TW201414679A - Processing method for collecting waste water containing ammonia and apparatus thereof - Google Patents

Abstract

A processing method for collecting waste water containing ammonia comprises adjusting a waste water containing ammonia into an acid waste water, separating a high concentration waste water from the acid waste water by a reverse osmosis membrane, adding an alkaline solvent into the high concentration waste water to generate an ammonia gas, and reacting an acid solvent with the ammonia gas, and thus an ammonium compound can be generated and collected. The present invention further provides a processing apparatus for collecting waste water containing ammonia. The high concentration waste water is separated from the acid waste water formed in a first pH adjusting tank by the reverese osmosis membrane, and then adjusted into an alkaline waste water to generate the ammonia gas in a second pH adjusting tank. After that, the ammonia gas is stripped and reacted with the acid solvent, so as to generate and collect the ammonium compound.

Description

Ammonia wastewater recycling treatment method and equipment thereof

The invention relates to a method for recovering waste water and a device thereof, and particularly relates to a method for recycling and treating ammonia-containing wastewater and an apparatus therefor.

With the gradual increase of climate, the chances of disasters and droughts in the world have gradually increased, which has made it increasingly difficult to effectively preserve and utilize the clean water resources that are indispensable for human survival. More importantly, the rapid growth of the global population and the rapid development of industrial technology have led to the increasing environmental pollution of human beings and the worsening of the problem of water conservation and utilization. Therefore, how to effectively recover pollutants in industrial waste water to reduce the pollution of pollutants to the environment has gradually become one of the problems that governments around the world need to solve urgently.

Special wastewater containing high concentrations of ammonia (ammonia, chemical formula NH ₃ , commonly known as ammonia or anhydrous ammonia) is commonly found in optoelectronic semiconductor, petroleum refining, coking, and fertilizer. Industrial process wastewater such as (fertilizer), iron (iron and steel) and food (foodstuff). High-concentration ammonia has corrosiveness, is toxic to aquatic organisms, and has carcinogenicity and mutagenic properties to humans. Therefore, some countries have already enacted legislation or are inclined to legislate to limit the nitrogen content in wastewater.

Currently, the biological anaerobic treatment process is used to denitrify the ammonia-containing wastewater. However, the denitrification efficiency of the conventional biological anaerobic treatment process is not high. Therefore, there is an urgent need to provide an apparatus and method that can more effectively treat ammonia-containing wastewater.

In order to solve the above problems, the present invention provides a method for recovering ammonia-containing wastewater and a recycling treatment device for ammonia-containing wastewater to improve recovery efficiency of ammonia-containing wastewater.

The invention provides a method for recycling ammonia-containing wastewater, which comprises the following steps. First, a first acid solvent is added to an ammonia-containing wastewater to form an acid waste water. Then, a reverse osmosis membrane (RO membrane) is used to isolate the acidic wastewater into a high concentration wastewater and a low concentration wastewater. Then, a first alkaline solvent is added to the high-concentration wastewater to generate ammonia gas in the high-concentration wastewater. Thereafter, a second acidic solvent is further reacted with ammonia gas to form an ammonium compound to recover the ammonium compound.

In an embodiment of the present invention, the ammonia-containing wastewater component further comprises hydrogen peroxide (hydrogen peroxide, chemical formula is H ₂ O ₂ , commonly known as hydrogen peroxide), and before the first acidic solvent is added to the ammonia-containing wastewater, It further includes the use of a catalyst to remove hydrogen peroxide from the ammonia-containing wastewater. The catalyst may be activated carbon fibers (ACF), manganese dioxide (manufactured by MnO ₂ ) or manganese ore (manganese ore). Moreover, before the use of the catalyst to remove hydrogen peroxide in the ammonia-containing wastewater, a second alkaline solvent may be added to the ammonia-containing wastewater to make the pH value of the ammonia-containing wastewater higher than 8.5. The components of the ammonia-containing wastewater, the first alkaline solvent and the second alkaline solvent may comprise at least one of sodium ion (chemical formula Na ⁺ ) and potassium ion (chemical formula K ⁺ ).

In an embodiment of the present invention, before the step of reacting the ammonia gas with the ammonia gas to form an ammonium compound, the method further comprises the step of separating the ammonia gas from the high concentration wastewater by using a stripping device. Wherein, the separating device may be at least one of a hydrophobicity membrane or a stripping column for performing membrane stripping. and, Before the separation of the ammonia gas from the high-concentration wastewater by the separation device, the step of filtering impurities in the high-concentration wastewater by a filter may be further included.

In an embodiment of the invention, after the recovery of the ammonium compound, the electro-deionization with bipolar membrane (EDI with bipolar membrane) device or an ion exchange resin (ion exchange resin) is further included. The ammonium compound is separated into an alkaline solution and an acidic solution. Wherein, the above alkaline solution is ammonia water, and the above acidic solution is sulfuric acid, hydrochloric acid or phosphoric acid.

