KR20190078459A - Method and apparatus for reusing inorganic wastewater - Google Patents

Abstract

A method and apparatus for reusing inorganic wastewater are disclosed. The disclosed inorganic wastewater reusing method comprises the steps of: partially removing hydrogen peroxide in alkaline wastewater to produce first treated water (S10); simultaneously removing residual hydrogen peroxide and organic materials in the mixed wastewater including the first treated water and acidic wastewater to produce second treated water (S20); simultaneously removing heavy metals and particulate matter in the second treated water to produce third treated water (S30); and simultaneously removing the remaining organic materials and ionic materials in the third treated water to produce fourth treated water (S40). The installation area can be reduced, and the cost can be reduced in terms of operating costs.

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for reusing inorganic wastewater,

A method and apparatus for reusing inorganic wastewater. More particularly, the present invention relates to a method and apparatus for reusing mixed wastewater containing acidic wastewater and alkaline wastewater in inorganic wastewater.

A large number of acid and alkaline inorganic chemicals are used in the semiconductor manufacturing process, where acidic and alkaline inorganic wastewater is generated.

Typical characteristics of acid wastewater are acidic conditions below pH 4 and include hydrogen peroxide, organic matter, particulate pollutants and heavy metal ions.

Common features of alkaline wastewater are alkaline conditions above pH 9 and include hydrogen peroxide, organic matter, particulate pollutants, ammoniacal nitrogen and heavy metal ions.

Conventional acidic and alkaline wastewater treatment technologies will be described as follows.

1) Acid wastewater treatment technology: Microbiological enzyme chemical process

The above process is a technique for introducing a microbial enzyme chemical to remove hydrogen peroxide contained in acidic wastewater in inorganic wastewater, and then introducing coagulation and sedimentation processes to remove particles and heavy metals. The microbial enzyme chemicals such as the catalase used in the present technology are high in cost, increase the equipment operation cost when used, and have a disadvantage of increasing the content of organic substances in the treated water because they are organic enzymatic substances. In addition, in the flocculation and sedimentation process at the downstream stage of the microbial enzyme system, there is a disadvantage in that the removal efficiency of the particulate matter and the heavy metal is not constant and fluctuates and the process stability is low. Further, since the concentration of the ionic material remaining in the final treated water is high, it is difficult to reuse.

2) Alkaline wastewater treatment technology: Multistage biological process for ammonia nitrogen removal

This process is a process for removing high concentrations of organic substances and ammonia nitrogen contained in alkaline wastewater using a multi-stage bioreactor leading to an anoxic tank-aeration tank-settling tank. In order to maintain multi-stage bioreactors, considerable know-how is required for large site area and maintenance, and due to the characteristics of multi-stage bioreactors, there is difficulty in operation due to large fluctuation of final treatment water quality at each stage of treatment efficiency change. In addition, only a small amount of organic substances contained in the wastewater are removed, and a large amount of ionic and particulate matter remains in the wastewater, making it difficult to reuse the wastewater.

The present invention relates to a process for the removal of expensive hydrogen peroxide and a multistage biological treatment process used in conventional processes for the treatment of semiconductor inorganic wastewater such as acid alkali wastewater by a carrier process and a separation membrane process, And particulate matter to remove wastewater from the waste water.

According to an aspect of the present invention,

A step (S10) of partially removing hydrogen peroxide in the alkaline wastewater to generate a first treated water;

(S20) of simultaneously removing residual hydrogen peroxide and organic matter in the mixed wastewater containing the first treated water and the acidic wastewater to generate a second treated water;

A step (S30) of simultaneously removing heavy metals and particulate matter in the second treated water to generate a third treated water; And

And a step (S40) of simultaneously removing the remaining organic matter and the ionic substance in the third treated water to produce a fourth treated water.

The step (S10) may be carried out by passing the alkaline wastewater through a first carrier which functions as a catalyst of the hydrogen peroxide decomposition reaction.

In the step S10, the alkaline wastewater can be treated at a space velocity of 5 hr ^-1 or less.

The step (S20) is carried out by passing the mixed wastewater through a microorganism immobilization support, and the microorganism immobilization support may include a second support which functions as a catalyst for the hydrogen peroxide decomposition reaction and microorganisms fixed to the second support.

At least one of the first carrier and the second carrier may contain activated carbon.

The method for reusing the wastewater may further include a step (S25) of discharging the oxygen generated in the step (S20) to the outside, which is performed without stopping the step (S20).

The method for reusing wastewater may not include the step of supplying external air to the microorganism immobilization pellets used in step S20.

The microorganism may comprise an aerobic microorganism.

The microorganism is selected from the group consisting of Pseudomonas sp. CP236 (Accession No .: KACC 91512P), Methylobacterium extorquens SMIC-1 (Accession No. KCTC 10946 BP), Mycobacterium sp. SMIC-1 (Accession No. KCCM 10999P), SMC-1 (Accession No. KCTC 10947 BP), Acinetobacter sp. SMIC-1 (Accession No. KCCM 10999P) sp. SMIC-2 (Accession No. KCCM 11000P) or a combination thereof.

In the step S20, the mixed wastewater can be treated at a space velocity of 10 hr ^-1 or less.

