JP2001087635A - Active sludge treatment device using dynamic filtration membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active sludge treatment device using a dynamic filtration membrane capable of stably conducting a filtration by stably forming a dynamic layer on the membrane. SOLUTION: At one side of a bioreactor 1, an air diffuser 3 is arranged and at the other side thereof, a plurality of dynamic filtration membranes 6 are also arranged along the vertical direction in parallel so that there is a proper space between the membranes wherein a plurality of equalizing plates 8 are arranged along the vertical direction in parallel with the line of the contiguous dynamic filtration membranes 6, and a treating water pipe 14 is installed in such a manner that the pipe is penetrated into each dynamic filtration membrane 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an activated sludge treatment apparatus using a dynamic filtration membrane, and to a technique for filtering sludge with a dynamic filtration membrane in activated sludge treatment of sewage, human waste, industrial wastewater, and the like.

[0002]

BACKGROUND OF THE INVENTION In conventional biological nitrogen removal methods,
As a method for maintaining a high concentration of microorganisms in a biological reaction tank, there is a method using a dynamic filtration membrane. The dynamic filtration membrane is obtained by arranging a spacer formed by a net or the like on the surface of a support, and arranging a nonwoven fabric covering the spacer. A dynamic layer of activated sludge particles is formed on the surface of the nonwoven fabric. The cake layer) is used as a filtration layer.

[0003]

In the activated sludge treatment using the above-mentioned dynamic filtration membrane, aerated air is diffused from a diffuser disposed in a biological reaction tank, and a swirling flow is generated in the tank by an air lift action. The activated sludge mixed liquid in the tank is supplied by cross-flow along the surface of the filtration layer by this swirling flow, and filtration is performed using a pressure difference between the inside and outside of the dynamic filtration membrane as a driving pressure.

[0004] By the way, if the flow velocity of the cross flow is too high, the dynamic layer is not formed on the nonwoven fabric to a thickness sufficient for filtration, and if it is too slow, the dynamic layer becomes excessively thick and the flux decreases. In other words, the control of the flow rate is an important factor for stably performing the filtration operation. However, the swirling flow caused by the aerated air is turbulent,
It has been difficult to always supply the activated sludge mixture in the tank with a uniform flow to a plurality of dynamic filtration membranes immersed in the tank.

The present invention has been made to solve the above-mentioned problems, and provides an activated sludge treatment apparatus using a dynamic filtration membrane capable of stably forming a dynamic layer on a dynamic filtration membrane and performing stable filtration. The purpose is to do.

[0006]

In order to solve the above-mentioned problems, an activated sludge treatment apparatus using a dynamic filtration membrane according to the present invention is provided with an air diffuser on one side in a biological reaction tank and another on the other side. A plurality of dynamic filtration membranes arranged along the vertical direction are arranged in parallel with an appropriate gap, and a plurality of straightening plates parallel to each other between adjacent dynamic filtration membranes are arranged along the vertical direction. A treated water pipe is provided in communication with the membrane.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 to FIG. 3, a biological reaction tank 1 forms an aerobic tank for treating an inflowing raw water 2 with activated sludge. Inside the tank, an air diffuser 3 is arranged on one side of the tank. A membrane separator 4 is immersed on the other side, and a blower 5 for supplying aerated air is connected to the diffuser 3.

The membrane separation device 4 is modularized by holding a plurality of dynamic filtration membranes 6 arranged in a vertical direction by a casing 7, and each of the dynamic filtration membranes 6 is arranged in parallel with an appropriate gap. A plurality of straightening plates 8 are arranged in parallel between the adjacent dynamic filtration membranes 6 and along the vertical direction. In each dynamic filtration membrane 6, a spacer 10 such as a net material is disposed on the surface of the support plate 9, a nonwoven fabric 11 is disposed so as to cover the spacer 10, and the periphery of the nonwoven fabric 11 is sealed with a sealant 12 in a watertight manner. The permeated liquid channel 13 is formed in the support plate 9.

[0009] Permeate flow path 13 of each dynamic filtration membrane 6
The treatment water pipe 14 communicating with the biological reaction tank 1 outside the tank
Is opened below the liquid level by a predetermined distance Δh. Hereinafter, the operation of the above configuration will be described. The aerated air supplied by the blower 5 is diffused from the diffuser 3 into the activated sludge mixture in the tank, and oxygen required for activated sludge treatment is supplied by the aeration. A swirling flow is generated inside the biological reaction tank 1 by an air lift action of aerated air, and the activated sludge mixed liquid in the tank is supplied to the membrane separation device 4 by a cross flow using the swirling flow.

The activated sludge mixture flowing into the membrane separation device 4 is regulated by the flow straightening plates 8 and flows vertically, and flows down the flow path between the adjacent straightening plates 8 as a uniform flow. In this state, the activated sludge mixture is filtered using the head difference Δh acting on the dynamic filtration membrane 6 as a driving pressure,
The filtered treated water is taken out through the treated water pipe 14. As described above, since the activated sludge mixed liquid in the tank is always supplied to the dynamic filtration membrane 6 by the regulating plate 8 and is supplied in a uniform flow, the flow rate thereof is controlled by the blower 5 and diffused from the air diffuser 3. By adjusting the amount of air and the flow rate thereof, it can be easily controlled, and a dynamic layer of activated sludge particles can be stably formed on the surface of the nonwoven fabric 11 to a thickness required for filtration. A stable filtration performance can be obtained using the dynamic layer as a filtration layer.

[0011]

As described above, according to the present invention, a plurality of straightening plates parallel to each other between adjacent dynamic filtration membranes are arranged in the vertical direction, and the tank is supplied in a cross flow along the membrane surface. By controlling the activated sludge mixed solution with a flow straightening plate and always supplying it in a uniform flow, the flow rate can be easily controlled by adjusting the air diffuser, and the activated sludge particles forming on the surface of the nonwoven fabric can be easily controlled. The dynamic layer can be stably maintained at a sufficient thickness required for filtration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an activated sludge treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement structure of a dynamic filtration membrane in the embodiment.

FIG. 3 is a cross-sectional view of the dynamic filtration membrane according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Biological reaction tank 2 Raw water 3 Aeration device 4 Membrane separation device 5 Blower 6 Dynamic filtration membrane 7 Casing 8 Rectifier plate 9 Support plate 10 Spacer 11 Nonwoven fabric 12 Seal material 13 Permeate flow path 14 Treatment water pipe

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ken Yoshizaki 2-47, Shikitsu-Higashi 1-chome, Naniwa-ku, Osaka-shi, Osaka (72) Inventor Shinichi Fukuhara Shin-ichi Fukuhara, Osaka-shi, Osaka No. 2-47, Kubota Co., Ltd. (72) Inventor Yusuke Oi 1-47, Shishitsuhigashi, Naniwa-ku, Osaka-shi, Osaka F-term (reference) 4D006 GA02 HA42 HA93 JA01A JA14A JA18A KA13 KA31 KA44 KB22 KE01Q MA03 MA16 MA40 PA01 PB08 PC62 4D028 BC17 CA09

Claims (1)

[Claims] An aeration device is arranged on one side in a biological reaction tank, and a plurality of dynamic filtration membranes arranged along the vertical direction on the other side are arranged in parallel with an appropriate gap therebetween.
Activated sludge treatment equipment using a dynamic filtration membrane, characterized in that a plurality of straightening plates parallel to each other between adjacent dynamic filtration membranes are arranged in the vertical direction, and a treated water pipe is provided in communication with each dynamic filtration membrane. .