WO2021208242A1

WO2021208242A1 - Microorganism-loaded 3d printing material for heavy metal sewage treatment, preparation method therefor, and use thereof

Info

Publication number: WO2021208242A1
Application number: PCT/CN2020/098647
Authority: WO
Inventors: 张鹏; 高铁岭
Original assignee: 华禹源环保科技(淄博)有限公司
Priority date: 2020-04-17
Filing date: 2020-06-29
Publication date: 2021-10-21
Also published as: CN111362427B; CN111362427A

Abstract

Disclosed are a microorganism-loaded 3D printing material for a heavy metal sewage treatment, a preparation method therefor, and the use thereof, which solve the technical problem that the biological treatment effect of heavy metal wastewater is weakened due to the shortcomings of existing biological fillers in the process of treating heavy metal sewage using existing microorganisms. The 3D printing material has a double-layer solid core composite monofilament structure, which is composed of an inner core layer and an outer surface layer, wherein the outer surface layer is coated on and connected to the surface of the inner core layer; the inner core layer is a microorganism-loaded gel layer composed of fenugreek gum, Caesalpinia spinosa gum, mantis egg-case, carbonized ginger, a microbial agent and deionized water; and the outer surface layer is a hard layer composed of polycaprolactone, polyethylene glycol and a magnetic liposome. Further disclosed are a method for preparing a microorganism-loaded 3D printing material for a heavy metal sewage treatment according to a raw material ratio, and the use thereof. The material can be widely used in the technical field of wastewater treatment materials.

Description

3D printing material for sewage treatment of heavy metal containing microorganisms and preparation method and application thereof

Technical field

The invention relates to the technical field of sewage treatment materials, in particular to a 3D printing material for sewage treatment of heavy metal containing microorganisms, and a preparation method and application thereof.

Background technique

Heavy metal wastewater refers to wastewater containing heavy metals discharged from industrial production processes such as mining and metallurgy, machinery manufacturing, chemical engineering, electronics, and instrumentation. Heavy metal (such as cadmium, nickel, mercury, zinc, etc.) wastewater is one of the industrial wastewater that pollutes the environment the most and harms humans the most. Heavy metals cannot be biodegraded into harmless substances. After the heavy metal wastewater enters the water body, except part of it is absorbed by aquatic organisms and fish, most of the other is easily absorbed by various organic and inorganic colloids and particulate matter in the water, and then accumulated and settled at the bottom of the water body. Its wastewater pollution has the following characteristics: toxicity has long-term persistence, can be enriched in large quantities by organisms, and cannot be degraded. When in a high-concentration metal environment, diet and excessive intake of heavy metals will cause poisoning, and even have serious consequences, becoming a serious hazard worldwide.

According to the principle of heavy metal wastewater treatment, the treatment methods of heavy metal wastewater are divided into two types of traditional methods. The first is to convert the heavy metals in the dissolved state into insoluble heavy metal compounds, which are removed from the wastewater by precipitation and floatation methods. Specific methods include: neutralization precipitation method, barium salt precipitation method, ferrite method, ion exchange method, ion float method, activated carbon method, coagulation electrolysis method, etc. The second is to concentrate and separate heavy metals in wastewater without changing their chemical forms. Specific methods include: reverse osmosis, electrodialysis, evaporation concentration, diffusion dialysis, ultrafiltration and other membrane separation methods. At present, because the first method is simple to handle and the cost is relatively low, the first method is used in most cases. From the perspective of heavy metal recovery, the second type of method is superior to the first type, because the former is that the heavy metals are concentrated in the original state and directly reused in the production process. Compared with the latter, the heavy metals need to be converted into multiple chemical forms before they can be reused. It's much simpler. However, its disadvantage is that it consumes a lot of money, especially it is not suitable for treating large-flow industrial wastewater, such as mine wastewater. Therefore, in actual production, one or several treatment methods are usually used in combination according to the quality and quantity of wastewater.

Compared with traditional methods, the use of microorganisms to remediate heavy metal pollution has a good effect, does not cause secondary pollution, and has a good application prospect. Using the surface structure characteristics of microorganisms and their biochemical metabolism, heavy metal elements are separated from the water body through biochemical methods, biological flocculation methods, etc., or their toxicity is reduced. In the process of using microorganisms to treat wastewater, biological fillers are often used as carriers for microorganisms. The microorganisms grow into biofilms on these fillers, and biologically treat the wastewater flowing through the biological fillers to achieve the purpose of sewage treatment.

