JPH09308893A - Biological filter method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an apparatus compact, in biological filtering treatment of waste water, by eliminating the necessity for arranging a storage tank for ensuring backward washing water separately from a treatment tank when a filter bed is backward washed and dispensing with washing water from the outside. SOLUTION: A treatment tank 1 is laterally demarcated into a front demarcation chamber 1A and a rear demarcation chamber 1B. The front and rear demarcation chambers 1A, 1B communicate with each other at the lower parts thereof and are packed with a floatable granular carrier 7, and air diffusers 8 are provided to the lower parts of both chambers 1A, 1B and the decomposition of org. matter and the removal of particles are performed by the descending flow of water to be treated in the front demarcation chamber 1A and diffused air from below and particles are removed by the ascending flow the water to be treated in the rear demarcation chamber 1B and diffused air from below to purify water to be treated. Water to be treated is repeatedly circulated from the rear demarcation chamber 1B to the upper part of the front demarcation chamber 1A by a circulating pump 12 to be purified. At a time of backward washing, water to be treated purified within the treatment tank 1 is repeatedly circulated from the front demarcation chamber 1A to the upper part of the rear demarcation chamber 1B as backward washing water to perform washing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wastewater containing domestic waste such as kitchen wastes of various food materials containing sewage, industrial wastewater containing various organic compounds, and purification treatment of river / lake water.

[0002]

2. Description of the Related Art Conventionally, in order to purify wastewater, a filter bed is provided in the treatment tank, and an air diffuser for ejecting air is installed in the lower part of the treatment tank. The pollutants of (3) are removed by the aerobic microorganisms immobilized on the filter material in the filter bed, and SS is simultaneously filtered. Then, as the operation of the treatment tank progresses, SS such as proliferating microorganisms and dead bodies of microorganisms adhere to the filter bed, which makes continuous operation for a long time difficult. Therefore, the treatment tank is backwashed at regular intervals.

At the time of this backwashing, conventionally, a storage tank storing backwashing cleaning water is installed separately from the processing tank or adjacent to the processing tank and treated with the cleaning water from the storage tank. The filter bed in the tank was backwashed. Further, when the backwash water storage tank was not installed, the backwash wash water was supplied from outside the treatment tank.

[0004]

When washing the filter bed during the conventional drainage filtration process, in order to secure the wash water for backwashing, it is necessary to place it in a separate place from the treatment tank or in the treatment tank. Since the storage tanks are installed adjacent to each other, the device becomes large and requires a large installation space. Further, a complicated work such as piping is required for a device that supplies the wash water for backwashing from the outside of the treatment tank without installing the storage tank.

From the above points, in the present invention, in the case of backwashing the filter bed in the treatment tank in the biological filtration treatment of wastewater, the storage tank for securing the wash water for the backwashing is separated from the treatment tank. It is an object of the present invention to provide a biological filtration method and a biological filtration device that do not need to be installed and do not require washing water from the outside of a treatment tank and can make the device compact.

[0006]

In order to solve the above-mentioned problems, the method of the present invention divides the processing tank laterally into two chambers, the front and rear compartments communicate with each other at the bottom, and the front compartment and The rear compartment is filled with buoyant granular carrier, the organic matter is decomposed and particles are removed by downward flow of the water to be treated and air diffusion from the lower part in the front compartment, and upward of the water to be treated in the rear compartment. Purify the water to be treated by removing particles by air flow and air diffusion from the bottom, and then purify the water to be treated by repeatedly circulating the water to be treated from the rear compartment to the upper portion of the front compartment before backwashing. At the time of backwashing, the purified water to be treated in the treatment tank is used as backwash water for backwashing.

Further, in the apparatus of the present invention, the treatment tank is divided into two chambers, the front compartment and the rear compartment are communicated with each other at the lower part, and the air diffusers are respectively installed under the front compartment and the rear compartment. Is
The front compartment and the rear compartment are filled with a buoyant granular carrier, and a mesh body for preventing passage of the buoyant granular carrier is horizontally installed above and below the front compartment and the rear compartment, and The raw water supply pipe and a transfer means for introducing the water to be treated in the front compartment to the upper part of the rear compartment are provided, and one of the cleaning water used for backwashing from the front compartment to the outside of the treatment tank is provided in the lower part of the front compartment. A drainage means for pulling out the portion is provided, a transfer means for introducing the treated water in the rear compartment to the upper portion of the front compartment, an outflow pipe for discharging the treated water out of the treatment tank, and the outflow water. It is characterized in that a return means for returning a part of the water to the raw water tank for a predetermined time is provided.