The step (S30) includes the steps of adding a coagulant to the second treated water to coagulate heavy metals and particulate matter in the second treated water (S31), filtering the coagulated material with a filter (S32) And a step (S33) of discharging the concentrated substance to the outside after filtration.

The coagulant may include an Al-based coagulant, an Fe-based coagulant, a Ca-based coagulant, or a combination thereof.

The step (S40) may be performed by passing the third treated water through the reverse osmosis membrane.

According to another aspect of the present invention,

A hydrogen peroxide removal device for partially removing hydrogen peroxide in alkaline wastewater using a first carrier functioning as a catalyst for the hydrogen peroxide decomposition reaction to produce a first treated water;

The hydrogen peroxide and organic matter remaining in the mixed wastewater containing the first treated water and the acidic wastewater are simultaneously treated with the microorganism-immobilized carrier comprising the second carrier functioning as a catalyst of the hydrogen peroxide decomposition reaction and the microorganism immobilized on the second carrier An apparatus for simultaneously removing hydrogen peroxide and organic matter to produce a second treated water;

An aggregating and filtering device for simultaneously removing heavy metals and particulate matter in the second treated water by using a flocculant and a filter to produce a third treated water; And

And a reverse osmosis device for simultaneously removing residual organic matter and ionic substances in the third treated water by using a reverse osmosis membrane to produce a fourth treated water.

The filter provided in the coagulation and filtration apparatus may be a microfiltration membrane or an ultrafiltration membrane having a pore size of 0.01 to 0.45 μm.

The reverse osmosis membrane provided in the reverse osmosis unit may be brackish water or seawater.

According to one embodiment of the present invention, in the reutilization treatment of the acid alkali wastewater generated in the semiconductor manufacturing process, hydrogen peroxide, organic matter, ionic material and particulate matter contained in the wastewater are effectively removed and the cooling water, And can be reused as waste water.

Especially, it can reduce cost in terms of installation area and operation cost by implementing an activated carbon process with microorganisms capable of simultaneously removing hydrogen peroxide and high concentration organic matter.

1 is a schematic view of an apparatus for recycling an inorganic wastewater according to an embodiment of the present invention.
FIG. 2 is a view schematically showing an example of an apparatus for simultaneously removing hydrogen peroxide and organic matter in the apparatus for recycling inorganic wastewater of FIG. 1;
FIG. 3 is a view schematically showing another example of an apparatus for simultaneously removing hydrogen peroxide and organic matter in the apparatus for recycling inorganic wastewater of FIG. 1;
Fig. 4 is a view schematically showing an example of the coagulation and filtration apparatus provided in the apparatus for recycling inorganic wastewater of Fig. 1;

Hereinafter, a method of recycling inorganic wastewater according to an embodiment of the present invention will be described in detail with reference to the drawings.

As used herein, the term "microbe immobilized media " means a carrier to which microorganisms are immobilized.

In the present specification, the term "upward flow" means a flow proceeding in the reverse direction of gravity, and "downward flow" means a flow proceeding in the gravity direction.

Herein, "front end or front end portion " means a portion or an end located in a direction opposite to the flow direction of the wastewater, and" rear end or rear end portion "means a portion or end portion located in the forward direction of the flow direction of the wastewater it means.

In the present specification, "space velocity" is a value obtained by dividing the supply rate (m ³ / hr) of the wastewater by the internal volume (m ³ ) of the wastewater treatment apparatus and is a reciprocal of the residence time. It means efficiency. Here, the content of the wastewater treatment apparatus refers to the apparent volume of the filler (carrier or microorganism-immobilized support) filled in the wastewater treatment apparatus.

The method for reclaiming wastewater according to an embodiment of the present invention may simultaneously treat alkaline wastewater and acid wastewater to remove hydrogen peroxide, organic matter, heavy metals, particulate matter, and ionic substances contained in each wastewater.

The alkaline wastewater and the acid wastewater may be electronic wastewater discharged from electronic industries such as semiconductor and LCD manufacturing processes, but the present invention is not limited thereto.

The alkaline wastewater may have a pH of 9 or higher.

In addition, the alkaline wastewater may include hydrogen peroxide, organic matter, particulate pollutants, ammonia nitrogen, heavy metal ions and other alkaline materials (e.g., NaOH).

The alkaline wastewater may contain up to 3,000 mg / L hydrogen peroxide.

The acidic wastewater may have a pH of 4 or less.

In addition, the acid wastewater may comprise hydrogen peroxide, organic matter, particulate pollutants, ammonia nitrogen, heavy metal ions and other acidic substances such as hydrochloric acid, sulfuric acid or nitric acid.

The organic material may include a biodegradable organic material.

The heavy metal may be present in the respective wastewater in a dissolved state.

Specifically, the method for reclaiming wastewater according to an embodiment of the present invention comprises the steps of: (S10) partially removing hydrogen peroxide in alkaline wastewater to produce a first treated water (S10), adding the mixed wastewater containing the first treated water and acidic wastewater (S30) of simultaneously removing heavy hydrogen and particulate matter in the second treated water to produce a third treated water, and a step (S30) of removing the residual hydrogen peroxide and the organic matter to generate a second treated water 3) removing the remaining organic matter and the ionic substance in the treated water simultaneously to generate the fourth treated water (S40).

