KR20040084586A - Treatment method of wastewater containing recalcitrant compounds and apparatus therefor - Google Patents

Abstract

PURPOSE: To remove recalcitrant compounds from wastewater, by using fenton oxidation and ozone bubble flotation. CONSTITUTION: The method comprises steps of after coagulating raw water in a coagulation tank (C), transferring the coagulated water to an automatic filtering device (J); after separating sludge and supernatant from the coagulated water, transferring the separated supernatant to a fenton oxidation tank (F); after putting additives in the supernatant with stirring to oxidize, transferring the oxidized water to an exit chamber (U) of a dissolved air flotation (DAF) tank (A); compulsorily removing floating materials in the oxidized water transferred to the exit chamber by being adhered to and adsorbed by ultrafine bubbles, which are exited and spread at an exit valve(14-1); after pressurizing ozone by an ozone pressurizer (K) where the ozone is supplied from an ozone generator (O), putting the pressured ozone in a bubble generator (G); after generating pressurized ozone bubble water by the bubble generator, transferring it through a transfer pipe(15) to an exit valve(14) to exit ultrafine ozone bubbles to the lower part exit chamber (V); contacting recalcitrant compounds with the ozone of the exited ultrafine ozone bubbles to oxidize and decompose the recalcitrant compounds; after continuously measuring the water quality of the treated water transferred to an outflow chamber (B), stopping the discharge of the treated water when the quality of the treated water is below the standard and transferring it to the fenton oxidation tank or the DAF tank again; after measuring the treated water flown in the outflow chamber after the retreatment, discharging it when the quality of water reaches to the standard value; and cutting-off the outflow of the treated water when the quality of water is below the standard and repeatedly oxidizing and decomposing the wastewater.

Description

Effluent quality control refractory wastewater treatment apparatus and method {omitted}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and a method for treating effluent degradable wastewater, and an apparatus and method for treating wastewater containing hardly decomposable organic substances such as chemical, plating, and dyeing wastewater.

Wastewater, such as chemical, plating, leather, and dyeing wastewater, discharges wastewater containing toxic substances and various kinds of hardly decomposable organic substances such as PVA, benzene, cresol, crylene, naphthalene, toluene, phenol, pyridine, trichloro, and ethylene. However, these hardly decomposable organic substances are not easily decomposed by microorganisms, and even if they are partially decomposed, the decomposition rate is very slow, and when discharged as it is, it remains in the natural world and adversely affects the natural ecosystem. do.

In the conventional biological treatment, this hardly decomposable organic substance is not treated well, and the chemical oxidation process is added to enable the treatment.

In recent years, oxidation and decomposition treatment methods using ultraviolet rays / hydrogen peroxide, ultraviolet rays / titanium dioxide, ozone / hydrogen peroxide and the like have been introduced.

However, in the ultraviolet decomposition process, when the pollution concentration in the water increases, the light is blocked by the suspended matter, the pollutants adhere to the lamp, and the efficiency decreases. In the titanium dioxide process, the catalytic activity decreases when the organic matter concentration is high. In the case of the fenton oxidation method, the input of expensive treatment agents such as hydrogen peroxide and auxiliary agents (iron salt, ferric sulfate, etc.) increases, and when the concentration is high, the treatment efficiency is lowered, and a lot of sludge is generated after the oxidation treatment. In order to do this, a sedimentation tank or the like must be introduced, and in the ozone oxidation treatment, not only a considerable amount of injected ozone is discharged to the atmosphere, but also an ozone contact tank and floating material separation facilities are required as an auxiliary device in the ozone generator.

As described above, in the decomposition treatment of hardly decomposable organic substances, the efficiency of oxidation / decomposition treatment decreases due to the characteristics of the wastewater and the concentration of pollution, and it is expensive. In addition, malfunction of the device, operation error, or sudden change of pollution concentration are caused. Treated water that does not meet the emission standard set by the effluent is discharged and causes a problem of polluting the environment.