Therefore, according to the present invention, raw water such as domestic waste water and waste containing waste is introduced as the water to be treated into the upper part of the front compartment of the treatment tank through the raw water supply pipe, and the downward diffusive air from the diffuser is provided. While making countercurrent contact with rising air and flowing the buoyant granular carrier in the filter bed, the aerobic microorganisms inhabiting the buoyant granular carrier decompose organic matters and remove particles in the water to be treated. The treated water is purified and transferred from the lower part of the treatment tank to the rear compartment, and passes through the filter bed by the floating granule carrier in the rear compartment in an upward flow while contacting the rising air from the lower part, resulting in floating granules. Particles are removed by aerobic microorganisms that inhabit the carrier. The floating granular carrier in the rear compartment does not flow because it stagnates upward because the water to be treated and the air flow from below are in only one direction.

Then, as a backwash preparation step, the water to be treated is introduced from the rear compartment to the upper portion of the front compartment by the transfer means provided in the rear compartment and repeatedly circulated to purify the whole water to be treated. In this backwash preparation step, the introduction of raw water is stopped (Fig. 2).

Next, at the time of backwashing, if the water to be treated in the front compartment is introduced into the upper portion of the rear compartment by the transfer means and repeatedly circulated, the water to be treated becomes a downward flow in the rear compartment, and diffused air in the lower portion. The buoyant granular carrier that has stagnated in countercurrent contact with rising air from the device begins to flow and SS is moved backward and washed. In the front compartment, both the water to be treated and the air flow become an upward flow, and the floating granular carrier stays at the top and does not flow, so SS can be captured (FIG. 3).

After backwashing, raw water is introduced into the front compartment by the raw water supply means and the flow is returned to the original state, whereby the floating granular carrier in the front compartment is fluidized to release the trapped SS. The drainage means pulls out and drains the washing water used for the partial backwash including the rich SS from the lower part of the front compartment to the outside of the treatment tank (FIG. 4).

On the other hand, the treated water is discharged from the upper part of the rear compartment to the outside of the treatment tank through the outflow pipe as clear water. Before this, the treated water mixed with SS is returned to the raw water tank for a predetermined time by the returning means. When the water to be treated is clarified after that, the returning means is stopped and the washing is completed (FIG. 4). Since the present invention having the above-described actions uses the purified water to be treated in the backwash treatment tank as the wash water for backwash, it is necessary to provide a storage tank for securing the wash water separately from the treatment tank. In addition, there is no need for cleaning water from outside the processing tank.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of an apparatus according to the present invention, FIG. 2 is a sectional view showing a backwash preparation step of the above, FIG. 3 is a sectional view showing a backwash step of the same, and FIG. It is sectional drawing which shows a cleaning completion process.

In the figure, 1 is a processing tank, which is partitioned by a partition wall 2 into two chambers, a front compartment 1A and a rear compartment 1B. A communication hole 3 is provided in the lower part of the partition wall 2, and water to be treated can communicate with the lower part of the front compartment 1A and the rear compartment 1B. The water to be treated is raw water from a raw water tank (not shown), and the raw water is introduced by a pump (not shown) from the raw water supply pipe 4 to the upper part of the front compartment 1A of the treatment tank 1.

Raw water refers to domestic wastewater, wastewater containing garbage, industrial wastewater containing various organic compounds, and river / lake water. A filter bed 5 is formed in the front compartment 1A and the rear compartment 1B. In the filter bed 5, a mesh 6 is horizontally installed above and below the front compartment 1A and the rear compartment 1B. Floating granular carrier 7 is filled between 6 and 6. The net body 6 allows the water to be treated to pass through but prevents the floating granular carrier 7 from passing through.

As the floating granular carrier 7, a polyether-based soft polyurethane foam granular material having continuous ventilation holes is used. The floating granular carrier 7 carries aerobic microorganisms that aerobically decompose organic impurities contained in the water to be treated. Since it uses a polyether-based flexible polyurethane foam, it is resistant to hydrolysis and has sufficient durability. Since the pores on the inner surface and the outer surface are in communication with each other, the microorganisms can enter the inside as well as the surface of the carrier, so that the culture is easy and the microorganisms do not peel off due to the water to be treated or the air flow, and the inside of the carrier To purify the water to be treated. Since such polyurethane foam is used as a carrier, microorganisms are protected in the carrier during backwashing and washing, and the next biological filtration starts up quickly and has high performance.

