KR100347864B1 - System of treated for industrial wastewater - Google Patents

Abstract

The present invention relates to an industrial wastewater treatment method, wherein wastewater containing cyanide and chromic acid together with wastewater containing heavy metals are fractionally purified for each wastewater treatment process to improve water quality and to concentrate the remaining heavy metals. In order to be able to reuse, wastewater containing heavy metals generated through the printed circuit board production process and the thin-film copper plating process is collected into the flush waste water equalization tank 1a and the waste pH is controlled by the line mixer 2a. The pretreatment is filtered through a pretreatment filtration device (3a) and collected in the pretreatment collection tank (11a), and the treated water from the pretreatment collection tank (11a) is temperature-corrected by the heat exchanger (12a) and permeated through the reverse osmosis membrane separator (13a). The water from the line mixer 2a is collected by the permeation tank 14a and recycled through the ion exchange resin tower 15a as the wash water for the production process and the plating process. The waste water is temperature-corrected by the heat exchanger 7a and permeated through the rotating or vibrating membrane separator 8a and collected in the permeate tank 9a and reused as the flushing water through the ion exchange resin tower 10a, and the rotation. Alternatively, the concentrated water concentrated in the vibrating membrane separator 8a may be collected in a concentrated water tank 10a and reused as a plating bath, or chemically reacted through a chemical treatment tank 17a and discharged while being filtered by an activated carbon filter 18a. In addition, the sediment generated in the chemical treatment tank (17a) is collected in the sediment storage tank (19a) to be dehydrated through the dehydrator (18a) to be treated with solids.

Description

Industrial wastewater treatment method {System of treated for industrial wastewater}

The present invention relates to an industrial wastewater treatment method for purifying heavy metal-containing industrial wastewater generated from metallurgical companies in order to prevent contamination in advance, and particularly, wastewater containing heavy metals generated through a printed circuit board production process and a thin film copper plate plating process. In addition, the present invention relates to an industrial wastewater treatment method in which wastewater containing a cyanide compound and chromium compound wastewater are fractionated and purified for each wastewater treatment process to improve water quality and to concentrate and reuse the remaining heavy metals.

The development of modern electronic communication industry is rapidly changing material civilization both in quantity and quality, and this electronic communication industry is based on the surface treatment of metal materials for mounting and assembling various electronic components.

That is, based on the metal surface treatment technology, a 1-3 mm electrodeposited copper foil or a thin copper sheet of rolled copper foil is bonded to the epoxy resin substrate with an adhesive to form a printed circuit, and the substrate surface is made of ferric chloride ( A printed circuit board (PCB) is completed by removing resist by etching with FeCl ₃ ) or strong acid.

In addition, as a representative industrial wastewater of metal surface treatment plants, various heavy metal wastewaters with high toxicity generated through the plating process of rolled copper foil are discharged from the washing water or the aging thickening solution in each process. Various hazardous industrial wastewaters such as wastewater, wastewater containing cyanide compounds, and chromic acid wastewater are emerging as a serious problem for environmental pollution. to be.

On the other hand, in most metal industry, such as steel electronics and semiconductor production plant, including metal surface treatment plant, as shown in Figure 5 mainly printed circuit board production process and thin film by chemical treatment methods such as neutralization, flocculation, sedimentation, dehydration treatment Industrial wastewater, including heavy metal wastewater, generated mainly in the copper plating process, is being removed.

That is, organic coagulants that are positive, anionic and nonionic polymer coagulants together with inorganic coagulants such as slaked lime {Ca (OH) ₂ }, lactic acid alumina {Al ₂ (SO ₄ ) ₃ }, and iron salts (FeCl ₃ or FeSO ₄ ). Coagulation sedimentation using, and neutralization reaction by adjusting the pH (pH) by using acid (HCl or H2SO4) and alkali (NaOH) to make the heavy metal to the metal hydroxide material by chemicals to precipitate.

The supernatant water during sedimentation is passed through a rapid filtration device filled with a filter medium such as activated carbon after discharge control, and then discharged to obtain suspended solids (SS), turbidity (NTU), chemical oxygen demand (COD), and normal hexane extraction. Water components such as substance (nH) were adjusted.

Therefore, the excessive use of a large amount of chemicals to remove heavy metals with concentrations ranging from a few ppm to several tens of ppm, as rivers, rivers, and seas become increasingly polluted by industrial wastewater, is a source of drinking water. Of course, the reproductive environment of fish and shellfish is seriously destroyed.

In addition, solids such as sludge or waste precipitated by chemicals are required to be landfilled after paying high costs as designated industrial wastes.In reality, heavy metal users have to pay additional landfill costs in addition to wastewater treatment costs. There are economic burdens and land pollution such as leachate generation due to landfill treatment of heavy metal waste, which is highly toxic, and the deterioration of the land is accelerating, causing serious environmental pollution.

