KR101405305B1 - Method for treating and reusing wastewater having highly concentrated ions - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a process for reusing wastewater in which a single or mixed ionic species is dissolved at a high concentration by using a reverse osmosis method, The reverse osmosis membrane is characterized by the fact that it has a recovery rate of 70% or more and a reusing water quality of 100 μs / ㎝ or less by mixing and arranging the reverse osmosis membrane in each processing step.
The present invention is characterized in that a high-pressure operation type reverse osmosis membrane is applied in a high concentration region with an electric conductivity of 15,000 μs / cm or more and a low-pressure operation reverse osmosis membrane is applied in a low concentration region of 15,000 μs / cm or less. In addition, the concentrated water separated in each treatment step is divided into a high concentration area (15,000 ㎲ / ㎝ or more) and a low concentration area (15,000 ㎲ / ㎝ or less), and a concentrated high concentration area reverse osmosis membrane And the concentrated water in the intermediate and low concentration regions is transferred to the raw wastewater and then mixed and processed in association with the existing arrangement. At this time, the concentrate water in the high concentration region is separated into the final concentrated water by using the high-pressure operation type reverse osmosis membrane and the re-condensed water is separated into the final concentrated water, resulting in the capacity of about 30% of the original wastewater. The ionic stream contained in the final concentrated water is about three times higher than the concentration of the ions contained in the raw wastewater, and thus can be reused in the production process. In addition, the final production water is about 70% of the raw wastewater and it is reused as the water in the production process because the electric conductivity is generated as pure water less than 100 ㎲ / ㎝.
In the mixed arrangement, the size and quantity of the high-pressure operation type or the low-pressure operation type reverse osmosis membrane are determined considering the treatment efficiency, the recovery rate and the operation time of each treatment step of each reverse osmosis membrane. 100 mu s / cm or less. Also, the number of reverse osmosis membranes in each treatment stage is determined by increasing until the amount of final concentrated water is less than 30% based on the raw wastewater, and increasing the amount of reverse osmosis membrane in the high concentration region is advantageous in minimizing the amount of reverse osmosis membrane. At this time, the wastewater throughput, ion exchange efficiency, and recovery rate of the high pressure operation type and low pressure operation type reverse osmosis membrane for each treatment step are determined by pilot plant, and information about optimal operation pressure is obtained in this process. The removal efficiency of ions in the reverse osmosis membrane is inversely proportional to the operating pressure and the recovery rate is proportional to the operating pressure. The optimal operating pressure is determined by the pressure at the point where the product of the treatment efficiency and the recovery rate is the maximum at the membrane area under the same reverse osmotic pressure do.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating and reusing highly concentrated ion-

The present invention relates to a method for reusing a wastewater containing a high concentration of 15,000 μs / cm or more on the basis of an electric conductivity by dissolving a single or mixed ionic species by separating an ionic stream and water using a reverse osmosis method. In detail, when applying the reverse osmosis method, high-pressure operation type reverse osmosis membrane of 40 bar or more and low pressure operation type reverse osmosis membrane of less than 20 bar are mixed and arranged in a process step, thereby ensuring a recovery rate of 70% or more and a reusing water quality of less than 100 μs / .

