KR20100121790A - Polymer compound and membrane manufacturing method for mbr processing - Google Patents

Abstract

PURPOSE: A polymer compound for manufacturing a separator of an MBR, and a manufacturing method of the separator using thereof are provided to improve the operating efficiency, and to secure the energy reduction effect. CONSTITUTION: A manufacturing method of a separator of an MBR comprises the following steps: forming a raw material with polyvinylidene fluoride, dimethylformamide, polyvinylpyrrolidone, polyethylene glycol, and methyl cellosolve(S1); forming a polymer solution by mixing and stirring the raw material(S2); forming a polymer coating layer by spreading the polymer solution to a non-woven fabric(S3); dipping the non-woven fabric with the polymer coating layer into a coagulation bath with 40~50deg C water, to solidify the polymer coating layer(S4); dipping the polymer coating layer into water to remove a remain solvent(S5); dipping the washed polymer coating layer to an aqueous solution with glycerine(S6); and drying the polymer coating layer(S7).

Description

Polymer compound for the manufacture of membrane for MBI and manufacturing method of membrane using same {POLYMER COMPOUND AND MEMBRANE MANUFACTURING METHOD FOR MBR PROCESSING}

The present invention relates to a polymer compound for preparing a membrane for MBR and a method for preparing the membrane, and more particularly, to a polymer compound for preparing a membrane for MBR, which can improve membrane surface properties according to membrane preparation, such as improving membrane fouling resistance. And it relates to a method for producing a separator using the same.

In general, membrane separation technology using membrane is applied among many methods that can cope with existing processes of treating purified water and wastewater, and recently, separation membrane technology through microfiltration membrane or ultrafiltration membrane is applied to treatment of sewage or wastewater. Increasingly, a representative method of applying a membrane to the treatment of sewage and wastewater is a membrane-bound activated sludge method, that is, a MBR (Membrane Bioreactor) method.

This MBR process combines biological treatment and membrane separation, and the membrane plays an important role. Despite the many advantages due to the fundamental problem of membrane contamination, such as lowering of processing efficiency and rising operating cost. Problems are being derived and the situation is in need of improvement.

The present invention has been made to solve the above-mentioned conventional problems, to improve the membrane surface characteristics according to the membrane production, such as to improve membrane contamination resistance, and to shorten the suction / rest period of the MBR process It is possible to improve energy efficiency while reducing operating power while improving operating efficiency, and to prepare a polymer compound for manufacturing MBR membranes and a method of preparing membranes using the same, which can improve the treatment efficiency of wastewater or sewage. The purpose is to provide.

The present invention is composed of polyvinylidene fluoride (PVDF), dimethyl formamide (DMF), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), methyl cellosolve (MC) mixed membrane for MBR Characterized in that the polymer compound for the production of membranes for MBR used in the manufacture of.

In this case, the polymer compound is 700 to 850 parts by weight of dimethyl formamide (DMF), 110 to 140 parts by weight of polyvinyl pyrrolidone (PVP) based on 100 to 130 parts by weight of polyvinylidene fluoride (PVDF), polyethylene glycol ( PEG) 110 to 140 parts by weight, methyl cellosolve (MC) is characterized in that it is made of a composition of 50 to 130 parts by weight.

On the other hand, the present invention is 700 to 850 parts by weight of dimethyl formamide (DMF), 110 to 140 parts by weight of polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG) based on 100 to 130 parts by weight of polyvinylidene fluoride (PVDF) 110-140 parts by weight of methyl cellosolve (MC) 50-130 parts by weight of the first step of composition and comprising; Mixing and stirring the prepared raw materials to form a polymer solution; A third step of forming the polymer coating layer on the surface by applying the polymer solution to a nonwoven fabric for use as a support of the separator; A fourth step of forming a film by solidifying the polymer coating layer by immersing the nonwoven fabric having the polymer coating layer in a coagulation bath containing water at a temperature of 40 to 50 ° C .; A fifth step of removing and washing the solvent remaining in the film by immersing in water having a temperature condition of 40 ° C. to 50 ° C. after the film formation; A sixth step of immersing in an aqueous solution containing glycerin after the washing step to post-treat the glycerin in the solidified membrane to moisturize it; After the post-treatment is characterized in that the membrane manufacturing method using a polymer compound for the preparation of the MBR separator prepared by the seventh step of drying.

