JPH06296992A - Method for decomposing waste liquid containing organic acid - Google Patents

Abstract

PURPOSE:To stably decompose the org. acid in a waste liq. into carbon dioxide with a relatively small-sized equipment by simultaneously applying electrolysis, ozonation and UV irradiation to the waste liq. CONSTITUTION:A UV lamp 7 and an ozone blowing diffuser ball 13 are provided on the bottom in a reaction vessel 4 consisting of a cylindrical tower, and a couple of ferrite electrode plates 8 are suspended at the upper part of the vessel 4. An org. acid-contg. waste liq. is charged into the vessel 4, oxygen supplied from a gaseous oxygen cylinder 1 is controlled to a specified ozone concn. by an ozonizer 2 to obtain an ozonized gas which is diffused into the waste liq. from the ball 13, the lamp 7 is lit, and a current is applied to the electrode plates 8 to bring about electrolytic oxidation. The TOC of org. acid is efficiently removed by such a combination of electrolytic oxidation, ozonation and UV irradiation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing an organic acid-containing waste liquid, for example, a lunch center, a seafood processing plant, a fruit canning factory, a beer factory, a brewing factory for liquor, etc. Applicable to the same method.

[0002]

2. Description of the Related Art Wastewater containing organic acids causes pollution of rivers and swamps, that is, causes eutrophication, and therefore it is necessary to remove the organic acids before discharging. As a conventional method, an underwater combustion method, an evaporation method, and a spray combustion method are used when a high concentration of organic acid is contained. Relatively low concentration of organic acid (1000m
g / l or less), a method for treating activated sludge with microorganisms is used.

[0003]

Since the reaction rate of the activated sludge treatment method using microorganisms is slow, a large site is required to carry out a large volume treatment. TOC of organic matter
(Total Organic Carbon) component remains considerably. p
It requires H and temperature control, especially in winter.
It is required to maintain a constant concentration at all times, and even temporary mixing of poisonous substances and temperature rise, for example, about 50 ° C. are not allowed.
There are problems such as the inability to mix in substances that violate the physiological action of microorganisms.

In view of the above-mentioned state of the art, the present invention is intended to provide a method capable of decomposing organic acids in water by a stable operation without the problems of the activated sludge treatment method by microorganisms.

[0005]

The present invention is characterized in that, in the decomposition of an organic acid-containing waste liquid, the organic acid in the waste liquid is decomposed to carbon dioxide gas by simultaneously performing electrolytic treatment, ozone treatment, and ultraviolet irradiation treatment. It is a method for decomposing waste liquid containing organic acid.

The general conditions of the electrolytic treatment, ozone treatment, and ultraviolet irradiation adopted in the decomposition of the organic acid-containing waste liquid in the present invention are as follows. Electrolytic treatment conditions Positive electrode: Ferrite, PbO _2, etc. Negative electrode: Ferrite, SUS316, Ti, Cu, etc. Current density: 1 A / dm ^{2 to} 20 A / dm ² Stirring: Stirring with a stirrer (or stirring with ozone-containing oxygen gas described later) ) Gap: 10 to 50 mm, 20 V Ozone treatment condition Ozone concentration: 10 to 50 mg / liter UV irradiation condition 20 watts or more, 1 hour or more irradiation

[0007]

[Action] Ozone - electrolyte - by reaction as is shown below in simultaneous reaction of the _{ultraviolet, · OH, · OH 2,} O 3 -, O 2
^- , O-, ^and other active radical species are generated, and these cause decomposition of the TOC component. 〇 electrolytic processing ^{_{OH 3 + + OH - → O}} 2 - + OH 2 OH 3 + + · OH → O 2 - + · OH 2 OH 3 + + OH - → O 3 - + · OH · OH + OH - → O ^{_{- + H 2 O O - +}} OH 2 → O 3 - 〇 ozone treatment, ultraviolet treatment _{O 3 + H 2 O + hν} → 2 · OH + O 2 Thus ozone - electrolyte - strong oxidizing by simultaneous reaction of the ultraviolet A large amount of OH etc., which is a characteristic radical, is generated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. The reaction tank 4 is composed of an acrylic resin cylindrical tower having an inner diameter of 11 cm and a height of 40 cm, and has an ultraviolet lamp (internal irradiation type low pressure mercury lamp) 7 and an ozone blowing diffuser ball 13 at the bottom of the tank.
The ferrite electrode plate 8 of 50 mm square was placed above the tank by suspending it from the ceiling with a gap of 30 mm.

Amount of air fed from the oxygen gas cylinder 1 is 2 liters /
Oxygen concentration of min oxygen is 30mg with ozone generator 2.
/ L, and this ozonized gas is fed into the sample solution shown in the following Table 1 through the ozone metering diffuser ball 13 via the flow meter 3 and the ultraviolet power source 6 is adjusted to 30 from the ultraviolet lamp 7. Irradiate the sample solution with watts of ultraviolet light,
An electrolytic solution density of 2.5 A / dm ² and a current of 1 A were passed between the electrode plates 8 to carry out electrolytic oxidation. In FIG. 1, 5 is a sample solution sampling cock, 9 is a constant current device, 10 is an ammeter, 11 is an ozone meter, and 12 is an exhaust gas ozone absorption tower.

[0010]

[Table 1] The results are shown in Table 2 below.

[0011]

[Table 2] From the results of Table 2 above, the TOC removal rate of the organic acid is 99% by the comprehensive treatment method of electrolytic oxidation + ozone treatment + ultraviolet irradiation.
It will be clear that was achieved.

[0012]

EFFECTS OF THE INVENTION According to the present invention, organic acids in wastewater can be decomposed by a stable operation without the problems of the activated sludge treatment method by microorganisms.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C02F 1/78 ZAB 9045-4D

Claims (1)

[Claims] 1. Decomposition of an organic acid-containing waste liquid, characterized in that in the decomposition of an organic acid-containing waste liquid, an organic acid in the waste liquid is decomposed to carbon dioxide gas by simultaneously performing electrolytic treatment, ozone treatment, and ultraviolet irradiation treatment. Law.