KR100447093B1 - Apparatus for treatment waste water of plating and method the same - Google Patents

Abstract

Disclosed is an apparatus and method for purifying plating wastewater. Such a wastewater purification apparatus includes a chlorine treatment unit for chlorination of cyan waste water, an equalization tank for storing chlorine-treated cyan waste water and alkali and acid wastewater, and an ozone treatment unit for oxidizing the wastewater discharged from the equalization tank by ozone; And first and second wastewater treatment lines each comprising an filtration unit for filtering ozonated wastewater, an ion exchange unit for removing impurity ions from the cyan wastewater passing through the filtration unit, and the first and second wastewater treatment lines. It is connected to each of the ion exchange of the, and includes a console valve for converting the waste water to the ion exchange of the other line when the processing limit of the ion exchange of one line.

Description

Plating wastewater purification treatment apparatus and its method {APPARATUS FOR TREATMENT WASTE WATER OF PLATING AND METHOD THE SAME}

The present invention relates to a plating wastewater purification apparatus and method, and more particularly, by continuously applying chlorine treatment, ion treatment, and ion exchange methods, it is possible to efficiently prevent environmental pollution, and equipped with a console valve for wastewater treatment line. The present invention relates to a plating wastewater purification apparatus and method capable of supplying and treating wastewater to another line when one line exceeds a treatment limit by connecting the two to each other.

In general, a large amount of acid, aqueous alkali solution and cyan-based compounds are used in the plating process, and these chemicals are discharged to the outside after plating to cause environmental pollution. Therefore, techniques for properly purifying the chemicals are being developed.

In particular, cyan is extremely toxic and extremely small amounts have a fatal effect on the human body, and in the plating process, such cyanide is a high concentration of about 50,000 ppm of cyan wastewater, which requires thorough purification.

Various methods such as alkali chlorine method, electrolytic oxidation method, ion exchange method, iron salt method, aeration method, ozone oxidation method and cyanhydrin method have been developed as cyanide purification methods. Especially, alkali chlorine method is mainly used among the above treatment methods. to be.

This alkaline chlorine method is a method of oxidatively decomposing cyanide in an alkaline solution using a powerful oxidizing agent. In this case, chlorine or sodium hypochlorite is used as the oxidizing agent, and sodium hypochlorite is mainly used for safety reasons.

However, the alkali chlorine method has a problem in that toxic substances harmful to the environment may be emitted by removing cyan by adding toxic chemicals.

In addition, when the wastewater purification apparatus is configured by the wastewater purification apparatus as described above, when excessive wastewater is supplied to each wastewater purification treatment line, the purification treatment capacity is exceeded, and each wastewater purification treatment line supplies wastewater. There is a problem in that the purification efficiency is lowered because the waste water must be stopped and the wastewater supplied to the line must be treated newly.

In particular, when a plurality of purification processing lines are driven, there is a problem in that if each line is overloaded, the operation must be stopped and restarted.

Accordingly, the present invention has been made to solve the above-mentioned problems, the object of the present invention is to install a console valve to selectively connect a plurality of purification treatment line by the overload occurs on the other side of the purification treatment line, The present invention provides a plating wastewater purification apparatus and method which can improve the purification treatment efficiency by eliminating overload by bypassing wastewater to a purification treatment line.

Another object of the present invention is to provide a plating wastewater purification apparatus and method capable of efficiently purifying wastewater by continuously applying chlorine treatment, ion treatment, and ion exchange methods.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows a plating waste water purification treatment line.

FIG. 2 is a flow chart showing a process of purifying wastewater by the plating wastewater treatment line shown in FIG.

In order to realize the object of the present invention, a preferred embodiment of the present invention is a chlorine treatment unit for the chlorine treatment of cyan waste water, a equalization tank for storing chlorine-treated cyan waste water and alkali and acid waste water, and is discharged from the equalization tank First and second wastewater treatment lines each comprising an ozone treatment unit for oxidizing waste water by ozone, a filtration unit for filtering ozonated wastewater, and an ion exchange unit for removing impurity ions from cyan wastewater passing through the filtration unit; ; And a plating valve connected to each of the ion exchange parts of the first and second waste water treatment lines, and converting the waste water into the ion exchange part of the other line when the treatment limit of the ion exchange part of one line is exceeded. Provided is a purification treatment device.

