JPH0929277A - Device for purifying quality of water of river - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device in which quality of water can be surely purified, and faclities can be easily protected and maintained in the case of a flood and sludge can be handled by installing the device on a river bed. SOLUTION: A closed biofilm purifying tank 2 is installed in a pool provided on a river bed and a variable weir 3 is provided downstream of the pool 1 so that the water level of the pool 1 can be made higher than a usual water level of rivers, and a flow-in port 12 is provided downstream of the biofilm purifying tank 2 and a flow-out pipe of purified water is provided upstream of the tank 2, and a delivery port 15 of a water transfer pipe 14 connected to the flow-out pipe is provided downstream of the weir 3 so as to be opened to a position lower than the water level on upstream side of the weir 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purifying device for purifying water from an urban river or the like.

[0002]

2. Description of the Related Art Recently, since the progress of pollution due to domestic wastewater from urban rivers is remarkable, the need for purification is being promoted. The conventional purification facility corresponding to this is installed on land,
In general, the method of pumping up the river water, purifying it at the facility, and then discharging it into the river is common. However, in urban areas, it is particularly difficult to secure a site for installing a purification facility, the energy cost required for purification is large, and management is troublesome.

Therefore, it has been attempted to install a purification facility directly on the river floor.

[0004]

However, in the conventional direct direct purification method for rivers, since various contact furnace materials are exposed, there is a problem that there is burial and damage due to earth and sand, etc., and labor is required for restoration. In addition, a large space is required on the river bed, and the flow velocity cannot be controlled, so that the water quality becomes unstable.

The present invention solves the above-mentioned problems and, by installing it on the riverbed, ensures water purification, protects facilities during floods,
The subject is a water purification device for rivers that is easy to maintain and manage sludge.

[0006]

In order to solve the above-mentioned problems, a water purification apparatus for a river or the like according to the present invention has a closed biofilm septic tank in a pool provided on a river bed, and is installed downstream of the pool. Is equipped with a variable weir that allows the water level above the pool to be higher than the normal water level of rivers, etc., with an inlet on the downstream side of the septic tank and an outlet pipe for purified water on the upstream side of the septic tank.
The discharge port of the water supply pipe connected to the outflow port is opened at a position lower than the water level on the downstream side of the variable weir and on the upstream side of the variable weir.

It is preferable that a constant amount of water is discharged from the discharge port after passing through the septic tank facility due to the difference in water level between the upstream and downstream regions of the weir and the diameter of the water supply pipe.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show a water purification device, which comprises a pool 1 installed on a river bed, a biofilm purification tank 2 and a variable weir 3 installed inside the pool 1. It consists of and.

The pool 1 is formed by excavating the river floor.
A closed biofilm septic tank 2 is installed in the pool 1, and a sand 4 is formed by forming a wall 4 between the septic tank 2 and the variable weir 3. The river bed is covered with a PC board 6.

The variable weir 3 may be a rubber dam, a tumbling type gate or the like for stopping the weir 3 from the river when air is taken in and out or the gate is raised and lowered. As a result, the water level above the pool 1 on the downstream side of the pool 1 can be made higher than the normal water level of a river or the like. Variable weir 3 when it rains
Is adjusted to eliminate the water level difference between the upstream region and the downstream region of the variable weir 3.

The biofilm septic tank 2 contains a large number of contact filter media 9 suspended in a closed concrete box body 7 by an appropriate means such as a FRP basket 8 and the like. Depending on the situation, one or more units will be installed. The box 7 is preferably constructed so that it can be opened and closed for maintenance or the like.

The contact filter medium 9 is, for example, Japanese Patent Application No. 6-1.
Similar to the one shown in No. 92942, the surface of a porous non-woven fabric made of fibers such as rayon, cotton, polyethylene, polypropylene, etc. is coated with an insoluble pyridinium type resin having a halogenated pyridinium group in the molecule to form a cross section. A star-shaped string or a strip-shaped one may be used.

A sludge storage section 10 having a sufficient size is formed at the bottom of each biofilm purification tank 2. Opening / closing sections 11 for removing sludge are provided on the front and rear walls of the bottom. It should be noted that instead of the opening / closing portion 11, a configuration may be adopted in which pull-out pipes (not shown) are provided on the bottom portion at regular intervals.

Next, the inflow port 12 of each biofilm septic tank 2 described above.
Is provided on the downstream side of the septic tank, and the purified water outlet 13 is provided on the upstream side of the septic tank 2. And each outlet 13
The water supply pipe 14 connected and connected to is buried in the ground, and its discharge port 15 is opened at a position lower than the water level on the downstream side of the variable weir 3 and on the upstream side of the variable weir 3.

The operation of the water purification apparatus having the above structure will now be described. The water level of the water accumulated on the pool 1 becomes higher than the water level in the downstream region by the variable weir 3. Therefore, the water in the septic tank is drawn out from the water supply pipe 14 and discharged to the downstream region, so that the water is introduced from the inflow port 12 of the septic tank 2. As a result, the water in the upstream region of the variable weir 3 is supplied from the inflow port 12 on the downstream side of the septic tank, passes through the septic tank, and then flows from the outflow port 13 on the upstream side to the discharge port 15 through the water supply pipe 14.