There are many types of existing biological fillers, such as shaped fixed fillers, suspended fillers, suspended fillers and combined fillers. The invention patent with publication number CN102531149A provides a biological filler for biological treatment of wastewater, which comprises: at least one piece of high-hardness polyurethane foam with pores and activated carbon particles in the pores; and enveloping the high-hardness polyurethane foam. Polyurethane foam cage, which is made of polymer, can play a triple role of biological carrier, filtering and adsorbing organic matter. High-hardness polyurethane as a biological carrier has high compression hardness, it is not easy to deform after filming, and the biofilm is not easy to fall off Activated carbon particles are filled in the high-hardness polyurethane, which can adsorb the organic matter in the wastewater and increase the biological treatment time of the organic matter, thereby improving the wastewater treatment effect. The disadvantages of this biological filler are:

(1) Before heavy metal sewage treatment, it is necessary to carry out biofilm culture on the biofilm, which is time-consuming and laborious. After the biofilm culture is completed, the biofilm is directly exposed to the external environment during the storage process, and the microorganisms in the biofilm It is extremely susceptible to the influence of the external environment, which reduces the survival rate of microorganisms.

(2) In the process of heavy metal sewage treatment, the microorganisms in the biofilm on the high-hardness polyurethane are completely exposed to the heavy metal sewage environment, and their activity is easily weakened;

(3) In the process of heavy metal sewage treatment, although high-hard polyurethane is used as the biological carrier, there is still a phenomenon that the biofilm and the high-hard polyurethane are separated.

The above three aspects are the three main factors that weaken the biological treatment effect of heavy metal wastewater and need to be resolved urgently.

Summary of the invention

The purpose of the present invention is to overcome the above shortcomings of the prior art and provide a microbial-loaded heavy metal sewage treatment 3D printing material and its preparation method and application. During the process, the activity of microorganisms is kept to the utmost extent, and the separation of microorganisms from the biological carrier is avoided.

The technical solution adopted by the present invention to solve the technical problem is: the present invention provides a microbial-loaded heavy metal sewage treatment 3D printing material, which is a double-layer solid core composite monofilament structure, which is composed of an inner core layer and an outer surface layer, and the outer surface layer is wrapped Cover the surface of the inner core layer; the inner core layer is a microbial-loaded gel layer composed of a mixture of fenugreek gum, spiny cloud solid gum, mulberry, ginger charcoal, microbial agents, and deionized water; the outer surface layer is made of polycarbonate Hard layer composed of a mixture of lactone, polyethylene glycol and magnetic liposome;

The raw materials for the inner core layer are composed of the following parts by weight: 1 to 5 parts of fenugreek gum, 1 to 10 parts of thorny cloud gum, 1 to 5 parts of cuttlefish, 1 to 10 parts of ginger charcoal, microbial bacteria 10-30 parts of deionized water, 10-60 parts of deionized water;

The raw materials for the outer surface layer are composed of the following parts by weight: 10-20 parts of polycaprolactone, 5-10 parts of polyethylene glycol, 1-5 parts of magnetic liposomes, and an appropriate amount of methylene chloride.

Preferably, the microbial agent is any one or several of Gram-negative bacteria, Magneto-vibrio, Magnetospirillum, Mycobacterium lycopersicum, Aspergillus oryzae, and Saccharomyces cerevisiae.

Preferably, the magnetic liposomes are magnetic liposomes coated with Fe3O4 nanoparticles prepared by a reverse phase evaporation method using lecithin and cholesterol as raw materials.

The preparation method of any one of the above-mentioned microorganism-loaded heavy metal sewage treatment 3D printing materials includes the following steps:

(1) Weigh the raw materials of the inner core layer and outer surface layer according to parts by weight;

(2) Add the fenugreek gum, spinach gum, mulberry, and ginger charcoal weighed in step (1) to the deionized water weighed in step (1), and stir to dissolve and disperse under the temperature control of 50～70℃. mixture;

(3) Cool the mixture obtained in step (2) to a temperature of 35°C, add the microbial agent weighed in step (1) and stir slowly to make it uniformly dispersed, to prepare a microbial-loaded 3D printing inner layer slurry;

(4) Dissolve the polycaprolactone and polyethylene glycol weighed in step (1) in an appropriate amount of dichloromethane, dry and pulverize into a powder after the mixing is complete, and compare with the magnetic lipid weighed in step (1) The body powder is evenly mixed to prepare a 3D printing outer layer slurry;

(5) The microbial-bearing 3D printing inner layer slurry prepared in step (3) and the 3D printing outer layer slurry prepared in step (4) are respectively loaded into a dual-channel coaxial extrusion 3D printing device, and the two Channel printer nozzle connection, 3D printing inner layer slurry with microorganisms is connected to the inner channel, 3D printing outer layer slurry is connected with the outer channel, the extrusion pressure of the inner and outer channels is adjusted, so that the inner channel 3D prints the inner slurry with microorganisms and the outer channel 3D The printing outer layer slurry is extruded simultaneously, during which the temperature of the inner layer slurry of the microorganism-loaded 3D printing is controlled at 10-30°C, and the temperature of the 3D printing outer layer slurry is controlled at 60-65°C, and finally the microorganism-loaded heavy metal sewage treatment 3D printing material is obtained .