As described above, the present invention has various problems in difficult-to-decomposable wastewater treatment. In order to reduce the cost in the fenton oxide (H 2 O 2) treatment, sludge is removed from a general chemical flocculation treatment, and then a fenton oxidation treatment process is introduced. The sludge generated from the fenton oxidation treatment is subjected to the flotation separation treatment in the flotation tank and the ozone oxidation treatment in the same apparatus, and the ozone injected for the ozone oxidation is ultra-saturated, minimizing the waste of ozone from being discharged to the atmosphere. On the other hand, in the discharge of treated water, a discharge standard value is set, and a method of blocking discharge of the treated water below the set discharge standard value is introduced.

As a method for achieving the above object, the apparatus is connected and configured in the order of chemical flocculation tank, automatic washing filtration device, fenton oxidation tank, flotation separator, and discharge water quality control device.

Inexpensive general chemical treatment method coagulates suspended solids in water, removes sludge in an automatic filtration system for a short time, transfers the supernatant water to the Fenton oxidation tank for oxidation treatment, and directs the oxidation treatment water directly into the flotation separation tank. In order to remove the suspended solids by flotation, the suspended solids generated during the fenton oxidation treatment are removed, and at the same time, the ozone oxidation treatment is performed in the same flotation tank to discharge the treated water.

In general ozone oxidation treatment, a considerable amount of injected ozone is discharged to the atmosphere, and in order to minimize it, ultra-saturation is saturated and discharged and diffused.

On the other hand, in the discharge of the last treated water, a discharge water quality control device is installed, and the discharge reference value is set in advance in this device, and the treated water transferred to the discharge chamber is continuously measured. It is an object of the present invention to provide a hardly decomposable wastewater treatment method for discharging when the discharge standard is reached and discharged when the discharge standard value is reached.

1 is a block diagram of a device

<Explanation of symbols for main parts of drawing>

C flocculation tank J automatic filtration

F Fenton Oxide O Ozonizer

K ozone pressurizer G ultra-fine air bubble generator

A Flotation tank R Discharge water quality control device

S Sludge P Flotation Separation Room

U All discharge chambers V Rear discharge chambers

M Reverse Transfer Pump B Discharge Room

1 Raw water inlet pipe 2 Solenoid valve

3 Coagulant injection line 4 Coagulant feed pipe

5 Pneumatic pipe 6 Air diffuser

7 Supernatant feed pipe 8 Hydrogen peroxide injection tube

9 Oxidation water transfer pipe 10 Agitator

11 Switchgear 12 Reverse feed pipe

13 Drain pipe 14 Ozone bubble discharge valve

14-1 Bubble discharge valve 15 Ozone bubble pump

15-1 Pressure Pipe 16 Supply Pipe

18 controllers with 17 sludge recovery

19 COD Meter 21 Bubble Water Supply Pipe

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of a device,

C is an agglomeration treatment tank which performs agglomeration treatment, and this agglomeration treatment tank is divided into two quarters and divided into two chambers. The agglomerated raw water is agglomerated and transferred to the next process. Raw water inflow pipe (1) is installed from the outside, the electromagnetic opening and closing valve (2) is attached to this pipe to open and close operation by the discharge water quality control device, the cohesive water transfer pipe (4) to transfer the treated water to the next process (4) ) Is attached at the top, and an air diffuser 6 is attached at the lower part and connected to the compressed air pressure feeding pipe 5, and this air diffuser is for stirring in a short time, and the flocculant injected by this stirring The flocculation treatment takes place in a short time, and the injection amount of the flocculant is controlled by the PH value control.

J is an automatic washing filtration device (Utility Model Registration No. 0275533), inside is a device composed of a filter cloth, 11 is an opening and closing device mounted on the lower part of the automatic washing filtration device and on the lower floor of the automatic filtration device. When dewatered and stored sludge (S) is discharged to the outside, 7 is a transfer pipe for transferring the filtered supernatant water to the next process, and the solenoid valve 2-1 is installed on the transfer pipe and the lower side thereof. In the reverse feed pipe 12 is connected, the electromagnetic opening and closing valve is opened and closed by the control unit 18 of the discharge water quality control device.

Automatic washing filtration system is composed of a pair of processing lines, alternately operating and rest time, sludge sedimented at the bottom during the rest time is natural dehydration.

Coagulated water flowing from the coagulation treatment tank (C) is separated into sludge and supernatant, and the separated supernatant is immediately filtered and transferred to the Fenton oxidation tank along the discharge path.

