was induced for 70 minutes, and freeze-dried to obtain a composite material with biodegradable microcapsules. The size D50 of the microcapsules in the composite material with biodegradable microcapsules was measured to be 2.583μm, and the loading rate of the microcapsules on the porous material was 0.52%. The following related performance tests were performed on it:

[0176] Six 200L blue plastic boxes were selected, and the above-mentioned biodegradable composite materials with microcapsules were placed in a volume ratio of 30%. 150L of wastewater was taken from two rivers (River 1 and River 2) and placed in three plastic boxes respectively. The air volume of the fan was adjusted to make the dissolved oxygen content of the wastewater in the box 3mg / L. The water body at 5cm above the horizontal plane in the plastic box was sampled on the 3rd and 7th days respectively, and the COD of the water body was tested. Mn NH 3 -N and TP indicators, each group of indicators were tested in parallel for 3 groups, and the average value was taken. According to the surface water environmental quality standard in the "Surface Water Environmental Quality Standard" (GB3838-2002), the wastewater treated with the microcapsule biodegradable composite material was tested for water quality, COD Mn NH 3The test results of -N and TP indicators are as follows Fig.26 , 27 and 28. The results show that the biodegradable composite material with microcapsules prepared above cannot effectively remove phosphorus, ammonia nitrogen and COD in wastewater. Whether the reaction time is 3 days or 7 days, the concentrations of various pollutants in the two rivers are not significantly purified.

[0177] The relevant parameters of the biodegradable composite materials with microcapsules in various embodiments and comparative examples are shown in Table 1:

[0178] Table 1

[0179]

[0180] It can be seen from the test results in the above table that the biodegradable composite material with microcapsules provided by the present invention has a high-efficiency sewage purification effect and can effectively degrade COD, total phosphorus and ammonia nitrogen concentration in water bodies.

[0181] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0182] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A biodegradable composite material having microcapsules, It is characterized in that It comprises a degradable porous material and a microcapsule loaded on the degradable porous material, wherein the loading rate of the microcapsule on the degradable porous material is 3% to 50%; the capsule core of the microcapsule comprises sewage treatment bacteria; The raw materials for preparing the capsule wall of the microcapsule include: a first polymer material with positive charge and a second polymer material with negative charge within a pH range of 4 to 5; The method for preparing the biodegradable composite material with microcapsules comprises the following steps: Dissolving the microcapsules in water to form a first solution, adjusting the pH value of the first solution to 4-5 and adding the degradable porous material to perform a complex coacervation reaction; The steps of dissolving the microcapsules in water to form a first solution are specifically as follows: The capsule wall of the microcapsule is dissolved in water to form a second solution, and the bacterial sludge of the sewage treatment bacteria is added to the second solution.

2. The biodegradable composite material with microcapsules according to claim 1, It is characterized in that The mass concentration of the second solution is 0.5% to 5%.

3. The biodegradable composite material with microcapsules according to claim 1, It is characterized in that The first polymer material is one or more of type A gelatin, peach gum, xanthan gum and gum arabic; and The second polymer material is one or more of maltodextrin, sodium carboxymethyl cellulose, sodium alginate and sodium caseinate.

4. The biodegradable composite material with microcapsules according to claim 1, It is characterized in that The loading rate of the microcapsules on the degradable porous material is 5% to 30%.

5. The biodegradable composite material with microcapsules according to claim 1, It is characterized in that The particle size of the microcapsule is 10 μm to 500 μm; the sewage treatment bacteria are selected from one or more of Bacillus subtilis, EM bacteria and composite bacteria.

6. The biodegradable composite material with microcapsules according to claim 5, It is characterized in that The particle size of the microcapsule is 10 μm to 100 μm.

7. The biodegradable composite material with microcapsules according to claim 1, It is characterized in that The raw materials for preparing the degradable porous material include the following components in parts by weight: 80-100 parts of phytoplankton, 12-28 parts of a binder, 5-10 parts of a foaming agent and 3-5 parts of a cross-linking agent; the phytoplankton is selected from one or more of Chlorella, Scenedesmus obliquus and Hylocereus hygrophila, the binder is one or more of starch, polylactic acid and sodium alginate, the foaming agent is carbonate and / or bicarbonate, the cross-linking agent is an inorganic salt and a weak acid, and the acidity coefficient pKa of the weak acid is greater than 4.

8. The biodegradable composite material with microcapsules according to claim 7, It is characterized in that The mass ratio of the inorganic salt to the weak acid is (1-10):(10-1).

9. The biodegradable composite material with microcapsules according to any one of claims 1 to 8, It is characterized in that The preparation method further comprises the steps of preparing the degradable porous material, which are specifically as follows: placing the phytoplankton in a plant nutrient solution to allow the algal cells to enter an exponential growth phase and concentrating the algal cells; and The concentrated algae cells, binder, foaming agent and cross-linking agent are dissolved in water for cross-linking and curing.

10. A water purifier, It is characterized in that The raw materials for preparing the water purifier include the biodegradable composite material with microcapsules as claimed in any one of claims 1 to 9.

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