The invention further provides a recovery treatment device for ammonia-containing wastewater, comprising a first pH adjusting tank, a reverse osmosis membrane, a second pH adjustment tank, a separation device and a recovery tank. (collecting tank), wherein the reverse osmosis membrane is connected between the first pH adjustment tank and the second pH adjustment tank, and the separation device is connected between the second pH adjustment tank and the recovery tank. The first pH adjustment tank is for containing an ammonia-containing wastewater, and is suitable for injecting a first acidic solvent to form an acidic wastewater into the ammonia-containing wastewater. The reverse osmosis membrane is used to isolate acidic wastewater into a high concentration wastewater and a low concentration wastewater. The second pH adjustment tank is for containing high concentration wastewater and is adapted to inject a first alkaline solvent to generate ammonia gas in the high concentration wastewater. The separation device is configured to separate ammonia gas from the high concentration wastewater, and is adapted to inject a second acidic solvent to react with the ammonia gas to form an ammonium compound. The recovery tank is used to recover ammonium compounds.

In an embodiment of the present invention, the ammonia-containing wastewater recovery processing apparatus further includes a first storage tank, wherein the first storage tank is connected to the first pH adjustment tank for storing the first An acidic solvent and is suitable for injecting the first acidic solvent into the first pH adjustment tank.

In an embodiment of the present invention, the ammonia-containing wastewater recovery processing apparatus further includes a second storage tank, wherein the second storage tank is connected to the second pH adjustment tank for storing the first alkaline solvent. And being adapted to inject the first alkaline solvent into the second pH adjustment tank.

In an embodiment of the invention, the ammonia-containing wastewater recovery processing device further includes a processing device containing a catalyst, and the ammonia-containing wastewater component is further Hydrogen peroxide is included and the first pH adjustment channel is in communication with the processing device and the reverse osmosis membrane. Moreover, the catalyst may be used to remove hydrogen peroxide in the ammonia-containing wastewater prior to injecting the first acidic solvent into the ammonia-containing wastewater. Among them, the catalyst is activated carbon, manganese dioxide or iron manganese sand. In addition, the above-mentioned ammonia-containing wastewater recovery processing apparatus may further include a third pH adjustment tank, wherein the third pH adjustment tank is connected to the processing device, and is adapted to inject a second alkaline solvent to utilize Before the catalyst removes hydrogen peroxide from the ammonia-containing wastewater, the pH of the ammonia-containing wastewater is adjusted to be higher than 8.5. In addition, the above-mentioned ammonia-containing wastewater recovery processing apparatus may further include a third storage tank, wherein the third storage tank is connected to the third pH-adjusting tank for storing the second alkaline solvent, and is suitable for the second The alkaline solvent is injected into the third pH adjustment tank. Wherein, the components of the ammonia-containing wastewater, the first alkaline solvent and the second alkaline solvent may comprise at least one of sodium ions and potassium ions.

In an embodiment of the invention, the separating device is at least one of a hydrophobic exchange membrane or a separation column.

In an embodiment of the present invention, the ammonia-containing wastewater recovery processing apparatus further includes a filter, wherein the filter is connected between the second pH adjustment tank and the separation device for filtering the high-concentration wastewater. Impurities.

In an embodiment of the invention, the ammonia-containing wastewater recovery processing apparatus further includes a fourth storage tank. The fourth storage tank is in communication with the separation device for storing the second acidic solvent and is adapted to inject the second acidic solvent into the separation device.

In an embodiment of the invention, the acidic wastewater has a pH of less than 6.5.

In an embodiment of the invention, the first alkaline solvent adjusts the pH of the high concentration wastewater to above 9.5.

In an embodiment of the invention, the ammonia-containing wastewater and the first alkaline solvent may comprise at least one of sodium ions and potassium ions.

In an embodiment of the present invention, the above-described components of the first ammonia-containing waste stream with an acidic solvent contains both sulfate ions (sulfate ion, the formula SO ₄ ^2-), chloride ions (chlorine ion, the formula Cl ^-) and At least one of phosphate ion (chemical formula PO ₄ ^3- ).

In an embodiment of the invention, the second acidic solvent is sulfuric acid (chemical formula H ₂ SO ₄ ), hydrochloric acid (hydrochloric acid, chemical formula HCl, commonly known as hydrochloric acid) and phosphoric acid (phosphoric acid, chemical formula At least one of H ₃ PO ₄ ).

In an embodiment of the present invention, the ammonia-containing wastewater recovery treatment device further comprises a bipolar membrane electrodialysis device connected to the recovery tank or an ion exchange resin for separating the ammonium compound into an alkaline solution. And an acidic solution. Wherein, the above alkaline solution is ammonia water, and the above acidic solution is sulfuric acid, hydrochloric acid or phosphoric acid.

Compared with the prior art, the present invention has a high efficiency in recovering ammonia in wastewater.

The above described features and advantages of the invention will be apparent from the following description.