In order to realize another object of the present invention, another preferred embodiment of the present invention includes a chlorine treatment step of collecting the CN wastewater generated from the plating process and entering each of the at least one wastewater treatment line to chlorine the CN wastewater; Storing chlorinated cyan waste water and alkali and acid waste water in an equalization tank; An ozone treatment step of oxidizing waste water flowing out of the equalization tank by ozone; A filtration step of filtering the ozonated wastewater to remove impurities contained in the wastewater; An ion exchange step of removing impurity ions from the filtered wastewater by an ion exchange method; And it provides a plating wastewater purification treatment method comprising a console valve step of eliminating the overload by supplying wastewater to the other purification treatment line when the ion exchange step is overloaded.

Hereinafter, with reference to the accompanying drawings will be described in detail the plating wastewater purification apparatus and method according to a preferred embodiment of the present invention.

1 and 2, the plating wastewater purification apparatus proposed by the present invention includes a first wastewater treatment line I for purifying the plating wastewater through a predetermined process, and the first wastewater treatment line I. The second wastewater treatment line (II) having the same configuration as) and the first and second wastewater treatment lines (I, II) are connected to each other to selectively supply wastewater from each line to another line (Console Valve; 19).

In the plating wastewater purification apparatus having such a structure, the first and second wastewater treatment lines (I, II) are subjected to a series of cyan wastewater and acid and alkaline wastewater (hereinafter, wastewater) generated in the plating process, etc. Purification removes impurities in the waste water. Therefore, the wastewater purified through the first and second wastewater treatment lines I and II is supplied and used again in the plating process.

The first and second wastewater treatment lines I and II as described above are purified by the following process, and the first and second wastewater treatment lines I and II have the same configuration. It will be described by one line below with.

The wastewater treatment method includes a chlorine treatment step (S200) for collecting wastewater generated from a plating process, preferably CN wastewater (S100), and entering the first wastewater treatment line (I) to chlorine the CN wastewater (S200). Storing the cyan waste water and alkali and acid wastewater in an equalization tank (S300), and an ozone treatment step of oxidizing wastewater discharged from the equalization tank by ozone (S400) and ozone treatment. The filtration step of filtering the waste water (S500), and the ion exchange step (S600) of removing impurity ions from the filtered cyan waste water.

In addition, when the treatment limit is exceeded in the ion exchange step (S600), by supplying and treating the wastewater to the second wastewater treatment line (II), the console valve step (S800) capable of continuously purifying without interruption of the purification process is further performed. Included.

In this purification method, in the chlorine treatment step (S200), the cyan waste water stored in the cyan storage tank 1 is supplied to the chlorine treatment unit (3). The chlorine treatment unit 3 is composed of two ion tanks.

In this chlorine treatment unit 3, cyan waste water is made alkaline by adding NaOH and the like, and complexed CN is removed by oxidatively decomposing cyan waste water using chlorine. In the base treatment unit, the reaction consists of the following two steps.

Primary Reaction: NaCN + 2NaOH + Cl ₂ → NaCNO + 2NaCl + 2H ₂ O

Secondary reaction: 2NaCNO + 3NaOH + 3Cl ₂ → 2CO ₂ + N ₂ + 6NaCl + 2H ₂ O

Thus, 2NaCN + 5NaClO + H ₂ O → N ₂ + 2CO ₂ + 2NaOH + 5NaCl.

That is, in the first reaction, alkali was added to the cyan wastewater at a pH of 10 to 10.5, oxidized with Cl ₂ or NaOH as an oxidizing agent, oxidized with CNO, and then H ₂ SO ₄ and NaOCl were injected in the _second reaction. Decomposition with CO ₂ and N ₂ . Chlorine gas, sodium hypochlorite are used for the oxidizing agent, and sulfuric acid and hydrochloric acid are used for the neutralizing agent.

