KR20090047641A - Wastewater treatment device by electroly-zation - Google Patents

Abstract

The present invention relates to an apparatus for treating wastewater by electrolysis, comprising: a collecting tank for collecting incoming wastewater; A pH adjusting tank for adjusting the pH by injecting caustic soda by introducing the wastewater collected for a predetermined time from the collecting tank, and injecting electrolyte from the salt dissolving tank; A flow rate adjusting tank for maintaining a constant pH and electrical conductivity of the wastewater introduced from the pH adjusting tank; An electrolysis tank for oxidizing and decomposing contaminants of the waste water by electrolyzing the wastewater introduced from the flow rate adjusting tank; A pressurized floatation tank in which wastewater passing through the electrolysis tank is introduced into the colloidal particles and the supernatant; A condenser to remove and flocculate the colloidal particles, which have been flocculated by electrical properties, by a scraper, and a dehydrator to dehydrate the concentrate transferred from the condenser and to cake; Intermediate secondary tank in which the supernatant separated from the pressure flotation tank is introduced and ferrous sulfate is aggregated to aggregate fine flocs; A settling tank for precipitating flocs aggregated in the intermediate collection tank; It consists of a discharge tank for discharging the supernatant of the settling tank.

Wastewater, Electrolysis, Wastewater Treatment Equipment, Pressurized Flotation Tank, PH Adjustment Tank, Caustic Soda, Electrolyte, Ferric Sulfate

Description

Wastewater treatment device by electroly-zation

The present invention relates to an apparatus for treating wastewater by electrolysis, and more particularly, to chemical contaminants in wastewater introduced by applying power to a plurality of electrode plates which are maintained at a predetermined interval inside the electrolysis tank. The present invention relates to an apparatus for treating wastewater by electrolysis which enables oxidation and decomposition of demand, COD), CN (CN), TN (total nitrogen), TP (total phosphorus), color, and E. coli by electrolysis.

It is well known that there is a lack of awareness of environmental conservation in the course of rapid economic development. Due to this lack of awareness of environmental conservation, the level of pollution as well as air quality has reached a very serious level. In particular, domestic sewage, livestock waste, and industrial wastewater cause pollution of public water and small and medium rivers.

Contaminants of conventional sewage, livestock waste, and industrial wastewater are mainly organic matter decomposable by certain microorganisms, but in recent years, due to rapid industrial development, population growth, and urban population concentration, various pollutants in wastewater The proportion of inorganic and organic components is increasing gradually. In particular, wastewater from livestock facilities, wastewater from leather factories, and wastewater from dyeing factories are industries that discharge malignant wastewater, and may be the biggest cause of polluting water quality such as rivers, lakes and coasts.

As mentioned above, the standard activated sludge method using the floating growth of microorganisms has been almost universally used in treating domestic sewage, livestock wastewater and industrial wastewater. However, the existing activated sludge method is difficult to remove and separate the impurities contained in the wastewater in public waters and urban rivers, and many problems have arisen in the maintenance of management.

In addition, the treatment of hardly degradable wastewater, such as leachate, dyeing wastewater and plating wastewater, is a method of performing biological treatment after chemical flocculation. However, the phosphorus removal effect of the chemical coagulation treatment is high, but nitrogen removal is insufficient.

Therefore, biological treatment of hardly degradable wastewater that has not been completely treated is not effective in treating wastewater, and wastewater such as leachate contains high concentration of chromaticity, and thus it is difficult to remove chromaticity to an appropriate level only by biological treatment.

In recent years, electrolysis devices have been attracting attention. By arranging a plurality of electrodes made of iron or aluminum having an anode and a cathode in an electrolytic cell, the waste water is passed through to oxidize the organic matter present in the waste water as molecular materials and ionic substances. It is a method of purifying by causing reduction and decomposition reactions.

However, since the electrolytic apparatus basically iron or aluminum constituting the electrode is easily oxidized by the waste water, there is a difference in the performance of the early and later installation, there was a problem of increased maintenance costs due to frequent replacement, each electrode is parallel Since the wastewater inflow is variable according to the situation, the treatment capacity cannot be changed, so when the wastewater inflow is small, the efficiency decreases, and aftertreatment of the by-products processed through the electrolysis device is required. There was a problem that the apparatus was enlarged.