In particular, heavy metals containing valuable materials, such as silver (Ag) and gold (Au), are precipitated using ion exchange resins or evaporation and separate precipitation methods, so heavy metal wastewater treatment is not a problem. The precious metals are cyanide compounds, which cause fatal cyanide (CN) wastewater, and thus have to be treated separately.

Therefore, the present invention was invented to solve all the problems of the conventional industrial wastewater treatment method by the method of reclaiming or precipitation filtration of heavy metal industrial wastewater, through a printed circuit board production process and thin film copper plate plating process of a metal industry Wastewater containing cyanide and chromium compounds, along with the generated wastewater containing copper heavy metals, are separated and purified by each wastewater treatment process to improve water quality and to concentrate and reuse the remaining heavy metals. The purpose is to provide an industrial wastewater treatment method that can be purified in the pre-contamination prevention, not post-treatment.

1 is a treatment process for treating wastewater containing a heavy copper metal generated through a printed circuit board production process and a thin film copper plating process by the industrial wastewater treatment method of the present invention.

Figure 2 is a process for treating the wastewater containing the cyanide compound generated through the printed circuit board production process and thin film copper plate plating process in the industrial wastewater treatment method of the present invention.

Figure 3 is a process for treating the wastewater containing chromium compounds generated through the printed circuit board production process and thin film copper plating process in the industrial wastewater treatment method of the present invention.

Figure 4 is a measurement graph showing the cyan removal rate according to the pH change measured by the treatment process of Figure 1;

Figure 5 is a schematic treatment process diagram for a conventional industrial wastewater treatment method.

In order to achieve the above object, the present invention provides a line mixer in which a wastewater containing a heavy copper metal generated through a printed circuit board production process and a thin film copper plate plating process is collected into a flushing waste water equalization tank 1a and a waste control agent is introduced ( 2a), the waste concentration is controlled by pretreatment filtration through the pretreatment filtration device (3a) and collected in the pretreatment collection tank (11a), the treated water from the pretreatment collection tank (11a) is temperature-corrected by the heat exchanger (12a) While passing through the reverse osmosis membrane separator 13a, the water is collected into the permeation tank 14a, and reused as the washing water for the production process and the plating process via the ion exchange resin tower 15a, while the waste water from the line mixer 2a is used. Temperature-corrected by the heat exchanger (7a) and permeated through the rotary or vibrating membrane separator (8a) and collected by the permeation tank (9a), and reused as water wash through the ion exchange resin tower (10a), and the rotation or The concentrated water concentrated in the vibrating membrane separator (8a) is collected in a concentrated bath (10a) and reused as a plating bath or chemically reacted through a chemical treatment tank (17a) and discharged while being filtered by an activated carbon filter (18a), In addition, the sediment generated in the chemical treatment tank (17a) is collected in the sediment storage tank (19a) is characterized in that the solids are treated while dehydrating through the dehydrator (18a).

The line mixer (2a) is characterized in that the sodium hydroxide (NaOH) is added as a majeure adjuster to control the majesty of the heavy metal wastewater to weak acidity of pH 4-7.

The pretreatment filtration device (3a) is a pretreatment filtration of the effluent wastewater through the multi-layer filter (4a) and the precision filter (5a) in sequence or through a backwash ultrafiltration membrane separator (6a) for pretreatment by a backwash fine filtration method It features.

The multi-layer filter 4a of the pretreatment filtration device 3a is characterized in that the sand, gravel, anthracite and activated charcoal are mixed or filled in a constant pressure vessel.

The precision filter 5a of the pretreatment filtration device 3a is formed of a membrane material of polypropylene or polyethylene having a particle size of 1-10 μm.

The ultrafiltration membrane separator 6a of the pretreatment filtration device 3a is a membrane material of polysulfone, polypropylene, polyethylene, polyacrylonitrile, and polyamide, and is a hollow fiber, tubular, or flat type microfiltration membrane having 0.01-5 μm pores or While formed in the form of an ultrafiltration membrane, each film is formed of a donut-shaped shape of 1-2 mm or a maze of 1-50 μm size on the front and back of the petal shape and is formed in the form of a candle sandwiched in a rod. .

The reverse osmosis membrane separator (13a) is a membrane material of polyamide, cellulose acetate, polyamide, characterized in that formed in a spiral wound or hollow fiber type.

The dehydrator 20a is characterized in that configured in the form of a belt press or filter press.