Preferably, step (4) is: dissolve the polycaprolactone and polyethylene glycol weighed in step (1) in an appropriate amount of dichloromethane at room temperature, and place the mixture in a fume hood after the mixing is complete. The dichloromethane evaporates and dries. After the dichloromethane is completely evaporated, the mixture is placed in liquid nitrogen for deep cooling, and then a pulverizer is used to pulverize to prepare a mixture of polycaprolactone and polyethylene glycol powder; (1) The weighed magnetic liposome powders are mixed uniformly to prepare a 3D printing outer layer slurry.

Preferably, the diameter of the nozzle of the dual-channel printer is 1 to 4 mm, and the diameter of the nozzle of the inner passage is 0.5 to 3 mm.

Preferably, the barrier layer between the inner channel and the outer channel is made of heat-resistant material.

An application of 3D printing materials for sewage treatment with microorganisms-carrying heavy metals. The printing parameters are set according to the shape of the required printing, and the above-obtained 3D printing materials for sewage treatment with microorganisms-carrying heavy metals are printed layer by layer, superimposed and formed to prepare sewage treatment organisms. Filler: The temperature of the bottom plate of the 3D printing equipment is controlled at -5～0℃, and the temperature of the molding room of the 3D printing equipment is controlled at 0～5℃.

Preferably, the biological filler for sewage treatment is stored at a low temperature of 5-10°C for later use.

Preferably, the biological filler for sewage treatment has a porous network-shaped three-dimensional structure with a pore diameter of 0.5-3 mm.

The beneficial effects of the present invention: The present invention provides a microbial-loaded heavy metal sewage treatment 3D printing material and its preparation method and application. The microbial-loaded heavy metal sewage treatment 3D printing material with a double solid core composite monofilament structure was developed for the first time. In the prior art, the present invention has the advantages that microorganisms do not need to be domesticated in advance, the survival rate of bacteria is high, the material structure is stable, and the effect is long. It can quickly adsorb heavy metal substances in sewage, is non-toxic and harmless, has little impact on the environment, and effectively guarantees It has the effect of biological treatment of heavy metal wastewater, has the effect of first adsorption and then conversion of heavy metal ions, shortens the sewage treatment cycle, realizes rapid and efficient heavy metal sewage treatment, and has simple preparation process, low cost, and stable performance. It is extremely useful in the field of heavy metal sewage treatment. High practical value.

(1) The 3D printing material for microbial heavy metal sewage treatment of the present invention is a double-layer solid core composite monofilament structure, which is composed of an inner core layer and an outer surface layer, and the outer surface layer is coated and connected to the surface of the inner core layer; the inner core layer is made of gourd A microbial-carrying gel layer composed of bajiao, thorny cloud gum, mulberry, ginger charcoal, microbial agents, and deionized water; the outer surface layer is composed of polycaprolactone, polyethylene glycol, and magnetic liposomes. Quality layer. The process of culturing biofilm on the bio-filler in the prior art is eliminated, which saves time, effort and cost. During the storage process, because the outer surface layer is coated and connected to the surface of the inner core layer, it effectively protects the microbial agents in the inner core layer and protects the microorganisms from the direct influence of the external environment, thereby ensuring the survival rate of the microorganisms and ensuring the activity of the microorganisms , It shortens the heavy metal sewage treatment cycle and realizes the efficient removal of heavy metal sewage.

(2) The polyethylene glycol in the outer surface of the 3D printing material of the microorganism-loaded heavy metal sewage treatment 3D printing material of the present invention has good water solubility. In the sewage, the polyethylene glycol on the outer surface layer is formed to form an interconnected microporous structure, which realizes the stable structure of the material, uniform size and high sewage contact area, and ensures the activity of microorganisms and good sewage treatment performance.

(3) The inner core layer of the present invention is a gel structure covering microbial inoculants, which improves the adhesion effect of microbial inoculants; in heavy metal sewage, the outer surface layer with micropores is wrapped outside the inner core layer to limit In the process of heavy metal wastewater treatment, the present invention avoids the phenomenon of separation of biofilm and biological filler in the prior art, and ensures the biological treatment effect of heavy metal wastewater.

(4) The present invention has a wide range of applications, and a 3D printer can be used to process 3D printing materials for microbial heavy metal sewage treatment to produce biological fillers for sewage treatment with structural and shape designs.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of the 3D printing material for the sewage treatment of microbial-loaded heavy metals according to the present invention;

Fig. 2 is a schematic structural diagram of the radial section shown in Fig. 1;

Fig. 3 is a schematic structural view of the axial section shown in Fig. 1;

4 is a schematic structural view of the axial section of the polyethylene glycol shown in FIG. 1 after being dissolved in sewage;

Figure 5 is a schematic view of the structure of the nozzle of the dual-channel printer of the present invention;

Figure 6 is a schematic diagram of the dual-channel coaxial contact structure provided by the present invention;

Fig. 7 is a biological filler for sewage treatment made by the present invention.