1 is a flow chart showing a method of recycling ammonia-containing wastewater according to an embodiment of the present invention. Referring to FIG. 1, the recovery treatment method of the ammonia-containing wastewater includes the following steps. First, as shown in step S110, a first acidic solvent is added to an ammonia-containing wastewater to adjust the originally alkaline ammonia-containing wastewater to be slightly acidic, that is, the pH value thereof is adjusted to be lower than 7, even adjusted to below 6.5, thereby forming an acidic wastewater. Next, as shown in step S120, the acidic wastewater is separated into a high concentration wastewater and a low concentration wastewater by using a reverse osmosis membrane. Then, as shown in step S130, a first alkaline solvent is further added to the high-concentration wastewater to generate ammonia gas in the high-concentration wastewater. Thereafter, a second acidic solvent is reacted with ammonia gas to form an ammonium compound as shown in step S140. In this way, ammonia in the ammonia-containing wastewater can be recovered by recovering the ammonium compound.

In more detail, ammonia may be present in the solution as a positively charged ammonium ion (chemical formula NH ₄ ⁺ ). Since the acidic liquid will positively charge the reverse osmosis membrane, it will facilitate the reverse osmosis membrane to repel the positively charged ammonium ions, thereby retaining more ammonium ions in the high concentration wastewater. Therefore, in this embodiment, step S110 is first performed to adjust the originally alkaline ammonia-containing wastewater to acidic wastewater by an acidic solvent. Next, in step S120, when the acidic wastewater is separated into high-concentration wastewater and low-concentration wastewater by the reverse osmosis membrane, the ammonium ion content in the high-concentration wastewater can be increased. At this time, the low-concentration wastewater with a low ammonium ion content can be recycled or reused, or discharged to a wastewater treatment plant for subsequent general wastewater treatment processes.

Then, since the alkaline environment would benefit ammonium ions state (NH ₄ ⁺⁾ is converted into a gaseous ammonia (NH _3). Therefore, in this embodiment, as shown in step S130, the first alkaline solvent is added to the high-concentration wastewater to adjust the pH value of the high-concentration wastewater to be alkaline, for example, to be adjusted to be higher than 9.5. Ammonia is produced in high concentration wastewater. Then, as shown in step S140, the second acidic solvent is reacted with the ammonia gas to form an ammonium compound, so that most of the ammonia in the ammonia-containing wastewater is recovered via the recovered ammonium compound, and the remaining wastewater is more ammonia-containing. It can be recycled and reused, or discharged to a wastewater treatment plant for subsequent general wastewater treatment processes. Compared with the prior art, the ammonia-containing wastewater is denitrified by a biological anaerobic process. This embodiment sequentially concentrates, converts the ionic ammonium ion into ammonia gas, and uses an acidic solvent to absorb the ammonia gas to form an ammonium compound. The ammonia-containing wastewater is then treated by recycling the ammonium compound, thereby enabling high ammonia recovery efficiency.

FIG. 2 depicts a flow chart of one embodiment of step S140 of FIG. 1. Referring to FIG. 2, in a preferred embodiment, step S140 is, for example, first conveying high-concentration wastewater containing ammonia gas to a filter to filter out impurities in the high-concentration wastewater (S142), and then The filtered high-concentration wastewater is sent to a separation device to separate ammonia gas from the high-concentration wastewater (S144). Then, the ammonia gas is adsorbed by the second acidic solvent when the ammonia gas is discharged from the separation device to form an ammonium compound (S146). In this way, ammonia in the ammonia-containing wastewater can be recovered via the recovery of the ammonium compound (S148).

In a preferred embodiment, the separation device is capable of using a hydrophobic exchange membrane for performing a membrane separation process. After the high-concentration wastewater containing ammonia is transported to the hydrophobic exchange membrane, the liquid waste water is blocked by the hydrophobic exchange membrane, while the gaseous ammonia gas can pass through the hydrophobic exchange. The membrane is changed to react with the second acidic solvent. In another preferred embodiment, the separation device is also capable of using a separation column. After the high-concentration wastewater containing ammonia is sent to the separation column, the liquid waste water remains at the bottom of the separation column, and the gaseous ammonia gas rises to the top of the separation column to react with the second acidic solvent.

It is to be noted that, in order to simplify the subsequent processing of by-products such as low-concentration wastewater in the above-described process and waste water after the ammonia gas is discharged, the anion component contained in the first acidic solvent is preferably contained in the ammonia-containing wastewater. The main anionic components are the same to avoid the main components of the above by-products being too complicated. Similarly, the cationic component contained in the first alkaline solvent is also preferably the same as the main cationic component contained in the ammonia-containing wastewater. Further, since the second acidic solvent directly reacts with the ammonia gas, the component of the acidic solvent can be selected depending on the desired ammonium compound, and the main anion component contained in the ammonia-containing wastewater can be eliminated.