On the other hand, sludge made of natural dehydration at rest time to open and close the opening and closing device 11 to the outside.

The condensed water flowing into the device is characterized in that the supernatant is separated and discharged to the outside in a short time 10 minutes before and after.

This device can be replaced by a settling tank.

F is a Fenton oxidation tank, 8 is hydrogen peroxide (H2O2) injection tube, 8-1 is an auxiliary (iron salt, ferric sulfate, etc.) injection tube, 10 is agitator, and 9 is connected to the floating separation tank by oxidized water transfer pipe. It is.

When the supernatant flows from the automatic filtration system, supplements (ferric salt, ferric sulfate, etc.) and hydrogen peroxide (H2O2) are injected in a predetermined order, the injection amount is adjusted by the controller, and the stirring operation is performed for a predetermined time. The oxidation treatment proceeds, and the oxidation treatment water is transferred to the floating separation tank A through the transfer pipe 9.

A is a floating separation tank (Utility Model Registration No. 0259168), where U is the whole discharge chamber, V is the rear discharge chamber, P is the separation chamber, and B is the discharge chamber. Part (B) stores the final treated water while supplying some of it to the bubble water and discharging the rest to the outside, 15-1 is connected to the pressurized bubble water pressure pipe, and 14-1 is connected to the pressure pipe 15-1. Discharge valve attached to discharge chamber, 15 is pressurized ozone bubble water pressure pipe, 14 is connected to pressure pipe 15, ozone discharge valve is attached to rear discharge chamber, and 13 is treated water in discharge chamber. A discharge pipe that is transported to the process or discharged to the outside.

Sufficient substances are generated in the oxidized water by auxiliary agents (ferrous salt, ferric sulfate, etc.) injected during the fenton oxidation treatment. When the floc formation is poor in the whole discharge chamber (U), anion, etc. A small amount of the auxiliary coagulant is injected, and the injected coagulant is formed by the flocculation by stirring and discharging force of the ultra low-density cloth discharge valve 14-1 discharged into the ultra low-density cloth discharge valve 14-1. It is attached to and adsorbed on the gun and forced to surface.

The ultra-fine foam discharge valve 14-1 and the ultra-fine ozone bubble discharge valve 14 perform a constant pressure discharge operation at a preset pressure.

The ultra-fine ozone bubbles discharged from the rear discharge chamber (V) diffuse into the discharge chamber at a rapid rate, contact with the hardly decomposable substances, oxidize and decompose the hardly decomposable organic substances, and the remaining ozone is reduced to oxygen to reduce the It increases the amount of dissolved oxygen.

In the flotation separation tank, the flotation separation process and the ozone oxidation treatment of suspended solids are simultaneously performed in the same apparatus.

O is an ozone generator that generates ozone and transfers it to an ozone pressurizing device (K) through a required pipe, and the ozone pressurizing device that receives ozone from the ozone generator pressurizes ozone at a predetermined pressure to generate an ultra-fine foam generator (G). Press it into

G is an ultra-fine foam generating device (Utility Model Registration No. 141776), which is connected to the pressurized ozone bubble water pressure feed pipe 15, and mixes the pressurized ozone and the bubble water supplied by the ozone pressurizing device K. After processing, ultra-fine ozone bubble water is generated and pumped to the discharge valve 14 through the pressure feed pipe 15.

G-1 is an ultra-fine foam generator (Utility Model Registration No. 141776), which is connected to a pressurized bubble water pressure feed pipe 15-1, mixes and processes compressed air pressurized from an air compressor and supplied bubble water. To generate ultra-low intensity catchers and pump them to the discharge valve 14-1 through the pressure feed pipe 15-1.