Label description: 1. Inner core layer; 2. Outer surface layer; 3. Microbial 3D printing inner slurry; 4. 3D printing outer slurry; 5. Microbial heavy metal sewage treatment 3D printing material; 6. Dual-channel printer Nozzle; 7. Interlayer; 8. Inner channel; 9. Outer channel; 10. Micro pores.

Detailed ways

The present invention will be further described below in conjunction with the drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are conventional methods unless there are special regulations; the raw materials and devices used are conventional commercial products unless there are special regulations.

Example 1, Example 2, Example 3, Example 4, a microbial-loaded heavy metal sewage treatment 3D printing material formula is shown in Table 1: (The unit of the content of each raw material in Table 1 is: parts by weight)

Table 1: 3D printing material formula for sewage treatment of heavy metal containing microorganisms

The main functions of the above-mentioned raw materials in this application are as follows:

The fenugreek gum, spiny cloud gum, mulberry, and ginger charcoal in the inner core layer provide attachment sites and nutrient supply for the microbial agents. The combination of fenugreek gum, spiny cloud gum and ginger charcoal promotes the inner core layer During the forming process, the flow properties of the inner slurry of the microbial-loaded 3D printing and the shape retention performance after the forming is completed.

The fenugreek gum and thorny cloud gum in the inner core layer are mixed and compounded. On the one hand, the viscosity and fluidity of the inner layer material can be adjusted, and the extrusion performance can be adjusted under the premise of ensuring microbial activity to achieve 3D printing; on the other hand, it has temperature Sensitivity, the viscosity will decrease as the temperature decreases, ensuring the integrity of the inner gel structure. In the early stage of the wastewater treatment process, fenugreek gum and spinach gum can achieve the gradient immersion of heavy metal ions in the sewage to realize the slow domestication process of microorganisms; with the end of the domestication process, fenugreek gum and spinach gum can act as microorganisms Provide nutrition and promote the effectiveness of microorganisms.

The mulberry cuttlebone in the inner core layer has a sponge-like structure with multiple layers of membranes inside; the ginger carbon has a loose and porous structure. On the one hand, mulberry and ginger charcoal can adjust the fluidity of the inner material in the 3D printing process; on the other hand, its internal porous membrane-like structure can provide a good environment and nutrient supply for the survival and growth of microorganisms; Third, it can play the role of ion adsorption in the sewage treatment process, thereby promoting the proliferation of microorganisms and speeding up the sewage treatment speed.

The microbial inoculum in the inner core layer has been disclosed in the prior art that the microbial inoculum is used alone or in combination, and has the performance of treating heavy metals in sewage or soil. The corresponding microbial inoculum can be selected according to the types of heavy metal ions in the sewage.

The deionized water, which is the raw material for the inner core layer, is the solvent. On the one hand, it can dissolve and disperse fenugreek gum and thorny cloud gum, so that it can be evenly mixed with cuttlefish and ginger charcoal; on the other hand, it can be used in the printer nozzle The inner core realizes the smooth extrusion of the inner core layer; thirdly, the specific heat capacity of deionized water is large, which makes the inner core layer increase and decrease the temperature slowly during the preparation and extrusion process, and the temperature is easier to control during the 3D printing process, which greatly reduces The influence of external temperature on the inner core layer is ensured to ensure the activity of microbial agents in the inner core layer.

The polyethylene glycol in the outer surface layer, on the one hand, can promote the fluidity of the 3D printing outer layer slurry during the formation of the outer surface layer at a lower temperature, thereby reducing the 3D printing temperature of the outer surface layer and ensuring the high activity of microorganisms; On the one hand, it dissolves in the sewage treatment process, realizes the microporous structure on the surface of the printing filament, and realizes the exchange of substances inside and outside the micropores.

The magnetic liposomes in the outer surface layer combine magnetic properties and liposome adsorption properties. When carrying out heavy metal sewage, liposomes carry charged ions, which can adsorb heavy metals through electrostatic interaction, and have coordinating atoms or ligands on the surface. , The magnetic field generated on the outer surface layer can exert a strong adsorption effect on heavy metal ions. The magnetic liposome can exert its own magnetic effect, attracting nearby heavy metal ions to the magnetic liposome, and carry out the adsorption effect, exerting the effect of heavy metal sewage treatment. Therefore, magnetic paper is used to exert the synergistic effect of magnetism and liposomes to realize the attraction, adsorption and aggregation of heavy metal sewage. On the one hand, it improves the treatment efficiency of heavy metal sewage, and on the other hand, it slows the infiltration of heavy metal ions into the inner core layer on the outside. The speed guarantees the high activity of the microbial agents in the inner core layer and the smooth progress of the domestication process.

