JP2691445B2 - Setting method of hollow fiber membrane for sewage treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hollow fiber for solid-liquid separation of a mixed liquid combined with a biological reaction tank (bioreactor) for aerobic or anaerobic biological treatment of sewage. The present invention relates to a method for setting a hollow fiber membrane in a hollow fiber membrane module for sewage treatment containing a bundle of membranes.

[Prior Art] Conventionally, as a solid-liquid separation membrane in this kind of sewage treatment, a membrane using a flat membrane or a tubular membrane is known.

However, in the solid-liquid separation using the conventional membrane, it is necessary to impart turbulence to the mixed liquid in order to prevent the occurrence of concentration polarization on the membrane surface and the adherence of the gel layer of sludge. There was a problem of becoming large.

In addition, the above-mentioned conventional film requires ball cleaning or the like to peel off and remove the gel layer attached to the film surface, and it is difficult to control the permeation flow rate.

In order to solve the above conventional problems, the present inventors have:
A honeycomb tube is installed in the mixed solution that has been subjected to the biological reaction treatment, a bundle of hollow fiber membranes is movably filled in the honeycomb tube, and the mixed solution is permeated by intermittently sucking the inside of the hollow fiber membrane. A sewage treatment method and apparatus have been developed in which the solid-liquid separation into a liquid and a concentrated liquid is performed, and at the same time, the suction / pause interval of the intermittent suction is controlled to control the permeation flow rate.

[Problems to be Solved by the Invention] The present invention has been made in order to promote the practical use of the sewage treatment apparatus according to the above-mentioned development, and an object thereof is to reliably and stably hold a bundle of hollow fiber membranes. It is an object of the present invention to provide a method for setting a hollow fiber membrane for sewage treatment which can be housed in a honeycomb tube and can be easily maintained such as replacement of the hollow fiber membrane.

[Means for Solving the Problem] A method for setting a hollow fiber membrane for treating sewage according to the present invention is directed to a honeycomb bundle of a large number of hollow fiber membranes for solid-liquid separation of a mixed liquid which is aerobically or anaerobically biologically treated. A hexagonal annular holder is installed at the upper end of a honeycomb tube that is movably accommodated in the tube, and a suction pipe is piped in the annular holder, and the suction pipe is provided at the corner of the hexagonal annular shape. In addition, a plurality of hollow fiber membranes are fixed at their upper ends in an open state, and at the corners of the annular holder, three branch pipes are branched from the suction pipe. The present invention is characterized in that a large number of hollow fiber membranes are fixed to each other, and further, the annular holding body is installed in every other honeycomb tube.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a sand removing device, and reference numeral 2 denotes a screen, which removes solids such as sand mixed in a stock solution of sewage.

3 is a variable capacity bioreactor in which the above-mentioned stock solution flows in through an inflow pipe 4. In the present embodiment, the water flows naturally, but it may be supplied by a pump (not shown) as appropriate. When the undiluted solution is oily wastewater such as kitchen wastewater, the oil is separated and then introduced into the bioreactor 3.

The inflow amount of the stock solution changes with time, and therefore, the mixed liquid containing the biological floc in the bioreactor 3, that is, the water level of the activated sludge mixed solution 5 fluctuates up and down (HWL, LWL). ing.

An air diffuser 6 is provided at the bottom of the bioreactor 3 so that air supplied from an aeration blower 7 is diffused into the mixture 5.

Reference numeral 8 denotes an outflow pipe which discharges the mixed solution 5 from the bottom of the bioreactor 3 by a pump 9.

The mixed liquid discharged from the outflow pipe 8 is sent to a solid-liquid separation tank 12 on the way, from which solids are removed by a screen 10 and a sand removing device 11.

The solid-liquid separation tank 12 accommodates a honeycomb tube 13 as shown in FIG.

As shown in FIG. 3, a hexagonal annular holder 14 is attached to the upper end of the honeycomb tube 13. A suction pipe 15 is provided in the annular holder 14 and is branched into three branch pipes 15a at each corner.

As shown in FIG. 4, the upper end of the hollow fiber membrane 16 is fixed to the branch pipe 15a in an open state, and the bundle-shaped hollow fiber membrane 16 is freely movable in the surrounding honeycomb tube 13. Hanging.

The hollow fiber membrane 16 has a diameter of, for example, a synthetic resin such as polyethylene having a myriad of fine holes of about 0.1 micron.
It is a thread-shaped hollow tube of about 0.8 mm. The hollow fiber membrane 16 is not limited to this, and any hollow fiber membrane that has been used or developed so far may be used.

The lower end of the hollow fiber membrane 16 is closed. The hollow fiber membrane 16 may be hung in a loop shape, and both ends may be fixed to the branch pipe 15a. Further, the honeycomb tube 13 may be oriented in any direction such as sideways or diagonal.