In addition, the wastewater containing the cyanide compound generated through the printed circuit board production process and the thin film copper plating process is collected into the flush wastewater equalization tank (1b), and the waste concentration is controlled by the line mixer (2b) into which the majesty adjusting agent is introduced. The pretreatment is filtered through a pretreatment filtration device 3b, and the filtered water from the pretreatment filtration device 3b is collected by the pretreatment collection tank 8a and temperature-corrected by the heat exchanger 9b, and from the heat exchanger 9b. While the treated water of the permeate through the reverse osmosis membrane separator (10b) is collected in the permeate water storage tank (11b) and reused as the wash water, while the concentrated water concentrated in the reverse osmosis (10b) is collected in the concentrated water tank (12b) and oxidized Oxidized or chemically reacted by the oxidation treatment tank 13b into which the treatment agent is added or ozone treatment by the ozone oxidation treatment tank 17b, and the treated water from the ozone oxidation treatment tank 17b is treated with an inorganic coagulant. While the supernatant is filtered by the rapid filter 15b while being chemically reacted through the chemical treatment tank 14b to which the coagulant is administered, the concentrated water from the concentrated tank 12b is passed through the precision filter 16b. Characterized in that it is reused in the plating bath.

The pretreatment filtration device (3b) is a pretreatment filtration method for passing the effluent waste water through the multilayer filter (4b) and the precision filter (5b), and a pretreatment filtration method passing through the rotary or vibration membrane separator (6b), and the ultrafiltration membrane It is characterized in that the selective permeation of any one of the pre-treatment filtration method passing through the separator (7b).

The oxidation treatment tank 13b is characterized in that sodium hypochlorite (NaOH) is added as an oxidizing agent and the water washing waste water, which is a cyanide compound waste water, is chemically reacted and oxidized.

The ozone oxidation treatment tank 14b is characterized in that an inorganic coagulant and an organic coagulant are administered to chemically treat alkaline treated water of pH 11-12.

In addition, the wastewater containing chromium compounds generated through the printed circuit board production process and the thin-film copper plating process is collected into the flushing waste water equalization tank (1c), and the concentration of the wastewater is controlled through a line mixer (2c) into which the majesty adjusting agent is introduced. The temperature is corrected by the heat exchanger (3c), the water washing waste water from the heat exchanger is pre-filtered through the pre-treatment filter (4c) and permeated to be collected in the permeate tank (9c) and reused as the wash water, the pre-treatment filter (4c) is not concentrated through the concentrated water is collected in the concentrated tank (10c) and the foreign matter is removed through the cation exchange resin tower (11c) is reused as a plating bath or evaporated to dry by the evaporator 12c solidified On the other hand, the water washing waste water from the heat exchanger (3c) is reduced through the reduction treatment tank (13c) to which the reducing agent is introduced is sent to the pretreatment filter (4c) or polymer agglomerated Is chemically reacted by the chemical treatment tank 14c into which is injected and discharged while filtered through the rapid filter 15c, and the concentrated water from the chemical treatment tank 14c is collected into the concentration tank 16c and the dehydrator 17c. While being dehydrated through the solidification treatment, flushing waste water below the standard concentration collected by the flushing waste water equalization tank 1c is filtered by a precision filter 18c and passed through an anion exchange resin tower 19c to deionization. The water is recycled through the activated carbon filter 20c to be washed with water, and furthermore, the washing water from the anion-exchange resin tower 19c is sent to a reduction treatment tank 13c for reduction.

The pretreatment filtration device 4c is characterized in that the effluent wastewater is passed through the rapid filter 5c, the precision filter 6c, and the reverse osmosis membrane separator 7c in pretreatment filtration or pretreatment through a rotary or vibrating membrane separator 8c. It is done.

The cation exchange resin tower (11c) is characterized in that the hydrochloric acid (HCl) is added to the resin regeneration material to remove foreign substances in the concentrated water.

The reduction treatment tank (13c) is characterized in that the sodium bisulfite or ferrous sulfate and sulfuric acid is added as a reducing agent while the water washing waste water, which is a chromium compound waste water, is neutralized for more than 30 minutes at a pH 2-3 for a reduction treatment.

The chemical treatment tank 14c is neutralized for at least 20 minutes at a stirring speed of 300-350rpm by adding sodium hydroxide as a chemical treatment agent, and the coagulant mixture is mixed at 50rpm agitation rate for 15 minutes or more with a polymer coagulant to wash the waste water into the supernatant water. Characterized in that the chemical reaction treatment.

The anion exchange resin tower 19c is characterized by using sodium hydroxide as a regeneration agent with a weakly basic anion exchange resin, or mixing sodium hydroxide and sodium chloride as a regeneration agent with a strong basic anion exchange resin.

Hereinafter, according to the industrial wastewater treatment method of the present invention, wastewater containing cyanide and wastewater containing chromic acid and wastewater containing heavy metals, which are mainly generated through a printed circuit board production process and a thin film copper plate plating process, are subjected to each treatment process. A detailed description will be given of a preferred embodiment in which a fractional purification process improves the water quality while at the same time remaining heavy metals can be concentrated and reused.