Polycaprolactone in the outer surface layer. Polycaprolactone is a biocompatible polymer with excellent mechanical properties. Because of its low melting point, it is widely used in melt extrusion 3D printing. The invention adopts polycaprolactone in the outer structure of sewage treatment materials, can exert its excellent mechanical properties, and is extruded by a printer nozzle at a lower temperature to realize the wrapping of the inner layer material and serve as a base connection The role of.

Dichloromethane, the raw material for the outer surface layer, is a low-boiling solvent, which can dissolve polycaprolactone and polyethylene glycol and make the two materials uniformly mixed.

The method for preparing a 3D printing material for microbial-loaded heavy metal sewage treatment as described in the foregoing embodiment 1, embodiment 2, embodiment 3, and embodiment 4 includes the following steps:

(2) Add the weighed fenugreek gum, spiny cloud fruit gum, cuttlefish and ginger charcoal from step (1) into the deionized water weighed in step (1), and stir to dissolve and disperse under the temperature control of 50～70℃ Form a mixture;

(4) Dissolve the polycaprolactone and polyethylene glycol weighed in step (1) in the appropriate amount of dichloromethane weighed in step (1). After the mixing is complete, the mixture is dried and pulverized into powder, and then Mix uniformly with the magnetic liposome powder weighed in step (1) to prepare a 3D printing outer layer slurry;

(5) As shown in Figures 5 and 6, the microbe-carrying 3D printing inner layer slurry 3 prepared in step (3) and the 3D printing outer layer slurry 4 prepared in step (4) are respectively loaded into the dual channel In the 3D printing equipment of shaft extrusion, it is connected with a dual-channel printer nozzle 6, and the microbial 3D printing inner layer slurry 3 is connected to the inner channel 8, and the 3D printing outer layer slurry 4 is connected to the outer channel 9 to adjust the extrusion pressure of the inner and outer channels. The microbe-carrying 3D printing inner slurry 3 in the inner channel 8 and the 3D printing outer slurry 4 in the outer channel 9 are simultaneously extruded, during which the temperature of the microbe-carrying 3D printing inner slurry 3 is controlled at 10-30°C, The temperature of the 3D printing outer layer slurry 4 is controlled at 60-65°C, and finally a microorganism-carrying heavy metal sewage treatment 3D printing material 5 is obtained.

As a preferred embodiment, the method for preparing a microbial-loaded heavy metal sewage treatment 3D printing material described in the above-mentioned embodiment 1, embodiment 2, embodiment 3, and embodiment 4, the above step (4) raw material for outer surface layer 2 Methyl chloride is a low-boiling solvent, which can dissolve polycaprolactone and polyethylene glycol and make these two materials uniformly mixed. The above step (4): Dissolve the polycaprolactone and polyethylene glycol weighed in step (1) in an appropriate amount of dichloromethane at room temperature. After the mixing is complete, place the mixture in a fume hood to remove the dichloromethane After the dichloromethane is completely volatilized, the mixture is placed in liquid nitrogen for deep cooling, and the mixture is cryogenically cooled in liquid nitrogen to make the mixture hard and facilitating the next step of pulverization; then use a pulverizer to pulverize to prepare polycaprolactone and polycaprolactone. Mixture powder of ethylene glycol; then mix the mixture powder and the magnetic liposome powder weighed in step (1) uniformly to prepare a 3D printing outer layer slurry.

As a preferred embodiment, the method for preparing a microbial-loaded heavy metal sewage treatment 3D printing material described in the above-mentioned embodiment 1, embodiment 2, embodiment 3, and embodiment 4 is shown in Figure 5, the diameter of the nozzle of the dual-channel printer D is 1 to 4 mm, and the nozzle diameter d of the inner channel 8 is 0.5 to 3 mm. The raw materials of the outer surface layer, mulberry, ginger charcoal, and magnetic liposomes are all powdered, and their particle size is subject to the extrusion of the printer nozzle. As a further preferred embodiment, the inner diameter of the outer channel where the outer surface layer is located (ie ( Dd)/2) is 0.5mm. Generally, the particle size of cuttlefish, ginger charcoal, and magnetic liposome is less than 0.2mm to achieve smooth extrusion of the outer surface.

As a preferred embodiment, the method for preparing a microbial-loaded heavy metal sewage treatment 3D printing material described in the foregoing embodiment 1, embodiment 2, embodiment 3, and embodiment 4, the inner channel 8 and the outer channel of the nozzle 6 of the dual-channel printer The barrier layer 7 between the channels 9 is made of heat-resistant material, which further prevents the heat of the 3D printed outer layer slurry 4 in the outer channel 9 from being transferred to the microorganism-carrying 3D printed inner layer slurry 3 in the inner channel 8 to ensure microbial bacteria The activity of the agent. The heat-resistant material has thermal insulation properties that can block heat flow transfer, and usually uses existing heat-resistant materials, such as glass fiber, asbestos, etc.; the barrier layer 7 can also be vacuum insulated, such as a vacuum insulated pipe.

