JP7181732B2 - Wastewater treatment equipment and wastewater treatment method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wastewater treatment apparatus and a wastewater treatment method.

Conventionally, a membrane separation activated sludge method that treats wastewater using a microfiltration membrane (MF (Microfiltration) membrane) or an ultrafiltration membrane (UF (Ultrafiltration) membrane) is known as a wastewater treatment method (for example, patent References 1 to 3.). In the membrane separation activated sludge method, there are usually a separation and removal process for separating and removing relatively large contaminants contained in wastewater, a precipitation process for precipitating relatively heavy contaminants among the contaminants that were not removed in the separation and removal process, a separation A biological treatment process in which contaminants that have not been removed in the removal process and the precipitation process are removed by microorganisms, and a membrane filtration process in which wastewater from which most of the contaminants have been removed after the biological treatment process is filtered with an MF membrane or a UF membrane is performed. and the treated wastewater after each step is discharged to a river or the like.

By the way, in the membrane filtration process, fouling may occur in which contaminants adhere to the surface of the MF membrane or UF membrane for filtering waste water. Correspondingly, an air diffuser is arranged near the MF membrane and the UF membrane, and a large amount of air bubbles are aerated to the MF membrane and the UF membrane from the air diffuser, thereby preventing fouling of the MF membrane and the UF membrane. It is

JP-A-62-180704 JP-A-7-185269 JP-A-10-015573

However, in the membrane filtration process, a large amount of power is consumed when a large amount of air bubbles are aerated to the MF membrane or the UF membrane, and reduction of power consumption is demanded. If the membrane filtration process is not performed, the power consumption will be reduced, but simple and rapid wastewater treatment will be impaired. Further, in recent years, there has been a demand for further speeding up of wastewater treatment by using membranes other than MF membranes and UF membranes and not performing the biological treatment process. As a result, contaminants removed by microorganisms must also be removed in the membrane filtration process, and fouling of membranes used in wastewater treatment becomes even more serious. As a result, fouling of membranes used for wastewater treatment may not be prevented. In this case, it is necessary to maintain the membrane itself used for wastewater treatment, but there is a problem that maintenance cannot be easily performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wastewater treatment apparatus and a wastewater treatment method that allow easy maintenance of the membrane itself used for wastewater treatment.

In order to achieve the above object, the wastewater treatment apparatus of the present invention is disposed between wastewater containing contaminants, soluble substances, and water, and a driving solution containing water and other than the wastewater, and a first membrane that removes the contaminants and soluble substances from the waste water and transfers water contained in the waste water to the driving solution when the pressure received is higher than the pressure received from the driving solution; A first membrane comprising: a first supply means for supplying the driving solution to the membrane; and a first water collecting means for collecting water transferred from the supplied driving solution and the waste water to the driving solution. When the element is disposed between an element, waste water containing contaminants, dissolved substances, and water, and a driving solution containing water and other than the waste water, and the pressure received from the waste water is higher than the pressure received from the driving solution a second membrane for removing the contaminants and soluble substances from the waste water and transferring water contained in the waste water to the driving solution; and second supply means for supplying the driving solution to the second membrane . and a second water collection means for collecting moisture transferred from the supplied driving solution and the waste water to the driving solution, wherein the first membrane and the The second membrane is characterized by comprising a plurality of regions each separable.

In order to achieve the above object, the wastewater treatment method of the present invention is disposed between wastewater containing contaminants, soluble substances and water, and a driving solution containing water and other than the wastewater, wherein a first membrane that removes the contaminants and soluble substances from the waste water and transfers water contained in the waste water to the driving solution when the pressure received is higher than the pressure received from the driving solution; A first membrane comprising: a first supply means for supplying the driving solution to the membrane; and a first water collecting means for collecting water transferred from the supplied driving solution and the waste water to the driving solution. When the element is disposed between an element, waste water containing contaminants, dissolved substances, and water, and a driving solution containing water and other than the waste water, and the pressure received from the waste water is higher than the pressure received from the driving solution a second membrane for removing the contaminants and soluble substances from the waste water and transferring water contained in the waste water to the driving solution; and second supply means for supplying the driving solution to the second membrane . and a second water collection means for collecting moisture transferred from the supplied driving solution and the waste water to the driving solution, wherein the first membrane and the In the wastewater treatment method performed by the wastewater treatment apparatus, wherein the second membrane is composed of a plurality of separable regions, the driving solution is supplied from the first supply means and the second supply means to the first a feeding step of supplying to the membrane and the second membrane , and the first membrane and the second membrane remove the contaminants from the waste water, and the moisture contained in the waste water is removed from the first membrane and the second membrane; a filtration step of permeating a second membrane and moving to the driving solution; and a water step.

According to the present invention, the membrane itself used for wastewater treatment can be easily maintained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows roughly the membrane element with which the waste water treatment apparatus which concerns on the 1st Embodiment of this invention is provided. 2 is a diagram schematically showing a state in which the membrane element of FIG. 1 can be split; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows roughly the structure of the membrane module with which the waste water treatment apparatus which concerns on the 1st Embodiment of this invention is provided. FIG. 4 schematically shows a modification of the membrane module of FIG. 3; BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows roughly the waste water treatment apparatus which concerns on the 1st Embodiment of this invention. It is the front view which looked at the waste water treatment apparatus of FIG. 5 from the left direction. FIG. 4 is a diagram schematically showing a membrane element included in a wastewater treatment apparatus according to a second embodiment of the invention; FIG. 8 is a side view schematically showing a waste water treatment apparatus provided with the FO membrane of FIG. 7; It is a figure which shows roughly the modification of the waste water treatment apparatus of FIG. It is a figure which shows roughly the modification of the waste water treatment apparatus of FIG. It is a vertical cross-sectional view schematically showing a waste water treatment apparatus according to a third embodiment of the present invention. FIG. 12 is a top view of the waste water treatment apparatus of FIG. 11; FIG. 12 is a cross-sectional view of the waste water treatment apparatus of FIG. 11 taken along line AA.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a membrane element provided in a wastewater treatment apparatus according to a first embodiment of the invention.

