JPH0221997A - Water treatment by ozone and device therefor - Google Patents

Abstract

PURPOSE:To allow the ozone dissolved in water to be treated to efficiently act on a material to be treated and to enhance its utilization rate by bringing the water to be treated into contact with a gas contg. concd. ozone, and retaining the water at atmospheric pressure while keeping the water out of contact with a gaseous phase. CONSTITUTION:The gas 8 contg. >=200ppm ozone is injected from a sparger 7, and brought into coutercurrent contact with water 6 to be treated in a contact vessel 1. The water is transferred into a closed vessel 2 through a communicating pipe 3, and retained. The material to be treated in the water is successively oxidized by the dissolved ozone. In this case, the water 6 introduced into the contact vessel 1 is discharged from a water discharge pipe 5 through a conduit 4 with the base 4b fixed to the uppermost part of the closed vessel 2. The discharge pipe 5 is fixed to the conduit 4 at a position lower than the liq. surface in the contact vessel 1, the upper end 4a of the conduit 4 is opened to the atmosphere, and the slender conduit 4 with a reduced area is used. As a result, the closed vessel 2 is substantially sealed, and the dissolved ozone is effectively consumed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention mainly uses ozone to sterilize wastewater with efficiency J=
<Regarding effective water treatment methods and equipment 6 [Prior art] Ozone has been used in water treatment for the purpose of sterilization since ancient times, but recently it has been recognized for its strong oxidizing power, color rendering properties, deodorizing properties, etc. It is used in various industrial wastewater treatment.

When using ozone for water treatment, it is necessary to efficiently avoid contact between the water to be treated and the ozone-containing gas.
Spray tower, packed tower, plate tower, or subflow dispersion group,
Bubble dispersion groups such as countercurrent dispersion groups, pressurized ozone dispersion groups (Jt), mechanical stirring type dispersion groups, and diector type dispersion towers have been put into practical use.

[Problem that the invention attempts to solve]

However, spray towers, packed towers, and plate towers require a high rate of reaction between the to-be-treated material in the treated water and ozone, and packed towers in particular are susceptible to dylene ringing. Also,
Pressurized ozone dispersants require the system to be kept under pressure (-), and mechanically stirred dispersants require strong stirring, which increases equipment costs and operating costs. The single-lid type has drawbacks such as the large amount of power required to circulate the liquid. With the exception of roughly pressurized ozone dispersion groups, the treated water that has come into contact with ozone is led out to a filtration channel or tank, and the dissolved ozone is immediately dissipated into the atmosphere, making effective use of ozone possible. There was a problem.

In view of the above-mentioned circumstances, an object of the present invention is to provide a water treatment method using ozone and an apparatus therefor, which can effectively utilize ozone absorbed in a liquid to be treated using a simple device.

[Means for solving problems]

In order to achieve the above object, in the method of the present invention,
After bringing the ozone-containing gas having an ozone concentration of 20 ppm or more into contact with the water to be treated, the water to be treated is allowed to stay under atmospheric pressure without contacting the gas phase.

In addition, the equipment has a contact tank with an ozone-containing gas spur relay installed at the inner bottom, a contact tank connected to the supply pipe for water to be treated at the top, and a communication pipe connected to the bottom of the contact tank at the bottom. , a closed tank whose height is l-*ν1; in the position of
1) Take 1 outlet pipe and turn it to the right with the conduit whose top end is open.

[Operation] Since the method d3 and the apparatus of the present invention have the above-described configuration, the IC ozone that is contacted and absorbed by the water to be treated effectively acts on the object to be treated without being dissipated.

(Actual example) The degree of ozone in the ozone-containing gas used in the method of the present invention is 201]11m or more (it is necessary to be 3), and if the concentration is less than 201111m, ozone dissolution14
There is little effect on utilizing the retained IC dissolved ozone.

The ozone-containing gas above 201]r)m uses air as a raw material, so the discharge power is too loud and is not practical, so it can be obtained by silently discharging oxygen-enriched gas.

No matter which method is used to enrich oxygen, J:
However, the Brellasil swing method, which uses an adsorbent such as molecular sieves, pressurized shielding, and deposits (reduced J]-Jl+), is preferable because oxygen enrichment can be achieved at low cost.