As shown in Fig. 1 to Fig. 3, the microbial-loaded heavy metal sewage treatment finally obtained by the method for preparing the microorganism-loaded heavy metal sewage treatment 3D printing material described in the above-mentioned Example 1, Example 2, Example 3, and Example 4 3D printing material, which is a double-layer solid core composite monofilament structure, which is composed of an inner core layer 1 and an outer surface layer 2. The outer surface layer 2 is covered and connected to the surface of the inner core layer 1; the inner core layer 1 is made of fenugreek glue, A microbial-carrying gel layer composed of a mixture of thorn cloud gum, mulberry cuttlebone, ginger charcoal, microbial inoculants, and deionized water; the outer surface layer 2 is a hard material composed of polycaprolactone, polyethylene glycol, and magnetic liposomes Floor.

As a preferred embodiment, the above-mentioned 3D printing material for heavy metal sewage treatment with microorganisms, the microbial agent can be Gram-negative bacteria, Magnetobacter bacterium, Magnetosspirillum, Mycobacterium lycopersicum, Aspergillus oryzae, Saccharomyces cerevisiae Any one or several. Microbial agents are used alone or in combination, and have the ability to treat heavy metals in sewage or soil. The corresponding microbial agents can be selected according to the types of heavy metal ions in the sewage.

As a preferred embodiment, the above-mentioned microbial-loaded heavy metal sewage treatment 3D printing material, the magnetic liposome is a magnetic liposome coated with ferroferric oxide nanoparticles prepared by a reversed-phase evaporation method using lecithin and cholesterol as raw materials Liposomes.

The present invention provides a microbial-loaded heavy metal sewage treatment 3D printing material. The outer surface layer has the function of wrapping and supporting the inner core layer containing the microbial agent, which can ensure that the structure is stable and not damaged under long-term use, and it effectively solves the publication number Technical problems existing in the invention patent of CN102531149A:

(1) The process of biofilm culture on biological fillers in the prior art is eliminated, which saves time, effort, and cost. During the storage process, because the outer surface layer is coated and connected to the surface of the inner core layer, it effectively protects the microbial agents in the inner core layer and protects the microorganisms from the direct influence of the external environment, thereby ensuring the survival rate of the microorganisms and ensuring the activity of the microorganisms , It shortens the heavy metal sewage treatment cycle and realizes the efficient removal of heavy metal sewage.

(2) The polyethylene glycol in the outer surface layer of the microbial heavy metal sewage treatment 3D printing material of the present invention has good water solubility. When the present invention is placed in heavy metal sewage, the polyethylene glycol in the outer surface layer quickly dissolves in the sewage , So that a large number of micropores are formed at the position of the outer surface layer of polyethylene glycol, which becomes a channel for the inner core layer to communicate with the external sewage. On the one hand, under the protection of the outer surface layer, the outer surface layer with micropores is wrapped in the inner core layer. In addition, the microbial agents coated with the gel structure of the inner core layer will not be completely exposed to the environment of heavy metal sewage, and the micropores of the outer surface layer become channels for the immersion and leaching of heavy metal sewage; on the other hand, the micropores close to the external sewage From one end to the end close to the microbial agent (that is, from the outside to the inside), the microbial agent continuously treats the heavy metals in the sewage on the inside, so that the concentration of heavy metal ions in the sewage in the micropores gradually decreases from the outside to the inside, realizing the microorganisms The process of slowly increasing the concentration of heavy metal ions in the gel microenvironment can also eliminate the need for individual domestication of microorganisms in advance in the prior art, which saves time and effort. Therefore, the present invention can weaken the stimulation of heavy metals on the microbial inoculants, ensure the activity of microorganisms, shorten the treatment cycle of heavy metal sewage, and realize the high-efficiency removal of heavy metal sewage.

(3) The inner core layer of the present invention is a gel structure that coats the microbial inoculum, which improves the adhesion effect of the microbial inoculum; the outer surface layer with micropores is wrapped outside the inner core layer to serve as a limiter; In the heavy metal wastewater treatment process, the present invention avoids the separation of the biofilm and the biological filler in the prior art, and ensures the biological treatment effect of the heavy metal wastewater.

The invention has a wide range of applications, and a 3D printer can be used to process a 3D printing material for microbial heavy metal sewage treatment to make a biological filler for sewage treatment with a structure and a shape design. The printing parameters are set according to the shape of the desired printing, and the microbial-carrying heavy metal sewage treatment 3D printing materials obtained in the above embodiment 1, embodiment 2, embodiment 3, and embodiment 4 are printed layer by layer and superimposed to form the sewage. Biological filler for processing. The temperature of the bottom plate of the 3D printing equipment is controlled at -5～0℃, and the temperature of the molding chamber of the 3D printing equipment is controlled at 0～5℃. During the printing process, it is ensured that the microbial agents in the inner core layer are in a low-temperature survival state. In the present invention, the prepared microorganism-carrying heavy metal sewage treatment 3D printing material is made into a hollow biological filler structure for sewage treatment with an existing shape and structure design. The structure of biological filler for sewage treatment can be ordinary three-dimensional structures such as spheres and squares, or three-dimensional structures with complex shapes. Membrane, porous block and bionic structures can also be obtained, such as the biological filler for sewage treatment shown in Figure 7. .