In more detail, the main components of ammonia-containing wastewater from the semiconductor industry or other industries usually do not contain only ammonium ions (NH ₄ ⁺ ), and may also contain sulfate ions (SO ₄ ^2- ). Chloride (Cl ^- ) or anion such as phosphate ion (PO ₄ ^3- ). For example, the main component of the ammonia-containing wastewater may be ammonium sulfate (chemical formula (NH ₄ ) ₂ SO ₄ ) wastewater, ammonium chloride (chemical formula NH ₄ Cl) wastewater or ammonium phosphate (ammonium). phosphate, formula (NH _{4) 3} PO ₄₎ wastewater. At this time, the first acidic solvent may be at least one of a solution of sulfuric acid (H ₂ SO ₄ ), a solution of hydrochloric acid (HCl) and a solution of phosphoric acid (H ₃ PO ₄ ).

In addition, in this embodiment, the main component of the ammonia-containing wastewater may further comprise sodium sulfate (sodium sulfate, chemical formula: Na ₂ SO ₄ ) wastewater and sodium phosphate (sodium phosphate, chemical formula: Na ₃ PO ₄ ) wastewater. Therefore, it is more likely that the composition contains sodium ions (Na ⁺ ) and potassium ions (K ⁺ ). At this time, the first alkaline solvent can be selected from sodium hydroxide (chemical formula NaOH, commonly known as caustic soda, caustic soda) solution and potassium hydroxide (potassium hydroxide, chemical formula KOH, commonly known as caustic potash, potassium soda) solution At least one of them.

Further, when step S146 is carried out, if a solution of sulfuric acid (H ₂ SO ₄ ) is used as the second acidic solvent, the ammonium compound will be ammonium sulfate ((NH ₄ ) ₂ SO ₄ ). Further, if a hydrochloric acid (HCl) solution is selected as the second acidic solvent, the ammonium compound will be ammonium chloride (NH ₄ Cl). Further, if a phosphoric acid (H ₃ PO ₄ ) solution is selected as the second acidic solvent, the ammonium compound is ammonium phosphate ((NH ₄ ) ₃ PO ₄ ).

3 is a flow chart showing a method for recycling ammonia-containing wastewater according to another embodiment of the present invention. Referring to FIG. 3, the recovery treatment method of the ammonia-containing wastewater in this embodiment is similar to the recovery treatment method of the ammonia-containing wastewater in the previous embodiment, and there are two main differences between the two.

First, the main component of the ammonia-containing wastewater in this embodiment further contains hydrogen peroxide. Therefore, before the step S110 of adding the first acidic solvent to the ammonia-containing wastewater to form the acidic wastewater, the step S105 is further included to remove the hydrogen peroxide in the ammonia-containing wastewater by using a catalyst. Among them, the catalyst may be activated carbon, manganese dioxide or iron manganese sand. In addition, because the higher pH value is more favorable for the catalyst to remove hydrogen peroxide from the ammonia-containing wastewater, the ammonia-containing wastewater may only be weakly alkaline, that is, its pH may be only between 7 and 8. Between, thus, the catalyst is less efficient in removing hydrogen peroxide. Therefore, before proceeding to step S105, step S100 may be further performed to add a second alkaline solvent to the ammonia-containing wastewater so that the pH of the ammonia-containing wastewater is higher than 8.5.

Similarly, in order to simplify the subsequent processing of by-products such as low-concentration wastewater in the subsequent process and waste water after the ammonia gas is discharged, the cationic component contained in the second alkaline solvent is preferably mainly contained in the ammonia-containing wastewater. The cationic components are the same to avoid the main components of the above by-products being too complicated. That is to say, when the main component of the ammonia-containing wastewater contains sodium sulfate (Na ₂ SO ₄ ) wastewater and sodium phosphate (Na ₃ PO ₄ ) wastewater, the composition contains sodium ions (Na ⁺ ) and potassium ions (K ⁺ The main component of the first alkaline solvent and the second alkaline solvent may be at least one of a sodium hydroxide (NaOH) solution and a potassium hydroxide (KOH) solution.

Second, in order to further recover and reuse an ammonium compound such as ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), ammonium chloride (NH ₄ Cl) or ammonium phosphate ((NH ₄ ) ₃ PO ₄ ), in the step After S140, a bipolar membrane electrodialysis device or an ion exchange resin can be further used to redox the ammonium compound to separate the ammonium compound into an alkaline solution and an acidic solution (S150). Among them, the alkaline solution may be ammonia water, and the acidic solution may be sulfuric acid, hydrochloric acid or phosphoric acid as the composition of the ammonium compound changes. The other steps are the same as in the previous embodiment, and are not described herein again.

In order to make it easier for those skilled in the art to understand the above-mentioned ammonia-containing wastewater recovery treatment method. Hereinafter, a recycling treatment apparatus for ammonia-containing wastewater will be further disclosed by a specific embodiment. However, the above-mentioned ammonia-containing wastewater recovery treatment method cannot be carried out only by using the following ammonia-containing wastewater recovery treatment equipment.