There are many cases where wastewater containing various kinds of high concentration ions is discharged from various industrial sites, but it is difficult to economically handle such wastewater. In particular, the recent tightening of environmental regulations and rising raw materials are increasing the need for reuse. Conventional methods for treating wastewater containing ionic species include evaporation, ion exchange, electrodialysis, and reverse osmosis. However, when the wastewater is present at a high concentration, there is a disadvantage in that the economic efficiency is low considering the facility cost and operation cost. The evaporation concentration method is introduced when the equipment cost is the highest among the above-mentioned methods and the operating cost due to energy consumption is also very high (average 5 - 100 thousand won / ton level) and there is no usual suitable treatment method. In addition, low-volatility ionic species (such as ammonia) evaporate and condense with water, so secondary treatment or reuse methods for condensate should be considered. The ion exchange method is advantageous in that it can separate ions by a relatively simple method using an ion exchange resin. However, when the ion concentration is high, the amount of the regenerated water and the concentrated water is increased and a large amount of secondary wastewater is generated. . The electrodialysis method is usually used as a facility for producing pure water by secondary treatment of a low-concentration ionic species. When the ionic concentration is high, the concentration is low and thus its effectiveness is low. The reverse osmosis method is widely used in seawater desalination or water purification. However, since the recovery rate of the high concentration ion is low (about 30% level), a large amount of double shielding water is generated. When the concentrated water is reprocessed, And the initial equipment cost is greatly increased. In addition, since the data and design parameters provided by the manufacturer of the reverse osmosis membrane are very limited except for the fields of seawater desalination or water treatment, quantitative design itself is difficult when various kinds of ions are mixed at a high concentration. In this case, since the concentrated water is returned to the sea, the concentrated water treatment is not considered and the recovery rate is also about 30%, which is not economical to apply to the wastewater. The reverse osmosis technology for the purified water is designed to remove ions of relatively low concentration because it is a concept of secondary treatment similar to the electrodialysis method. In this process, the concentrate is generated at a recovery rate of 50%, and in the case of wastewater, secondary treatment is required for the concentrated water, so it is difficult to apply the concentrate in a high concentration range.

   The detailed theoretical background of the reverse osmosis method is described below.

The seawater desalination facilities by the reverse osmosis method are designed to remove the ionic substances dissolved in water (Na ⁺ , Cl ^- , Mg ^{2 +} , Ca ^{2 +,} etc.) and to pass pure water through the semi permeable membrane And filtering the dissolved ionic material. In 1748 abhe Nalet first discovered osmotic phenomena, and in the 1920s, theoretical studies on osmotic phenomena were completed in the 1920s as Gibbs' theory of thermodynamics was established. When a pressure higher than the osmotic pressure is applied to the high concentration solution side, the solvent on the high concentration solution side flows backward to the low concentration solution side as opposed to the osmosis phenomenon, which is called reverse osmosis phenomenon. The osmotic pressure is about 0.6 - 0.8 kgf / cm ² per 1000 mg / L of solute, almost proportional to the dissolved salt concentration. On the other hand, when the external pressure is higher than the osmotic pressure, water moves to the fresh water with low solute concentration. (Reverse Osmosis). Using this reverse osmosis principle, reverse osmosis is the process of separating various salts and organic materials through a semipermeable membrane using a pressure gradient as a driving force. The reverse osmosis membrane consists of a support layer and an active layer. The support layer can be divided into a porous polysulfone UF layer, which is in contact with the polyamide membrane, and a support layer, which is made of a fabric EH nonwoven fabric, which increases the mechanical strength. The polysulfone support layer is a microporous asymmetric membrane, which is obtained by dissolving polysulfone in a polar aprotic solvent on the fabric surface and then quenching it in the non-solvent solution to form an asymmetric ultrafiltration composed of a surface layer and a porous layer. The solution is cast on a nonwoven fabric at about 100 - 150 ㎛, and when the solvent is removed after quenching, it is left to a thickness of about 40 - 60 탆. The polysulfone backing layer can be applied as an ultrafiltration membrane with a molecular weight molecular weight (MWCO) of approximately 50,000. A polyamide composite membrane is prepared by interfacial polymerization of a polyfunctional amine system and a polyfunctional acyl halide compound on the porous polysulfone support layer. The polyamide composite thin film is obtained as an ultra thin film which is thinly coated on the polysulfone surface layer.

In order to overcome the above-mentioned conventional problems, the present invention overcomes the limitations of the conventional reverse osmosis technology, and in order to apply it to wastewater containing a high concentration ion stream discharged from an industrial site, the recovery rate is increased to 70% It was devised so that it can be treated at a pure level. In detail, it is possible to quantify the efficiency and operating conditions of each process step and to apply a high-pressure operation type reverse osmosis membrane operating at a temperature of 40 bar or more to a high concentration area and apply a low-pressure operation type reverse osmosis membrane at a low- To optimize the entire process.