The membrane element of FIG. 1 includes a forward osmosis membrane 1 (hereinafter referred to as "FO (Forward Osmosis) membrane 1"). Two types of solutions with different solute concentrations come into contact with the FO membrane 1, and based on the forward osmosis action in which the low-concentration solvent moves to the high-concentration side solution, the FO membrane 1 absorbs impurities and soluble substances in the wastewater. to remove At this time, if an MF membrane, a UF membrane or an RO (Reverse Osmosis) membrane is used instead of the FO membrane 1 as the semipermeable membrane, the MF membrane, UF membrane or RO membrane can be used to remove contaminants and soluble substances from the waste water. However, if the FO membrane 1 is used, there is no need to apply such pressure. Therefore, the FO membrane 1 is superior to the MF membrane, UF membrane and RO membrane in terms of energy efficiency.

In the present embodiment, the FO membrane 1 is immersed in waste water (supply solution), and a drive solution (DS (Draw Solution)) such as seawater is passed through a channel formed inside the FO membrane 1 . Since the driving solution has a higher solute concentration than the waste water, the pressure received by the FO membrane 1 from the waste water is higher than the pressure received from the driving solution. 1 inside the driving solution, contaminants and dissolved substances remain on the surface of the FO membrane 1 on the drain side. After that, the water that permeates the FO membrane 1 flows out from the flow path formed inside the FO membrane 1 together with the driving solution, and is discharged from the wastewater treatment apparatus.

The membrane element of FIG. 1 is composed of a disk-shaped FO membrane 1 (removal means), a fixed boss 3, a supply pipe 4 (supply means) and a water collection pipe 5 (water collection means). The pipe 4 and the water collection pipe 5 are integrated to form a retainer for attaching the FO membrane 1 .

In FIG. 1, the supply pipe 4 extends from the driving solution passing portion 32 of the fixed boss 3 toward the outer peripheral portion of the FO membrane 1, and on both sides of the supply pipe 4, there are many holes for supplying the driving solution to the FO membrane 1. (supply hole) is provided. In addition, the water collecting pipe 5 extends from the mixed liquid passing portion 33 of the fixed boss 3 toward the outer peripheral portion of the FO membrane 1, and on both sides of the water collecting pipe 5 is a mixed solution ( hereinafter simply referred to as "mixed liquid") are provided with a large number of holes (water collecting holes) for collecting water.

In FIG. 1, the driving solution flows into the supply pipe 4 from the driving solution passing portion 32 of the fixed boss 3, and then flows formed inside the FO membrane 1 through a large number of holes provided on both sides of the supply pipe 4. flow into the road. At this time, since the FO membrane 1 is immersed in the waste water, the pressure that the FO membrane 1 receives from the waste water is higher than the pressure that the FO membrane 1 receives from the iso-driving solution, and water in the waste water permeates into the FO membrane 1 . The permeated water is mixed with the driving solution and flows through the channel inside the FO membrane 1 toward the water collecting pipe 5 . Subsequently, the mixed liquid flows into the water collecting pipe 5 through a large number of holes on both sides of the water collecting pipe 5 and then collected from the water collecting pipe 5 to the mixed liquid passing portion 33 of the fixed boss 3 . As described above, the FO membrane 1 is provided with the supply pipe 4 having a plurality of supply holes and the water collection pipe 5 having a plurality of water collection holes, whereby the driving solution is efficiently supplied to the FO membrane 1 and effective membrane separation is performed. It can be performed.

The FO membrane 1 used in the present invention has a channel through which the driving solution flows. be able to.

FIG. 2 is a diagram schematically showing a state in which the membrane element of FIG. 1 can be split.

The membrane element has a complicated structure in which a retainer composed of a fixed boss 3, a supply pipe 4 and a collection pipe 5 holds the FO membrane. A structure that can be divided into a plurality of FO membrane members that form the area surrounded by the water pipes 5 and that can be attached to and detached from the retainer can be employed. Such a structure can improve maintainability of the FO membrane element. The divided FO membrane member may have a fan shape, an isosceles triangle shape, or the like. By using a plurality of FO membrane members having the same shape, a disk-shaped or regular polygonal FO membrane can be formed.

FIG. 3 is a cross-sectional view schematically showing the structure of a membrane module provided in the wastewater treatment apparatus according to the first embodiment of the invention.