The present invention can improve the membrane surface properties according to the production of the separation membrane, such as to improve the resistance to membrane fouling and increase the permeate flow rate can increase the treatment efficiency of waste water, thereby inhalation / rest in the MBR process Operation efficiency can be improved, such as shortening the cycle, and power can be saved by improving the operation efficiency, thereby saving energy.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The polymer compound for preparing a membrane for MBR according to an embodiment of the present invention is polyvinylidene fluoride (PVDF), dimethyl formamide (DMF), polyvinyl pyrrolidone (PVP; polyvinyl pyrrolidone), Polyethylene glycol (PEG), methyl cellosolve (MC) is composed of a compound mixed.

At this time, 700 to 850 parts by weight of dimethyl formamide (DMF), 110 to 140 parts by weight of polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG) 110 based on 100 to 130 parts by weight of the polyvinylidene fluoride (PVDF). 140 parts by weight, methyl cellosolve (MC) is preferably composed of 50 to 130 parts by weight of the composition.

The polyvinylidene fluoride (PVDF) serves as a main polymer to form a membrane for membrane bioreactor (MBR), and when it exceeds 130 parts by weight, the polyvinylidene fluoride (PVDF) is formed on the membrane of the nonwoven fabric serving as a support for the membrane. This thick film is formed and pores on the surface of the membrane are not well formed, which may lower the separator properties. If the amount is less than 100 parts by weight, the polymer viscosity is low, so that it is easily dispersed into the nonwoven fabric when applied to the nonwoven fabric, which is a support of the separator. The film is not formed on the surface of the film.

At this time, polyvinylidene fluoride (PVDF) is a polymer for forming a film serves to increase the chemical and mechanical stability.

The dimethyl formamide (DMF) plays a role of dissolving the polymer as a solvent (solvent), and if it exceeds 850 parts by weight, the viscosity of the polymer is lowered so that the polymer solution penetrates too much into the inside of the nonwoven fabric as a support to form a uniform film This becomes difficult and less than 700 parts by weight of the polymer is not easily dissolved and the viscosity is too high to make the film difficult.

At this time, dimethyl formamide (DMF) is excellent in the admixture with water to act to favor the pore formation on the membrane surface.

The polyvinyl pyrrolidone (PVP) is used as a pore forming agent, and serves to form pores while imparting hydrophilicity to the membrane. When the polyvinyl pyrrolidone (PVP) exceeds 140 parts by weight, the viscosity of the polymer solution is greatly improved. As a result, the thickness of the membrane is increased and pores on the surface of the membrane are not well formed, and when less than 110 parts by weight, the role of imparting hydrophilicity to the membrane is insignificant and the role of forming pores is also negligible.

At this time, the polyvinyl pyrrolidone (PVP) is very excellent in hydrophilicity and solubilized in a solvent can improve the dispersibility.

The polyethylene glycol (PEG) is used as a pore forming agent (pore forming agent) and serves to form pores on the surface of the membrane, if it exceeds 140 parts by weight, the mechanical properties of the membrane is weakened, the strength is weak and less than 110 parts by weight In this case, the role of forming pores is insignificant.

The methyl cellosolve (MC) acts as a non-solvent to impart instability to the polymer solution to form large pores, and when it exceeds 130 parts by weight, the polymer solution is too high and the membrane instability is too high to facilitate film formation. If the amount is less than 50 parts by weight, the instability of the polymer solution cannot be imparted to form a large pore.