As a preferred embodiment, the biological filler for sewage treatment is stored at a low temperature of 5-10°C for later use. On the basis of ensuring the survival of the microbial inoculum, the microbial inoculum is put in a dormant state, and the biochemical reaction in the microbial cell is almost completely stopped.

As a preferred embodiment, the biological filler for sewage treatment has a porous network three-dimensional structure with a pore diameter of 0.5-3 mm.

Polycaprolactone is a hydrophobic polyester polymer material, while polyethylene glycol is a hydrophilic polymer material. Therefore, during the melting process, there will be poor interaction between the two and reduce the interaction between the molecules of the mixture. Polyethylene glycol has a lower melting point than polycaprolactone. The synergistic effect of the two factors leads to a low melting temperature of the outer layer material, which is more suitable for extrusion under low temperature conditions. During the extrusion process, since the temperature of the printer bottom plate and the environment is much lower than the temperature of the inner and outer passages of the printer nozzle, the heavy metal sewage treatment 3D printing material is extruded from the printer nozzle and falls on the printer bottom plate. The 3D printing material quickly solidifies, and generates tension on the heavy metal sewage treatment 3D printing material just extruded near the printer nozzle, and guides the extrusion of the printing filament. The polycaprolactone molecular chain and the polyethylene glycol molecular chain in the outer surface material have a relative relationship. Poor connection effect. Therefore, under the action of tension, the connection between the polycaprolactone molecular chain and the polyethylene glycol molecular chain is easily broken, forming discontinuous holes. When the biological filler for sewage treatment is placed in the sewage , The polyethylene glycol of the outer surface layer will dissolve in the sewage, and further increase the pores of the outer surface layer, forming a micro-pore structure connecting the external sewage and the microbial agent in the inner core layer.

Compared with the prior art biological filler, the biological filler for sewage treatment of the present invention is prepared by layer-by-layer printing and superimposition of the microbial-loaded heavy metal sewage treatment 3D printing material of the present invention. The advantages also have the following advantages:

(1) The polycaprolactone in the outer surface layer of the 3D printing material for sewage treatment of microbial heavy metal sewage has good biodegradability, and can be completely degraded in 6-12 months in a natural environment. The whole process is: before the polycaprolactone in the outer surface layer is degraded, the outer surface layer has the function of wrapping and supporting the inner core layer containing the microbial agent, which can ensure that the structure is stable and not damaged under long-term use. In the process of heavy metal sewage treatment, as the inner core layer provides attachment sites and nutrient supply for the microbial inoculants, the fenugreek gum, thorny cloud gum, mulberry, and ginger charcoal gradually deplete, and the continuous microbial inoculants gradually deplete Then it firmly adheres to the inner wall of the outer surface layer, and the nutrition comes from the liposomes in the outer surface layer of magnetic liposomes and the nutrients in the heavy metal sewage. At this time, the outer surface layer remains intact, and most of the microbial agents Imprisoned in the outer surface. As the polycaprolactone in the outer surface layer is continuously degraded, the outer surface layer is continuously fragmented and separated into small pieces to be dispersed in the heavy metal sewage. At this time, most of the microbial agents are still adsorbed on the divided small pieces. To the role of biological fillers in the prior art. Finally, after the polycaprolactone is completely degraded, the microbial agent is completely mixed in the heavy metal sewage. In the above-mentioned whole process, the microbial inoculants in the heavy metal wastewater have been undergoing biological treatment.

(2) Before the polycaprolactone in the outer surface layer is degraded, the reuse of the prepared biological filler for sewage treatment is realized. Store at low temperature before use. After use, it needs to be placed in sewage to maintain microbial activity for transfer and reuse, or it can be transferred directly in a short time.

In the description of the present invention, it should be understood that the terms "left", "right", "upper", "lower", "top", "bottom", "front", "rear", "inner", " The orientation or positional relationship indicated by “outer”, “back”, “middle”, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply the pointed device or The element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

However, the above are only specific embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

A microbial heavy metal sewage treatment 3D printing material, which is characterized in that it is a double-layer solid core composite monofilament structure, which is composed of an inner core layer and an outer surface layer, and the outer surface layer is coated and connected to the inner core layer. Surface; the inner core layer is a microbial-loaded gel layer composed of a mixture of fenugreek gum, thorny cloud gum, mulberry, ginger charcoal, microbial agents, and deionized water; the outer surface layer is made of polycaprolactone, A hard layer composed of a mixture of polyethylene glycol and magnetic liposomes;