The step (S10) may be carried out by passing the alkaline wastewater through a first carrier which functions as a catalyst of the hydrogen peroxide decomposition reaction.

The first carrier decomposes hydrogen peroxide (H ₂ O ₂ ) as shown in the following reaction formula (1).

[Reaction Scheme 1]

(1) 2H ₂ O ₂ ? 2H ₂ O + O _2?

The first carrier is not a reactant in the hydrogen peroxide decomposition reaction but serves only as a catalyst, and thus is not consumed, so that the lifetime is semi-permanent.

The first carrier may comprise activated carbon. However, the present invention is not limited thereto, and the first carrier may include various other materials which function as a catalyst for the hydrogen peroxide decomposition reaction.

The activated carbon can be sold as a hydrogen peroxide decomposition only in activated carbon manufacturers, for example, be a company Norit ROW 0.8 and Calgon Corporation CENTAUR ^® HSL 8x30 products.

Further, the first carrier may be particulate matter.

In addition, the first carrier may have an average particle diameter of 5 to 40 meshes, for example, 8 to 30 meshes.

In addition, the first carrier may have a spherical or other various shapes.

In the step S10, the alkaline wastewater can be treated at a space velocity of 5 hr ^-1 or less.

The first treated water discharged in the step (S10) must satisfy both of the following two conditions. First, the lower limit of the concentration of hydrogen peroxide in the first treated water should be high enough to produce the amount of oxygen necessary for promoting the growth of the microorganism. Second, the upper limit of the concentration of hydrogen peroxide in the first treated water should be low enough that the viable microorganisms do not kill most of the microorganisms used in step S20, so that the viable microorganisms have sufficient organic decomposition ability. In this regard, I will explain later.

For the same reason, the step (S10) in the waste water reuse method is an essential step that can never be omitted. That is, when the alkaline wastewater is directly mixed with the acidic wastewater without the pretreatment in the step S10 and then supplied to the step S20, most of the microorganisms used in the step S20 are killed due to the high concentration of hydrogen peroxide Thus, the organic matter is not decomposed in the step S20, so that the object of the present invention, that is, simultaneous removal of hydrogen peroxide and organic matter in the wastewater, can not be achieved.

The first treated water discharged in the step (S10) may contain hydrogen peroxide of 250 mg / L or less.

The first treated water and the acidic wastewater may be mixed to form the mixed wastewater.

The step (S20) may be performed by passing the mixed wastewater through the microorganism immobilization carrier.

The microorganism-immobilized carrier may comprise a second carrier which functions as a catalyst for the hydrogen peroxide decomposition reaction, and a microorganism immobilized on the second carrier.

The second carrier may be the same as or similar to the first carrier. Therefore, as in the first carrier, the second carrier can also decompose hydrogen peroxide (H ₂ O ₂ ) as in the reaction formula (1).

In addition, the second carrier may have a high proportion of macropores, which are spaces in which the microorganisms are fixed.

When the microorganisms are in direct contact with hydrogen peroxide, at least a part of them may be killed and the organic matter decomposing ability may be weakened or lost. Specifically, in the step S20, the mixed wastewater is primarily in direct contact with a part of the microorganism immobilization support. At this time, a part of hydrogen peroxide contained in the mixed wastewater is decomposed by contact with the second carrier to generate oxygen, and a part of the microorganisms contained in the microorganism immobilization support contact with hydrogen peroxide in the mixed wastewater, do. Thereafter, when the hydrogen peroxide in the mixed wastewater is continuously decomposed and reduced to a predetermined concentration or lower, the surviving microorganisms which are not killed after that are not killed due to the low concentration of hydrogen peroxide even in contact with hydrogen peroxide. That is, since the microorganism-immobilized carrier usually forms a layer, microorganisms near the supply side of the mixed wastewater among the microorganism-immobilized carriers can not be killed, but microorganisms located farther away are not killed, It is possible to maintain high organic decomposition ability by proliferation under the supply of oxygen.

The microorganism may comprise an aerobic microorganism.

For example, the microorganism may be selected from the group consisting of Pseudomonas sp. CP236 (Accession No .: KACC 91512P), Methylobacterium extorquens SMIC-1 (Accession No. KCTC 10946 BP) (Acinetobacter sp. SMIC-1) (Accession No. KCCM 10999P), SMI-1 (Mycobacterium sp. SMIC-1) (Accession No. KCTC 10947 BP) -2 (Cupriavidus sp. SMIC-2) (Accession No. KCCM 11000P) or a combination thereof.

The mixed wastewater may include total organic carbon (TOC) of 20 mg / L or less and hydrogen peroxide of 250 mg / L or less. For example, when the TOC is 20 mg / L, the theoretical oxygen demand (ThOD) is about four times the TOC, so that oxygen (O ₂ ) of 80 mg / L is required. Accordingly, according to Reaction Scheme 1, 170 mg / L of hydrogen peroxide is required to supply 80 mg / L of oxygen to the microorganism.

The mixed wastewater may have a pH of 4.0 to 8.0 and a temperature of 18 to 30 캜.

In the step S20, the mixed wastewater can be treated with a space velocity (SV) of 10 hr ^-1 or less. For example, if it is desired to remove more than 50% of the TOC in the mixed wastewater, the mixed wastewater may be treated at a space velocity of 7 hr ^-1 or less in the step (S20).