In FIG. 1, reference numeral 17 denotes a return pipe, which is a solid-liquid separation tank 12;
The concentrated liquid in the inside is returned to the bioreactor 3.

Reference numeral 18 is a suction device, which is in communication with the suction pipe 15 in the annular holder 14, and by making the hollow fiber membrane 16 in a low pressure state, the solid content, microorganisms, viruses and the like in the mixed liquid. Only the removed liquid part is allowed to permeate into the hollow fiber membrane 16 for solid-liquid separation.

Reference numeral 19 denotes an intermittent timer, which appropriately changes the suction operation time of the suction device 18 to change the suction time and the pause time.

 Next, the operation of the above embodiment will be described.

First, solids such as sand are removed from the undiluted solution of organic sewage by a sand remover 1 and a screen 2 and introduced into the bioreactor 3 through an inflow pipe 4.

The organic sewage introduced into the bioreactor 3 becomes the activated sludge mixture 5 here. The water level of the activated sludge mixture 5 changes up and down in the bioreactor 3 in accordance with the fluctuation of the inflow from the inflow pipe 4 and the outflow from the outflow pipe 8.

Since air is supplied from the air diffuser 6 at the bottom of the bioreactor 3, the organic matter in the sewage flowing into the bioreactor 3 is adsorbed by the aerobic microbial floc and further oxidatively decomposed and purified.

The treated water containing the activated sludge is sent from a discharge pipe 8 to a solid-liquid separation tank 12 by a pump 9.

The water in the mixed liquid flowing into the solid-liquid separation tank 12 passes through the fine holes of the hollow fiber membrane 16 in the honeycomb tube 13 and is sucked into the suction pipe 15, and the permeated liquid is processed from the water pipe 20. Withdrawn as water.

The concentrated liquid that is not sucked by the hollow fiber membrane 16 is returned to the bioreactor 3 through the return pipe 17.

The suction device 18 is intermittently operated by an intermittent timer 19 to control the permeation flow rate. The intermittent timer 19 may be controlled by a computer.

The honeycomb tube 13 may be installed in the bioreactor 3 to make the whole apparatus compact.

In each of the above embodiments, the processing in the aerobic bioreactor has been described, but the present invention is not limited to this, and may be an anaerobic bioreactor. In this case, the bioreactor needs to be capped, trapped and heated.

In the above embodiment, the suction time of the suction device 18 is controlled by the intermittent timer 19; however, the present invention is not limited to this.

FIG. 6 shows another embodiment in which the branch pipe 15a in the annular holder 14 is made continuous and the hollow fiber membranes 16 are arranged in a hot screen.

[Effects of the Invention] A bundle of hollow fiber membranes can be securely and stably accommodated in a honeycomb tube, and maintenance such as replacement of the hollow fiber membranes is easy.

[Brief description of the drawings]

FIG. 1 is a flow diagram of a sewage treatment system showing one embodiment of the present invention, FIG. 2 is a partial sectional view of a honeycomb tube, and FIG.
FIG. 4 is a plan view of a honeycomb tube, FIG. 4 is a plan view of an annular holder, FIG. 5 is a perspective view showing a state in which a hollow fiber membrane is held by the annular holder, and FIG. 6 is another embodiment of the annular holder. FIG. DESCRIPTION OF SYMBOLS 1 ... Sand removal apparatus, 2 ... Screen, 3 ... Bioreactor, 4 ... Inflow pipe, 5 ... Mixed liquid, 6 ... Aeration pipe, 7
... aeration blower, 8 ... outlet pipe, 9 ... pump, 10 ...
... Screen, 11 ... Sand removal device, 12 ... Solid-liquid separation tank, 13
...... Honeycomb tube, 14 …… annular holder, 15 …… suction pipe, 15a …… branch pipe, 16 …… hollow fiber membrane, 17 ……
Return pipe, 18 …… Suction device, 19 …… Intermittent timer, 20 ……
Water pipe.

Claims (3)

(57) [Claims] 1. A hexagonal hexagon at the upper end of a honeycomb tube in which a bundle of a large number of hollow fiber membranes for solid-liquid separation of a mixed solution which has been aerobically or anaerobically bioreacted is freely accommodated in the honeycomb tube. An annular holding member having an annular shape is installed, a suction pipe is arranged in the annular holding member, and the upper ends of a large number of hollow fiber membranes are fixed to the suction pipe in an open state at the corners of the hexagonal annular shape. A method for setting a hollow fiber membrane for treating sewage. 2. The sewage according to claim 1, wherein three branch pipes are branched from a suction pipe at a corner portion of the annular holder, and a large number of hollow fiber membranes are fixed to each branch pipe. Method for setting hollow fiber membrane for treatment. 3. The method for setting a hollow fiber membrane for treating sewage according to claim 1 or 2, characterized in that the annular holding bodies are placed on every other honeycomb tube.