In addition, the conventional electrolysis device performs only the role of chromaticity and sterilization as an auxiliary means of the wastewater treatment facility, the simultaneous removal of COD, CN, T-N, T-P and the like was not made.

In order to solve the above problems in the present invention, the object is the COD (Chemical Oxygen Demand, COD), CN (CN), TN (total nitrogen), TP (total phosphorus), The present invention provides a wastewater treatment apparatus through electrolysis, which enables oxidation and decomposition of chromaticity and E. coli by electrolysis.

In addition, it is possible to efficiently remove COD, CN (CN), TN, TP, color and E. coli in the wastewater by adjusting the treatment process according to the requirements according to the water quality of the incoming wastewater and the water quality of the treated water. It is possible to obtain good treated water economically and stably because it does not need additional equipment due to inflow load fluctuations such as water quality change by constructing the decomposition cell in series and maintaining the pH and electrical conductivity at a constant level as electrolysis pretreatment. The present invention provides a wastewater treatment apparatus by electrolysis.

In addition, it is intended to devise an optimal treatment plan using electrolysis, and to provide a treatment method using electrolysis considering optimum operating conditions and its practicality.

In order to achieve the above object, the present invention is to inject salt aqueous solution from the salt dissolving tank as an electrolytic material to reduce the electrical resistance and to add pH caustic soda to maintain the pH to 9 to 10 electrolysis of the pH adjusting tank and the flow adjusting tank Placed in front of the tank, the incoming wastewater can be oxidized and decomposed to the optimum conditions in the electrolysis tank.

In addition, electrolysing the wastewater introduced from the flow rate adjusting tank to electrolyze and decompose contaminants in the wastewater, and pressurized wastewater passing through the electrolysis tank to separate colloidal particles and supernatant. Flotation tanks were installed.

In addition, a condenser to remove and concentrate the colloidal particles flocculated by electrical properties by a scraper, and a dehydrator for dehydrating cakes by dehydrating the concentrate transferred from the concentrator; The supernatant separated from the pressurized floatation tank was introduced, and an intermediate secondary tank was installed in which ferric sulfate was added to aggregate fine flocs.

According to the present invention as described above, it is possible to obtain a stable treated water quality actively according to the water quality of the high concentration of hardly-decomposable wastewater and the requirements of the treated water, and the problems of management and maintenance costs that act as a problem of biological treatment It is an economical wastewater treatment system that is not affected by climate. In addition, it can be applied to pollutants such as chromaticity and E. coli. In particular, by effectively removing TN and TP, it is possible to stably obtain good water quality, and to significantly reduce sludge and secondary pollution by wastewater treatment chemicals used in general wastewater treatment. Can be reduced. In addition, the installation is simple, the installation area is minimized, and the treatment conditions can be applied differently depending on the amount of wastewater introduced, which makes the wastewater treatment device capable of efficient purification.

In order to achieve the above object, the present invention is a collection tank for collecting the waste water introduced;

A pH adjusting tank for adjusting the pH by injecting caustic soda by introducing the wastewater collected for a predetermined time from the collecting tank, and injecting electrolyte from the salt dissolving tank;

A flow rate adjustment tank for maintaining the pH and electrical conductivity of the wastewater introduced from the PH adjustment tank;

An electrolysis tank for oxidizing and decomposing contaminants of the waste water by electrolyzing the wastewater introduced from the flow rate adjustment tank;

A pressurized floatation tank in which wastewater passing through the electrolysis tank is introduced into the colloidal particles and the supernatant;

A condenser to remove and flocculate the colloidal particles, which have been flocculated by electrical properties, by a scraper (Sc -raper), and to concentrate and dehydrate the concentrate transferred from the condenser;

Intermediate secondary tank in which the supernatant separated from the pressure flotation tank is introduced and ferrous sulfate is aggregated to aggregate fine flocs;

A settling tank for precipitating flocs aggregated in the intermediate collection tank;

It consists of a discharge tank for discharging the supernatant of the settling tank.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart showing an apparatus for treating wastewater using electrolysis according to the present invention.

First, a wastewater tank is collected for a predetermined time by installing a water collecting tank to collect the wastewater flowing in. The collected waste water is introduced into the PH adjusting tank from the sump.