4 is a schematic view showing the structure of a recycling treatment apparatus for ammonia-containing wastewater according to an embodiment of the present invention. Referring to FIG. 4, the ammonia-containing wastewater recovery processing apparatus 100a includes a first pH adjustment tank 110a, a reverse osmosis membrane 120, a second pH adjustment tank 110b, a separation device 130, and a recovery tank. 140a. The reverse osmosis membrane 120 is connected between the first pH adjustment tank 110a and the second pH adjustment tank 110b, and the separation device is connected between the second pH adjustment tank 110b and the recovery tank 140a. .

The first pH adjustment tank 110a is for containing ammonia-containing wastewater, and is suitable for injecting a first acidic solvent to adjust the originally alkaline ammonia-containing wastewater to acidic wastewater. Then, the reverse osmosis membrane 120 is used to isolate the acidic wastewater into high-concentration wastewater and low-concentration wastewater. Among them, the low-concentration wastewater with low ammonia content can be recycled or reused, or discharged to the wastewater treatment plant for subsequent general wastewater treatment process, and the high-concentration wastewater with higher ammonia content is injected into the second pH-adjusting tank 110b. in. Further, the first alkaline solvent can be further injected into the second pH adjustment tank 110b to generate ammonia gas in the high concentration wastewater.

Thereafter, the high-concentration wastewater containing ammonia gas may first be filtered by a filter 150 connected between the second acid-base adjusting tank 110b and the separating device 130, and then transported to the hydrophobic exchange membrane or separated. In a separation device 130 such as a tower, to waste from a high concentration Ammonia gas is separated from the water. Wherein, the ammonia gas reacts with the injected second acidic solvent in the process of discharging the separation device 130 to form an ammonium compound, and the ammonium compound is recovered in the recovery tank 140a, and the remaining wastewater is low in ammonia content. It can be recycled or discharged to a wastewater treatment plant for subsequent general wastewater treatment processes. Similarly, the composition of the ammonium compound formed at this time may also be ammonium sulfate, ammonium chloride or ammonium phosphate depending on the composition of the second acidic solvent selected. In addition, the ammonia-containing wastewater is denitrified by a biological anaerobic process compared to the prior art, and this embodiment forms an ammonium compound by concentrating, converting ionic ammonium ions into ammonia gas, and using an acidic solvent to absorb ammonia gas. The ammonia-containing wastewater is then treated by recycling the ammonium compound, thereby enabling high ammonia recovery efficiency.

In addition, when the main component of the ammonia-containing wastewater further contains anion such as sulfate ion (SO ₄ ^2- ), chloride ion (Cl ^- ) or phosphate ion (PO ₄ ^3- ), the main component may be selected to contain the above anion. The hydride (such as at least one of sulfuric acid, hydrochloric acid and phosphoric acid) is used as the first acidic solvent. Similarly, when the main component of the ammonia-containing wastewater further contains a cation such as sodium ion (Na ⁺ ) or potassium ion (K ⁺ ), a hydroxide having a main component containing the above cation (such as sodium hydroxide and hydrogen) may be selected. At least one of the potassium oxides is used as the first alkaline solvent. In this way, it is possible to simplify the subsequent processing of by-products such as low-concentration wastewater and waste water after the ammonia gas is discharged. Further, since the second acidic solvent directly reacts with the ammonia gas, the component of the acidic solvent can be selected depending on the desired ammonium compound, and the main anion component contained in the ammonia-containing wastewater can be eliminated.

Moreover, the ammonia-containing wastewater recovery treatment apparatus 100a in this embodiment may further include a plurality of storage tanks 160a, 160b, and 160c. The storage tank 160a is in communication with the first pH adjustment tank 110a and serves to store the first acidic solvent to inject the first acidic solvent from the storage tank 160a into the first pH adjustment tank 110a according to the demand. Furthermore, the storage tank 160b is connected to the second pH adjustment tank 110b, and is used for storing the first alkaline solvent to inject the first alkaline solvent from the storage tank 160b into the second pH adjustment tank 110b according to the demand. in. In addition, the storage tank 160c is connected to the separation device 130 and is used for storing the second acidic solvent to inject the second acidic solvent from the storage tank 160c into the separation device according to the demand. Ammonia gas is adsorbed to form an ammonium compound.

Further, the ammonia-containing wastewater recovery treatment apparatus 100a may further include a plurality of pumps 170a, 170b, 170c, 170d, 170e, and 170f. The pump 170a can be connected between the storage tank 160a and the first pH adjustment tank 110a for injecting the first acidic solvent from the storage tank 160a into the first pH adjustment tank 110a, and pumping 170b. Then, it can be connected between the first pH adjustment tank 110a and the reverse osmosis membrane 120 for transporting the acidic wastewater from the first pH adjustment tank 110a to the reverse osmosis membrane 120. Furthermore, the pump 170c can be connected between the reverse osmosis membrane 120 and the second pH adjustment tank 110b for injecting high concentration wastewater from the reverse osmosis membrane 120 into the second pH adjustment tank 110b, and pumping 170d is connectable between the storage tank 160b and the second pH adjustment tank 110b for injecting the first alkaline solvent from the storage tank 160b into the second pH adjustment tank 110b.

