JPS6064688A - Electrolytic oxidation treatment of waste water - Google Patents

Abstract

PURPOSE:To enable the adaptation of biological treatment by treating an org. substance within a short time, by a method wherein a part of raw water is diluted to be subjected to electrolytic oxidation treatment and, after a part of the electrolyzed liquid is discharged, raw water is supplied to an electrolytic cell in an amount same to the discharged amount to be again subjected to electrolytic treatment. CONSTITUTION:At first, a part of raw water is diluted so as to reduce, for example, a TOC concn. to 5,000ppm and electrolytic oxidation treatment is applied to the diluted water. If the concn. of the electrolyzed liquid reaches a predetermined concn., for example, 1,500ppm as the TOC concn., the signal from a TOC meter 4 is inputted to a converter 3 and a control order is issued to open the value 10 of a discharged system while the valve 9 of a recirculation system is closed and a difinite amount of the electrolyzed liquid is discharged by a constant time pump 8. In the next step, the valve 9 of the recirculation is opened while the valve 10 of the discharge system is closed and, thereafter, a definite amount of raw water to be treated is supplied to a constant time electrolytic cell 5 from a raw water storage tank 1 and the concn. of the electrolyzed liquid is adjusted to the predetermined TOC concn. of 5,000ppm at the start time of electrolysis.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for electrolytically oxidizing wastewater containing organic matter.

Traditionally, combustion treatment,
Methods such as evaporative condensation treatment, electrolytic oxidation treatment, and biological treatment have been used, but when combustion treatment is used, there are problems with the treatment of harmful gases contained in exhaust gas and safety, and evaporative condensation treatment decreases thermal efficiency, generates odor due to thermal decomposition,
There is a problem with distillation of BOD and COD components into condensed water.
In any case, there are many drawbacks in terms of equipment cost, economy, safety and efficiency. In addition, it takes a long time to directly decompose wastewater containing organic matter to a low δλ degree by electrolytic oxidation treatment, and in order to reduce the load on electrolytic oxidation treatment, an oxidizing agent is used as a pretreatment for electrolytic oxidation treatment. For example, when oxidation treatment is performed using permanganate, sodium hypochlorite, or Fenton's reagent, the treatment process becomes complicated due to the generation of precipitates, etc., and a sufficient treatment effect is not obtained.

Considering the aspects of treatment cost, safety, biological treatment,
For example, the activated sludge method is the most promising, but it is difficult to apply biological treatment due to the presence of organic substances that have an inhibitory effect on microorganisms contained in wastewater.Ia1. There are many cases.

An object of the present invention is to provide a highly practical treatment method that solves the above-mentioned problems.

In the electrolytic oxidation treatment of wastewater containing a large amount of organic substances having an ultraviolet effect against microorganisms such as complexing agents generated in the plating process, the present invention first processes a portion of the wastewater with a TOC concentration of 01 ppm. at a predetermined concentration, e.g. C,
After diluting the solution to ppm, the solution is electrolytically oxidized to a predetermined concentration, for example, Csppm, and then a part of the electrolyte is discharged. The treated raw water CtPpm wastewater is discharged so that the electrolyte concentration is 1fcC*pPm, the same amount is replenished into the electrolytic cell, and the electrolytic oxidation treatment is performed again until the electrolyte GJi becomes Cmppm, and the initial concentration of the electrolyte is [C! Treated raw water C while controlling Ppm to reach the end point concentration Csppm,
This is an electrolytic oxidation treatment method for wastewater containing organic matter, characterized in that a fixed amount of ppm wastewater is supplied to an electrolytic cell and subjected to electrolytic oxidation treatment.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The figure shows an example of an electrolytic oxidation treatment apparatus for carrying out the method of the present invention. In figure 0, the treatment apparatus has a storage tank 1 for treated raw water, an electrolytic tank 5 that feeds the treated raw water, and a tank for measuring the amount of electrolyte solution. TOC meter 4, electrolyte discharge system and circulation system pipes, valves 10 and 9 for opening and closing the discharge system and circulation system pipes, and TOC meter 4;
It is equipped with a converter 3 and the like that control valves 9 and 10 in response to commands from the C meter 4. In addition, 2 is a pump that supplies the raw water in the treatment tank 1 to the electrolytic tank 5, 8 is a pump common to the circulation system discharge system, 7 is a power source for electrolysis, and 6 is an electrolytic electrode.

First, a portion of the wastewater shown in Table 1 is first treated with, for example, TOC.
The solution was diluted to a concentration of 5,000 pprn, the solution was deoxidized under the electrolysis conditions shown in Table 2, and the TOC concentration of the electrolyte was measured using the TOC meter 4 shown in the figure.

[Table 1] Water quality of wastewater [Table 2] Electrolytic conditions Electrolyte concentration power i At a predetermined concentration, for example, TOC concentration, 1.
When it becomes 500 ppm or less, a signal indicating that the Toe meter 4 is empty is input to the converter 3, a control command is issued, and the valve l of the discharge system is activated.
0, close the circulation system valve 9, and pump 8 for a certain period of time.
A certain amount of electrolyte Vol. is discharged. Next, the valve 9 of the circulation system is opened, the valve 10 of the discharge system is closed, and a certain amount of treated raw water (Vol) is supplied from the post-treated raw water storage tank 1 to the electrolytic cell 5 for a certain period of time using the supply pump 2, and electrolyzed. The concentration of the solution is adjusted to a predetermined TOC concentration of 5,000 ppm at the start of electrolysis.

Similarly, the treated raw water in the treated raw water storage tank 1 is supplied in fixed amounts to the electrolytic tank 5 in accordance with changes in the concentration of the electrolytic solution for electrolytic oxidation treatment.

According to the electrolytic oxidation treatment method of the present invention, wastewater containing organic matter can be decomposed to a low concentration in a short time, and the treated liquid can be subjected to biological treatment, so that residual organic matter can be easily removed. can.

In the electrolytic oxidation treatment apparatus of the example, a TOC meter was used as the concentration meter, but the effect remains the same even if a COD meter is used in place of the TOC meter.

[Brief explanation of drawings]

The figure is an explanatory diagram of the electrolytic oxidation treatment procedure of the present invention. In the figure, 1 is treated raw water storage tank, 2 is treated raw water supply pump, 3
4 is a converter, 4 is a TOC meter, 5 is an electrolytic cell, 8 is a circulation pump, 9 is a valve (circulation), and 10 is a valve (discharge). Patent applicant: NEC Corporation

Claims (1)

[Claims] (1) Part of the treated raw water is diluted to a predetermined concentration and subjected to electrolytic oxidation treatment in an electrolytic solution until the predetermined concentration is reached, and when the electrolyte reaches a predetermined level of punishment, a portion of the electrolyte is discharged. Then, the same amount of treated raw water as the discharged amount is supplied from the raw water storage tank to the electrolytic tank, the concentration of the electrolyte is adjusted to the concentration at the start of electrolysis, and the process of electrolytic treatment is repeated again. A method for electrolytic oxidation treatment of wastewater containing organic matter.