FIG. 1 shows an embodiment of the apparatus of the present invention, and reference numeral 1 in the figure is an ozone contact tank which releases exhaust gas from one end. A closed tank 2 is provided (') adjacent to the contact tank 1, and the lower portions of the contact tank 1 and the closed tank 2 are connected by a communicating pipe 3. At the top of the sealed tank 2, there is a sealed tank 2.
The base 4b of the conduit 4 is higher than the upper end of the contact tank 1, with the upper end 4a being open so as not to generate a gas phase in the inner upper part.
is being taken away. A discharge pipe 5 is attached (
is being pulled.

A supply pipe 6a for supplying water to be treated 6 derived from a biological treatment system or the like is connected to the upper part of the contact tank 1 of the IC1. In addition, a sparger 7 is attached to the bottom of the contact tank 1 to disperse and blow in ozone-containing gas. A pressure feed pipe 8a for pressurized supply of ozone-containing gas 8 which has been converted into ozone by discharge is connected thereto.

To perform C water treatment using the above-mentioned apparatus, the water to be treated 6 is introduced from the conduit 6a at a predetermined flow rate m, and the ozone-containing gas 8 is distributed and supplied via the sparge 1 to 7 at a predetermined flow width.
-ru. The dispersed osin-containing gas is brought into countercurrent contact with the water to be treated and absorbed, while reacting with the substances to be treated in the water to be treated, leading to the next step of utilizing oxygen from the upper end of the contact tank 1, or The ozone is released into the atmosphere through the M equipment.

m spouted from the sparge 17-7 near the communication pipe 3.
The water to be treated that has come into contact with highly concentrated ozone passes through the communication pipe 3 and moves to the closed tank 2, where it stays there. During this residence, the dissolved ozone subsequently oxidizes the material to be treated.

In addition, since the sealed tank 2 is in communication with the contact tank 1, when water to be treated is introduced into the contact tank 1, it passes through the conduit 4 and into the drain pipe 5.
More leakage. At this time, since ozone-containing gas bubbles are dispersed in the contact tank 1, the liquid level in the contact tank 1 becomes higher than the position of the discharge pipe 5, but it is a natural flow and no power is required. Further, although the upper end 4a of the conduit 4 is open, the area of the elongated groove is small, so the closed tank 2 is substantially sealed, and there is no influence of the atmosphere on it. Therefore, closed tank 2
The ozone dissolved in the water to be treated that remains inside the tank is effectively consumed.

Examples 1 to 4, Comparative Examples 1 to 7 Activated sludge treated water of sewage was flowed as the water to be treated at different flow rates to change the contact time in the contact tank.

As the ozone-containing gas, an oxygen-enriched gas of approximately 9QVO1% is created using a pressure +7-swing method, and is passed through an ozone generator to produce ozone-containing gas of various i degrees. The amount of ozone injected into the treated water was adjusted, and the number of coliform bacteria in the treated water before and after treatment was measured.

In addition, the device uses a contact tank with an inner diameter of 100 a A closed tank was used. The results are shown in Tables 1 to 3.

As is clear from Tables 1 to 3, the number of coliform bacteria is significantly reduced by avoiding retention in a closed tank, but when the ozone content concentration is 1511 pm, the satisfactory 2i result is 111.
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〔Effect of the invention〕

As mentioned above, the method of the present invention is easy to use.
Since it is a gravity flow, the equipment cost and operating cost are low, and the water to be treated that has come into contact with gas containing ossin with a high degree of a content enters the closed tank, stagnates, and reacts with the material to be treated. It has many advantages such as high utilization rate of dissolved ozone and excellent treatment function.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the apparatus of the present invention. 1... Contact tank, 2... Closed tank, 3... Communication pipe, 4
... Conduit, /Ia ... Upper end, 4b ... Base, 5
... Publication pipe, 6... Water to be treated, 6a... Supply pipe,
7...Sparger 8...Ozone-containing gas, 8a...
・Pressure pipe.

Claims (2)

[Claims] (1) After bringing the ozone-containing gas with an ozone concentration of 20 ppm or more into contact with the water to be treated, the water to be treated is heated under atmospheric pressure.
A water treatment method using ozone, which is characterized by allowing water to remain in the water without coming into contact with the gas phase. (2) Has an ozone-containing gas sparger at the inner bottom;
A contact tank having an upper part connected to a supply pipe for water to be treated, a closed tank having a lower part connected to the lower part of the contact tank by a communicating pipe and having a height lower than the upper end of the contact tank, A conduit having a base attached to the top and extending upward, a discharge pipe attached to a side lower than the upper end of the contact tank, and an upper end open to the atmosphere. Water treatment equipment using ozone.