In addition, the pump 170e may be connected between the second pH adjustment tank 110b and the filter 150 for injecting the high concentration wastewater containing ammonia from the second pH adjustment tank 110b into the separation device 130 via the filter 150. The pump 170f can be connected between the storage tank 160c and the separation device 130 for injecting the second acidic solvent from the storage tank 160c into the separation device 130. It should be noted that, in other embodiments not shown, when the composition of the first acidic solvent and the second acidic solvent are the same, the first pH adjustment tank and the separation device can share the same storage tank and pump. To store and transport acidic solvents.

FIG. 5 is a schematic view showing the structure of a recycling treatment apparatus for ammonia-containing wastewater according to another embodiment of the present invention. Referring to FIG. 5, the ammonia-containing wastewater recovery treatment apparatus 100b in this embodiment is similar to the ammonia-containing wastewater recovery treatment apparatus 100a in the previous embodiment, and the differences include the following points.

First, the main component of the ammonia-containing wastewater in this embodiment further contains hydrogen peroxide, and thus the ammonia-containing wastewater recovery treatment apparatus 100b may further include a treatment device 180 containing the catalyst, and the first pH adjustment tank 110a is in communication with the processing device 180 and the reverse osmosis membrane 120. The catalyst may be activated carbon, manganese dioxide or iron manganese sand for removing hydrogen peroxide in the ammonia-containing wastewater before injecting the first acidic solvent into the ammonia-containing wastewater. value It should be noted that because the higher pH value is more favorable for the catalyst to remove hydrogen peroxide from the ammonia-containing wastewater, the ammonia-containing wastewater may only be weakly alkaline, that is, its pH may only be between Between 7 and 8, thus making the catalyst less efficient in removing hydrogen peroxide. Therefore, the ammonia-containing wastewater recovery treatment apparatus 100b in this embodiment may further include a third pH adjustment tank 110c, a storage tank 160d, and a pump 170g.

In this embodiment, the third pH adjustment tank 110c is in communication with the processing device 180, and is adapted to inject a second alkaline solvent to contain the hydrogen peroxide in the ammonia-containing wastewater before the catalyst is used to remove the hydrogen peroxide in the ammonia-containing wastewater. The pH of the ammonia wastewater is adjusted to be above 8.5. Furthermore, the storage tank 160d is connected to the third pH adjustment tank 110c for storing the second alkaline solvent, and the pump 170g is connected between the storage tank 160d and the third pH adjustment tank 110c for The second alkaline solvent is injected into the third pH adjustment tank 110c from the storage tank 160d.

Similarly, when the main component of the ammonia-containing wastewater further contains a cation such as sodium ion (Na ⁺ ) or potassium ion (K ⁺ ), the hydroxide of the above cation may be selected as the main solvent of the second alkaline solvent. ingredient. In this way, it is possible to simplify the subsequent processing of by-products such as low-concentration wastewater and waste water after the ammonia gas is discharged. In addition, in other embodiments not shown, when the composition of the first alkaline solvent and the second alkaline solvent are the same, the second pH adjustment tank and the third pH adjustment tank can share the same storage. Tanks and pumps to store and transport alkaline solvents.

Second, in order to further recover and reuse the ammonium compound including at least one of ammonium sulfate, hydrochloric acid and phosphoric acid, the ammonia-containing wastewater recovery treatment apparatus 100b in this embodiment may further include two other recovery tanks 140b. , 140c, another pump 170h, and a bipolar membrane electrodialysis device 190. The pump 170h can be connected between the recovery tank 140a and the bipolar membrane electrodialysis device 190 for injecting ammonium compounds from the recovery tank 140a into the bipolar membrane electrodialysis device 190. Furthermore, the bipolar membrane electrodialysis device 190 is capable of separating the ammonium compound into an alkaline solution and an acidic solution, and then transferring the alkaline solution and the acidic solution to the two recovery tanks 140b, 140c, respectively. Among them, the alkaline solution may be ammonia water, and the acidic solution may be sulfuric acid, hydrochloric acid or phosphoric acid as the composition of the ammonium compound changes. In addition, in other embodiments, the bipolar membrane electrodialysis device 190 can also be ionized. Replace with resin. The functions and connection relationships of other components are substantially the same as those of the previous embodiment, and will not be described herein.