For example, in the step S20, the mixed wastewater can be treated at a space velocity of 0.5 to 10 hr ^-1 , for example, 3 to 7 hr ^-1 .

The method for recovering wastewater may further include discharging the oxygen generated in step S20 to the outside (S25). In addition, the oxygen discharge step S25 may be performed without interruption of the step S20 because part of the oxygen generated by the decomposition reaction of hydrogen peroxide is consumed by the microorganisms, so that the remaining amount of oxygen to be degassed is small Because.

The step (S30) includes the steps of adding a coagulant to the second treated water to coagulate heavy metals and particulate matter in the second treated water (S31), filtering the coagulated material with a filter (S32) And a step (S33) of discharging the concentrated substance to the outside after filtration.

The flocculant used in step (S31) may include an Al-based flocculant, an Fe-based flocculant, a Ca-based flocculant, or a combination thereof.

The Al-based flocculant may include a monomolecular flocculant, a polymer flocculant, or a combination thereof.

The monomolecular coagulant is _{Al 2 (SO 4) 3 ·} 18H 2 O, Na 2 Al 2 O 4, Al 2 (SO 4) 3 (NH 3) 2 SO 4, Al 2 (SO 4) 3 (NH 3) ₂ SO ₄ , Al ₂ (SO ₄ ) ₃ K ₂ SO _4, or a combination thereof.

The polymer flocculant is _{[Al 2 (OH) n Cl} 6-n] m (m≤10, 1≤n≤5), [Al 2 (OH) n (SO 4) 3-n / 2] m (m _{≤10, 1≤n≤5), Al a (} OH) b (SO 4) c (SiO x) d, Al a (OH) b (Cl) c (Si) d, Al a (OH) b (Cl ) _c (Ca) _d, or combinations thereof.

In addition, the Al-based flocculant may contain 3 wt% or more of Al.

The Fe-based flocculating agent is _{Fe (OH) 3, Fe (} OH) of the _trihydrate, FeCl _3, FeCl _{3 hydrate, [Fe 2 (SO 4)} 3] m, [Fe 2 (SO 4) 3] in the _m hydrate , FeSO ₄ .7H ₂ O, or a combination thereof.

In addition, the Fe-based flocculant may contain 5% by weight or more of Fe.

The Ca-based coagulant may include CaO, Ca (OH) _2, or a combination thereof.

In addition, the Ca-based coagulant may contain 5% by weight or more of Ca.

The amount of the coagulant injected varies depending on the concentration of the heavy metal in the wastewater and the concentration of the particulate matter, and the typical injection concentration may be several ppm to several tens of ppm on the basis of weight, for example, 100 to 4,000 ppm. The pH of the wastewater recycling method according to an embodiment of the present invention is in the range of 5.5 to 9, the agglomeration reaction time is 5 to 60 minutes, the agitation agitation strength May be a velocity gradient (s ^-1 ) of 100 to 1,500 s ^-1 .

The filter used in step S32 may be a microfiltration membrane or an ultrafiltration membrane.

The microfiltration membrane may have a nominal pore size of 0.01 m or more.

The ultrafiltration membrane may have a molecular weight cutoff of 100,000 Daltons or more.

The filter may be used in the form of a hollow fiber module or a tubular module.

When the filter is used in the form of a hollow fiber membrane module, the operation flux may be 10 to 30 L / m ² · hr and the recovery rate may be 80 to 98%. When the filter is used in the form of tubular membrane module, 500 L / m ² · hr and the recovery rate may be 80 to 98%.

The recovery rate of the filter means the percentage of the value obtained by dividing the flow rate filtered by the filter by the flow rate flowing into the filter.

The step S33 may be performed by removing the concentrated sludge after the filtration in the step S32 after being discharged in the step S31.

The reverse osmosis membrane used in the step S40 may remove ammonia nitrogen and other organic substances from the third process water when operated under a pressure condition higher than the osmotic pressure of the third process water.

The reverse osmosis membrane may be a brackish water reverse osmosis membrane (BWRO) or a seawater reverse osmosis membrane (SWRO).

The operation flux of the reverse osmosis membrane may be 15 to 35 L / m ² · hr, and the recovery rate may be 60 to 90%.

The recovery rate of the reverse osmosis membrane is determined by dividing the flow rate (i.e., the flow rate of the fourth treatment water (TW4)) filtered by the reverse osmosis membrane by the flow rate (i.e., the flow rate of the third treatment water (TW3) .

The method for reusing wastewater (particularly, the step (S20)) can simultaneously reduce hydrogen peroxide and organic matter in the mixed wastewater, thereby reducing the cost of site and apparatus for device installation.

In addition, the waste water recycling method is environmentally friendly because it minimizes the use of chemicals.

1 is a schematic view of an apparatus 100 for recycling inorganic wastewater according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus 100 for recycling inorganic wastewater according to an embodiment of the present invention includes a hydrogen peroxide removal device 110, hydrogen peroxide and organic matter simultaneous removal devices 120 and 120 ', a flocculation and filtration device 130, And a reverse osmosis device (140).