R is a discharge water quality control device (Utility Model Registration No. 0289623), which is composed of a control unit 18, a COD meter unit 19, and a reverse feed pump unit (M), and the control unit is an electromagnetic valve attached to the raw water inlet pipe. (2) and the opening and closing of the solenoid valve (2-1) attached to the upper water feed pipe (7) of the automatic washing filter, and the reverse feed pump (M) is the suction pipe 20 on the suction side discharge chamber ( B), 12 is a reverse feed pipe 12, which connects the reverse feed pump discharge side and the Fenton oxidation tank to each other, and the COD meter is connected to the discharge chamber B, and the discharge reference value is set in advance. Continuously measure the treated water to be discharged to discharge chamber (B) based on the above, and if it does not meet the discharge standard, operate the reverse feed pump (M) to transfer the treated water from the discharge chamber to the Fenton oxidation tank and at the same time Solenoid valve (2) attached to the pipe, electrons attached to the upper feed water transfer pipe (7) of the automatic filtration system The valve 2-1 is closed to stop the inflow of raw water and the transfer of supernatant water.

The treatment water that is not discharged to the discharge reference value by the operation to the discharge chamber is transferred to the Fenton oxidation tank is reprocessed.

The treated water below the discharge standard value may be transferred to a flotation tank for reprocessing.

As the reprocessing operation proceeds, the treated water transferred to the discharge chamber reaches the discharge reference value, and the discharged water quality control device measures this and stops the reverse transfer pump and opens the electromagnetic switch valve 2 · 2-1.

The operation of the embodiment configured as described above will be described.

As raw water flows into the coagulation treatment tank, compressed air is discharged from the air diffuser, the required amount of coagulant is injected from the coagulant injection pipe, and the coagulant is reacted and coagulated in a short time by the discharge fluctuation force of the compressed air. It is conveyed to the automatic filtration device J through the conveying pipe 4.

The flocculation water transferred to the automatic filtration system is separated from the sludge and the supernatant as flocs are formed, and the separated supernatant is immediately filtered and transferred to the Fenton oxidation tank F along the conveying pipe 7 through the conveying passage.

When the supernatant is introduced into the Fenton oxidizing tank F, the stirring device rotates at a predetermined speed, and the necessary amount of auxiliary agent (iron salt, ferric sulfate, etc.) and hydrogen peroxide are injected through the injection pipe (8) for a predetermined time. Oxidation is carried out, and the oxidation treatment water is transferred to the whole discharge chamber U of the floating separation tank through the transfer pipe 9.

When the oxidized water is transferred to the whole discharge chamber U, the ultra-fine air bubble generator G-1 instantly provides the bubble water supplied from the supply pipe 21 and the compressed air pressurized by the external air compressor. By mixing and processing to generate a pressurized bubble water, and pressurizes it to the discharge valve 14-1 through the pressure feed pipe 15-1. The discharge valve delivers the ultra-fine air bubbles to the entire discharge chamber U at the set constant pressure. The ultra-fine cloth that is discharged and volcanized is attached to and adsorbed on the suspended solids in the water to force the sludge to float on the surface, and the suspended solids are discharged to the outside along the recovery passage, and the separated separated water is separated from the rear ( Naturally, it is transferred to the discharge chamber (V).

On the other hand, the ozone generated by the operation of the ozone generator (O) is sucked into the ozone pressurizing device (K) and pressurized to a predetermined pressure is pressed into the ultra-miniature bubble generator (G), the ultra-fine bubble generator is a supply pipe ( 16) the bubble water and the compressed ozone supplied from the instant are mixed and processed in an instant to generate a pressurized ozone bubble water, which is then pumped to the ozone discharge valve 14 through the pressure pipe 15, and the ozone discharge valve is ultrafine at the set positive pressure. Ozone bubbles are discharged into the discharge chamber (V), and the ultra-fine ozone bubbles discharged rapidly diffuse into the discharge chamber and come into contact with the hardly decomposable substance to oxidize and decompose the untreated hardly decomposable organic substance in the Fenton oxidation tank for a predetermined time. The residual ozone is reduced to oxygen while passing through the floating separation chamber (P) to increase the dissolved oxygen in the water, and the suspended solids generated during the ozone oxidation process are continuously discharged. Is attached to, adsorbed on the intensity Po is forced to become the surface of the water and thus the sludge to recover discharged to the outside, the wastewater along the bottom of a feed is conveyed to the discharge chamber (B).