The membrane module of FIG. 3 includes a first membrane element E1, a second membrane element E2, a rotating shaft 2, and a fixed boss 3. The first membrane element E<b>1 and the second membrane element E<b>2 are fixed to the rotating shaft 2 by fixing bosses 3 . The rotating shaft 2 is attached to a waste water treatment tank filled with waste water by bearings 6 provided at both ends in such a state that the module is submerged. A supply unit 30 for supplying the driving solution to the supply pipe 4 is provided at the right end inside the rotating shaft 2 , and the supply unit 30 is connected to the swivel joint 9 . A water collecting portion 31 for collecting the mixed liquid collected from the water collecting pipe 5 is provided at the left end portion inside the rotating shaft 2 , and the water collecting portion 31 is connected to the swivel joint 9 . The inside of the fixed boss 3 is divided into a driving solution passing portion 32 through which the driving solution supplied from the supply portion 30 passes, and a mixed solution passing portion 33 through which a mixed solution of moisture and the driving solution that permeates the FO membrane passes. ing.

In FIG. 3, the driving solution passes through the swivel joint 9 on the right side of the rotating shaft 2, then passes through the supply part 30 and the driving solution passing part 32 in sequence and is supplied to the supply pipe 4. As shown in FIG. Further, the liquid mixture collected in the water collecting pipe 5 passes through the liquid mixture passing portion 33 and the water collecting portion 31 in order, passes through the swivel joint 9, and is discharged to the outside of the membrane module. The membrane module having such a configuration is connected to the driving device 7 and rotated around the rotating shaft 2 by driving the driving device 7 . The interval between adjacent membrane elements can be appropriately set in consideration of the membrane separation efficiency of the FO membrane 1 and the removal efficiency of fouling substances on the FO membrane surface.

4 is a diagram schematically showing a modification of the membrane module of FIG. 3. FIG.

The membrane module shown in FIG. 4 has basically the same structure and operation as the membrane module shown in FIG. It differs from the membrane module in FIG. 3 in that it is fixed in place. By adopting the configuration of FIG. 4, a membrane module in which a plurality of membrane elements are firmly fixed can be produced, and the durability of the wastewater treatment apparatus itself can be enhanced.

FIG. 5 is a side view schematically showing the waste water treatment apparatus according to the first embodiment of the invention.

The wastewater treatment apparatus of FIG. 5 comprises a first membrane module 10a, a second membrane module 10b and a third membrane module 10c. It is composed of a rotating shaft 2 to be fixed. A plurality of FO membranes 1 constituting one membrane module are installed so as to alternately overlap the FO membranes 1 constituting adjacent membrane modules.

Specifically, the first membrane module 10a includes an FO membrane 1a (first removing means), a first rotating shaft 2a for fixing the FO membrane 1a, and a first rotating shaft 2a separated from the FO membrane 1a. It has an FO membrane 1aa (second removing means) fixed to 2a and other FO membranes, and rotates around a first rotation axis 2a. The second membrane module 10b includes an FO membrane 1b (third removing means), a second rotating shaft 2b for fixing the FO membrane 1b, and a second rotating shaft 2b separated from the FO membrane 1b. Other FO membranes are fixed and rotate around a second rotation axis 2b. The FO membrane 1b constituting the second membrane module 10b is installed so as to be interposed between the FO membranes 1a and 1aa constituting the first membrane module 10a.

By immersing the wastewater treatment apparatus in FIG. 5 in wastewater and slowly rotating the membrane modules 10a to 10c, a shear flow is generated in the vicinity of the FO membrane surface, and the fouling substances accumulated on the surface of the FO membrane are effectively removed. can be removed.

6 is a front view of the waste water treatment apparatus of FIG. 5 viewed from the left.

The rotation direction of the membrane modules is not particularly limited, and the rotation directions of the adjacent membrane modules may be the same or opposite, but the first membrane module 10a and the third membrane module 10c is preferably the same as the direction in which the adjacent second membrane module 10b rotates. With such a configuration, a shear flow can be generated more efficiently in the vicinity of the FO membrane surface, and fouling substances accumulated on the surface of the FO membrane can be more effectively removed.

Wiper mechanisms (cleaning means) such as brushes, sponges and rubber plates can be provided on the surfaces of the supply pipe 4 and the water collection pipe 5 provided in the membrane element (FIGS. 1 and 3). By providing this wiper mechanism, fouling substances accumulated on the surface of the FO membrane facing the membrane element provided with the wiper mechanism can be effectively removed when the membrane element rotates. For example, in the waste water treatment apparatus of FIG. 5 , a wiper mechanism is provided on the surface of the supply pipe 4 and/or the water collection pipe 5 provided on the FO membrane 1a or the FO membrane 1aa to rotate the membrane element so that the adjacent FO membrane 1b can efficiently remove the fouling material accumulated on the surface of the In addition, by providing a wiper mechanism on the surface of the supply pipe 4 and/or the water collection pipe 5 provided on the FO membrane 1b and rotating the membrane element, the fouling substances accumulated on the surface of the adjacent FO membrane 1a or FO membrane 1aa can be removed. can be efficiently removed. Also, another cleaning means for cleaning the wiper mechanism (cleaning means) can be provided on the opposing membrane element. Furthermore, a baffle plate may be provided near the FO film 1 . Thereby, a shear flow can be more efficiently generated around the FO membrane.

Since the FO membrane 1 has channels formed therein, it may expand or contract due to the pressure and osmotic pressure of the driving solution. In order to prevent this, a support member (reinforcing means) can be provided inside or outside the FO membrane 1 . When a support material is provided inside the FO membrane 1, for example, a porous body made of a resin such as polyester or a non-woven fabric is used as the support material, and the FO membrane 1 is laminated on the surface of the support material to form a laminated structure. can be done. Further, when a support material is provided outside the FO membrane 1 , a mesh made of resin such as nylon or polyethylene can be provided on the surface of the FO membrane 1 . By providing such a support (reinforcing means), expansion or contraction of the FO membrane 1 can be prevented and sufficient strength can be imparted to the FO membrane 1, whereby stable wastewater treatment can be performed.