   Therefore, in order to treat and reuse wastewater containing a high concentration of a single or mixed ionic stream using a reverse osmosis method, (2) It is difficult to optimize the process due to lack of data. (2) Overcome the low recovery rate (less than 30%) for the reverse osmosis membrane of high concentration ion stream and optimize the reverse osmosis membrane process so that the recovery rate is over 70% A method of deriving a design factor and a process.

In order to achieve the above-mentioned object, the basic design factors for the production quantity, concentration quantity, and treatment efficiency of the wastewater ion concentration area and operating pressure condition are obtained in the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane, Evaluate each processing step, and (3) Optimize the arrangement that integrates each processing step. In the present invention, a high-pressure operation type reverse osmosis membrane is applied in a high concentration region having an electric conductivity of 15,000 占 / / cm or more, and a low-concentration region of less than 15,000 占 / / cm is used as a concentration indicator. A low-pressure operation type reverse osmosis membrane is applied and arranged in the order of processing steps. In addition, the concentrated water separated in each treatment step is divided into a high concentration area (15,000 ㎲ / ㎝ or more) and a low concentration area (15,000 ㎲ / ㎝ or less), and a concentrated high concentration area reverse osmosis membrane And the concentrated water in the intermediate and low concentration regions is transferred to the raw wastewater and then mixed and processed in association with the existing arrangement. At this time, the concentrate water in the high concentration region is separated into the final concentrated water by using the high-pressure operation type reverse osmosis membrane and the re-condensed water is separated into the final concentrated water, resulting in the capacity of about 30% of the original wastewater. The ionic stream contained in the final concentrated water is about three times higher than the concentration of the ions contained in the raw wastewater, and thus can be reused in the production process. In addition, the final production water is about 70% of the raw wastewater and it is reused as the water in the production process because the electric conductivity is generated as pure water less than 100 ㎲ / ㎝.

In the mixed arrangement, the size and quantity of the high-pressure operation type or the low-pressure operation type reverse osmosis membrane are determined considering the treatment efficiency, the recovery rate and the operation time of each treatment step of each reverse osmosis membrane. 100 mu s / cm or less. Also, the number of reverse osmosis membranes in each treatment stage is determined by increasing until the amount of final concentrated water is less than 30% based on the raw wastewater, and increasing the amount of reverse osmosis membrane in the high concentration region is advantageous in minimizing the amount of reverse osmosis membrane. At this time, the wastewater throughput, ion exchange efficiency, and recovery rate of the high pressure operation type and low pressure operation type reverse osmosis membrane for each treatment step are determined by pilot plant, and information about optimal operation pressure is obtained in this process. The removal efficiency of ions in the reverse osmosis membrane is inversely proportional to the operating pressure and the recovery rate is proportional to the operating pressure. The optimal operating pressure is determined by the pressure at the point where the product of the treatment efficiency and the recovery rate is the maximum at the membrane area under the same reverse osmotic pressure do.

According to the present invention, in order to separate ions and reused water from wastewater containing a high concentration of mixed ion flow having an electric conductivity of 15,000 μs / cm or more, the conventional reverse osmosis method has a drawback that the recovery rate is as low as 30% Although it is difficult to optimize the process design due to the absence of the factor, the optimization design method according to the present invention is applied, and the process is performed by mixing the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane to minimize the amount of reverse osmosis membrane, 100 ㎲ / ㎝ or less.

FIG. 1 is a process diagram of a high-pressure operation type and a low-pressure operation type reverse osmosis membrane according to a preferred embodiment of the present invention in order to treat and reuse wastewater containing a high-concentration ion stream.
FIG. 2 is a reverse osmosis membrane system pilot plant device for evaluating the amount of water, concentrated water, and treatment efficiency for each of the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane to secure basic design factors.
3 is a graph showing the correlation between the rate of decrease in the electrical conductivity and the recovery rate in the high-pressure operation type reverse osmosis membrane according to the first embodiment.
FIG. 4 is a graph showing the correlation between the rate of decrease in the electrical conductivity and the recovery rate in the low-pressure operation type reverse osmosis membrane according to Example 2. FIG.
5 is a graph showing a weighting result of the reverse osmosis membrane according to the change in electric conductivity at the optimum operating pressure condition according to the third embodiment.
Fig. 6 is a view showing the mass balance of the process step constituted by Fig. 1. Fig.