1 illustrates a treatment process for purifying wastewater containing a heavy copper metal generated through a printed circuit board production process and a thin film copper plating process by the industrial wastewater treatment method of the present invention, and FIG. 2 illustrates the industrial wastewater of the present invention. As a treatment method, a treatment process for purifying wastewater containing cyanide compounds generated through a printed circuit board production process and a thin film copper plate plating process is illustrated, and FIG. 3 is a process for producing a printed circuit board as an industrial wastewater treatment method of the present invention. And a treatment process for purifying wastewater containing chromium compounds generated through the thin film copper plate plating process, respectively.

As shown in the figure, wastewater containing cyanide and wastewater containing chromic acid together with wastewater containing copper heavy metals are fractionally purified for each treatment process. First, the wastewater containing heavy metals is purified and washed with water. Referring to the heavy metal-containing wastewater treatment process that allows the remaining heavy metals to be reused by being reused, as shown in FIG. 1, the wastewater containing heavy metals is collected into the corresponding wastewater equalization tank (1a), and the waste regulator is introduced. The majesty (pH) is adjusted while passing through a static line mixer (2a).

Washing waste water passing through the line mixer (2a) is properly mixed and treated with a weak acid concentration of pH 4-7 by sodium hydroxide (NaOH) is introduced into the majeure adjuster, and then the pre-treatment filter (3a) Pretreatment filtration through the multi-layer filter (4a) and microfiltration (5a) sequentially or pretreatment filtration by backwash precision filtration or ultrafiltration membrane separator (6a), which is a pretreatment filtration system (6a). It is collected at 11a.

In particular, the multi-layer filter (4a) is a mixture of sand, gravel, anthracite and activated carbon in a constant pressure vessel or filled with these filter media alone or two or more so that the waste water is passed through these filter layers from the top to the bottom, while the precision The filter 5a is formed of a membrane material such as polypropylene or polyethylene having a particle size of 1-10 μm to precisely filter foreign matters in the wastewater.

In addition, the backwash precision filter or ultrafiltration membrane separator 6a, which is the pretreatment filtration device 3a, is a hollow fiber, tubular, or flat plate type membrane material such as polysulfone, polypropylene, polyethylene, polyacrylonitrile, and polyamide. It is formed in the form of a filtration membrane or an ultrafiltration membrane, and each pore is formed through the particle removal size of 0.01-5㎛, each membrane is 1-50㎛ size on the front and back of the donut-shaped or petal shape of 1-2㎜ thickness A specific labyrinth is formed to form a candle that is stacked on each other and inserted into a rod so that foreign matters can be removed without washing the wastewater coming into contact with the outer surface as much as the maze.

The treated water from the pretreatment collection tank 11a is temperature-corrected by the heat exchanger 12a at a temperature of about 20-25 ° C., and spiral wound or hollow fiber of membrane material such as polyamide, cellulose acetate or polyamide. A water flush used in the production process of a printed circuit board and the plating process of a thin film copper plate through the reverse osmosis membrane separator (13a) formed of (Hollow fiber) and collected into a permeation tank (14a) and passing through an ion exchange resin tower (15a). The concentrated water that is not reused or concentrated without passing through the reverse osmosis membrane separator 13a is sent to the concentration tank 10a.

In addition, the water effluent not filtered by the pretreatment filtration device 3a in the line mixer 2a is temperature-compensated by a heat exchanger 7a in the form of a plate, a tube, or a counter current, and a rotating or vibrating membrane. The suspended solids, organic matter, or ionic components contained in the washing waste water are removed through the separator 8a and collected in the permeation tank 9a while being passed therethrough, followed by traces of heavy metals or ionic substances through the ion exchange resin tower 10a. (Mainly, Na +, Cl-) is removed, purely treated and reused as washing water, or immediately sent to washing water in the production process and plating process for reuse without passing through the ion exchange resin tower 10a.

In addition, the concentrated water concentrated in the rotary or vibrating membrane separator 8a is collected in a concentrated bath 10a and reused as a plating bath, or chemically reacted through a chemical treatment tank 17a, and then neutralized or aggregated or precipitated. And filtered through the activated carbon filter (18a) to be discharged, or the sediment generated in the chemical treatment tank (17a) is collected in the sediment storage tank (19a) is dehydrated through the dehydrator (18a) and the solids are treated.

In particular, the dehydrator 20a is used in the form of a belt press or a filter press, and the filtrate dehydrated through the dehydrator 20a is sent to a flushing waste water equalization tank 1a in which the flushing waste water is collected.

Wastewater containing heavy metals to be purified through the heavy metal-containing wastewater treatment method was able to obtain the measurement results as shown in Table 1 below during the treatment process. The heavy metal wastewater generated in was used.

[Experimental Table 1]

On the other hand, when looking at the waste water treatment process containing cyanide compounds to purify the waste water containing the cyanide compound and reuse it as the wash water, the residual heavy metals can be concentrated and reused, as shown in Figure 2, flushed waste water containing the cyanide compound The maize concentration is controlled by a heavy alkalinity of pH 10-11 while passing through the line mixer (2b) into which the sewage waste equalizer 1b is collected and acid is used.