When reinforcing means such as a net is provided outside the FO membrane, cleaning means such as fine bristles can be further provided on the surface of the reinforcing means. With such a configuration, the cleaning means such as fine hairs provided on the reinforcing means exhibits a cleaning function when the membrane element rotates, so that the fouling substances accumulated on the facing surface of the FO membrane 1 can be removed more efficiently. be able to.

Next, a wastewater treatment method performed by the wastewater treatment apparatus according to the first embodiment of the present invention will be described.

As described above, the wastewater treatment apparatus according to the first embodiment of the present invention includes multiple membrane elements. Each membrane element consists of an FO membrane 1, a fixed boss 3, a supply pipe 4 and a water collection pipe 5 (Fig. 1). ). A supply unit 30 for supplying the driving solution to the supply pipe 4 is provided at the right end inside the rotating shaft 2, and a water collection unit 31 for collecting the mixed liquid collected from the water collection pipe 5 is provided at the left end. is provided (Fig. 3). The inside of the fixed boss 3 is divided into a driving solution passing portion 32 through which the driving solution supplied from the supply portion 30 passes, and a mixed solution passing portion 33 through which a mixed solution of moisture and the driving solution that permeates the FO membrane passes. (Fig. 3).

The driving solution flows through the supply part 30 into the driving solution passage part 32 and is then supplied to the supply pipe 4 (FIG. 3). After that, the driving solution is supplied to the channel formed inside the FO membrane 1 through a number of holes provided on both sides of the supply pipe 4 (supply step) (FIG. 1). At this time, since the FO membrane 1 is immersed in the waste water, the pressure received by the FO membrane 1 from the waste water is higher than the pressure received from the driving solution. As a result, water contained in the waste water permeates the FO membrane 1 and moves to the driving solution, and contaminants and soluble substances in the waste water are removed by the FO membrane 1 (filtration step). Then, the water that has permeated the FO membrane 1 is mixed with the driving solution and flows through the flow path inside the FO membrane 1 toward the water collecting pipe 5 . The mixture of water and driving solution that has permeated the FO membrane 1 flows into the water collecting pipe 5 through a large number of holes on both sides of the water collecting pipe 5 ( FIG. and discharged from the wastewater treatment equipment (collection step) (Fig. 3).

That is, according to the present embodiment, if the driving solution (DS) is supplied to the supply pipe 4 (supply means) adjacent to the FO membrane 1, the supply step, the filtration step and the water collection step can be performed without applying a strong pressure. As the process progresses, contaminants and soluble substances are removed from the waste water, and the water content in the waste water can be easily transferred to the driving solution side, so membrane separation with high energy efficiency can be performed. In addition, since the FO membrane 1 can be divided into a plurality of FO membrane members forming the area surrounded by the supply pipe 4 and the water collection pipe 5, the FO membrane 1 itself used for wastewater treatment can be easily maintained. can. Note that the sewage treatment method according to the present embodiment can be continuously performed for a long period of time by dividing the membrane element and performing maintenance on a regular basis.

Next, a second embodiment of the invention will be described. In the second embodiment of the present invention, a waste water treatment apparatus using FO membranes 11a and 11b having basically the same function as the FO membrane 1 described in the first embodiment will be described.

FIG. 7 is a diagram schematically showing a membrane element provided in a wastewater treatment apparatus according to a second embodiment of the invention.

The membrane elements in FIG. 7 are a membrane element E1 (first membrane element) having an FO membrane 11a and a membrane element E2 (second membrane element) having an FO membrane 11b. It is a configuration that can be divided into two. A supply pipe 14 (supply means) into which the driving solution flows is provided at one end of the FO membranes 11a and 11b in the horizontal direction. is provided. At the other lateral end of the FO membranes 11a and 11b, a water collection pipe 15 (water collection means) is provided for collecting a mixture of the water permeating the FO membranes 11a and 11b and the driving solution. The water tube 15 is provided with a large number of holes (water collection holes) in the portion in contact with the FO membranes 11a and 11b.

In FIG. 7, the driving solution is supplied to the supply pipe 14, and then flows into the channels formed inside the FO membranes 11a and 11b through a large number of supply holes of the supply pipe 14. In FIG. At this time, since the FO membranes 11a and 11b are immersed in the waste water, the pressure received by the FO membranes from the waste water is higher than the pressure received from the driving solution, and only water in the waste water penetrates into the FO membranes 11a and 11b. Contaminants and dissolved substances remain on the surface of the FO membranes 11a and 11b on the drain side. The moisture permeated through the FO membranes 11a and 11b and the driving solution are mixed and flow toward the water collecting pipe 15 through the channels inside the FO membranes 11a and 11b. After that, the liquid mixture collected from the many water collection holes of the water collection pipe 15 moves inside the water collection pipe 15 and is discharged from the waste water treatment tank. As described above, the FO membranes 11a and 11b are provided with the supply pipe 14 having a plurality of supply holes and the water collection pipe 15 having a plurality of water collection holes, thereby efficiently supplying the driving solution to the FO membranes 11a and 11b. effective membrane separation.

FIG. 8 is a side view schematically showing a waste water treatment apparatus provided with the FO membranes 11a and 11b of FIG.