On the other hand, when describing a method for producing a membrane using a polymer compound for producing a membrane for MBR according to the present invention as described above.

Referring to Figure 1, the manufacturing method of the membrane using the polymer compound for the preparation of the membrane for MBR of the present invention 700 to 850 parts by weight of dimethyl formamide (DMF) based on 100 to 130 parts by weight of polyvinylidene fluoride (PVDF) And a raw material having a composition of 110 to 140 parts by weight of polyvinyl pyrrolidone (PVP), 110 to 140 parts by weight of polyethylene glycol (PEG) and 50 to 130 parts by weight of methyl cellosolve (MC) (S1).

When the raw material is prepared and provided, the mixed raw materials are mixed and stirred to make a polymer solution to be applied to manufacture the separator (S2).

At this time, the polymer solution is preferably manufactured to maintain the viscosity of 400 ~ 1000cP, if the viscosity is less than 400cP film production is impossible or cause the wrinkles on the nonwoven fabric of the support causing product defects and viscosity If the thickness exceeds 1000 cP, the film thickness increases and the pore formation on the surface of the film becomes difficult.

In other words, as shown in FIG. 2, the polymer solution was added with polyvinylidene fluoride (PVDF) to dimethyl formamide (DMF) as a solvent, but stirred under heating conditions at 80 ° C. to 90 ° C. (S21). And, after the first process, polyvinyl pyrrolidone (PVP) is added, but the second step (S22) of stirring and mixing while the heating condition is removed, and when the second process is completed, polyethylene glycol (PEG) and methyl cellosolve It is preferably prepared through the third step (S23) of adding and stirring (MC).

Here, the polyethylene glycol (PEG) is preferably stored in an oven at 30 ~ 40 ℃ condition added in a molten state.

When the preparation of the polymer solution is completed, the polymer solution is applied to the nonwoven fabric used as the support so that the polymer coating layer is formed on the surface of the nonwoven fabric (S3).

At this time, in applying the polymer solution to the nonwoven fabric, it is preferable to use a casting knife coating device that performs line spraying so that uniform coating can be performed over the entire surface.

The nonwoven fabric is preferably a structure that is a little loosely woven structure rather than a tightly woven structure, the polymer coating layer formed on the surface of the nonwoven fabric is easily peeled off by allowing the polymer solution to penetrate a certain amount into the tissue of the nonwoven fabric. This is to prevent damage or damage.

The nonwoven fabric having the polymer coating layer is immersed in a coagulation bath containing water to solidify the polymer coating layer to form a film (S4).

At this time, the water in the coagulation bath used for the solidification of the polymer coating layer is preferably maintained at a temperature of 40 ~ 50 ℃, Figure 3 shows the surface structure of the solidified film derived in the state immersed in water having a temperature of 45 ℃. Electron scanning microscope (SEM) photographs show that pores are formed to ensure a certain amount of transmission.

After the film is formed, the solvent remaining in the solidified film is immersed in water having a temperature condition of 40 ° C. to 50 ° C. and then washed (S5).

After washing, the solution is immersed in an aqueous solution containing glycerin and is post-treated to allow the glycerin to penetrate into the solidified membrane to moisturize (S6).

After the post-treatment for moisturizing effect is dried (S7), and then attached to the membrane module to prepare a membrane as shown in the example of FIG.

On the other hand, using the membrane prepared by the method for producing a membrane using the polymer compound for the MBR membrane production according to the present invention as described above was tested by applying to the MBR process system.

In other words, the MBR membrane according to the present invention and the membrane of another company was immersed in the same reactor and tested under the same operating conditions, Figure 5 is a comparison graph showing the permeate flow rate, Figure 6 is a comparison graph showing the operating differential pressure.

At this time, the active sludge concentration in the reaction vessel is 5,000 ~ 7,000mg / L and the operating conditions of the MBR process system is usually changed to intake / rest = 7 minutes / 3 minutes, but to intake / maintenance = 5 minutes / 1 minutes to reduce membrane contamination Drive.