That is, the line mixer (2b) Majesty adjusting agent is a cyanogen (CN ^-) contained in the washing waste water of the membrane separation process is difficult, because if this is Majesty adjusted to not more than pH 11 and pH 10-11 in the sire is preferably regulated, In particular, the line mixer 2b allows the flushing wastewater and the majesty agent to be mixed in a short time.

The wastewater that has been suitably controlled while passing through the line mixer 2b passes through the multilayer filter 4b and the precision filter 5b sequentially with the pretreatment filter 3b, or rotates with the pretreatment filter 3b. Pretreatment is filtered by a backwash precision filtration method that passes through the vibrating membrane separator 6b or passes through the ultrafiltration membrane separator 7b, which is a pretreatment filtration device 3b, and the foreign matter is precisely filtered to the pretreatment collection tank 8b. Is collected.

In addition, together with the multilayer filter 4b constituting the pretreatment filter device 3a, the precision filter 5b, the rotary or vibration membrane separator 6b, and the ultrafiltration membrane separator 7b are pretreated in the above-described heavy metal-containing wastewater treatment process. It is configured as a filtration device (3a of FIG. 1), and in particular, foreign matter remaining in the ultrafiltration membrane separator 7b and backwashed in the ultrafiltration membrane separator 7b, as well as about 5-20% of concentrated water that does not pass through the vibrating membrane separator 6b. The containing backwash water is also sent to the concentrated water tank 12b.

The treated water from the pretreatment collection tank 11b is temperature-controlled at a constant temperature by the heat exchanger 9b and is permeated through the reverse osmosis membrane separator 10b formed in a spiral wound or hollow fiber type of membrane material, and then permeated water storage tank 11b. ), The concentrated water not collected through the reverse osmosis membrane separator (10b) is sent to the concentration tank (12b), or reused as the wash water used in the production process of the printed circuit board and the plating process of the thin film copper plate.

In addition, the concentrated water collected in the concentrated tank 12b is reused as a plating bath of the plating process while foreign matter particles of about 5 μm are removed through the precision filter 16b, or an oxidation treatment agent such as sodium hypochlorite is introduced. It is sent to the oxidation treatment tank (13b) and the oxidation treatment proceeds as follows.

NaCN + NaOCl → NaCNO + NaCl ... ①

2NaCNO + 3NaOCl + H ₂ O → 2Co ₂ + N ₂ + 2NaOH + 3NaCl ... ②

In other words, if we put together the relations ① × ② + ②,

2NaCN + 5NaOCl + H ₂ O → is the scheme of _{2Co 2 + N 2 + 2NaOH +} 5NaCl.

This requires 5 mol of NaOCl to oxidize 2 mol of CN, but the amount of NaOCl needed to oxidatively decompose 1 kg of cyan is about 7.2 kg.

That is, (5NaOCl / 2CN) = {5 × (23 + 16 + 36) / 2 × (12 + 14)}

= 375/52 ≒ 7.2 kg, NaOCl can be obtained.

Alternatively, ozone oxidation treatment of the treated water may be performed through the ozone oxidation treatment tank 17b. Since cyanide is decomposed to ozone at a pH of 9.5 or higher, the pH is adjusted to 11-12 for the best efficiency. It is oxidized.

_{^{CN - + O 3 → CNO -}} + O 2 ... ①

^{_{2CNO - + 3O 3 + H 3}} O → 2HCO3 - + N 2 + 3O 2 ... ②

In other words, if we summarize the relation between ① × ② and ②,

2CN ^- is a scheme of the _{^{+ N 2 + 5O 2 - +}} 5O 3 + H 2 O → 2HCO3.

The treated water oxidized through the oxidation treatment tank 13b or the ozone oxidation treatment tank 17b is chemically treated by the chemical treatment tank 14b to which the inorganic coagulant and the organic coagulant are administered, and then the supernatant is filtered. Is filtered through a rapid filter (15b) is filled and discharged, and the sludge generated in the chemical treatment by the chemical treatment tank (14b) is subjected to a post-treatment, such as a separate landfill.

As described above, the wastewater containing the cyanide compound generated from the copper cyanide plating bath purified through the wastewater treatment method containing the cyanide compound was subjected to the treatment process to obtain the measurement results as shown in Table 2 below.

[Experimental Table 2]

In particular, it was found that the cyanide removal rate was increased as shown in Measurement Table 1 and the accompanying drawings of FIG.

[Measurement Table 1]

Hydrogen ion concentration (pH) Cyan removal rate (%) 7.0 0 7.7 3.4 9.0 42 9.5 51 10.0 82 10.5 91.5

On the other hand, chromium compounds are also generated in electroplating, electrolytic salts, alumite, leather, photoresist, and other chromium-mate treatments after galvanization. Has become a serious lethal dose.