In the wastewater treatment apparatus of FIG. 8, upper and lower ends of a plurality of membrane elements are fixed to a crank 12 (displacement means), and membrane elements E1 and E2 are alternately arranged at regular intervals. The crank 12 has a base shaft portion and an uneven portion, the membrane element E2 is fixed to the base shaft portion, and the membrane element E1 is fixed to the uneven portion. The crank 12 is connected to a driving device 7, and by driving the driving device 7 to rotate the crank shaft, the membrane element E1 moves up and down at a constant cycle while the membrane element E2 remains fixed. As a result, the FO film 11a (first removing means) is displaced with respect to the FO film 11b (second removing means). A cam mechanism may be used instead of the crank mechanism 12 to move the FO film 11a. Furthermore, although only the membrane element E1 is vertically moved in FIG. 8, the membrane element E2 may be vertically moved at the same time by changing the shape of the crank.

By displacing the FO membrane 11a relative to the FO membrane 11b, a shear flow can be generated in the vicinity of the surfaces of the FO membranes 11a and 11b, and the fouling substances accumulated on the surface of the FO membrane can be effectively removed. can be effectively removed.

Next, the wastewater treatment method performed by the wastewater treatment apparatus according to this embodiment will be described.

As described above, in the wastewater treatment apparatus (FIG. 8) according to this embodiment, a plurality of membrane elements E1 and E2 are alternately arranged at regular intervals. Each membrane element E1, E2 is composed of three separable FO membranes, and a supply pipe 14 and a water collection pipe 15 are provided at both ends of each FO membrane 11a, 11b (FIG. 7). The upper and lower ends of each membrane element E1, E2 are fixed to a crank 12 (displacement means), and the crank 12 is connected to the driving device 7. As shown in FIG.

When the driving device 7 drives and the crank 12 rotates, the membrane element E1 moves up and down while the membrane element E2 remains fixed. On the other hand, the driving solution was supplied to the supply pipe 14 provided in each membrane element E1, E2, and then the driving solution was formed inside the FO membranes 11a, 11b through a large number of holes (supply holes) of the supply pipe 14. It is supplied to the channel (supply step). At this time, since the FO membranes 11a and 11b are immersed in the waste water, the pressure that the FO membranes receive from the waste water is higher than the pressure that the DS receives from the waste water. and the waste water is freed of contaminants and dissolved substances (filtration step). Subsequently, the water that permeates the FO membranes 11a and 11b is mixed with the driving solution, and flows through the flow path inside the FO membrane 1 toward the water collecting pipe 15 (water collecting means). After that, the liquid mixture collected from a large number of holes (collection holes) of the water collection pipe 15 moves inside the water collection pipe 15 provided in each of the membrane elements E1 and E2, and is discharged from the wastewater treatment equipment (water collection step).

That is, according to the present embodiment, if the driving solution is supplied to the supply pipes 14 provided in the FO membranes 11a and 11b of the membrane elements E1 and E2, the supply step and filtration can be performed without applying a strong pressure. As the step and the water collection step proceed to remove contaminants and soluble substances from the waste water, and water in the waste water can be easily transferred to the driving solution side, membrane separation with high energy efficiency can be performed. . Moreover, since the membrane elements E1 and E2 can be divided into a plurality of FO membranes 11a and 11b, respectively, maintenance of the FO membrane 1 itself used for wastewater treatment can be easily performed. By dividing the membrane elements E1 and E2 and maintaining them periodically, the waste water treatment method according to the present embodiment can be performed continuously for a long period of time.

FIG. 9 is a diagram schematically showing a modification of the wastewater treatment apparatus of FIG.

The wastewater treatment apparatus of FIG. 9 is basically the same in construction and operation as the wastewater treatment apparatus of FIG. 13 (vibrating means), which is different from the wastewater treatment apparatus of FIG.

In FIG. 9, by fixing the lower end portion of the membrane element E1 to the elastic member 13 (vibrating means), when the clamp shaft is rotated to move the membrane element E1 up and down, the lower end portion of the membrane element E1 is in a state of wastewater treatment. Since the FO membrane 11a is appropriately fixed to the bottom of the bath, the degree of freedom of displacement of the FO membrane 11a with respect to the FO membrane 11b can be increased. The elastic member 13 is made of resin, metal, or the like, which has corrosion resistance against drainage water. be.

FIG. 10 is a diagram schematically showing a modification of the waste water treatment apparatus of FIG. 9;

The wastewater treatment apparatus of FIG. 10 has basically the same configuration and operation as the wastewater treatment apparatus of FIG. It is different from the wastewater treatment apparatus in FIG. 9 in that it is connected.

Specifically, in the wastewater treatment apparatus of FIG. 10, the membrane element E2 is fixed, the upper end of the membrane element E1 is fixed to a linear fixing member, and the lower end is fixed to the bottom of the wastewater treatment tank. It is configured to be fixed to an elastic member (vibrating means) such as a spring. By vibrating the fixing member at a predetermined frequency using the vibrator 8, the FO film 11a can be vibrated and displaced with respect to the FO film 11b at a constant period. The waste water treatment apparatus of FIG. 10 has a smaller amplitude of vibration of the FO membrane 11a than the waste water treatment apparatus of FIGS. can do.

In FIG. 10, the vibrating direction of the membrane element E1 is not limited to the vertical direction, but may be the lateral direction or the circular arc direction in which the FO membranes are kept facing each other. has the effect of removing The vibration direction of the membrane element E1 can be set by adjusting the vibrating direction of the fixing member that fixes the upper end of the membrane element E1. Mechanism can be selected.