In summary, since the acidic liquid causes the reverse osmosis membrane to be positively charged, it is advantageous for the reverse osmosis membrane to repel the ammonium ion to retain more ammonium ions in the high concentration wastewater. Therefore, the present invention first adjusts the acidity and alkalinity of the ammonia-containing wastewater to be acidic, and then, when the acidic wastewater is separated into high-concentration wastewater and low-concentration wastewater by using a reverse osmosis membrane, the recovery efficiency of the reverse ion membrane for the ammonium ion can be improved. . Then, the pH value of the high-concentration wastewater is adjusted to be alkaline, so that the ionic ammonium ion (NH ₄ ⁺ ) is converted into gaseous ammonia gas. Thereafter, an acidic solvent is used to adsorb and ammonia gas to form an ammonium compound. In this way, most of the ammonia in the ammonia-containing wastewater can be recovered by recovering the ammonium compound, and even the ammonia water can be further separated and recovered from the ammonium compound. Therefore, the present invention is more efficient in recovering ammonia than the prior art.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100a, 100b‧‧‧Recycling equipment for ammonia-containing wastewater

110a, 110b, 110c‧‧‧ pH adjustment tank

120‧‧‧ reverse osmosis membrane

130‧‧‧Separation device

140a, 140b, 140c‧‧ ‧ recycling tank

150‧‧‧Filter

160a, 160b, 160c, 160d‧‧‧ storage tanks

170a, 170b, 170c, 170d, 170e, 170f, 170g, 170h‧‧ ‧ pump

180‧‧‧Processing device

190‧‧‧Bipolar membrane electrodialysis unit

Steps S100, S105, S110, S120, S130, S140, S142, S144, S146, S148‧‧

1 is a flow chart showing a method of recycling ammonia-containing wastewater according to an embodiment of the present invention.

FIG. 2 depicts a flow chart of one embodiment of step S140 of FIG. 1.

3 is a flow chart showing a method for recycling ammonia-containing wastewater according to another embodiment of the present invention.

4 is a schematic view showing the structure of a recycling treatment apparatus for ammonia-containing wastewater according to an embodiment of the present invention.

FIG. 5 is a schematic view showing the structure of a recycling treatment apparatus for ammonia-containing wastewater according to another embodiment of the present invention.

S110, S120, S130, S140‧‧ steps

Claims (33)