As described above, the wastewater having undergone the chlorine treatment step (S200) is a storage step (S300) to be stored in the equalization tank (5).

That is, the cyan waste water that has passed through the chlorine treatment unit 3 is supplied to the equalization tank 5, and in addition to the cyan waste water that has passed through the chlorine treatment unit 3, the wastewater generated from the plating process and Alkali wastewater is supplied.

In this way, the equalization tank 5 stores CN wastewater, acid and alkali wastewater. Then, the wastewater stored in the equalization tank (5) is supplied to the first filter (7) connected to the equalization tank (5) and filtered, and goes through a circulation process to return to the equalization tank (5) again. In this process, impurities contained in the wastewater are first filtered.

Then, after the equalization tank storage step (S300), the ozone treatment step (S400) for oxidizing the waste water by ozone is carried out.

That is, an ozone treatment unit 9 is connected between the first filter 7 and the equalization tank 5, and the ozone treatment unit 9 receives cyanide wastewater from which Complexed CN has been removed through the chlorine treatment unit 3. Free CN is removed by secondary removal using the oxidizing property of ozone. The scheme is as follows.

CN- + O ₃ → CNO- + O ₂

CNO- + 2H + + 2H ₂ O → NH ₂ + + CO ₂

CNO- + NH ₂ + → NH ₂ CONH ₂

NH ₂ CONH ₂ + O ₃ → N ₂ ↑ + CO ₃ ↑ + 2H ₂ O

Therefore, CN- + OCN- + 2O ₃ + 2H + → N ₂ ↑ + 2CO ₂ ↑ + O ₂ ↑.

As described above, after the ozone treatment step S400 is performed, the filtration step S500 for filtering the wastewater discharged from the equalization tank 5 is performed. In this filtration step (S500), the wastewater is passed through the second filter 11 to remove secondary impurities in the wastewater.

After the filtration step (S500), the ion exchange step (S600) for supplying the wastewater to the ion exchange unit 13 to remove the impurity ions contained in the wastewater by cation and anion exchange is performed.

That is, by sequentially passing the waste water through the cation tank 15 in which the cation resin is stored and the anion tank 17 in which the anion resin is stored, Ni and SO ₄ contained in the waste water are removed.

In more detail, the cation resin 15 is stored in the cation tank 15. Such cation exchange resins include polyhydric phenol, a resin obtained by condensing formaldehyde, a resin having a sulfonic acid group -SO ₃ H, a resin having a carboxyl group -COOH, and the like.

Therefore, when the wastewater is supplied to the cation tank 15, Ni ions are removed by the cation resin.

Further, waste water from which Ni ions have been removed is supplied to the anion tank 17. Anion exchange resin is stored in the anion tank 17, and this anion exchange resin contains a resin obtained by condensing m-phenylenediamine and formaldehyde.

This anion exchange resin removes impurity ions, ie, SO ₄ , contained in the supplied wastewater.

The wastewater from which Ni and SO ₄ contained in the wastewater are removed through the above process is stored in the storage tank 27, and if necessary, is recycled by being supplied to the plating line again.

On the other hand, in the wastewater treatment lines I and II as described above, an overload may occur and the wastewater treatment limit may be exceeded. Therefore, the console valve step (S800) is added to eliminate this overload.

In the console valve step (S800), when the treatment limit is exceeded in the ion exchange step (S600), the wastewater of the first wastewater treatment line (I) using the console valve 19 to the second wastewater treatment line (II). By reorienting and supplying), the overload of the first wastewater treatment line I is eliminated.

In more detail, the console valve 19 is connected by the ion exchange unit 13 and the first connecting pipe 21 of the first wastewater treatment line I and the second wastewater treatment line II. It is connected by the ion exchange part 23 and the 2nd connection pipe 25, respectively. And ion exchange between the first wastewater treatment line I and the second wastewater treatment line II by selectively opening and closing the connecting pipes 21 and 25 connected to the first and second wastewater treatment lines I and II. The parts 13 and 23 can be connected to each other or closed.