In order to produce a recovered water having a recovery rate of 70% or more from a wastewater containing a high concentration of electric conductivity of 15,000 / / ㎝ or more with a concentration of 100 / / ㎝ or less according to the present invention, And the basic design factors for the production quantity, concentration quantity and treatment efficiency according to the operating pressure condition are obtained, and ② each process step is determined by analyzing and evaluating the result, and the process steps of each are integrated to form the high pressure driving type reverse osmosis membrane and the low pressure Optimize the arrangement of the operating type reverse osmosis membrane.

Examples 1 and 2 are described in order to achieve the above-mentioned object (1).

The removal efficiency of ions in the reverse osmosis membrane is inversely proportional to the operating pressure and the recovery rate is proportional to the operating pressure. In the present invention, a pilot plant of the reverse osmosis membrane system shown in FIG. 2 capable of applying a high-pressure operation type reverse osmosis membrane and a low-pressure operation type reverse osmosis membrane is used to treat the wastewater mixed with nitrate ion and ammonium ion from a high- The efficiency and recovery rate were evaluated.

≪ Example 1 >

(Reverse conductivity: 32,000 ㎲ / ㎝) mixed with 20,000 mg / L nitrate ion and 8,000 mg / L ammonium ion was applied to the reverse osmosis membrane system pilot plant of FIG. 2, The correlation between the efficiency and the recovery rate, that is, the correlation between the reduction rate of the electric conductivity in the high-pressure operation type reverse osmosis membrane and the recovery rate, is shown in FIG.

As the operating pressure and recovery rate were checked by varying the operating pressure in the range of 10 - 80 bar for the high - pressure operating type reverse osmosis membrane, the treatment efficiency was decreased with increasing operating pressure, but the recovery rate was increased. When the product of the treatment efficiency and the recovery rate is taken as the weight, the maximum value can be confirmed at about 50 bar.

The treatment efficiency and recovery rate of the wastewater were evaluated according to the operating pressure while the high-pressure operation type reverse osmosis membrane was used to process the wastewater from the high-concentration region to the low-concentration region in stages. The operation efficiency and the recovery rate were evaluated based on the maximum weighted operation pressure Table 1 shows the results of the evaluation of the treatment efficiency and the recovery rate of the high-pressure operation type reverse osmosis membrane by ion concentration region.

[Table 1]

The optimum operating pressure decreased as the ion concentration of the influent was lower, and the treatment efficiency and recovery rate increased.

≪ Example 2 >

 A low-pressure operation type reverse osmosis membrane was applied to the reverse osmosis membrane system pilot plant shown in FIG. 2 by using a wastewater (electric conductivity of 7,000 μs / cm) mixed with nitrate ions at a concentration of 3,500 mg / L and ammonium ions at a concentration of 1,200 mg / The correlation between the efficiency and the recovery rate, that is, the correlation between the reduction rate and the recovery rate of the electric conductivity in the low-pressure operation type reverse osmosis membrane, is shown in FIG.

The treatment efficiency and recovery rate of the reverse osmosis membrane with low pressure operation were varied in the range of 13 - 20 bar. As a result, the treatment efficiency decreased and the recovery rate increased as the operating pressure increased. Similar to the high - pressure operation type reverse osmosis membrane, High treatment efficiency and recovery rate were confirmed. When the product of the treatment efficiency and the recovery rate is taken as the weight, the maximum value can be confirmed at about 17 bar.

In addition, treatment efficiency and recovery rate of the wastewater were evaluated by varying the operating pressure step by step using the low-pressure operation type reverse osmosis membrane from the medium concentration area to the low concentration area, and the product of the treatment efficiency and the recovery rate was calculated based on the maximum weighted operation pressure Table 2 shows the results of the evaluation of the treatment efficiency and the recovery rate of the low-pressure operation type reverse osmosis membrane by ion concentration region.