The wastewater treatment process containing chromium compounds that purifies and recycles the wastewater containing chromium compounds and reuses them as flushing water shows the chromium compound-containing wastewater treatment process so that the residual heavy metals can be reused. The waste concentration is collected while passing through the line mixer 2c into which the waste washing water equalization tank 1c is introduced and the sifting agent is introduced.

When the pH of the washed wastewater is adjusted to 6.5 or more by the sodium hydroxide which is introduced into the waste mixer of the line mixer 2c, the wastewater temperature is properly adjusted and managed through the heat exchanger 3c. It passes through the filtration device 4c.

The effluent wastewater passing through the pretreatment filtration device 4c is sequentially passed through a hollow filter filled with a filter medium and a precision filter 6c having a pore size of 1-5 μm, and then a reverse osmosis membrane separator of a hollow fiber type or spiral wound type 7c. Passed through pre-filtered and collected in the permeate tank, or immediately pre-filtered through the rotating or vibrating membrane separator (8c) and permeate while being collected in the permeate tank (9c) is reused as water wash.

In addition, the concentrated water that does not pass through the pre-treatment filter (4c) is concentrated and collected by the concentration tank (10c) is removed while the foreign material is removed through the cation exchange resin tower (11c) is added hydrochloric acid (HCl) to the resin regeneration agent plating. It can be reused as a bath or evaporated to dryness by the evaporator 12c.

In addition, the flushing waste water from the heat exchanger (3c) is reduced through a reducing treatment tank (13c) in which sodium bisulfite or ferrous sulfate is added sulfuric acid as a reducing agent is sent back to the pretreatment filter (4c), Alternatively, the chemical reaction is carried out by a chemical treatment tank 14c into which a polymer coagulant is injected, and filtered through a rapid filter 15c filled with sand or activated carbon media. The chromium compound wastewater is discharged through the reduction treatment tank 13c. Phosphorus flushing water is reduced by neutralization at pH 2-3 for at least 30 minutes.

In addition, the chemical treatment tank (14c) is added to the sodium hydroxide as a chemical treatment agent neutralization reaction for 20 minutes or more at a stirring speed of 300-350rpm, the polymer coagulant is added to the coagulation and mixing at 50rpm stirring speed for more than 15 minutes washing water waste water It is chemically treated with supernatant.

Then, the concentrated water from the chemical treatment tank 14c is collected into the concentration tank 16c and dehydrated through the dehydrator 17c to be solidified, and the cake as a solid is separately treated, and collected in the flush waste water equalization tank 1c. Washing waste water below the standard concentration is filtered by a precision filter (18c) and passed through an anion exchange resin tower (19c), deionized and reused as a wash water through an activated carbon filter (20c), and the anion exchange resin The flushing wastewater from the tower 19c is sent to a reduction treatment tank 13c for reduction treatment.

That is, the washing waste water, which is a chromium compound, is reduced by the following chemical reaction by sodium bisulfite or ferrous sulfate and sulfuric acid added through the reduction treatment tank 13c.

First, when neutralizing with ferrous sulfate,

2H ₂ CrO ₄ + FeSO ₄ + 6H ₂ SO ₄ → Cr ₂ (SO ₄ ) ₃ + 3Fe ₂ (SO ₄ ) ₃ + 8H ₂ O

FeSO ₄ , 7H ₂ O (kg) = 6FeSO ₄ , 7H ₂ O / 2Cr = 1666.8 / 104 = 16㎏

H ₂ SO ₄ (kg) = 6H ₂ SO ₄ / 2Cr = 588/104 = 5.7 kg.

In addition, when neutralizing sodium bisulfite,

4H ₂ CrO ₄ + 2NaHSO ₃ + 3H ₂ SO ₄ → 2Cr ₂ (SO ₄ ) ₃ + 3Na ₂ SO ₄ + 10H ₂ O

NaHSO ₃ (kg) = 6NaHSO ₃ / 4Cr = 624/208 = 3 kg

H ₂ SO ₄ (kg) = 3H ₂ SO ₄ / 4Cr = 294/208 = 1.4 kg.

In addition, when using the Fe powder to reduce Cr6 ^{6 +} 1kg, a reducing agent 1.07kg H ₂ SO ₄ 5.65kg enters, sodium sulfite (Na ₂ SO ₃ ) is required 3.63 and sulfuric acid 2.83kg, the reduction reaction is pH 2 It is preferable to use at -3 to 30 minutes or more.

In addition, the washed wastewater containing chromium compound was added with sodium hydroxide to a pH of 8.5-9.5 in a chemical treatment tank (14), and increased for 20 minutes or more, and mixed with a polymer coagulant for 15 minutes or more. Stirring at 300-350rpm using a 0.2 kW monomotor and coagulation were the best when aggregating at 50rpm or less.