The FO membranes 11a and 11b used in this embodiment have the cleaning means and reinforcing means described for the FO membrane 1 according to the first embodiment of the present invention, and the same cleaning means as the cleaning means provided in the reinforcing means. measures can be applied. For example, wiper mechanisms (cleaning means) such as brushes, sponges, and rubber plates can be provided laterally at the upper and/or lower ends of the multistage FO membranes 11a and 11b. By using such a cleaning means, when the FO membrane 11a is displaced with respect to the FO membrane 11b, it is possible to effectively remove fouling substances accumulated on the surface of the opposing FO membrane. Also, another cleaning means for cleaning the wiper mechanism (cleaning means) can be provided on the opposing membrane element. Furthermore, a baffle plate may be provided in the vicinity of the FO films 11a and 11b. Thereby, a shear flow can be generated more efficiently around the FO films 11a and 11b.

Further, in the present embodiment, a support member (reinforcing means) can be provided inside or outside the FO membranes 11a and 11b. When a support material is provided inside the FO membranes 11a and 11b, for example, a porous material made of a resin such as polyester or a non-woven fabric is used as the support material, and the FO membranes 11a and 11b are laminated on the surface of the support material. can be a structure. Further, when a support material is provided outside the FO membranes 11a and 11b, a mesh made of resin such as nylon or polyethylene can be placed on the surface of the FO membranes 11a and 11b. By providing such a support member (reinforcing means), expansion of the FO membranes 11a and 11b can be prevented and sufficient strength can be imparted to the FO membranes.

When reinforcing means such as a net is provided outside the FO membrane, cleaning means such as fine bristles can be further provided on the surface of the reinforcing means. With such a configuration, the cleaning means such as fine hairs provided on the reinforcing means exhibits a cleaning function when the FO membrane is displaced, so that the fouling substances accumulated on the facing surface of the FO membrane can be removed more efficiently. can be done.

In addition, the FO membranes 11a and 11b are arranged in the direction in which the mixture of the water and the driving solution permeating the FO membrane 11a passes through the channel formed inside the FO membrane 11a, and in the direction in which the water and the driving solution permeating the FO membrane 11b pass. It is preferable that the liquid mixture is installed in a direction opposite to the direction in which the mixed liquid passes through the channel formed inside the FO membrane 11b. When water in the wastewater permeates the FO membranes 11a and 11b, the osmotic pressure of the FO membranes 11a and 11b may cause some of the FO membranes 11a and 11b to expand or contract. 11b as a whole can be suppressed from being deformed.

Next, a third embodiment of the invention will be described. In the third embodiment of the present invention, a wastewater treatment apparatus using the FO membranes 11a and 11b (FIG. 7) described in the second embodiment, which is the wastewater treatment apparatus described in the second embodiment. A waste water treatment apparatus having a different configuration will be described.

FIG. 11 is a longitudinal sectional view schematically showing a waste water treatment apparatus according to a third embodiment of the invention.

The wastewater treatment apparatus shown in FIG. 11 includes a vibrating frame 16 (first fixing means) capable of vibrating vertically and a fixing frame 17 (second fixing means) fixed to the wastewater treatment tank. A plurality of membrane elements E1 are fixed to the vibrating frame 16 at regular intervals, and a plurality of membrane elements E2 are fixed to the fixed frame 17 at regular intervals. The upper end of the vibrating frame 16 is connected to a cam mechanism 18 (displacement means), and the vibrating frame 16 is connected to a fixed frame 17 by elastic members such as springs and rubber. When the vibrating frame 16 is connected to the fixed frame 17, the membrane elements E1 and E2 are alternately arranged at regular intervals, and the vibrating frame 16, the fixed frame 17, and the FO membranes 11a and 11b are connected to the waste water in the waste water treatment tank. being immersed. Each membrane element E1, E2 is composed of three separable FO membranes 11a, 11b.

12 is a top view of the wastewater treatment apparatus of FIG. 11. FIG.

In FIG. 12, the vibrating frame 16 is installed so as to fit inside the fixed frame 17 . The cam mechanism 18 is connected to the driving device 7, and when the driving device 7 is driven, the cam mechanism 18 rotates. As a result, the vibrating frame 16 moves vertically at a constant cycle, and the vibrating frame 16 is displaced with respect to the fixed frame 17 at a constant cycle. As a result, the adjacent FO film 11a vibrates relative to the FO film 11b. With such a configuration, a shear flow is generated in the vicinity of the surfaces of the FO membranes 11a and 11b, and fouling substances accumulated on the surfaces of the FO membranes 11a and 11b can be effectively removed. Note that a crank mechanism or various vibrators may be used instead of the cam mechanism 18 to vibrate the vibrating frame 16 .

13 is a cross-sectional view of the waste water treatment apparatus of FIG. 11 taken along line AA.

Each of the vibrating frame 16 and the fixed frame 17 has a supply port for supplying the driving solution to the flow path formed inside the FO membranes 11a and 11b, and a mixed liquid of the moisture and the driving solution that permeates the FO membranes 11a and 11b. A water collection port is provided to collect water. 7, a supply pipe 14 for supplying a driving solution (DS) to the FO membranes 11a and 11b is provided at one end of the FO membranes 11a and 11b in the horizontal direction. , 11b are provided with a number of holes (supply holes) for supplying the driving solution. Further, at the other lateral end of the FO membranes 11a and 11b, a water collecting pipe 15 (water collecting means) for collecting a mixture of the driving solution and the moisture permeating the FO membranes 11a and 11b is provided. is provided with a large number of holes (collection holes) for collecting the mixed liquid from the FO membrane.