[Table 2]

The optimum operating pressure was relatively constant without influencing the ion concentration range of the influent. The lower the ion concentration, the higher the treatment efficiency and recovery rate than the high - pressure operation type reverse osmosis membrane. Therefore, it was confirmed that it is effective to apply a relatively low-cost, low-pressure operation type reverse osmosis membrane at a low concentration range as compared with Example 1, rather than an expensive high-pressure operation type reverse osmosis membrane.

In order to attain the object of the above (2), the embodiment 3 is described.

Based on the results obtained in the above Examples 1 and 2, the processing steps of the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane according to the concentration range of the mixed ion flow and the evaluation method And the actual data are put in order.

≪ Example 3 >

 The high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane having the same membrane area per mixed ion flow concentration region based on the commonly used electric conductivity as a concentration index of mixed ion species in the wastewater were optimized Figure 5 shows the results of the weighted evaluation method under operating pressure conditions, that is, the result of weighting the reverse osmosis membrane according to the change in the electric conductivity at the optimum operating pressure condition. The weights are defined as the result of multiplying the treatment efficiency × recovery rate × throughput by the values of the operation results for each reverse osmosis membrane condition. When securing the optimal reverse osmosis membrane and the operation conditions at the electric conductivity region, Optimization.

The weight of the reverse osmosis membrane with high - pressure operation was high in the section of 5,000 ㎲ / ㎝ or less and the weight of the high - pressure operation reverse osmosis membrane was high in the section of 5,000 ㎲ / ㎝ or more. Also, in the range of 5,000 - 15,000 ㎲ / It was confirmed that the weight of the low-pressure operation type reverse osmosis membrane was not large. Therefore, considering that the price of high-pressure operating type RO membrane is more than three times higher than that of low-pressure operating RO membranes, low-pressure operation type reverse osmosis membrane is used in the region where electric conductivity is 15,000 ㎲ / ㎝ or less even in the region of 15,000 ㎲ / It was decided that the high - pressure operation type reverse osmosis membrane should be used as a basic design factor and a method of deriving these results was devised and quantified.

Table 3 shows the evaluation results of the process steps of the RO membranes selected for the electrical conductivity regions in which the treatment efficiency and the recovery rate of the selected RO membranes were determined based on the weights and the costs.

[Table 3]

In order to attain the above-mentioned object (3), the fourth embodiment is described.

The integrated process was designed by arranging the reverse osmosis membranes according to the concentration range of the mixed ions obtained in Example 3, the operating conditions, and the process step results.

<Example 4>

FIG. 1 shows a process chart for a process in which a high-pressure operation type and a low-pressure operation type reverse osmosis membrane are mixedly arranged.

High - voltage operation type reverse osmosis membrane was applied in the region of high electric conductivity of 15,000 ㎲ / ㎝ or more and reverse osmosis membrane of low pressure operating type in the low concentration region of 15,000 ㎲ / ㎝ or less. In addition, the concentrated water separated in each treatment step is divided into a high concentration area (15,000 ㎲ / ㎝ or more) and a low concentration area (15,000 ㎲ / ㎝ or less), and a concentrated high concentration area reverse osmosis membrane And the concentrated water in the middle and low concentration regions was transported to the raw wastewater and mixed and then processed in association with the existing array. At this time, the concentrate water in the high concentration region is separated into the final concentrated water by using the high-pressure operation type reverse osmosis membrane and the re-condensed water is separated into the final concentrated water, resulting in the capacity of about 30% of the original wastewater. The ionic stream contained in the final concentrated water is about three times higher than the concentration of the ions contained in the raw wastewater, and thus can be reused in the production process. In addition, the final production water is about 70% of the raw wastewater and it is reused as the water in the production process because the electric conductivity is generated as pure water less than 100 ㎲ / ㎝.

