JPS6084200A - Water treating apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvement of water treatment equipment. A method for purifying wastewater using activated sludge is known. In this method, the filtered water is supplied to a bulk denitrification tank, where it is denitrified in a state containing activated sludge of high wave strength, and then in the nitrification phase, the organic content contained in the V wastewater is completely oxidized by the activated sludge, and ammonia is removed. It purifies treated water by nitrifying the nitrogen content. In addition, the treated liquid is sent to the solid-liquid separation 'IVM', where the activated sludge is collected and the nitrification process is carried out.
j 11. In this type of treatment method, for example, Fukaya nitrification (
Treatment equipment equipped with η (vertical aeration tank) has been proposed.

This deep 1-type nitrification tank is equipped with deep descending channels and deep ascending channels for circulating the liquid, and while oxygen-containing gas is blown into the tank, all of the treated water is circulated through the above channels, and activated sludge is It performs purification treatment, and high oxygen solubility is obtained due to the high hydrostatic pressure at the bottom, and as it circulates, the treated water and oxygen can be kept in contact for a long time, making it possible to perform efficient wastewater treatment. It has the advantage of being possible. However, in conventional processing equipment equipped with such a deep nitrification tank, liquid is sent from the nitrification tank to the denitrification tank, liquid is sent from the denitrification tank to the nitrification IQ, and the liquid is separated in the solid-liquid separation tank. Since all of the activated sludge is returned to the nitrification tank using a pump, a large amount of power is required for this purpose, which poses a problem in terms of economic efficiency.

The present invention was devised in view of these problems, and an object of the present invention is to provide an apparatus that can perform efficient return water treatment with less power.

For this reason, the present invention is designed to allow liquid and sludge to flow in and out between each phase by utilizing the natural flow of liquid and returned sludge using various water level differences and by utilizing the air lift effect by aeration in the deep existing nitrification tank. This eliminates the need for a pump and reduces power consumption.

An embodiment of the present invention will be described below with reference to the drawings.

In the above, (1) is a denitrification tank, (2) is a deep nitrification tank (vertical aeration tank) for nitrifying the treated water sent from this denitrification tank, and (3) is a tank from the treated water after nitrification treatment. This is a solid-liquid separation tank for separating activated sludge. 9 of these three tanks
In other words, the water level (Ll) and (L3) of the denitrification tank (1) and the solid-liquid separation tank (3) during operation are equal to the inner pipe water level (Lx) of the deep nitrification tank (2) (during operation). The deep nitrification tank (2) is placed so that the water level is higher than the water surface level (water surface level) in the deep nitrification tank (2).

The deep nitrification tank (2) is usually configured to have a depth of about 50 to 150 m. This phase is composed of an inner tube (4) and an outer tube (5).
) (between the outer tube and the inner tube) is configured as an upward flow path CB). In order to circulate the liquid from this ascending channel CB) to the descending channel (A), the outer 'i'7 (5) and the inner pipe (4) are connected at each water level (water level during operation). A flow path (6) is provided at the top of 4'Y.

A diffuser (7) is provided in each of the ascending channel CB) and the descending channel (A), so that oxygen-containing gas can be supplied within the channel. This aeration serves to supply oxygen to the activated sludge in the tank and to move and circulate the treated water in the tank at a sufficient flow rate due to the air lift effect in the flow path.

In this example, the upper part of CI (5) is closed between the outer wall of the inner pipe at a position lower than the water level level (L2) in the inner pipe, and the inside of the outer pipe is released to the atmosphere into the closed upper part. The inner pipe (4) extends upward from the upper end of the outer pipe, and connects the above-mentioned flow path (61i, i) with the inner pipe (4) that protrudes upward. The upper part of the outer pipe (5) is configured as a head tank (51) with an enlarged diameter, and the defoaming group (8) is connected to the upper part of the outer pipe (5).
) and a flow path (6) are connected to this head tank (51). A flow path (9) for draining the liquid from the upward flow path (B) to the denitrification tank (1) and the same upward flow path CB ) to flow out the treated liquid from the solid-liquid separation tank (3) (1 (
1 is the outer tube (5) of the deep nitrification tank and the denitrification tank (1), respectively.
), solid-liquid separation tank (3), and is provided between the rising flow path and
The liquid inside is made to flow into the denitrification m(1) and the solid-liquid separation tank (3) by utilizing the air lift effect.

In addition, in order to supply the liquid from the denitrification tank (1) and the return sludge from the solid-liquid separation tank (3) to the downward flow path (A) in the inner pipe,
A flow path (c) is provided between the denitrification tank (1) and the inner pipe (4) and between the solid-liquid separation tank (3) and the inner pipe (4). These flow paths α and Oa utilize the fact that during operation ((), the water level (L,) in the desorption tank and solid-liquid separation tank is higher than the water level in the inner pipe (L,). This allows liquid and sludge to naturally flow down into the inner pipe (4i).