The raw materials for the inner core layer are composed of the following components by weight: 1 to 5 parts by weight of fenugreek gum, 1 to 10 parts of thorny cloud gum, 1 to 5 parts of cuttlefish, 1 to 10 parts of ginger charcoal, 10-30 parts of microbial agents, 10-60 parts of deionized water;

The raw materials for the outer surface layer are composed of the following parts by weight: 10-20 parts of polycaprolactone, 5-10 parts of polyethylene glycol, 1-5 parts of magnetic liposomes, and an appropriate amount of dichloromethane.
The 3D printing material for sewage treatment of heavy metal containing microorganisms according to claim 1, characterized in that the microbial agents are Gram-negative bacteria, Magnetobacter, Magnetosspirillum, Mycobacterium, Aspergillus oryzae, Any one or several of Saccharomyces cerevisiae.
The 3D printing material for microbial-loaded heavy metal sewage treatment according to claim 1, wherein the magnetic liposome is a coated Fe3O4 nanometer prepared by a reversed-phase evaporation method using lecithin and cholesterol as raw materials. Granular liposomes with magnetic properties.
According to any one of 1 to 3, a method for preparing a 3D printing material for microbial-loaded heavy metal sewage treatment, which is characterized in that it comprises the following steps:

(1) Weigh the raw materials of the inner core layer and the outer surface layer according to parts by weight;

(2) Add the fenugreek gum, spiny cloud gum, mulberry, and ginger charcoal weighed in step (1) to deionized water, and stir to dissolve and disperse to form a mixture under temperature control of 50 to 70°C;

(3) Cool the mixture obtained in the step (2) to a temperature of 35°C, add the microbial agent weighed in the step (1) and stir slowly to make it uniformly dispersed to prepare a microbial-loaded 3D printing inner layer slurry material;

(4) Dissolve the polycaprolactone and polyethylene glycol weighed in step (1) in an appropriate amount of dichloromethane. After the mixing is complete, the mixture is dried and pulverized into powder, and then weighed with step (1) The magnetic liposome powders are mixed uniformly to prepare a 3D printing outer layer slurry;

(5) The microbe-carrying 3D printing inner layer slurry prepared in the step (3) and the 3D printing outer layer slurry prepared in the step (4) are respectively loaded into a dual-channel coaxial extrusion 3D printing device And connected with a dual-channel printer nozzle, the microbe-carrying 3D printing inner layer slurry is connected to the inner channel, the 3D printing outer layer slurry is connected to the outer channel, and the extrusion pressure of the inner and outer channels is adjusted to make the microbe-carrying 3D printing inner layer slurry and outer channel The 3D printing outer layer slurry is extruded simultaneously, during which the temperature of the microbe-carrying 3D printing inner layer slurry is controlled at 10-30°C, and the 3D printing outer layer slurry temperature is controlled At 60-65°C, the 3D printing material for sewage treatment with microorganism-carrying heavy metals is finally obtained.
A method for preparing microbial-loaded heavy metal sewage treatment 3D printing materials according to claim 4, wherein the step (4) comprises: weighing the polycaprolactone in the step (1) at room temperature. Dissolve the ester and polyethylene glycol in an appropriate amount of dichloromethane. After the mixing is complete, place the mixture in a fume hood to volatilize and dry the dichloromethane. After the dichloromethane is volatilized, place the mixture in Cryogenically in liquid nitrogen, then use a pulverizer to pulverize to prepare a mixture powder of polycaprolactone and polyethylene glycol; then mix the mixture powder with the magnetic liposome powder weighed in step (1) to prepare Obtain the 3D printing outer layer slurry.
The method of claim 4, wherein the diameter of the nozzle of the dual-channel printer is 1-4mm, and the diameter of the nozzle of the inner channel is 0.5-3mm. .
The method for preparing a 3D printing material for microorganism-carrying heavy metal sewage treatment according to claim 4, wherein the barrier layer between the inner channel and the outer channel is made of heat-resistant material.
An application of microbial-loaded heavy metal sewage treatment 3D printing material, characterized in that the printing parameters are set according to the shape of the desired printing, and the microbial-loaded heavy metal sewage treatment 3D printing material obtained in any one of claims 4-7 is processed Layer-by-layer printing and overlay molding are used to prepare biological fillers for sewage treatment; the temperature of the bottom plate of the 3D printing equipment is controlled at -5 to 0°C, and the temperature of the molding chamber of the 3D printing equipment is controlled at 0 to 5°C.
The application of a microorganism-carrying heavy metal sewage treatment material according to claim 8, wherein the biological filler for sewage treatment is stored at a low temperature of 5-10°C for later use.
The application of a microorganism-carrying heavy metal sewage treatment material according to claim 8, wherein the biological filler for sewage treatment is a porous network three-dimensional structure with a pore size of 0.5-3 mm.