In the mixed arrangement, the size and quantity of the high-pressure operation type or the low-pressure operation type reverse osmosis membrane are determined considering the treatment efficiency, the recovery rate and the operation time of each treatment step of each reverse osmosis membrane. 100 mu s / cm or less. Also, the number of reverse osmosis membranes in each treatment stage is determined by increasing until the amount of final concentrated water is less than 30% based on the raw wastewater, and increasing the amount of reverse osmosis membrane in the high concentration region is advantageous in minimizing the amount of reverse osmosis membrane.

A detailed description of the process flow of FIG. 1 will be given below to explain the fourth embodiment.

Step 1: The raw water of the raw water storage tank (T0) is transferred to the first stage high-pressure operation type reverse osmosis membrane (M1-1) by using the high-pressure operation pump ( PH ) of the first stage and the processed water is treated in the first stage production water storage tank T1-1). At the same time, the concentrated water is returned to the first-stage concentrated water storage tank T1-2.

Step 2: The first stage production water stored in the first stage production water storage tank (T1-1) is transferred to the second stage high-pressure operation type reverse osmosis membrane (M2) by using the second stage high pressure operation pump (P2) Is collected in the second stage production water storage tank (T2). At the same time, the concentrated water is returned to the first-stage concentrated water storage tank T1-2.

Step 3: The second stage product water stored in the second stage product water storage tank (T2) is transferred to the third stage high-pressure operation type reverse osmosis membrane (M3) by using the third stage high pressure operation pump (P3) Stage production water storage tank T3. At the same time, the concentrated water is returned to the first-stage concentrated water storage tank T1-2.

Step 4: The third stage of production water stored in the third stage water storage tank (T3) is transferred to the fourth stage low-pressure operation type reverse osmosis membrane (M4) using the fourth stage low pressure operation pump (P4) Stage production water storage tank T4. At the same time, the concentrated water is returned to the raw water storage tank T0.

Stage 5: Stage 4 Stage 4 is stored and transported to a 5-stage low-pressure operation reverse osmosis membrane (M5) using a 5-stage low-pressure operation pump (P5) Stage production water storage tank T5. At the same time, the concentrated water is returned to the raw water storage tank T0.

Step 6: The 5th stage water stored in the 5th stage water storage tank (T5) is transferred to the 6 stage low-pressure operation type reverse osmosis membrane (M6) by using the 6 stage low pressure operation pump (P6) Collected in the reused water storage tank (T6), and used as reused water. At the same time, the concentrated water is returned to the raw water storage tank T0.

The concentrated water generated in the first, second and third stages is conveyed to and mixed with the first-stage concentrated water storage tank (T1-2), and a high-pressure operation type pump (P1-2) for the first-stage concentrated water treatment separately configured from the entire reverse osmosis membrane array flow The produced water is transferred to the high-pressure operation type reverse osmosis membrane (M1-2) for the first-stage concentrated water treatment, and the processed product water is transferred to the first-stage production water storage tank (T1-1) and mixed therewith, . The concentrated water generated at this time is separated and discharged as the final concentrated water, which is no longer re-introduced into the process. The final concentration is less than 30% of the total wastewater generation and the ionic concentration is very high as 100,000 ㎲ / ㎝ in terms of electrical conductivity, so ion reusability can be favored and reusable.

The concentrated water generated in the steps 4, 5, and 6 is returned to the raw water storage tank T0 and mixed with the raw water, and then subjected to the one-step process.

The mass balance for the process designed according to Example 4 is summarized in FIG.