In the pH adjusting tank, the pH is adjusted to 9 to 10 by injecting caustic soda to adjust the optimum pH to induce flocculation of the flocculant. In particular, when the incoming wastewater is high in suspended solids, colloidal particles, and the like, the concentration of phosphorus is abnormally high and the chromaticity is high.

In addition, when the electrolyte is insufficient in the waste water, the electrolytic efficiency decreases due to an increase in electrical resistance, resulting in an increase in power ratio. For this reason, electrolyte is injected into the pH adjusting tank from the salt dissolving tank. In particular, the electrical conductivity in the wastewater is preferably maintained 5 to 15ms.

Waste water into which caustic soda and electrolyte are introduced in the pH adjusting tank is introduced into the flow adjusting tank to maintain a constant pH and electrical conductivity and to adjust the flow rate.

The wastewater of the flow rate adjustment tank is forced to enter the electrolysis tank by a pump to undergo electrolysis, thereby oxidizing and decomposing contaminants of the waste water. In the electrolysis process, it is preferable to supply a direct current by using a DC power supply-only rectifier capable of converting a positive electrode and a negative electrode to maintain a constant constant voltage constant current. Electrolyzing the wastewater flowing into the electrolysis tank produces hydroxide ions, hypochlorous acid, generator oxygen, and the like, and these oxidizing substances act on the organic substances to cause oxidation, thereby removing the organic substances.

In particular, the electrolytic bath according to the present invention has an electrolytic cell connected in series, and the electrolytic bath has an advantage of being less affected by the external environment as a closed type. Therefore, when the electrolysis tank is operated, the wastewater is pushed to the inside of the electrolysis tank equipped with the anode and cathode cells by pressurization so that the electrolysis reaction starts and ends only in the electrolysis tank without contact with external air until the end point. The reaction takes place. At this time, the voltage supplied to the electrolysis tank is 5V per cell, the current is to maintain 200A, the waste water passing through the electrolysis tank is to maintain a pressure of 1 to 2kg / cm ² .

Wastewater passing through the electrolysis tank is separated into colloidal particles and supernatant in a pressurized floatation tank. The colloidal particles are floccated by electrical properties and float on the surface of the upper part of the pressure relief tank.

The floc is first removed by a scraper and transferred to a concentration bath.

The floc transferred to the thickener is caked through a dehydrator.

On the other hand, the supernatant separated from the pressure flotation tank flows into the intermediate secondary collection tank and aggregates fine floc by adding ferric sulfate or ferric chloride as a flocculant. It is preferable that the said coagulant is a polyvalent cation metal salt.

A sedimentation tank is provided for sedimenting floc aggregated in the intermediate secondary collection tank, and the supernatant of the sedimentation tank is discharged by installing a discharge tank.

The present invention is a contaminant in rivers, lakes, coastal sewage, livestock waste, industrial wastewater and leachate, dyeing wastewater, plating wastewater, COD, CN (CN), TN (total nitrogen), TP (total phosphorus), chromaticity And a wastewater treatment apparatus capable of treating E. coli and the like.

1 is a flow chart showing an apparatus for treating wastewater by electrolysis according to the present invention.

Claims (1)

A sump collecting the inflowing wastewater; A pH adjusting tank for adjusting the pH by injecting caustic soda by introducing the wastewater collected for a predetermined time from the collecting tank, and injecting electrolyte from the salt dissolving tank; A flow rate adjustment tank for maintaining the pH and electrical conductivity of the wastewater introduced from the PH adjustment tank; An electrolysis tank for oxidizing and decomposing contaminants of the waste water by electrolyzing the wastewater introduced from the flow rate adjustment tank; A pressurized floatation tank in which wastewater passing through the electrolysis tank is introduced into the colloidal particles and the supernatant; A condenser to remove and flocculate the colloidal particles, which have been flocculated by electrical properties, by a scraper (Sc -raper), and to concentrate and dehydrate the concentrate transferred from the condenser; Intermediate secondary tank in which the supernatant separated from the pressure flotation tank is introduced and ferrous sulfate is aggregated to aggregate fine flocs; A settling tank for precipitating flocs aggregated in the intermediate collection tank; A discharge tank for discharging the supernatant of the settling tank; Waste water treatment apparatus by electrolysis, characterized in that consisting of.

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