The hydrogen peroxide removal device 110 serves to partially remove the hydrogen peroxide in the alkaline wastewater RW2 by using a first carrier (not shown) functioning as a catalyst of the hydrogen peroxide decomposition reaction to generate the first treated water TW1 .

The hydrogen peroxide and organic matter simultaneous removal devices 120 and 120 'may be constructed by using a microorganism immobilization support (not shown) including a second carrier functioning as a catalyst for hydrogen peroxide decomposition reaction and a microorganism immobilized on the second carrier, And simultaneously removes the remaining hydrogen peroxide and organic substances in the mixed wastewater RW3 containing the water TW1 and the acid wastewater RW1 to generate the second treated water TW2.

2 is a view schematically showing an example of an apparatus 120 for simultaneously removing hydrogen peroxide and organic matter in the apparatus 100 for recycling inorganic wastewater of FIG.

As shown in FIG. 2, the simultaneous removal apparatus 120 for hydrogen peroxide and organic matter can be operated in an upward flow.

Hereinafter, the operation and effect of the simultaneous removal device 120 of hydrogen peroxide and organic matter will be described in detail.

First, the mixed wastewater RW3 is regulated in flow rate by a pump (not shown) and fed into the vessel 121 via the valve V1.

Next, the mixed wastewater (RW3) passes through the microorganism immobilization support (122), the hydrogen peroxide contained in the mixed wastewater (RW3) is decomposed by the catalytic action of the second support to generate oxygen, At least some of the microorganisms are killed and the generated oxygen is partially consumed by the viable microorganisms and the remainder exits the microorganism immobilization support 122 together with the second treated water TW2. The oxygen-consuming microorganisms are proliferated to improve the organic matter-decomposing ability. At this time, the biodegradable organic substances contained in the mixed wastewater (RW3) are decomposed by the viable microorganisms. The mixed wastewater RW3 is converted into the second treated water TW2 while passing through the microorganism immobilization support 122. [

Finally, the second treated water TW2 is discharged to the outside through the valve V2.

FIG. 3 is a view schematically showing another example of an apparatus 120 'for simultaneous removal of hydrogen peroxide and organic matter in the apparatus 100 for recycling inorganic wastewater of FIG.

Referring to FIG. 3, an apparatus 120 'for simultaneously removing hydrogen peroxide and organic matter includes a container 121', a microorganism immobilization support 122 ', and a vent valve V3.

The microorganism immobilization support 122 'is filled in the container 121'.

Since the microorganism-immobilized support 122 'is the same as the microorganism-immobilized support described above, a detailed description thereof will be omitted here.

As shown in FIG. 3, the simultaneous removal device 120 'for hydrogen peroxide and organic matter can be operated in a downward flow.

Hereinafter, the operation and effect of the simultaneous removal device 120 'for hydrogen peroxide and organic matter will be described in detail.

First, mixed wastewater RW3 is regulated in flow rate by a pump (not shown) and fed into the container 121 'through the valve V1.

Next, the mixed wastewater RW3 passes through the microorganism immobilization support 122 ', the hydrogen peroxide contained in the mixed wastewater RW3 is decomposed by the catalytic action of the second support to generate oxygen, At least some of the microorganisms are killed and the generated oxygen is partially consumed by the surviving microorganisms and the remainder is accumulated in the container 121 '. The oxygen-consuming microorganisms are proliferated to improve the organic matter-decomposing ability. At this time, biodegradable organic substances contained in the mixed wastewater (RW3) are decomposed by the microorganisms. The mixed wastewater RW3 is converted into the second treated water TW2 while passing through the microorganism immobilization support 122 '.

On the other hand, the oxygen stored in the container 121 'is discharged to the outside by periodically automatically turning on / off the vent valve V3. At this time, since the amount of oxygen stored in the container 121 'is small, the process of passing the mixed wastewater RW3 through the microorganism immobilization support 122' can be performed without interruption during the oxygen discharge process Can proceed.

Although not specifically shown in FIG. 3, a facility for preventing the mixed wastewater RW3 from being discharged through the vent valve V3 may be further provided when the vent valve V3 is on .

Finally, the second treated water TW2 is discharged to the outside through the valve V2.

The simultaneous removal step (S20) of hydrogen peroxide and organic matter and the simultaneous removal device 120, 120 'for hydrogen peroxide and organic matter are used for a wastewater treatment facility of an electronic workplace where a large amount of hydrogen peroxide and wastewater containing high concentration organic matter are generated, The same effect can be obtained.

(1) Hydrogen peroxide and organic matter can be treated as a single device without separately treating them, thus reducing the site for installing the device.

(2) Since microorganisms consume oxygen generated by the decomposition of hydrogen peroxide, the amount of oxygen stored in the container is lower than that of a conventional down-stream activated carbon process in which only hydrogen peroxide is decomposed.

(3) In the prior art, the water passing process should be stopped for the degassing. However, since the method and apparatus for simultaneously removing hydrogen peroxide and organic substances according to the embodiment of the present invention does not require a large amount of degassing, It is possible to degas the inside of the container by on / off control.

(4) Since the oxygen supply is maintained at a sufficient concentration due to the decomposition of hydrogen peroxide, there is no need for a separate air supply, which has conventionally been required for the operation of biological water treatment processes in the past.

