KR100270175B1 - Membrane separation - Google Patents

Abstract

PURPOSE: A method for preventing concentration polarization resulting from membrane fouling is provided, which is accompanied by applying direct current between membranes while giving supersonic vibration to the membranes. CONSTITUTION: In the wastewater treatment using membranes such as micro filtration, ultrafiltration, nano filtration, and reverse osmosis, a membrane cell that is inserted with conductive plastic net or metal wire net is interposed between membranes, and direct current having a current density of 0.1 to 80Å/dm¬2 is applied. In addition, supersonic wave is applied to the membranes to membrane fouling.

Description

Membrane Separation Method

The present invention utilizes membrane separation techniques such as reverse osmosis membranes, nano membranes, ultrafiltration membranes, ultra-precision filtration membranes, and the like to reduce concentration polarization and clogging due to contaminants during the production of various industrial waters, separation and recovery of solutes, and various wastewater treatments. It is about how to prevent.

Membrane separation technology is a unit operation that pressurizes a liquid on a thin film to separate, purify, and concentrate solutes in a solution.

In order to purify various wastewater, economic and time loss such as biological and chemical treatment is inevitably accompanied by the increase in the size of treatment facilities, selection of appropriate chemicals and administration and special management by specialist management personnel, and the generation of slatch. Excessive burden on the situation.

Membrane separation technology is the most reliably separating the useful and harmful components in such waste water, so the separation material can be recycled or intensive treatment, and the treated effluent can be recycled to heavy water.

However, the membrane separation technology is important for the selection of membranes such as membrane type, pressure resistance, and chemical resistance, but the biggest difficulty is concentration polarization due to contamination of membranes with solid particles of ultra-fine particles such as dissolved solvents or alkali metals. Due to the increase in pressure and the amount of permeated water is reduced or the membrane is not at all, the replacement cycle of the membrane is short, so the practicality is not widely used.

To this end, membrane fouling prevention chemicals are added to the treated water or used after washing with caustic soda, tertiary soda, citric acid, sodium hypochlorite, phosphoric acid and hydrochloric acid.

This method again requires treatment of the wash water and complicated and cumbersome management, resulting in economic losses.

The decrease in the amount of permeation is caused by the concentration polarization of the membrane surface and the surface fouling of the membrane by hydraulic pressure.

Membrane contamination is due to physical and chemical factors such as alkaline metals, proteins, salts and fats that adhere to the membrane surface.

The present invention is a means for solving the problems as described above by inserting a conductive plastic mesh or metal mesh serving as a permeate passage between the membrane and the membrane to replace each other and the current density 0.1 ~ 80A in the network by the DC method Electrostatic vibration is applied to the treated water and the membrane in order to make the positive and negative electrodes interact with each other within the range of / dm2 and to increase the effect. The purpose is to maximize the efficiency of water and wastewater purification in various industries by obtaining more high quality permeate.

1 is a structure of a separator cell.

FIG. 2 is a layout of two membrane cells stacked and replaced.

3 is a plan view of a separator cell.

4 is an ultrasonic diaphragm.

5 is a composite diagram of the separator cell and the ultrasonic diaphragm.

6 is a membrane separation permeation efficiency comparison table.

<Explanation of symbols for main parts of drawing>

1: separator 2: conductive plastic net

3: permeate channel 4: polypropylene resin

5: 5 "cell squeezed board hole 6: treated water passage

7: ultrasonic vibrating plate 8: ultrasonic vibrator

9: insulator

Hereinafter, described in detail by the accompanying drawings as follows.

1 and 2 illustrate the structure of a separator cell and two stacked separators a and b, wherein a conductive plastic mesh or a metal mesh is inserted between the separator and the separator. When a permeate passage is made and electricity flows in the polarized manner so that positive and negative electrodes interact with each other within a range of current density of 0.1-80 A / dm 2 by direct current method a) Separation membrane cell b) An electric field is formed in the treated water between the membranes so that all substances in the water are electrophoresed toward the negative electrode (-) to prevent foreign substances from adhering to the membranes with the positive polarity. Make it smooth.

Figure 3 shows a) b) the plane of the separator cell (4) The polypropylene resin layer plays a role of mechanical strength and housing in securing the passage of treated water between the separator cell and the separator cell and stacking the separator. Denoted at 5 is a board hole for laminating and crushing a separator plate.

Fig. 4 shows an ultrasonic wave generating vibrator attached to a corrosion resistant (7) stainless steel plate as an ultrasonic wave generating plate and an ultrasonic wave generating vibrator on a corrosion resistant (7) stainless steel plate as an ultrasonic wave generating plate. It helps to break down the concentration polarization of the material by equalizing the material, acting to accelerate it even more effectively.

FIG. 5 illustrates a composite arrangement of the separator cell and the ultrasonic diaphragm. Referring to the embodiment in detail, (10) the treated water pump is sent to the treated water inlet at a pressure of 5 to 60 kg / cm 2. (5) receiving electrophoresis and ultrasonic vibration through the treated water passage of the separator cell (12) concentrated or separated at the outlet of the concentrated water and transported to a recycling or intensive post-treatment unit, and the permeate between the membrane and the separator (3 13) It flows out into the permeate passage (13) and is recycled or discharged into the heavy water through the permeate outlet.

FIG. 6 shows a comparison table indicating the amount of permeated water when the wastewater is passed through the separator in time.

As described above, in the membrane separation treatment technique, a conductive plastic net or metal net is inserted into the permeate passageway between the separator and the separator, and a DC voltage is applied to each other and an ultrasonic vibration is applied to the laminated separator plate. Reducing the burden of environmental preservation costs and minimizing the installation area by drastically improving the treatment of various industrial waters and the purification of wastewater by eliminating pollution and material concentration polarization, which are the biggest difficulties, It will also contribute to the recycling of resources and the conservation of the environment.

Claims (2)

In the treatment of industrial water and wastewater by separating membrane by reverse osmosis membrane, nano membrane, ultrafiltration membrane, precision filtration membrane, etc., the membrane cell in which conductive plastic or metal mesh is inserted into the permeate passageway between the membrane and the membrane is replaced or laminated. Membrane separation method to conduct electricity in a polar conversion method so that the positive and negative (+) interaction within the current density of 0.1 ~ 80A / ㎡ in a way. The membrane separation treatment method of claim 1, by applying ultrasonic vibration to the membrane and the treated water to homogenize the material of the treated water to prevent concentration polarization phenomenon and to prevent contamination of the membrane.