The treated water to be discharged to the discharge chamber (B) is continuously measured by the discharge water quality control device, and if a value less than the preset discharge standard value is measured, the control unit 18 operates the reverse feed pump (M). On the other hand, the treated water delivered to the discharge chamber by closing the solenoid valve 2 attached to the raw water inlet pipe 1 and the solenoid valve 2-1 attached to the supernatant water transfer pipe 7 in the automatic filtration device is fentonized. The feed back to the bath is performed for reprocessing.

When the treated water transferred to the discharge chamber B by the reprocessing operation as described above reaches the discharge reference value, the control unit 18 measures this and stops the reverse feed pump M, and installs the raw water inlet pipe 1. The solenoid valve 2-1 attached to the upper water feed pipe 7 is opened in the solenoid valve 2 and the automatic filtration device, and the treated water transferred to the discharge chamber by this operation is discharged through the discharge pipe 13. Discharged.

The treated water below the discharge standard may be transferred to the whole discharge chamber U of the floating separation tank for reprocessing.

In the present invention, in the difficult-to-decompose wastewater treatment, which requires a lot of equipment and treatment costs, a flocculation treatment is first performed to remove suspended solids in the water, and a fenton oxidation treatment is introduced, and the fenton oxidation treatment water is floated. It carries out the floating separation treatment by transferring to the separation device and at the same time proceeds the ozone oxidation treatment in the same device to maximize the treatment efficiency by saving facility cost and shortening the processing time.

Sludge and supernatant can be separated in a short time by introducing automatic washing filtration instead of sedimentation tank to remove suspended solids in the flocculation water, and sludge thickening facilities can be omitted because sludge natural dehydration proceeds during the idle time of the device. In addition, the dehydration treatment may be omitted, thereby reducing the facility cost and treatment cost.

Floating material is generated by the injection of auxiliary agent in the fenton oxidation, and the sedimentation tank is introduced to remove the floating material, and the facility cost is reduced by simultaneously performing the floating separation treatment in the floating separation tank which performs ozone treatment instead of the sedimentation tank.

Ozone oxidation treatment requires separate ozone contact tank and floating material removal device. Ozone oxidation treatment is performed in floating separation tank and floating separation treatment is performed in the same flotation separation tank. .

In discharged treated water, the discharged water quality is controlled by the discharged water quality control device to block discharge of the treated water below the discharge standard value, thereby contributing to the protection of the water system.

Claims (1)

Raw water is introduced into the coagulation treatment tank to inject coagulant to perform coagulation treatment, and the coagulation water is transferred to an automatic washing filter (J), Separating the flocculated water transferred to the automatic washing filtration device (J) into sludge and supernatant water, and transferring the separated supernatant water to the Fenton oxidation tank (F), Auxiliaries (iron salts, ferric sulfate, etc.) and hydrogen peroxide are injected into the supernatant water fed to the Fenton oxidation tank F, the oxidation treatment is carried out by stirring, and the oxidation treatment water is discharged to the whole discharge chamber of the floating separation tank ( U), Suspended solids in the oxidized water transported to the whole discharge chamber (U) are attached to and adsorbed on the ultra-fine cloth discharged and diffused by the discharge valve (14-1), and forced floating separation treatment; Pressurizing the ozone into the bubble generator (G) by pressurizing the ozone by the pressurizing device (K) supplied with ozone from the ozone generator (O), The bubble generating device (G) pressurized with the pressurized ozone generates pressurized ozone bubble water and pressurizes it to the discharge valve 14 through the pressure feed pipe 15 to discharge the ultra-fine ozone bubbles into the rear discharge chamber V. Steps, Oxidizing and decomposing the hardly decomposable substance by contacting ozone with the hardly decomposable organic substance by the diffusing force of the ultra-fine ozone bubble discharged into the rear discharge chamber (V), Continuously measuring the water quality of the treated water transferred to the discharge chamber (B) to stop the discharge of the treated water below the discharge standard value, and transferring it back to the Fenton oxidation tank or the floating separation tank for reprocessing; Reprocessing is carried out and the treated water flowing into the discharge chamber reaches the discharge standard value, the discharge water quality control device measures this and discharges again, A effluent treatment control method for effluent quality characterized by oxidizing and decomposing the hardly decomposable wastewater while blocking the discharge of the treated water below the discharge standard value through the above steps.