(5) Oxygen generated by the decomposition of hydrogen peroxide passes between the supports, thereby reducing contamination such as clogging.

(6) Since the decomposition of hydrogen peroxide by the carrier is due to the catalytic action, the carrier is not consumed, the lifetime of the carrier is semi-permanent, and environment-friendly because no chemical is used.

(7) In the decomposition of organic matter by microorganisms, since the carrier has only the supporting function, the lifetime of the carrier is semi-permanent even considering the wear and loss.

The coagulation and filtration apparatus 130 simultaneously removes heavy metals and particulate matter in the second treated water TW2 using a flocculant (not shown) and a filter (not shown) to generate third treated water TW3 Role.

FIG. 4 is a view schematically showing an example of the coagulation and filtration apparatus 130 provided in the apparatus 100 for recycling inorganic wastewater of FIG.

4, the flocculation and filtration apparatus 130 may include a flocculation tank 131, a flocculant reservoir 132, a filter 133, and a sludge reservoir 134.

The flocculation reaction tank 131 cools the heavy metals and the particulate matter in the second treated water TW2 by bringing the flocculant supplied from the flocculant storage tank 132 into contact with the second treated water TW2. A pH sensor and a stirrer may be installed in the flocculation reaction tank 131.

The filter 133 serves to filter the aggregate in the effluent discharged from the flocculation reaction tank 131.

The sludge storage tank 134 is a place for storing the sludge SW, which is a substance that remains in the filter 133 after being discharged from the flocculation reaction tank 131, without being filtered. The sludge SW stored in the sludge storage tank 134 is periodically discharged to the outside.

Hereinafter, the function and effect of the coagulation and filtration apparatus 130 will be described in detail with reference to FIG.

First, the second treated water TW2 and a flocculant (not shown) of the flocculent storage tank 132 are supplied to the flocculation tank 131. In the flocculation reaction tank 131, heavy metals and particulate matter in the second treated water TW2 are agglomerated.

Thereafter, the effluent discharged from the flocculation reaction tank 131 is pumped by the pump P and supplied to the filter 133. The filter 133 filters out the agglomerated material (i.e., agglomerates), and the agglomerates are stored in the sludge storage tank 134 and then discharged to the outside.

The filtered water 133 is discharged to the third treatment water (TW3) and supplied to the reverse osmosis unit (140) at the subsequent stage, and the concentrated water is circulated to the flocculation reaction tank (131).

Referring back to FIG. 1, the reverse osmosis unit 140 performs a function of simultaneously removing residual organic substances and ionic substances in the third treated water TW3 using a reverse osmosis membrane to generate a fourth treated water TW4 .

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these embodiments.

Example

Experimental Examples 1-1 to 1-4

(Fabrication of device)

Four simultaneous removal devices of hydrogen peroxide and organic matter operated in an upward flow with the same configuration as shown in Fig. 2 were produced. Specifically, a closed container was prepared except for the lower wastewater inflow portion and the upper treatment water outflow portion. Thereafter, microorganisms were immobilized on activated carbon having a particle size of 8 to 30 mesh (CENTAUR HSL 8x30, manufactured by Calgon) having hydrogen peroxide removal function to obtain a microorganism-immobilized carrier. Thereafter, the microorganism-immobilized carrier was filled in the container. As the microorganisms, Pseudomonas sp. CP236 (accession number: KACC 91512P) and Methylobacterium extorquens SMIC-1 (Accession No. KCTC 10946 BP), which decompose methanol, (Mycobacterium sp. SMIC-1) (Accession No. KCTC 10947 BP) decomposing tetramethylammonium hydroxide (TMAH), which is a nitrogenous organic substance, Were mixed in a weight ratio of 1: 1.

(Operation of the apparatus)

Water containing 250 mg / L hydrogen peroxide and 20 mg / L TOC was used as the wastewater. The organics constituting the TOC in the wastewater contained acetic acid, methanol, acetone, isopropyl alcohol and tetramethylammonium hydroxide. The four devices were designed to treat raw water at a space velocity (SV) of 3, 4, 7 and 10 hr ^-1 , respectively, by varying the filling amount of the microorganism-immobilized carrier.

Experimental Example 1-1 1-2 1-3 1-4 Space velocity (hr ^-1 ) 3 4 7 10

Experimental Examples 2-1 to 2-4

Except that an apparatus for simultaneous removal of hydrogen peroxide and organic matter operated in a downward flow having the configuration of FIG. 3 was used instead of the simultaneous removal of hydrogen peroxide and organic matter operated in an upward flow with the configuration of FIG. 2, The microorganism-immobilized carrier was prepared in the same manner as in 1-1 to 1-4, and the apparatus was operated. However, the vent valve V3 was controlled so as to automatically repeat the on / off operation periodically every minute.

Experimental Example 2-1 2-2 2-3 2-4 Space velocity (hr ^-1 ) 3 4 7 10

Evaluation Example 1: Average TOC removal rate and average hydrogen peroxide concentration in treated water

The TOC removal rate and the concentration of hydrogen peroxide in the treated water were measured by operating the devices for simultaneous removal of hydrogen peroxide and organic matter prepared in Experimental Examples 1-1 to 1-4 and 2-1 to 2-4 for 60 days, The average values are shown in Table 3 below.

