JP2002273457A - High-speed agitating reducing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device which can surely reduce oxidizing materials. SOLUTION: A treating tank 7 is provided with a chemicals injecting means 1 for injecting a reducer, an underwater pump 2 for jetting water, a mixing nozzle 3 which is connected with the chemicals injecting means and the underwater pump and simultaneously jets the reducer and water and a reaction tube 4 through which the reducer and the water jetted from the mixing nozzle 3 pass as turbulence. It is desirable that the reducer is at least one kind selected from the group composed of sodium hydrogensulfite, sodium sulfite, sodium thiosulfate, L-ascorbic acid, salts of L-ascorbic acid, gaseous sulfur dioxide and a mixture of gaseous sulfur dioxide and sodium sulfite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing halogenated acid generated by excessive oxidation of halogen ions contained in tap water, industrial water, groundwater, well water and the like.

[0002]

2. Description of the Related Art Ozone oxidation treatment of raw water containing halogen ions produces residual ozone or oxidized substances such as halogenated acids such as bromate ions, which may cause problems in carcinogenicity. Specifically, for example, harmful bromate ions are generated from ozone oxidation and the like from halogen ions, such as detection of trace amounts of bromate ions from tap water that has been subjected to ozone treatment. ing. As a solution for this, methods such as control of the ozone injection rate, reduction by treatment with activated carbon and biological activated carbon, and an ammonia-added ozone oxidation method have been adopted.

On the other hand, an apparatus for rapidly mixing ozone, chlorine, and the like into water is disclosed in US Pat. No. 4,199,983.

[0004]

The control of the ozone injection rate is one of the ideal methods for suppressing the generation of a small amount of halogenated acid. However, it is difficult to perform feedback control because of the small amount. there were.

The method of removing halogenated acid by the adsorption action of activated carbon and the reduction action on the surface can maintain a high efficiency while the activated carbon is new, but the bioactive carbon tends to have a reduced surface reducing power. However, there was a problem that the efficacy could not be maintained when the value fell.

[0006] The addition of ammonia or the like has a problem that the adverse effect of the surplus drug is expected.

[0007] Therefore, there has been a demand for an apparatus capable of reliably reducing the oxidized substance.

[0008]

In order to solve such problems, a high-speed stirring reduction system of the present invention comprises a chemical injection means for injecting a reducing agent, a submersible pump for blowing water,
A mixing nozzle connected to the chemical injecting means and the submersible pump to simultaneously blow the reducing agent and water; and a reaction tube through which the reducing agent and water blown from the mixing nozzle pass as turbulent flows.

By using the high-speed stirring reduction system of the present invention, it is possible to bring the reducing agent into contact with the halogenated acid more efficiently due to the effect of strong stirring by turbulence than mixing of chemicals by a stirring blade or the like.

[0010] Further, the system of the present invention can efficiently carry out the treatment with a simple device such as a submersible pump or a nozzle. Therefore, it is not necessary to separately provide a mechanical equipment for mixing chemicals, and further, a reaction tube is provided. This prevents the diffusion of the turbulent flow and maintains a strong stirring action, so that the reducing agent and the halogenated acid can be stably and sufficiently brought into contact with each other, and the outflow of untreated halogenated acid can be prevented. It can be prevented reliably.

The reducing agent is selected from the group consisting of sodium bisulfite, sodium sulfite, sodium thiosulfate, L-ascorbic acid, salts of L-ascorbic acid, sulfur dioxide, and a mixture of sulfur dioxide and sodium sulfite. Desirably more than species.

Further, when adding a reducing agent, it is preferable to add a pH adjuster.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart showing one embodiment of the high-speed stirring reduction system of the present invention.

In FIG. 1, a treatment tank 7 is divided into a first tank provided with an inlet 5 for receiving inflow water 5a and a second tank provided with an outlet 6 for discharging treated water 6a by a partition wall 7a. Have been.

The high-speed stirring reduction system according to the present invention comprises a chemical injection means 1 for injecting a reducing agent into a first tank of a processing tank 7.
And a mixing nozzle 3 connected to the chemical injecting means and the submersible pump and for simultaneously discharging the reducing agent and water. The mixing nozzle 3 is provided in the second tank in the front of the mixing nozzle 3 in the discharging direction. And the reaction tube 4 attached to the partition wall 7a.

The treated water in the first tank is jetted into the reaction tube by a submersible pump, or is attracted by this jet and flows into the reaction tube.

As the reducing agent to be added, sodium hydrogen sulfite, sodium sulfite, sodium thiosulfate, L-ascorbic acid and its salts, sulfur dioxide, a mixture of sulfur dioxide and sodium sulfite, etc. are used.

A reducing agent such as sodium hydrogen sulfite reacts stoichiometrically with an oxidizing substance in an equivalent amount, so that it is reliable as a treatment method and is safe as it is recognized as a food additive.

The inflow water 5a entering the first tank from the inflow port 5 is:
It contains a halogenated acid such as bromate ion such as ozonized water, which is reduced to harmless bromine ion by the high-speed stirring reduction system of the present invention.

