KR20090057772A - Sewage and waster water treatment using the electro coagulation and electro precipitation - Google Patents

Abstract

A wastewater treatment apparatus using electrocoagulation and precipitation is provided to purify waste water cleanly with simple structure of the apparatus and to extend lifetime of electrodes. A wastewater treatment apparatus using electrocoagulation and precipitation includes a coagulation vessel(1) and a precipitation vessel(2). A plurality of plate-shaped electrodes(11) are installed in the coagulation vessel vertically. A plurality of reticular electrodes(21) are arranged inside the extraction reaction tub vertically. An inlet hole(1a) is formed on a part which is adjacent to the floor of the coagulation vessel. An outlet hole(1b) is formed on an upper part of the coagulation vessel. The inlet hole is formed in the in-between of the precipitation vessel. The outlet hole is formed on the top of the precipitation vessel. An iron oxide outlet(1c) is formed on the bottom of the coagulation vessel.

Description

Sewage and waster water treatment using the electro coagulation and electro precipitation}

The present invention relates to a wastewater treatment apparatus, and more particularly, to a wastewater treatment apparatus using electro-agglomeration and precipitation that enables the removal of various iron ions remaining by precipitation of ions having different solubility according to pH.

While industrial life is becoming more convenient, wastewater is becoming a major problem for nature. Various kinds and methods of wastewater treatment apparatuses for treating wastewater have been developed to prevent water pollution by such wastewater. Among such conventional wastewater treatment devices, an electrochemical treatment method having a simple configuration and high treatment efficiency has been in the spotlight.

However, this electrochemical wastewater treatment apparatus using an electrolytic treatment technique is a combination of iron metal ions generated by ^{(Fe 3+, Fe 2+, Fe} (OH) 2 -, Fe (OH) 4 -, Fe 2 O 3 -) There was a problem that the processing of is not done well.

That is, since these various kinds of iron metal ions have different solubility ranges according to pH, only neutral ions can be removed by neutralization, and the remaining iron metal ions remain. There was a problem.

The present invention was developed to solve the problems of the prior art as described above, the heavy and light metal by the adsorption and charge neutralization of the hydrolyzed iron metal ions by electrolysis of iron, cross-linking between particles, sieving flux phenomenon , Induces colloid destabilization to remove contaminants by agglomeration, and the remaining ferrous metal ions are removed by _trivalent hydrated iron (Fe (OH) ₃ ) to make the wastewater clean. It is an object to provide a treatment apparatus.

Wastewater treatment apparatus using electro-agglomeration and precipitation to achieve the object of the present invention is configured by vertically arranged plate-shaped electrodes in the interior of the tank to produce hydroxyl complexes to the hydroxyl complex acts as a nucleus of impurities An agglomeration reaction tank which causes the impurities to aggregate into hydrates; It is characterized in that it comprises a precipitation reaction tank configured to vertically arrange the mesh-shaped electrodes inside the tank to react with impurities in the agglomeration reactor and to precipitate the remaining hydroxyl complex.

The present invention induces destabilization of heavy / light metals and colloids by electrolysis of iron in agglomeration reaction vessels to induce adsorption and charge neutralization of hydrolyzed iron metal ions, crosslinking between particles, and sieving flocculation to aggregate and remove contaminants. And, by removing the remaining iron metal ions with trivalent hydrate iron (Fe (OH) ₃ ) in the precipitation reaction tank there is an effect that can be more cleanly rectified waste water.

In addition, the device can be configured more simply by applying the current applied to the electrodes of each reactor to the electrodes at both ends in a bipolar type, and eluting electrodes (iron, aluminum, etc.) can be more effectively eluted and at regular intervals. Reversing has the effect of automatically cleaning the electrode surface and extending its life.

Hereinafter, an apparatus for treating wastewater using electrocoagulation and precipitation according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an apparatus for treating wastewater using electrocoagulation and precipitation according to the present invention, FIG. 2 is a perspective view of an electrode installed in a coagulation reactor constituting a wastewater treatment apparatus according to the present invention, and FIG. It is a perspective view of the electrode provided in the precipitation reactor which comprises a wastewater treatment apparatus.