Average TOC Removal Rate (%) Average hydrogen peroxide concentration in treated water (mg / L) Example 1-1 87.3 0.06 Examples 1-2 83.4 0.09 Example 1-3 64.1 0.15 Examples 1-4 47.4 0.34 Example 2-1 74.9 0.13 Example 2-2 66.4 0.2 Example 2-3 57.2 1.52 Examples 2-4 47.8 4.0

The TOC removal rate and the hydrogen peroxide removal rate are both higher than those of the apparatuses of Experimental Examples 2-1 to 2-4 in which the apparatuses of Experimental Examples 1-1 to 1-4 operated in an upward flow are operated in a downward flow, Respectively.

In addition, the processing speed of the waste water of less than 7 hr ^-1 Experimental Examples 1-1 to 1-2 and 2-1 to 2-2 are the apparatus, the processing speed of the waste water at least 7 hr ^-1 Experimental Example 1-3 to 1 TOC removal rate and hydrogen peroxide removal rate were higher than those of the apparatuses of Examples 1-4 and 2-3-2-4.

Example 1

A waste water recycling apparatus 100 having the same construction as that shown in Fig. 1 was manufactured and operated as follows.

The hydrogen peroxide-

Except for the lower wastewater inlet and the upper wastewater outlet, the enclosed vessel was filled with activated hydrogen peroxide (Calgon CENTAUR ^® HSL 8x30) with hydrogen peroxide removal capability. The particle size of the activated carbon used was 8 to 30 mesh, and the activated carbon was charged under the condition that the space velocity (SV) was 4 hr ^-1 .

A device for simultaneous removal of hydrogen peroxide and organic matter (120)

The hydrogen peroxide and organic matter simultaneous removal device 120 operated in an upward flow having the same configuration as that shown in FIG. 2 was manufactured and operated. Specifically, except for the lower wastewater inflow portion and the upper treatment water outflow portion, the closed vessel was filled with the microorganism immobilization support. Specifically, a microorganism-immobilized carrier was obtained by immobilizing microorganisms on activated carbon having a particle size of 8 to 30 mesh (Calgon CENTAUR HSL 8x30) having a function of removing hydrogen peroxide. Then, the microorganism-immobilized carrier was filled in the vessel under the conditions of a space velocity (SV) of 4 hr ^-1 . As the microorganisms, Pseudomonas sp. CP236 (accession number: KACC 91512P) and Methylobacterium extorquens SMIC-1 (Accession No. KCTC 10946 BP), which decompose methanol, (Mycobacterium sp. SMIC-1) (Accession No. KCTC 10947 BP) decomposing tetramethylammonium hydroxide (TMAH), which is a nitrogenous organic substance, Were mixed in a weight ratio of 1: 1.

Coagulation and filtration equipment (130)

The coagulation and filtration apparatus 130 having the same configuration as that shown in FIG. 4 was manufactured and operated. Specifically, 900 ppm by weight of FeCl ₃ having an Fe content of 38% by weight was injected as a coagulant to remove dissolved heavy metals and particulate matter. At this time, the pH of the water to be treated was adjusted to 6.3, and the pH controlling agent used was sulfuric acid (98 wt%) and sodium hydroxide (1N). Thereafter, the mixture was agitated for 5 minutes with a stirrer to progress the flocculation reaction, and the particulate matter was filtered with a microfiltration membrane (TMF, tubular type UF) having a membrane pore size of 0.02 μm. The operating flux of the microfiltration membrane was 250 L / m ² · hr and the recovery rate was 90%.

Reverse osmosis systems (140)

(BWRO, Brackish water reverse osmosis membrane) was used in the reverse osmosis membrane to remove ions and remaining organic matter. The operation flux was 20 L / m ² · hr and the recovery rate was 80%.

Evaluation example 2

The wastewater and the water quality of each unit process water evaluated by the above-mentioned operation conditions are shown in Table 4 below.

Item acid
Wastewater
(RW1) Alkaline
Wastewater
(RW2) 1st
Treated water
(TW1) Mixed wastewater
(RW3) The second treated water
(TW2) Third treated water
(TW3) Fourth treated water
(TW4) Hydrogen peroxide (mg / L) 157 1,524 10 110 ≪ 0.1 ≪ 0.1 ≪ 0.1 Electrical Conductivity (㎲ / ㎝) - - - - - 4,740 328 NH ₃ -N (mg / L) - - - - - 141 8.8 Al (mg / L) - - - - 0.1 0.02 - TOC (mg / L) - - - 21.8 10.5 8.5 0.17 Turbidity (NTU) - - - - 93 0.61 -

The performance of each unit device will be described with reference to Table 4 below.

The hydrogen peroxide-

As a result of the analysis of the first treated water (TW1), it was confirmed that the hydrogen peroxide contained in the alkaline wastewater (RW2) was removed by 99% in the hydrogen peroxide removing device (110).

A device for simultaneous removal of hydrogen peroxide and organic matter (120)

As a result of analyzing the second treated water (TW2), hydrogen peroxide was measured below the detection limit, and the total organic carbon (TOC) index, which is an indicator of organic matter, was also found to be reduced by 52%. From the results, it was confirmed that hydrogen peroxide and organic matter were simultaneously removed in the device 120 for simultaneous removal of hydrogen peroxide and organic matter.