In addition, when the concentration of the washing waste water collected in the washing waste water equalization tank (1c) is less than the reference concentration of 200 mg / ℓ, the anion exchange resin tower (19c) is filtered by a separate precision filter (18c) for removing turbidity components. After deionization through), the chemical oxygen demand or surfactant in the waste water remains, so the treated water purified and purified through the activated carbon filter 20c is reused as the wash water, and the anion exchange resin tower 19c The water washing waste water from) is sent to a reduction treatment tank 13c for reduction treatment.

In addition, in the case of a small amount of the wastewater passing through the anion exchange tower (19c), using a weakly basic ion exchange resin and regeneration treatment using sodium hydroxide as a regenerant, in particular, to increase the regeneration efficiency when using a strong base ion exchange resin 1 wt% sodium hydroxide and 9 wt% sodium chloride are mixed and regenerated to be sent to a reduction treatment tank 13c.

Thus, the wastewater containing chromium compound purified through the chromium compound wastewater treatment method was able to obtain the measurement results as shown in Table 3 below through the treatment process.

[Experimental Table 3]

According to the industrial wastewater treatment method of the present invention as described above, the industrial wastewater is recycled to the wash water of the production process after the physical purification treatment in order to prevent pre-pollution, not post-treatment, and the heavy metals as raw materials of the production process are properly concentrated. It can be recovered and reused as raw materials, that is, wastewater containing heavy metals and wastewater containing chromium compounds and chromium compounds as well as wastewater generated through the printed circuit board production process and thin film copper plating process of heavy metal producers. It is expected to improve the water quality by fractional purification treatment for each wastewater treatment process, and as a result, it is expected to reduce landfilling of toxic heavy metal wastes, thereby preventing water quality and land pollution due to leachate generation and land degradation.

Claims (18)