Next, the wastewater treatment method performed by the wastewater treatment apparatus according to this embodiment will be described.

A wastewater treatment apparatus (FIGS. 11 to 13) according to the present embodiment includes a vibrating frame 16, a fixed frame 17 and a cam mechanism 18, and a plurality of membrane elements E1 and E2 are installed at regular intervals on each frame. . Each membrane element E1, E2 is composed of three separable FO membranes 11a, 11b, and a supply pipe 14 and a water collection pipe 15 are provided at both ends of each FO membrane 11a, 11b (FIG. 7). Further, the membrane elements E1 and E2 are immersed in waste water, and the driving device 7 is connected to the cam mechanism 18 .

When the driving device 7 drives and the cam mechanism 18 rotates, the vibration frame 16 moves up and down while the fixed frame 17 remains fixed (FIG. 11). On the other hand, the driving solution is supplied to the vibrating frame 16 and the fixed frame 17 (FIG. 13), is supplied to the supply pipe 14 provided in each membrane element E1, E2, and then the driving solution is supplied to the supply pipe 14 through a number of holes ( (supply hole) to flow paths formed inside the FO membranes 11a and 11b (supply step). At this time, since the FO membranes 11a and 11b are immersed in the waste water, the pressure received by the FO membranes 11a and 11b from the waste water is higher than the pressure received from the driving solution, and water contained in the waste water permeates the FO membranes 11a and 11b. and the effluent is freed of contaminants and solubles (filtration step). Next, the water that has permeated the FO membranes 11a and 11b is mixed with the driving solution and collected in the water collecting pipe 15 through the channels inside the FO membranes 11a and 11b. After that, the liquid mixture collected from a large number of holes (collection holes) of the water collection pipe 15 moves inside the water collection pipe 15 provided in each of the membrane elements E1 and E2, and is discharged from the wastewater treatment equipment (water collection step).

That is, according to the present embodiment, if the driving solution is supplied to the supply pipe 14 provided in the FO membranes 11a and 11b, the supply step, the filtration step, and the water collection step proceed without applying a strong pressure, Since contaminants and soluble substances can be removed from the wastewater, and water in the wastewater can be easily transferred to the driving solution side, membrane separation with high energy efficiency can be performed. In addition, since the membrane elements E1 and E2 can be divided into a plurality of FO membranes 11a and 11b, the FO membranes 11a and 11b themselves used for wastewater treatment can be easily replaced and the membrane elements E1 and E2 can be maintained. can. By dividing the membrane elements E1 and E2 and maintaining them periodically, the waste water treatment method according to the present embodiment can be performed continuously for a long period of time.

The driving solution may be supplied to the supply pipes 14 provided in the FO membranes 11a and 11b by supply means independent of the vibrating frame 16 and fixed frame 17. FIG. Alternatively, the mixed liquid may be discharged from the water collecting pipe 15 provided in the FO membrane by means of outflow means independent of the vibrating frame 16 and the fixed frame 17 .

In addition, the FO membranes 11a and 11b are arranged in the direction in which the mixture of the water and the driving solution permeating the FO membrane 11a passes through the channel formed inside the FO membrane 11a, and in the direction in which the water and the driving solution permeating the FO membrane 11b pass. It is preferable that the liquid mixture is installed in a direction opposite to the direction in which the mixed liquid passes through the channel formed inside the FO membrane 11b. When water in the wastewater permeates the FO membranes 11a and 11b, the osmotic pressure of the FO membranes 11a and 11b may cause some of the FO membranes 11a and 11b to expand or contract. 11b as a whole can be suppressed from being deformed.

For the FO membrane used in this embodiment, the cleaning means and reinforcing means described for the disk-shaped FO membrane according to the first embodiment of the present invention, and further the cleaning means provided for the reinforcing means may be applied. can be done. For example, by providing a wiper mechanism (cleaning means) such as a brush in the lateral direction of the upper end and/or the lower end of each of the multistage FO membranes, the vibrating frame 16 is moved up and down to relatively displace the FO membranes. It is possible to effectively remove the fouling substances on the surfaces of the FO membranes facing each other. Also, another cleaning means for cleaning the wiper mechanism (cleaning means) can be provided on the opposing membrane element. Furthermore, a baffle plate may be provided in the vicinity of the FO films 11a and 11b. Thereby, a shear flow can be more efficiently generated around the FO membrane.

Further, in the present embodiment, in order to prevent expansion of the FO membranes 11a and 11b and to impart sufficient strength to the FO membranes 11a and 11b, support materials (reinforcing means) are provided inside or outside the FO membranes 11a and 11b. can be provided. When a support material is provided inside the FO membranes 11a and 11b, for example, a porous material made of a resin such as polyester or a non-woven fabric is used as the support material, and the FO membranes 11a and 11b are laminated on the surface of the support material. can be a structure. Further, when a support member is provided outside the FO membranes 11a and 11b, a mesh made of resin such as nylon or polyethylene can be installed on the surface of the FO membranes. When reinforcing means such as nets are provided outside the FO membranes 11a and 11b, cleaning means such as fine bristles may be further provided on the surface of the reinforcing means. Therefore, the fouling substances accumulated on the surfaces of the facing FO films 11a and 11b can be removed more efficiently.