A total of 6 stages of reverse osmosis membranes were arranged in order to obtain a recovery rate of 70% for each mixed ion concentration region. In the first, second and third stages, a high-pressure operation type reverse osmosis membrane was applied, The low-pressure operation type reverse osmosis membrane is applied to the low-concentration region. Since the concentrated water generated in stages 1, 2 and 3 is higher in concentration than the raw water, it is processed using a separate high-pressure operation type reverse osmosis membrane (M1-2) for treatment of one-stage concentrated water, the concentrated water is finally separated, (Step 2), and then processed in a sequential manner. The concentrated water generated in steps 4, 5, and 6 is less than 15,000 ㎲ / ㎝ and mixed with raw water. In this embodiment, the reverse osmosis membrane of the high-pressure operation type reverse osmosis membrane treatment step for treating the high concentration area concentrated water may be increased or decreased depending on the water quality of the reclaimed water when the ion concentration of the concentrated water is 40,000 / / The process step in the flow can be further increased from step 6 to 7 or more stages to meet the recovery efficiency and reclaimed water quality standards.

T0: raw water reservoir
T1-1: 1st stage production water storage tank
T1-2: First-stage concentrated water storage tank
T2: 2nd stage production water storage tank
T3: Stage 3 production water reservoir
T4: Stage 4 production water tank
T5: 5-stage production water storage tank
T6: Stage 6 production water storage tank (final reused water storage tank)
P1-1: High-pressure pump
P1-2: High-pressure operation pump for the first stage concentrated water treatment
P2: Two-stage high-pressure operation pump
P3: Three-stage high pressure pump
P4: Four-stage low pressure pump
P5: 5-stage low-pressure operation pump
P6: Six-stage low-pressure operation pump
M1-1: High-pressure operation type reverse osmosis membrane
M1-2: High-pressure operation type reverse osmosis membrane for first stage concentrated water treatment
M2: Two-stage high-pressure operating reverse osmosis membrane
M3: 3 stage high pressure operating type reverse osmosis membrane
M4: Low-pressure operation type reverse osmosis membrane
M5: 5 stage low-pressure operating type reverse osmosis membrane
M6: Low-pressure operation type reverse osmosis membrane
10: raw water reservoir
20: High / medium pressure pump
30: High pressure type / low pressure type reverse osmosis filter
40: Flowmeter
50: microfilter

Claims (7)

The present invention relates to a method for treating and reusing highly concentrated ion-containing wastewater for separating and reusing ionized water and water by using a reverse osmosis method in a wastewater in which a single or mixed ionic species is dissolved at a high concentration,
The steps of securing the basic design factors for the production quantity, concentration quantity and treatment efficiency of the ion concentration area and the operating pressure condition of the wastewater in the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane,
A low - pressure operation type reverse osmosis membrane which is operated at a high pressure operating type of the reverse osmosis membrane which is operated at 40 - 80 bar when the electric conductivity of the wastewater is 15,000 ㎲ / ㎝ or more and 13 - 20 bar when it is less than 15,000 ㎲ / ,
In order to determine the operating pressure of the reverse osmosis membrane, the processing efficiency, recovery rate and throughput are secured in the pressure range of 40 - 80 bar for the high pressure operation type reverse osmosis membrane and 13 - 20 bar for the low pressure operation type reverse osmosis membrane through the pilot test. Selecting a low-pressure operation type reverse osmosis membrane and a high-pressure operation type reverse osmosis membrane, determining a maximum value as respective operating pressure conditions,
And a step of optimizing the arrangement of the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane. delete delete delete The method according to claim 1,
In the step of optimizing the arrangement, the high-pressure operation type reverse osmosis membrane and the low-pressure operation type reverse osmosis membrane are mixed and arranged in a process step so that the recovery rate is 70% or more and the quality of the treated water is 100 μs / Treatment and recycling of high concentration ion containing wastewater. The method according to claim 1,
In the optimization of the arrangement, each concentrated water generated after the reverse osmosis membrane permeation is selected to be 15,000 / / ㎝ or more on the basis of electric conductivity, passed through a separate high-pressure operation type reverse osmosis membrane and processed, And the re-condensed concentrated water is separated into the final concentrated water, wherein the final concentrated water generated is less than 30% of the original wastewater. The method according to claim 1,
Wherein the step of optimizing the arrangement comprises selecting one of the concentrated water generated after the permeation of the reverse osmosis membrane and having a conductivity of less than 15,000 占 / / cm, mixing the wastewater with the conventional stepwise arrangement, &Lt; / RTI &gt;

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