The pretreatment filtration device is controlled by the line mixer (2a) in which wastewater containing heavy metals generated through the printed circuit board production process and thin film copper plating process is collected into the flush wastewater equalization tank (1a) and the maize control agent is injected. (3a) is pre-filtered and collected in the pre-treatment tank (11a), the treated water from the pre-treatment tank (11a) is temperature-corrected by the heat exchanger (12a) and permeated through the reverse osmosis membrane separator (13a) while permeating tank ( 14a) and recycled through the ion exchange resin tower 15a to the wash water of the production process and the plating process, while the water wastewater from the line mixer 2a is temperature compensated by the heat exchanger 7a and rotated or Permeated through the vibrating membrane separator (8a) and collected in the permeation tank (9a) and reused as the washing water through the ion exchange resin tower (10a), and the concentrated water concentrated in the rotary or vibrating membrane separator (8a) is concentrated It is collected in the tank (10a) and reused as a plating bath or chemically reacted through the chemical treatment tank (17a), filtered by activated carbon filter (18a) and discharged while being precipitated material generated in the chemical treatment tank (17a) Industrial wastewater treatment method characterized in that the sediment storage tank (19a) is collected and dehydrated through the dehydrator (20a). The industrial wastewater treatment method according to claim 1, wherein the line mixer (2a) is introduced with sodium hydroxide (NaOH) as a sediment modifier to wash down the wastewater, which is a heavy metal wastewater, with a slightly acidic pH of 4-7. The pretreatment filtration device (3) according to claim 1, wherein the pretreatment filtration device (3a) is a pretreatment filtration through the multi-layer filter (4a) and the precision filter (5a) in order to pass through the water or the backwash microfiltration through a backwash ultrafiltration membrane separator (6a). Industrial wastewater treatment method characterized in that the pretreatment filtered. The industrial wastewater treatment according to claim 1 or 3, wherein the multilayer filter (4a) of the pretreatment filtration device (3a) is made by mixing sand, gravel, anthracite, and activated carbon in a constant pressure container or filling it alone. Way. 4. The industrial wastewater treatment method according to claim 1 or 3, wherein the precision filter (5a) of the pretreatment filtration device (3a) is formed of a membrane material of polypropylene or polyethylene having a particle size of 1-10 µm. The ultrafiltration membrane separator (6a) of the pretreatment filtration device (3a) is a membrane material of polysulfone, polypropylene, polyethylene, polyacrylonitrile and polyamide. It is formed in the form of 0.01-5㎛ pores of precision filtration membrane or ultrafiltration membrane, and each membrane is formed with a donut-shaped shape of 1-2 mm or a maze of 1-50㎛ size on the front and back of petal shape and overlaps each other. Industrial wastewater treatment method, characterized in that the form of the inserted candle. The method of claim 1, wherein the reverse osmosis membrane separator (13a) is formed of a spiral wound or hollow fiber as a membrane material of polyamide, cellulose acetate, and polyamide. The industrial wastewater treatment method according to claim 1, wherein the dehydrator (20a) is configured in the form of a belt press or a filter press. Pretreatment filtration as the waste concentration is controlled by the line mixer (2b) where wastewater containing cyanide compounds generated through the printed circuit board production process and thin film copper plating process is collected into the flushing waste water equalization tank (1b), and the maize control agent is introduced. Pretreatment filtration through the apparatus 3b, and the filtered water from the pretreatment filtration apparatus 3b is collected by the pretreatment collection tank 8a and temperature-corrected by the heat exchanger 9b, and further treated by the heat exchanger 9b. While the water is permeated through the reverse osmosis membrane separator 10b, the water is collected into the permeate water storage tank 11b and reused as the wash water, while the concentrated water concentrated in the reverse osmosis membrane 10b is collected in the concentrated water tank 12b so that the oxidizing agent is Oxidized or chemically reacted by the introduced oxidation treatment tank 13b or ozone oxidation treatment by the ozone oxidation treatment tank 17b, and the treated water from the ozone oxidation treatment tank 17b is composed of an inorganic coagulant and an organic solvent. While the supernatant is filtered by the rapid filter (15b) while being chemically reacted through the chemical treatment tank (14b) in which the treatment is administered, the concentrated water from the concentrated tank (12b) is plated through the precision filter (16b). Industrial wastewater treatment method characterized in that to be reused as a bath. The pretreatment filtration method according to claim 9, wherein the pretreatment filtration device (3b) is a pretreatment filtration method in which the flush waste water passes through the multilayer filter (4b) and the precision filter (5b) sequentially, and the pretreatment passing through the rotary or diaphragm separator (6b). An industrial wastewater treatment method characterized in that the selective permeation of any one of the filtration method and the pretreatment filtration method passing through the ultrafiltration membrane separator (7b). The industrial wastewater treatment method according to claim 9, wherein the oxidation treatment tank (13b) is characterized in that sodium hypochlorite (NaOH) is added as an oxidizing agent, and water washing waste water, which is a cyanide compound waste water, is chemically reacted and oxidized. The industrial wastewater treatment method according to claim 9, wherein the ozone oxidation treatment tank (14b) is administered with an inorganic coagulant and an organic coagulant to chemically treat alkaline treated water having a pH of 11-12. Wastewater containing chromium compounds generated through the printed circuit board production process and thin film copper plating process is collected into the flush wastewater equalization tank (1c) and the waste concentration is controlled by the line mixer (2c) where the majesty adjuster is injected. Temperature-corrected by (3c), and the water washing waste water from the heat exchanger is pretreated through the pretreatment filter (4c) and permeated and collected in the permeate tank (9c) and reused as the wash water, and the pretreatment filter (4c). ), The concentrated concentrated water that does not penetrate) is collected in the concentrated water tank (10c), and the foreign matter is removed through the cation exchange resin tower (11c) and reused as a plating bath or evaporated and dried by the evaporator (12c) to solidify. The water washing waste water from the heat exchanger (3c) is reduced through a reduction treatment tank (13c) into which a reducing agent is introduced and sent to the pretreatment filtration device (4c) or a polymer coagulant is added. The chemical reaction is carried out by the chemical treatment tank 14c to be introduced and discharged while being filtered through the rapid filter 15c, and the concentrated water from the chemical treatment tank 14c is collected into the concentration tank 16c, thereby dehydrating the dehydrator 17c. While being dehydrated through the solidification treatment, the flushing waste water below the standard concentration collected by the flushing waste water equalization tank 1c is filtered by a precision filter 18c and deionized while passing through an anion exchange resin tower 19c. An industrial wastewater treatment method characterized in that it is reused as washing water through an activated carbon filter (20c), and the washing water from the anion exchange resin tower (19c) is sent to a reduction treatment tank (13c) for reduction. 14. The pretreatment filtration device (4c) according to claim 13, wherein the pretreatment filtration (4c) is a pre-filtration or rotating or vibrating membrane separator (8c) by passing the water through the rapid filter (5c), microfiltration (6c) and reverse osmosis membrane separator (7c) Industrial wastewater treatment method characterized in that the pretreatment through. The industrial wastewater treatment method according to claim 13, wherein the cation exchange resin tower (11c) is introduced with hydrochloric acid (HCl) as a resin regeneration material to remove foreign substances from concentrated water. The reduction treatment tank (13c) is a reduction treatment while the sodium bisulfite or ferrous sulfate and sulfuric acid is added as a reducing agent to neutralize the washing waste water of the chromium compound waste water at pH 2-3 for more than 30 minutes Industrial wastewater treatment method characterized in that. The chemical treatment tank 14c is neutralized by at least 20 minutes at a stirring speed of 300-350 rpm, and a coagulant is mixed at 15 rpm or more at 50 rpm for 15 minutes. Industrial wastewater treatment method characterized in that the flushing waste water is chemically treated with supernatant. The method of claim 13, wherein the anion exchange resin tower (19c) is characterized by using sodium hydroxide as a regeneration agent with a weakly basic anion exchange resin, or a mixture of sodium hydroxide and sodium chloride as a regeneration agent with a strong base anion exchange resin. Industrial wastewater treatment method.