Further, it is important to neutralize residual ozone contained in the ozonated water with a reducing agent from the viewpoint that it is not necessary to carry out waste ozone treatment with a catalyst or activated carbon.

[0021]

An embodiment of the present invention will be described below.

(Embodiment 1) The processing tank 7 shown in FIG.
, A submersible pump was placed. 0.720mg-BrO ₃
/ L potassium bromate solution is introduced as influent water 5a,
When a 2.64 mg / L L-ascorbic acid solution was added as a reducing agent, the bromate ion was 0.078 mg-L.
BrO ₃ / L. In terms of molarity, 5.02
15.0 μm to reduce μmol / L BrO ₃
This means that ol / L ascorbic acid was required, and it can be calculated that 3.0 mol of L-ascorbic acid is required to remove 1 mol of bromate ions.

With respect to reducing agents other than L-ascorbic acid, that is, sodium bisulfite, sodium thiosulfate and sodium sulfite, bromate ions were similarly removed by adding a reducing agent.

Table 1 shows the results.

[0025]

[Table 1]

The reaction formula between the bromate ions and the respective reducing agents is as follows:

[0027]

(Equation 1)

(Equation 2)

(Equation 3)

(Equation 4)

In the case of sodium sulfite, the molar ratio was somewhat higher, probably because it reacts with dissolved oxygen or oxygen in the air. However, in the case of other reducing agents, almost the theoretical amount of reaction occurred.

Example 2 As in Example 1, to remove 1 mol of iodate ions, 3.0 mol of L-ascorbic acid was required.

As for the reducing agents other than L-ascorbic acid, iodate ions were removed by adding the reducing agent in the same manner as in Example 1.

Table 1 shows the results.

Example 3 As in Example 1, 3.0 mol of L-ascorbic acid was required to remove 1 mol of chlorate ions.

As for the reducing agent other than L-ascorbic acid, chlorate ions were removed by adding the reducing agent in the same manner as in Example 1.

Table 1 shows the results.

Embodiment 4 Ozone water obtained by blowing ozone gas into pure water is introduced into the treatment tank 7 shown in FIG. 1 as the inflow water 5a, and the reducing agents shown in Table 2 are added to reduce the consumption of the reducing agent. The amount was measured.

Table 2 shows the results.

[0037]

[Table 2]

In the above reaction formula with a halogenated acid, the tendency is the same as when the molar ratio of sodium thiosulfate is twice that of the other reducing agents. Ozone reacts with the reducing agent in substantially the same amount as the halogenated acid.

[0039]

According to the present invention, it is possible to reliably remove halogenated acids, for example, bromate ions and residual ozone in water after the oxidation treatment. In addition, since the reducing agent used is a substance recognized as a food additive, it is safe for the human body even when applied to clean water. Even when ozone treatment is performed for the oxidation treatment, residual ozone can be reduced, so that waste ozone treatment is not required.

Furthermore, due to the strong stirring effect of the turbulence,
The reducing agent can efficiently contact the halogenated acid.

Further, since the system of the present invention can efficiently carry out the treatment with a simple device such as a submersible pump or a nozzle, there is no need to separately provide a mechanical equipment for mixing chemicals, and further, a reaction tube is provided. This prevents the diffusion of the turbulent flow and maintains a strong stirring action, so that the reducing agent and the halogenated acid can be stably and sufficiently brought into contact with each other, and the outflow of untreated halogenated acid can be prevented. It can be reliably prevented.

Thus, not only the equipment cost and the operating cost can be reduced, but also the work such as maintenance and management can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a high-speed stirring reduction system of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chemical injection means 2 Submersible pump 3 Mixing nozzle 4 Reaction tube 5 Inflow port 5a Inflow water 6 Outflow port 6a Outflow water 7 Treatment tank (1st tank, 2nd tank) 7a Partition wall 8 Turbulence area

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Koji Shinkawa, Inventor F-term in Nishihara Environmental Sanitation Research Institute, 3-6-18, Shibaura, Minato-ku, Tokyo 4D050 AA02 AA04 AB44 BA04 BA06 BA07 BC10 BD01 4G035 AB37 AC22

Claims (2)

[Claims] 1. A chemical injecting means for injecting a reducing agent, a submersible pump for blowing water, a mixing nozzle connected to the chemical injecting means and the submersible pump for simultaneously discharging the reducing agent and water, and a mixing nozzle blown out of the mixing nozzle. A high-speed stirring reduction system comprising a reaction tube through which a reducing agent and water pass in a turbulent manner. 2. The method according to claim 1, wherein the reducing agent is sodium hydrogen sulfite,
2. The method according to claim 1, wherein the sulfite is at least one selected from the group consisting of sodium sulfite, sodium thiosulfate, L-ascorbic acid, salts of L-ascorbic acid, sulfur dioxide, and a mixture of sulfur dioxide and sodium sulfite. 2. The high-speed stirring reduction system according to 1.