As shown, the wastewater treatment apparatus according to the present invention is configured by vertically arranging the plate-shaped electrodes 12 inside the tank 11 so that hydroxyl complexes are generated so that the hydroxyl complex is a nucleus of impurities. An agglomeration reaction tank (1) which acts to agglomerate impurities into hydrates; It is configured by vertically arranging the mesh-shaped electrode 22 in the tank 21, and comprises a precipitation reaction tank 2 for reacting with impurities in the agglomeration reaction tank 1 and depositing the remaining hydroxyl complex.

The wastewater treatment apparatus configured as described above may be used in connection with an existing wastewater treatment facility or used independently.

The flocculation reaction tank (1) is an iron metal ion electrolysis and hydroxyl complex hydrolysis of iron or aluminum _{(Fe (OH) 2, Fe} (OH) 3, Fe (OH) 2 -, Fe (OH) 4 -, Fe ₂ O ₃ ⁻ ) or aluminum metal ions (Al ³⁺ , Al (H ₂ O) ₆ ³⁺ , Al (H ₂ O) ₅ OH ²⁺ , Al (H ₂ O) ₄ ) (OH) ²⁺ , Al (OH) ²⁺ , Al ₂ (OH) ₂ ⁴⁺ , Al (OH) ⁴ⁿ , Al ₆ (OH) ₁₅ ³⁺ ) are absorbed due to adsorption, charge neutralization, cross-linking between particles, and sieving flux It induces destabilization of foreign substances such as light metals and colloids and serves to aggregate contaminants.

These hydroxyl complexes have high affinity with foreign substances such as heavy / light metals and colloids, and aggregate the foreign substances by acting as the counter ion of the sludge during aggregation.

The agglomeration reaction tank 1 minimizes electrical corrosion by fabricating FRP lining on fiber reinforced plastics (FRP) or iron plate.

As shown in Fig. 1, the agglomeration reaction tank 1 is formed at a portion adjacent to the bottom of the tank 11, and a water outlet 1b is formed at the upper end of the tank 11.

Thus, by forming the inlet port (1a) and the outlet port (1b) of the flocculation reaction tank 1, the waste water is moved from the lower part to the upper part so that sludge does not precipitate.

The electrode 11 installed in the agglomeration reaction tank 1 is formed in a plate shape as shown in FIG. Can be adjusted according to the nature of the waste water.

When the electrode is composed of iron (Fe) in the agglomeration reaction tank 1 as described above, iron oxide (Fe ₂ O ₃ ) is generated at the anode, and when the distance between the electrodes 11, which are water paths, is narrow, the flow path is caused by the iron oxide. Can be blocked. Therefore, in order to minimize the blockage by iron oxide, the iron oxide outlet 1c was formed at the bottom of the agglomeration reaction tank 1, and only the slope was formed to be inclined toward the portion where the iron oxide outlet 1c was formed.

The hydroxyl complex that reacts in the agglomeration reactor 1 to agglomerate foreign substances has a high affinity with the dispersible colloid component (charge neutralization), and acts as a nucleus (counter ion) of the sludge generated in the agglomeration. The hydroxyl complex is removed in the form of a hydrate at the cathode, but the remaining hydroxyl complex can act as a secondary pollutant.

The precipitation reactor 2 described above is provided as a means for removing the remaining hydroxyl complex.

The precipitation reaction tank 2 has a mesh-shaped electrode 21 configured as shown in FIG. 3, the inlet port 2a is formed in the middle of the bath 21, and the outlet port 2b is the bath 21. The waste water is formed at the top of the effluent so that the waste water flows horizontally and passes between the meshes of the network constituting the electrode 22, thereby increasing the reactivity.

The electrode 22 installed in the precipitation reaction tank 2 is made of an insoluble material such as IrO ₂ / Ti, and the residual hydroxyl group is oxidized by oxygen (O ₂₎ at the anode and removed by inducing a reduction reaction at the cathode. do.