Further, when the vibrating frame 16 is connected to the fixed frame 17 by a stretchable member, the power required to rotate the cam mechanism 18 can be minimized by adjusting the strength of the stretchable member and the buoyancy of the frame. Further, the driving device 7 is provided above the water surface of the waste water, and the entire unit including the vibrating frame 16 and the fixed frame 17 can be lifted up and taken out of the waste water treatment tank. can do.

After the wastewater treatment by the wastewater treatment apparatuses according to the first to third embodiments of the present invention described above is completed, contaminants and soluble substances in the wastewater are removed from the FO membranes 1, 11a, and 11b. Since it adheres to the surface, a dehydrated cake can be easily obtained.

Moreover, the wastewater treatment apparatuses according to the first to third embodiments of the present invention can be applied to the renewal of existing sewage treatment plants. As the driving solution, seawater that has been subjected to purification treatment, filtration treatment, or the like may be used. In existing sewage treatment plants, the standard activated sludge method (biological treatment) is often used, but the wastewater treatment apparatus of the present invention can remove organic substances and the like without carrying out biological treatment. The wastewater treatment apparatus of the present invention can generate biogas that can be used as energy based on the discharged contaminants and soluble substances, thereby contributing to the effective utilization of resources.

Thus, the wastewater treatment equipment of the present invention can be easily applied to existing wastewater treatment plant equipment, enables rapid treatment without complicated biological treatment equipment, and is a highly energy-efficient process. enable design.

Although the present invention has been described using the above-described embodiments, the present invention is not limited to the above-described embodiments.

The present invention allows easy maintenance of the membrane itself used for wastewater treatment.

1, 1c FO film 1a FO film (first removing means)
1aa FO film (second removal means)
1b FO film (third removal means)
2 Rotating shaft 2a First rotating shaft 2b Second rotating shaft 3 Fixed boss 4 Supply pipe 5 Water collection pipe 6 Bearing 7 Drive device 8 Vibrator 9 Swivel joint E1 First membrane element E2 Second membrane element 10 Membrane module 10a First membrane module 10b Second membrane module 10c Third membrane module 11a, 11b FO membrane 12 Crank 13 Elastic member 14 Supply pipe 15 Water collection pipe 16 Vibration frame 17 Fixed frame 18 Cam mechanism 30 Supply part 31 Water collection part 32 Driving solution passing portion 33 Mixed solution passing portion

Claims (8)

Waste water containing contaminants, dissolved substances, and water, and a driving solution containing water and other than the waste water, when the pressure received from the waste water is higher than the pressure received from the driving solution. a first membrane for removing the contaminants and soluble substances from the waste water and transferring water contained in the waste water to the driving solution ; a first membrane element comprising a supplied driving solution and a first water collecting means for collecting water transferred from the waste water to the driving solution;
Waste water containing contaminants, dissolved substances, and water, and a driving solution containing water and other than the waste water, when the pressure received from the waste water is higher than the pressure received from the driving solution. a second membrane for removing the contaminants and soluble substances from the waste water and transferring water contained in the waste water to the driving solution ; a second membrane element having a driving solution supplied and a second water collecting means for collecting water transferred from the waste water to the driving solution;
A waste water treatment apparatus , wherein each of the first membrane and the second membrane is composed of a plurality of separable regions. Each of the first supply means and the second supply means has a plurality of supply holes for supplying the driving solution, and each of the first water collection means and the second water collection means 2. A waste water treatment apparatus according to claim 1, comprising a plurality of water collecting holes for collecting the supplied driving solution and the water transferred from the waste water to the driving solution. 3. A waste water treatment apparatus according to claim 1, further comprising cleaning means for cleaning said first membrane and said second membrane . 4. A waste water treatment apparatus according to claim 3, wherein said first membrane or said second membrane has another cleaning means for cleaning said cleaning means. 5. A wastewater treatment apparatus according to any one of claims 1 to 4, wherein said first membrane or said second membrane has reinforcing means. 6. A wastewater treatment apparatus according to claim 5 , wherein said reinforcing means comprises cleaning means. 3. The driving solution is passed through channels formed inside the first membrane and the second membrane while the first membrane and the second membrane are immersed in waste water. 7. Wastewater treatment equipment according to any one of 1 to 6. Waste water containing contaminants, dissolved substances, and water, and a driving solution containing water and other than the waste water, when the pressure received from the waste water is higher than the pressure received from the driving solution. a first membrane for removing the contaminants and soluble substances from the waste water and transferring water contained in the waste water to the driving solution ; a first water collecting means for collecting water transferred from the supplied driving solution and the waste water to the driving solution; waste water containing contaminants, soluble substances and water; is disposed between a driving solution containing water and other than the waste water, and removes the contaminants and dissolved substances from the waste water when the pressure exerted by the waste water is higher than the pressure exerted by the driving solution; a second membrane for transferring water contained in the liquid to the driving solution; a second supply means for supplying the driving solution to the second membrane ; and a second membrane element having a second water collecting means for collecting the moved water, wherein the first membrane and the second membrane each comprise a plurality of separable regions. In a wastewater treatment method carried out by a wastewater treatment system comprising:
a supplying step of supplying the driving solution from first supply means and second supply means to the first membrane and the second membrane ;
The first membrane and the second membrane remove the contaminants from the waste water, and water contained in the waste water passes through the first membrane and the second membrane to move to the driving solution. a filtering step;
and a water collecting step of collecting the driving solution and the water transferred to the driving solution from the first water collecting means and the second water collecting means.

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