For example, when the ion exchange unit 13 of the first wastewater treatment line I exceeds the treatment limit, the console valve 19 opens the first connecting pipe 21. When the first connection pipe 21 is opened, the wastewater flows into the console valve 19 from the ion exchange unit 13 of the first wastewater treatment line I, and the introduced wastewater passes through the second connection pipe 25. It is supplied to the ion exchange part 23 of the 2nd wastewater treatment line (II) through. Therefore, the wastewater is purified through the ion exchange unit 23 of the second wastewater treatment line II until the overload of the ion exchange unit 13 of the first wastewater treatment line I is eliminated. When the overload of the first wastewater treatment line I is removed, the wastewater may be treated in the first wastewater treatment line I by closing the second connection pipe 25 of the console valve 19 again.

Of course, even when the second wastewater treatment line II is overloaded, the wastewater is supplied to the first wastewater treatment line I by the reverse of the above-described process, thereby eliminating the overload.

Through the above-described process, impurities such as cyanide and the like contained in the wastewater are removed and purified.

As described above, the plating wastewater purification apparatus and method according to the preferred embodiment of the present invention have the following advantages.

First, by installing a console valve, if one side line exceeds the treatment limit by switching the wastewater to the other line to supply the purification process can be made continuously without interruption to improve the treatment efficiency.

Second, the waste water is purified and reused without being discharged to the outside, so the consumption of water is low, and it is pollution-free and thus environmentally friendly treatment is possible.

Third, the chlorine treatment, ozone treatment, filtration treatment, and ion exchange method can be applied continuously to improve the purification efficiency of wastewater.

Fourth, there is an advantage that the installation cost and maintenance cost of the facility is reduced by selectively using several waste water lines by the console valve.

The present invention can be variously modified by those skilled in the art to which the present invention pertains without departing from the scope of the present invention as claimed in the claims, and is not limited to the specific preferred embodiments described above. .

Claims (5)

A chlorine treatment unit for chlorination of cyan waste water, an equalization tank for storing chlorine-treated cyan waste water and alkali and acid waste water, an ozone treatment unit for oxidizing waste water discharged from the equalization tank by ozone, and filtration of ozone treated waste water First and second wastewater treatment lines each comprising a filtration unit and an ion exchange unit for removing impurity ions from the cyan wastewater passing through the filtration unit; And A plating wastewater purification treatment comprising a console valve connected to the ion exchange portions of the first and second wastewater treatment lines, respectively, and converting the waste water into the ion exchange portion of the other line when the treatment limit of the ion exchange portion of one line is exceeded. Device. The plating wastewater purification apparatus according to claim 1, wherein the ion exchange part comprises a cation tank storing cations to remove Ni contained in the waste water, and an anion tank storing anions to remove SO ₄ contained in the waste water. The first or second wastewater of claim 2, wherein one side of the console valve is connected to an ion exchange portion of the first wastewater treatment line and the other side is connected to an ion exchange portion of the second wastewater treatment line. Plating wastewater purification apparatus for selectively supplying wastewater to the second or first wastewater treatment line when the treatment line is overloaded. A chlorine treatment step of collecting CN wastewater and entering the first and second wastewater treatment lines, respectively, to chlorine the CN wastewater; Storing chlorinated cyan waste water and alkali and acid waste water in an equalization tank; An ozone treatment step of oxidizing waste water flowing out of the equalization tank by ozone; A filtration step of filtering the ozonated wastewater to remove impurities contained in the wastewater; An ion exchange step of removing impurity ions from the filtered wastewater by an ion exchange method; And And a console valve step of eliminating the overload by supplying the wastewater to the other purification treatment line when the ion exchange step is overloaded. The method of claim 4, wherein the ion exchange step includes a cation tank to remove Ni contained in the wastewater, and an anion tank to remove SO ₄ contained in the wastewater.