The river water is set so that a constant amount of water passes through the septic tank depending on the water level difference between the upstream and downstream regions of the variable weir 3 and the diameter of the water pipe 14.

By the way, when river water is continuously passed through the inflow port 12 into the septic tank at a constant rate, a large amount of microorganisms are immobilized on the contact filter medium 9 having a large surface area to form biomass. Then, solid matter such as organic matter contained in river water is adsorbed and captured on the contact filter medium 9 and ingested as a nutrient source for microorganism groups (protozoa, micro metazoa, etc.) including bacteria forming a biofilm. To be done. Therefore, the biofilm tank is predominantly aerobic on the inflow side.

Dissolved oxygen is consumed as water flows down, and the biofilm tank gradually changes anaerobically. When the biomass becomes large, the dissolved oxygen is also exhausted so that the anaerobic microbial environment is constantly maintained. Therefore, an anaerobic microbial environment is inevitably created from the center of the biofilm tank to the outflow side.

As described above, microorganisms mainly nitrifying and oxidatively decomposing on the inflow side and denitrifying bacteria mainly denitrifying on the outflow side are accumulated and fixed. Air decomposition and nitrification are performed, and in the latter half, formation of an anaerobic microbial environment and denitrification are performed, and the inflowing river water is purified by biodegradation of biofilm, and flows from the outlet 13 through the water pipe 14. It is discharged from the discharge port 15 to the downstream side of the variable weir 3.

Further, the pollutants of the water passing through the septic tank 2 are biodegraded by the biofilm, purified and sent, but a part thereof is separated from the biofilm and becomes sludge to form a sludge storage section 1.
Precipitates to 0. The sludge that has settled may be flushed out by simultaneously opening and closing the opening / closing sections 11 at the bottom of the bottom during flooding, and the collected sludge may be dried and returned to the field as compost. If a drawing pipe is provided, discharge it outside the tank by drawing.

Furthermore, since the inflow port 12 of the septic tank is provided on the downstream side, mud, sand, dust, SS contained in the river
Substances and solids settle in the sand settling section 5 and their inflow into the septic tank is regulated. The precipitate may be removed regularly.

In the case of heavy rain or the like, the height of the variable weir 3 is lowered and adjusted so that the water levels in the upstream and downstream are equal. As a result, the water level difference between the upstream region and the downstream region of the variable weir 3 disappears, so the water absorption capacity of the water supply pipe 14 is lost, and the water flow in the septic tank automatically stops.

As described above, the following effects can be obtained by the water purification device having the above structure. (1) The biofilm biofilm septic tank 2, which is the main body of the septic facility, is below the riverbed, so it does not require space on the riverbed, and the biofilm septic tank 2 does not hinder flood control even in the event of a flood. (2) Since the inflow port 12 of the biofilm septic tank 2 is provided on the downstream side, mud, sand, dust, SS substances and solids contained in the river settle in the sand settling section 5 and flow into the biofilm septic tank 2. Is regulated. Therefore, clogging of the biofilm tank can be reduced. (3) The water purification by the biofilm method purifies water to a certain extent by setting the contact speed and distance (residence time) depending on the sludge load, and the facility volume can be set according to the amount of treated water. The normal flow rate is preferably designed to be about 0.5 cm / s or less. (4) Due to the water level difference between the upstream and downstream of the variable weir 3, the biofilm septic tank 2
In principle, it does not consume electric energy such as pumps because it is a system that allows river water to pass through and clean the water quality with a biofilm. (5) Since the biofilm septic tank 2 is hermetically closed, it is not exposed to the eyes and there is no concern about the generation of odors or harmful insects. (6) The water flow in the biofilm septic tank 2 can be automatically stopped by adjusting the height of the variable weir 3, so that sediment and the like will not flow into the biofilm septic tank 2 in the event of a flood, etc. It is possible to prevent the septic tank 2 from being damaged. (7) Sludge is stored inside the biofilm septic tank 2 so that it is easy to process. (8) Maintenance is very easy and its cost is very low.

[Brief description of drawings]

FIG. 1 is an overall view of a water purification device for rivers according to the present invention.

FIG. 2 is a vertical sectional view of the purification device.

FIG. 3 is a plan view of the purification device.

[Explanation of symbols]

 1 pool 2 biofilm septic tank 3 variable weir 12 inflow port 13 outflow port 14 water pipe 15 discharge port

Claims (2)

[Claims] 1. A sealed biofilm septic tank is installed in a pool provided on a river bed, and a variable weir is provided on the downstream side of the pool so that the water level above the pool can be higher than the normal water level of a river or the like.
The water inlet is provided on the downstream side of the septic tank, the purified water outlet is provided on the upstream side of the septic tank, and the outlet of the water pipe connected to the outlet is on the downstream side of the variable weir and on the upstream side of the variable weir. A water purification device for rivers, which is opened at a position lower than the water level of. 2. The river according to claim 1, wherein a constant amount of water passes through the septic tank facility and is discharged from the discharge port depending on the difference in water level between the upstream and downstream regions of the weir and the diameter of the water pipe. Water purification equipment such as.