Reference numeral 8 denotes an air diffuser provided at the bottoms of the front compartment 1A and the rear compartment 1B. Air or pure oxygen is supplied from a pump (not shown) provided outside the processing tank 1 through a supply pipe 9. Is supplied into the processing tank 1.

A circulation pump 10 as a transfer means and a transfer pipe 11 communicating with the upper side of the rear compartment 1B are provided above the front compartment 1A. The water to be treated is introduced from the transfer pipe 11 to the upper part of the rear compartment 1B.

A circulation pump 12 as a transfer means and a transfer pipe 13 communicating with the upper side of the front compartment 1A are provided above the rear compartment 1B, and the circulation pump 12 is started at the time of purifying the water to be treated to start the rear compartment. The water to be treated in 1B is introduced from the transfer pipe 13 to the upper part of the front compartment 1A.

A motor-operated valve 14 and a discharge pipe 15 as a discharge means are provided in the lower portion of the front compartment 1A, and the motor-operated valve 14 is opened after backwashing so that a portion of the bottom of the processing tank 1 including a rich SS is reversed. The washing water used for washing is drawn from the discharge pipe 15 to the treatment tank 1
Discharge to the outside. The transfer means, the return means, and the discharge means can be unified by using an air lift device.

Reference numeral 16 denotes an outflow pipe provided at the upper part of the rear compartment 1B for discharging the water to be treated to the outside of the treatment tank 1. The outflow pipe 16 is provided with a motor-operated valve 17 and a return pipe 18 which are branched from the outflow pipe 16 and serve as a return means, and after backwashing, the treated water mixed with SS discharged from the outflow pipe 16 for a predetermined time (about About 5 minutes) Open the motor operated valve 17 and return a part of it to the raw water tank (not shown) through the return pipe 18.

[0022]

According to the present invention, when the water to be treated is biologically purified in the front compartment of the treatment tank and the water to be treated is filtered in the rear compartment and backwashed, Since the purified water to be treated is used as cleaning water, a storage tank to secure cleaning water is provided separately from the processing tank as in the past, and cleaning water from outside the system is no longer required, and the equipment is compact and the installation space is small. It can be small. Further, when the present invention is applied to a septic tank, a precipitation step is unnecessary and a compact septic tank is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a preparatory step for backwashing the apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a backwash process of the device according to the present invention.

FIG. 4 is a cross-sectional view showing a cleaning completion step of the device according to the present invention.

[Explanation of symbols]

 1 Treatment Tank 1A Front Compartment Room 1B Rear Compartment Room 2 Partition Wall 3 Communication Hole 4 Raw Water Supply Pipe 5 Filter Bed 6 Reticulate Body 7 Floating Granular Carrier 8 Diffuser 9 Supply Pipe 10 Circulation Pump 11 Transfer Pipe 12 Circulation Pump 13 Transfer Pipe 14 Electric valve 15 Discharge pipe 16 Outflow pipe 17 Electric valve 18 Return pipe

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01D 29/08 540A 29/38 580F

Claims (2)

[Claims] 1. A treatment chamber is laterally divided into two chambers, the front compartment and the rear compartment communicate with each other at a lower portion, and the front compartment and the rear compartment are filled with a buoyant granular carrier to form the front compartment. Decomposes organic matter and removes particles by downward flow of treated water and diffused air from the lower part, and removes particles by upward flow of treated water and diffused air from the lower part in the rear compartment. Before water is purified, the water to be treated is circulated repeatedly from the rear compartment to the upper part of the front compartment to purify the water, and during backwash, the purified water in the treatment tank is cleaned. A method for biofiltration, characterized by using as backwash water for backwashing and backwashing. 2. The treatment tank is divided into two chambers, the front compartment and the rear compartment are communicated with each other at the lower portion, and an air diffuser is installed at each of the lower portions of the front compartment and the rear compartment. And the rear compartment is filled with a buoyant granular carrier, and a mesh body for preventing passage of the buoyant granular carrier is horizontally installed above and below the front compartment and the rear compartment, and a raw water supply pipe is provided in the front compartment. Also, a transfer means for introducing the water to be treated in the front compartment to the upper portion of the rear compartment is provided, and at the bottom of the front compartment, part of the wash water used for backwashing is withdrawn from the front compartment to the outside of the treatment tank. Drainage means is provided, and transfer means for introducing the water to be treated in the rear compartment to the upper portion of the front compartment, an outflow pipe for discharging the water to be treated out of the treatment tank, and the outflow water for a predetermined time in the rear compartment. A biological filtration device, which is provided with a returning means for returning a part to the raw water tank.