Coagulation and filtration equipment (130)

As a result of the analysis of the third treated water TW3, it was confirmed that the turbidity (NTU: Nepthelometric Turbidity Unit) contained in the second treated water TW2 was removed by 99% and the Al concentration was reduced by 80% It was confirmed that the particulate matter and the heavy metal were removed simultaneously.

Reverse osmosis systems (140)

As a result of the analysis of the fourth treatment water TW4, it was confirmed that the electrical conductivity indicating the amount of the ionic substance contained in the third treatment water TW3 was removed by 93%. In particular, it was confirmed that 94% of the ammonia nitrogen was removed to produce water suitable for reuse. It was also confirmed that the TOC was removed by 98%, and the ionic substance and the residual organic matter were simultaneously removed.

Although the present invention has been described with reference to the drawings and embodiments, it is to be understood that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: waste water recycling apparatus
110: hydrogen peroxide removal device
120, 120 ': Device for simultaneous removal of hydrogen peroxide and organic matter
121, 121 ': container 122, 122': microorganism immobilization support
130: coagulation and filtration device 140: reverse osmosis device
RW1: Acid waste water RW2: Alkaline waste water
RW3: mixed wastewater TW1, TW2, TW3, TW4: treated water

Claims (16)

A step (S10) of partially removing hydrogen peroxide in the alkaline wastewater to generate a first treated water;
(S20) of simultaneously removing residual hydrogen peroxide and organic matter in the mixed wastewater containing the first treated water and the acidic wastewater to generate a second treated water;
A step (S30) of simultaneously removing heavy metals and particulate matter in the second treated water to generate a third treated water; And
And a step (S40) of simultaneously removing the remaining organic matter and the ionic substance in the third treated water to produce a fourth treated water. The method according to claim 1,
Wherein the step (S10) is carried out by passing the alkaline wastewater through a first carrier which functions as a catalyst of a hydrogen peroxide decomposition reaction. The method according to claim 1,
Wherein the alkaline wastewater is treated at a space velocity of less than or equal to 5 hr < ^-1 > at the step (S10). The method according to claim 1,
The step (S20) is carried out by passing the mixed wastewater through the microorganism-immobilized carrier, wherein the microorganism-immobilized carrier comprises a second carrier which functions as a catalyst for the hydrogen peroxide decomposition reaction and a microorganism immobilized on the second carrier . The method according to claim 2 or 4,
Wherein at least one of the first carrier and the second carrier comprises activated carbon. The method according to claim 1,
Further comprising the step (S25) of discharging the oxygen generated in the step (S20) to the outside, which is performed without stopping the step (S20). 5. The method of claim 4,
Wherein the step of supplying external air to the microorganism-immobilized carrier used in step (S20) is not included separately. 5. The method of claim 4,
Wherein the microorganism comprises an aerobic microorganism. 9. The method of claim 8,
The microorganism is selected from the group consisting of Pseudomonas sp. CP236 (Accession No .: KACC 91512P), Methylobacterium extorquens SMIC-1 (Accession No. KCTC 10946 BP), Mycobacterium sp. SMIC-1 (Accession No. KCCM 10999P), SMC-1 (Accession No. KCTC 10947 BP), Acinetobacter sp. SMIC-1 (Accession No. KCCM 10999P) sp. SMIC-2) (Accession No. KCCM 11000P) or a combination thereof. The method according to claim 1,
Wherein the mixed wastewater is treated at a space velocity of 10 hr < ^-1 > or less in the step (S20). The method according to claim 1,
The step (S30) includes the steps of adding a coagulant to the second treated water to coagulate heavy metals and particulate matter in the second treated water (S31), filtering the coagulated material with a filter (S32) And a step (S33) of discharging the concentrated substance after filtration to the outside. The method according to claim 1,
Wherein the flocculant comprises an Al-based flocculant, an Fe-based flocculant, a Ca-based flocculant, or a combination thereof. The method according to claim 1,
Wherein the step (S40) is performed by passing the third treated water through a reverse osmosis membrane. A hydrogen peroxide removal device for partially removing hydrogen peroxide in alkaline wastewater using a first carrier functioning as a catalyst for the hydrogen peroxide decomposition reaction to produce a first treated water;
The hydrogen peroxide and organic matter remaining in the mixed wastewater containing the first treated water and the acidic wastewater are simultaneously treated with the microorganism-immobilized carrier comprising the second carrier functioning as a catalyst of the hydrogen peroxide decomposition reaction and the microorganism immobilized on the second carrier An apparatus for simultaneously removing hydrogen peroxide and organic matter to produce a second treated water;
An aggregating and filtering device for simultaneously removing heavy metals and particulate matter in the second treated water by using a flocculant and a filter to produce a third treated water; And
And a reverse osmosis device that uses the reverse osmosis membrane to simultaneously remove remaining organic matter and ionic substances in the third treated water to produce a fourth treated water. 15. The method of claim 14,
Wherein the filter provided in the coagulation and filtration apparatus is a microfiltration membrane or an ultrafiltration membrane having a pore diameter of 0.01 to 0.45 μm. 15. The method of claim 14,
Wherein the reverse osmosis membrane provided in the reverse osmosis device is brackish water or seawater.

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