In other words, the precipitation tank (2) in the flocculation reaction tank (1) a hydroxyl group complex of ferrous ions (Fe ^{2 +,} Fe ^{3 +,} Fe (OH) ₃ ^+, Fe (OH) ₂ produced from ^-, Fe (OH) _{^{4 -, Fe 2 O 3 -}} ) , or aluminum metal ions _{^{(Al 3+, H 2 O (}} Al) 6 3+, (H 2 O) Al 5 OH 2+, Al (H 2 O) 4) (OH ) ²⁺ , Al (OH) ²⁺ , Al ₂ (OH) ₂ ⁴⁺ , Al (OH) ⁴ⁿ , Al ₆ (OH) ₁₅ ³⁺ ) are removed with trivalent hydrated iron.

In addition, in the case of organic matter, it is oxidized and removed by the electric Fenton reaction.

The reactions in each of these tanks (1, 2) are usually well known reactions, and detailed description thereof will be omitted.

In the wastewater treatment apparatus configured as described above, when electricity is continuously supplied to the electrodes 12 and 22, the life is shortened due to the scale of the electrodes, and the positive and negative terminals are grounded to the electrodes at both ends by using a reverse rectifier. The current was supplied, and the reversal time was alternated at intervals of approximately 1 to 10 minutes, thereby acting as a positive electrode as a whole to slow down the corrosion rate.

That is, currents are supplied to the electrodes 11 and 21 provided in the coagulation reactor 1 and the precipitation reactor 2 in a bipolar type.

1 is a block diagram of a wastewater treatment apparatus using electrocoagulation and precipitation according to the present invention,

2 is a perspective view of an electrode installed in a coagulation reactor constituting the wastewater treatment apparatus according to the present invention,

3 is a perspective view of an electrode installed in the precipitation reactor constituting the wastewater treatment apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: flocculation reactor

  1a: Inlet 1b: Outlet 1c: Sludge outlet

  11: bath 12: electrode

2: precipitation reactor

  2a: inlet 2b: outlet

  21: bath 22: electrode

Claims (5)

An agglomeration reaction tank 1 in which the plate-shaped electrodes 12 are arranged vertically in the tank 11 to generate hydroxyl complexes, and the hydroxyl complex acts as a nucleus of the impurities to aggregate the impurities; ; It comprises a deposition reactor (2) configured to vertically arrange the network-like electrode 22 in the tank 21 to precipitate the hydroxyl group complex and iron metal ions remaining with the impurities in the agglomeration reaction tank (1). Wastewater treatment apparatus using electrocoagulation and precipitation characterized in that configured. The method of claim 1, The inlet port 1a of the coagulation reaction tank 1 is formed at a portion adjacent to the bottom of the tank 11, and the outlet port 1b is formed at the upper end of the tank 11 so that the waste water is moved from the bottom to the upper side so that sludge is formed. Configured not to settle, The inlet port 2a of the precipitation reactor 2 is formed in the middle of the tank 21, and the outlet port 2b is formed at the upper end of the tank 21 so that the waste water flows horizontally to pass through the net body constituting the electrode 22. Wastewater treatment apparatus using electrocoagulation and precipitation characterized in that to increase the reactivity. The method according to claim 1 or 2, The electrode 11 installed in the agglomeration reaction tank 1 is iron (Fe) or aluminum (Al), Electrode agglomeration and precipitation using wastewater treatment apparatus, characterized in that the electrode 21 installed in the precipitation reaction tank (2) is made of an insoluble material. The method of claim 3, wherein Electrostatic coagulation and precipitation using wastewater treatment apparatus, characterized in that the current is supplied to the electrodes (11, 21) installed in the coagulation reaction tank (1) and the precipitation reaction tank (2). The method of claim 4, wherein The bottom surface of the coagulation reaction tank (1) is a wastewater treatment apparatus using electro-agglomeration and precipitation, characterized in that the inclined to be gradually lowered toward the iron oxide outlet (1c).

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