As shown in Figure 5, the separation membrane according to the present invention is superior to the separation membrane of the other products in the overall permeate flow rate, it can be seen that the decrease in permeation flow rate due to membrane contamination is also significantly lower over time. have.

In addition, as the membrane fouling occurs more severely, the operation differential pressure is significantly increased. As shown in FIG. 6, the separation membrane according to the present invention has a significantly lower increase in the differential pressure than other products and lower the differential pressure under the same operating conditions as a whole. You can see it appear.

This indicates that the membrane prepared by the present invention has a higher membrane fouling resistance than the conventional membrane and can increase the permeate flow rate.

1 is a flow chart showing a method for producing a separator in the present invention.

Figure 2 is a flow chart showing a polymer solution manufacturing process in the membrane production method of the present invention.

Figure 3 is a SEM photograph showing an example of the membrane surface structure of the separator in the present invention.

Figure 4 is an exemplary view showing a module assembly state of the separator in the present invention.

Figure 5 is a comparison graph showing the permeate flow rate for the separator of the present invention.

Figure 6 is a comparison graph showing the operation differential pressure for the separator of the present invention.

Claims (5)

In the polymer compound for manufacturing a membrane for MBR, It is composed of polyvinylidene fluoride (PVDF), dimethyl formamide (DMF), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), methyl cellosolve (MC), Polymer compound for the production of membrane for MBR characterized in that it is used. The method of claim 1, The polymer compound is dimethyl formamide (DMF) 700 to 850 parts by weight, polyvinyl pyrrolidone (PVP) 110 to 140 parts by weight, polyethylene glycol (PEG) based on 100 to 130 parts by weight of polyvinylidene fluoride (PVDF) 110 to 140 parts by weight, methyl cellosolve (MC) A high molecular compound for the preparation of membranes for MBR, characterized in that the composition consists of 50 to 130 parts by weight. 700 to 850 parts by weight of dimethyl formamide (DMF), 110 to 140 parts by weight of polyvinyl pyrrolidone (PVP), and 110 to 140 parts by weight of polyethylene glycol (PEG) based on 100 to 130 parts by weight of polyvinylidene fluoride (PVDF) A first step of preparing and preparing a raw material with 50 to 130 parts by weight of methyl cellosolve (MC); Mixing and stirring the prepared raw materials to form a polymer solution; A third step of forming the polymer coating layer on the surface by applying the polymer solution to a nonwoven fabric for use as a support of the separator; A fourth step of forming a film by solidifying the polymer coating layer by immersing the nonwoven fabric having the polymer coating layer in a coagulation bath containing water at a temperature of 40 to 50 ° C .; A fifth step of removing and washing the solvent remaining in the film by immersing in water having a temperature condition of 40 ° C. to 50 ° C. after the film formation; A sixth step of immersing in an aqueous solution containing glycerin after the washing step to post-treat the glycerin in the solidified membrane to moisturize it; Separation membrane production method using a polymer compound for MBR membrane production, characterized in that it comprises a seventh step of drying after the post-treatment. The method of claim 3, wherein In the second step, polyvinylidene fluoride (PVDF) is added to dimethyl formamide (DMF) as a solvent, but the first step of stirring under heating conditions at 80 to 90 ° C; A second step of adding polyvinyl pyrrolidone (PVP) after the first step but stirring and stirring while removing heating conditions; After the second process, polyethylene glycol (PEG) and methyl cellosolve (MC) is added to form a polymer solution through a third process of stirring and mixing to prepare a membrane manufacturing method using a polymer compound for MBR membrane production . The method according to claim 3 or 4, The polymer solution is a membrane production method using a polymer compound for the MBR membrane production, characterized in that the manufacturing to maintain the viscosity of 400 ~ 1000cP.

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