For this reason, the flow path α→ is provided horizontally or slightly downwardly in the direction of the inner pipe, and one end of the flow path α→ is connected to l19 at the outer position of the overflow channel α→ provided in the soil part of deffl C (1). The other end communicates with the inner pipe (4) at a position above the water level (L,). In addition, the flow path (6) is also provided horizontally or in a slightly downwardly inclined shape in the direction of the inner pipe, and one end thereof communicates with the trough α for charging sludge that the solid-liquid separation phase (3) has at its upper side. , and the other end communicates with the inner pipe (4) at a position n above the water level (L, ), similar to the flow path α■.

In addition, to explain what is shown in the other sections, (g) is a scraper installed above the solid-liquid separation phase to scrape the sludge that has surfaced due to the adhesion of gas deposited in the solid-liquid separation phase (3). The denitrification basin (1) is closed at the top to prevent oxidation.Also, αQ is a coagulation and sedimentation treatment device.

The outer tube (5) of the deep nitrification tank (2) may have a configuration in which the upper part is completely open for fC storage, or the upper part is completely closed and a pressure regulating valve is provided. If the former method is adopted, it is necessary to position the upper edge of the outer tube (5) as high as the inner tube.

Next, the operation of the device of the present invention will be explained.

In the above-described apparatus of the present invention, the supply of liquid from the denitrification tank (1) to the deep nitrification tank (2) and the return of sludge from the solid-liquid separation tank (3) to the deep nitrification tank (2) are carried out at the water level. This is carried out by gravity flow utilizing the difference, and the supply of liquid from the deep nitrification tank (2) to the denitrification tank (1) and solid-liquid separation tank (3) is carried out by the air lift effect in the ascending channel.

To explain its action in detail, treated water such as urban sewage or industrial wastewater (raw water) is supplied to the denitrification tank (1), where it is treated in a state containing a high concentration of activated sludge. Reduction treatment of nitrite nitrogen and nitrate nitrogen (No.
＋CH.

OH-+H+CO,+H,O+OH-) I, denitrifies.

The treated water that overflowed from this denitrification tank (1) through the overflow channel flows down the flow path (ell) naturally, and is transferred to the deep nitrification tank (2).
flows into the downward flow path (A). This deep nitrification tea
In (2), an oxygen-containing gas is supplied to the aeration device (7) from the air diffuser (7), and the activated sludge oxidizes the organic components contained in the treated water and nitrates the ammonia nitrogen (N).
I,” + 02→No, +I(++ H,O) l
This process removes organic components and converts ammonia nitrogen into nitrite nitrogen and nitrate nitrogen.
This is done while circulating through the descending channel (A) and the ascending channel CB). During this treatment, a part of the treated water rises to the airlift effect and is returned to the removal tank (1) through the flow path (9), and another part of the treated water also rises through the flow path due to the airlift effect. The solid-liquid fraction 4'3 (3) vc flows out through αQ, where the activated sludge is floated and separated. The activated sludge that has been floated and separated is collected by a scraper (G) and returned to the descending flow path (A) of the deep nitrification tank (2) by gravity through flow path a2. In addition, the activated sludge is separated in the solid-liquid separation phase (3), and the treated liquid is overflowed from the overflow seki θgin and discharged outside the tank, and is further sent to the coagulation method device 06, etc. According to the invention described above, excess sludge is discharged from trough α through pipe a pass. The flow of return sludge and liquid between tanks can be carried out by natural flow and the air lift effect in the deep nitrification tank, without using pumps, etc., making water treatment equipment economical to operate with less power. It has the excellent effect of being able to be used in a variety of ways.

[Brief explanation of drawings]

The drawings are overall explanatory diagrams showing one embodiment of the present invention. In the figure, (1) is a denitrification tank, (2) is a deep nitrification tank,
(3) is a solid-liquid separation tank, (4) is an inner pipe, (5) is an outer pipe, (
6), (9), shout, 0 repeat, (c) is the flow path, (A)
(B) shows a descending flow path, and (B) shows an ascending flow path. Patent applicant Nippon Takokan Co., Ltd.

Claims (1)

[Claims] In a water treatment device having a denitrification tank, a deep nitrification tank for nitrifying the treated water sent from the denitrification tank, and a solid-liquid separation phase 1 for separating activated sludge from the treated water after the nitrification treatment. The deep-layer nitrification tank is made up of an inner tube and an outer tube, with a descending flow path inside the inner tube and an upward flow path inside the outer tube. : In order to perform 1fAI PJ, the water level at which all stages of the flow path, denitrification tank, and solid-liquid separation phase that connect the outer pipe and the inner pipe below each water surface level, the denitrification tank, and the solid-liquid separation phase are kept during operation is higher than the water level of the inner pipe. In addition to providing a flow path for all of the liquid to flow from the rising flow path to the solid-liquid separation phase and a flow path for all of the liquid to flow from the rise flow path to the solid-liquid separation phase, the liquid and solid from the denitrification tank are 1. A water treatment device characterized by having flow paths for allowing return sludge from a liquid separation phase to naturally flow down into inner pipes.