The invention relates to a method for recovering ammonia-containing wastewater, comprising: adding a first acidic solvent to an ammonia-containing wastewater to form an acidic wastewater; and separating the acidic wastewater into a high-concentration wastewater and a low-concentration wastewater by using a reverse osmosis membrane; Adding a first alkaline solvent to the high-concentration wastewater to generate ammonia gas in the high-concentration wastewater; and reacting the ammonia gas with the second acidic solvent to form an ammonium compound to recover the ammonium compound. The method for recovering ammonia-containing wastewater according to claim 1, wherein the component of the ammonia-containing wastewater further comprises hydrogen peroxide, and further comprises: before the first acidic solvent is added to the ammonia-containing wastewater. A catalyst removes the hydrogen peroxide in the ammonia-containing wastewater. The method for recovering ammonia-containing wastewater according to claim 2, wherein the catalyst is activated carbon, manganese dioxide or iron manganese sand. The method for recovering ammonia-containing wastewater according to claim 2, wherein before the catalyst is used to remove the hydrogen peroxide in the ammonia-containing wastewater, a second base is further added to the ammonia-containing wastewater. The solvent is such that the pH of the ammonia-containing wastewater is higher than 8.5. The method for recovering ammonia-containing wastewater according to claim 4, wherein the ammonia-containing wastewater, the first alkaline solvent and the second alkaline solvent comprise at least one of sodium ions and potassium ions. . The method for recovering ammonia-containing wastewater according to claim 1, wherein the acid wastewater has a pH of less than 6.5. The method for recovering ammonia-containing wastewater according to claim 1, wherein the first alkaline solvent adjusts a pH of the high-concentration wastewater to be higher than 9.5. The method for recovering ammonia-containing wastewater according to claim 1, wherein the ammonia-containing wastewater and the first alkaline solvent comprise at least one of sodium ions and potassium ions. The method for recovering ammonia-containing wastewater according to claim 1, wherein before the reaction of the second acidic solvent with the ammonia gas to form the ammonium compound, the method further comprises: using the separation device from the high concentration wastewater; The ammonia gas is separated. The method for recovering ammonia-containing wastewater according to claim 9, wherein the separation device is at least one of a hydrophobic exchange membrane or a separation column. The method for recovering ammonia-containing wastewater according to claim 9, wherein before separating the ammonia gas from the high-concentration wastewater by using the separation device, the method further comprises filtering the high-concentration wastewater by using a filter. Impurities. The method for recovering ammonia-containing wastewater according to claim 1, wherein the ammonia-containing wastewater and the first acidic solvent comprise at least one of a sulfate ion, a chloride ion and a phosphate ion. The method for recovering ammonia-containing wastewater according to claim 1, wherein the second acidic solvent is at least one of sulfuric acid, hydrochloric acid and phosphoric acid. The method for recovering ammonia-containing wastewater according to claim 1, wherein after recovering the ammonium compound, the method further comprises separating the ammonium compound into a base by using a bipolar membrane electrodialysis device or an ion exchange resin. Sexual solution and an acidic solution. The method for recovering ammonia-containing wastewater according to claim 14, wherein the alkaline solution is ammonia water, and the acidic solution is sulfuric acid, hydrochloric acid or phosphoric acid. The invention relates to a recycling treatment device for ammonia-containing wastewater, comprising: a first acid-base adjusting tank for accommodating an ammonia-containing wastewater, and suitable for injecting a first acidic solvent, so that the ammonia-containing wastewater forms an acidic wastewater; a reverse osmosis membrane connected to the first pH adjustment tank for isolating the acidic wastewater into a high concentration wastewater and a low concentration wastewater; a second pH adjustment tank connected to the reverse osmosis membrane for containing the high concentration wastewater, and adapted to inject a first alkaline solvent to generate ammonia gas in the high concentration wastewater; a separation device, Connected to the second pH adjustment tank for separating the ammonia gas from the high concentration wastewater, and adapted to inject a second acidic solvent to react with the ammonia gas to form an ammonium compound; and a recovery tank, Connected to the separation device for recovering the ammonium compound. The apparatus for recycling ammonia-containing waste liquid according to claim 16, further comprising a first storage tank, wherein the first storage tank is connected to the first pH adjustment tank for storing the first An acidic solvent and adapted to inject the first acidic solvent into the first pH adjustment tank. The apparatus for recycling ammonia-containing waste liquid according to claim 16, further comprising a second storage tank, wherein the second storage tank is connected to the second pH adjustment tank for storing the first An alkaline solvent and adapted to inject the first alkaline solvent into the second pH adjustment tank. The recycling treatment device for ammonia-containing wastewater according to claim 16, further comprising a processing device containing a catalyst, and the component of the ammonia-containing wastewater further comprises hydrogen peroxide, wherein the first pH adjustment The tank is connected between the treatment device and the reverse osmosis membrane, and the catalyst is used to remove the hydrogen peroxide in the ammonia-containing wastewater before the first acidic solvent is injected into the ammonia-containing wastewater. The recycling treatment device for ammonia-containing wastewater according to claim 19, wherein the catalyst is activated carbon, manganese dioxide or iron manganese sand. The apparatus for recovering ammonia-containing wastewater according to claim 19, further comprising a third pH adjustment tank, wherein the third pH adjustment tank is connected to the processing device, and is suitable for injecting a dibasic solvent to adjust the pH of the ammonia-containing wastewater to above 8.5 before the catalyst is used to remove the hydrogen peroxide in the ammonia-containing wastewater. For example, the recycling treatment equipment for ammonia-containing waste liquid described in claim 21 of the patent application includes a third storage tank, wherein the third storage tank is connected to the third pH adjustment tank for storing the second alkaline solvent, and is suitable for injecting the second alkaline solvent into the third pH adjustment tank in. The apparatus for recycling ammonia-containing wastewater according to claim 21, wherein the ammonia-containing wastewater, the first alkaline solvent and the second alkaline solvent comprise at least one of sodium ions and potassium ions. . The recycling treatment device for ammonia-containing wastewater according to claim 16, wherein the acidic wastewater has a pH of less than 6.5. The apparatus for recycling ammonia-containing wastewater according to claim 16, wherein the first alkaline solvent adjusts a pH of the high-concentration wastewater to be higher than 9.5. The apparatus for recycling ammonia-containing wastewater according to claim 16, wherein the ammonia-containing wastewater and the first alkaline solvent comprise at least one of sodium ions and potassium ions. The apparatus for recycling ammonia-containing wastewater according to claim 16, wherein the separation device is at least one of a hydrophobic exchange membrane or a separation column. The recycling treatment device for ammonia-containing wastewater according to claim 16, further comprising a filter, wherein the filter is connected between the second pH adjustment tank and the separation device for filtering the height Impurities in the concentration of wastewater. The apparatus for recycling ammonia-containing waste liquid according to claim 16, further comprising a fourth storage tank, wherein the fourth storage tank is connected to the separating device for storing the second acidic solvent, and The second acidic solvent is injected into the separation device. The apparatus for recycling ammonia-containing wastewater according to claim 16, wherein the ammonia-containing wastewater and the first acidic solvent comprise at least one of a sulfate ion, a chloride ion and a phosphate ion. The apparatus for recovering ammonia-containing wastewater according to claim 16, wherein the second acidic solvent is at least one of sulfuric acid, hydrochloric acid and phosphoric acid. The apparatus for recycling ammonia-containing wastewater according to claim 16 further includes a bipolar membrane electrodialysis device connected to the recovery tank or an ion exchange resin for separating the ammonium compound into a base. Sexual solution and an acidic solution. The apparatus for recycling ammonia-containing wastewater according to claim 32, wherein the alkaline solution is ammonia water, and the acidic solution is sulfuric acid, hydrochloric acid or phosphoric acid.