TW202120440A - Wastewater treatment system and method using catalyst - Google Patents

Abstract

A wastewater treatment system comprises hypochlorous acid, catalyst, an activation tower and an aeration oxidation apparatus. The hypochlorous acid is used to promote the oxidation reaction. The activation tower is used to activate the catalyst with an activation solution when the catalyst loses some active ability. The aeration device communicates to the activation tower, and into which the catalyst, hypochlorous acid, an oxidizing gas and a waste water are introduced, so that the waste water is oxidized by the oxidizing gas by use of the catalyst to reduce the COD of the waste water.

Description

Wastewater treatment system and method using catalyst

The present invention relates to a waste water treatment system and method, in particular to a waste water treatment system and method using hypochlorous acid for COD treatment.

Wastewater treatment methods are generally divided into primary treatment, secondary treatment and tertiary treatment. The primary treatment, for example, is a sedimentation method, which removes solid garbage, oil, sand, hard particles and other sedimentable substances in the sewage. The secondary treatment decomposes the organic compounds in the sewage into inorganic substances, and begins to process the chemical oxygen demand (COD), generally using biological treatment method aeration, etc. The tertiary treatment is activated carbon to detoxify. The tertiary treatment is the wastewater treatment process after the secondary treatment, which is mainly to denitrify and dephosphorize the water after the secondary treatment, use the activated carbon adsorption method or reverse osmosis method to remove the remaining pollutants in the water, and use ozone or Chlorine disinfection kills bacteria and viruses. In addition, currently known wastewater treatment methods include activated sludge method, biological treatment method, combustion treatment method through sintering, and catalyst-free wet oxidation treatment method of Zimmerman process.

Biological treatment requires a long time to decompose organic matter, etc. As for the treatment of ammonia and other difficult-to-decompose nitrogen compounds, complicated engineering is required, and it is suitable for the growth of algae, bacteria and other microorganisms due to the dilution required The disadvantages of long concentration, and adjustment of pH suitable for the growth of microorganisms, and a large area for treatment. The combustion treatment method has disadvantages such as the cost of fuel costs due to the need for combustion, and the problem of secondary pollution caused by the discharged gas. The catalyst-free wet oxidation treatment method is a method of treating waste water in the presence of oxygen at high temperature and pressure to oxidize or decompose organic matter and/or inorganic COD components. Although it is an excellent treatment method, it is usually Its processing efficiency is low and it is necessary to install a secondary processing device.

In view of this, there have been many studies to improve the treatment efficiency of the wet oxidation treatment method, and various methods of using catalysts have been proposed. From the perspective of high purification performance and good economic efficiency of wastewater, the wet oxidation treatment method using solid catalyst has attracted wide attention. Japanese Patent Laid-open No. 49-44556 and No. 49-94157 propose a catalyst formed by placing precious metals such as palladium and platinum on a carrier such as alumina, silica, silica gel, and activated carbon. Taiwan Patent Application No. 083112298 proposes a catalyst mixture comprising oxides of manganese and oxides of at least one metal selected from the group of iron, titanium and zirconium. However, the conventional wet oxidation treatment method needs to be carried out under high pressure and high temperature, which will increase the energy required for pressurization and heating, and increase the cost of wastewater treatment.

However, there is room for improvement in the aforementioned catalyst for wastewater treatment.

According to an embodiment of the present invention, an objective is to provide a wastewater treatment system and method, which can utilize catalysts for wastewater treatment.

According to an embodiment of the present invention, a wastewater treatment system includes hypochlorous acid, most catalysts, an activation tower, and an aeration oxidation device. Hypochlorous acid is used to promote the oxidation reaction. The catalysts include a majority of activated carbon, a majority of transition metals, and a majority of noble metals, and the noble metals are bonded to the activated carbons via the transition metals. The activation tower is used to activate the catalysts with an activation solution when the catalysts lose part of their activity. The aeration oxidation equipment is connected to the activation tower, and is introduced with the catalysts, the hypochlorous acid, the gas for oxidation and a waste water, and the catalysts are used to oxidize the waste water with the gas for oxidation, thereby Reduce the COD concentration of the wastewater.

In one embodiment, the wastewater treatment system further includes: an adjustment bucket. The adjusting barrel includes a first inflow pipeline, a second inflow pipeline, a discharge pipeline and a body. The first inflow pipe is used for flowing bleach water. The second inflow pipeline is used to flow the waste water. The discharge pipeline is used to discharge the adjusted waste water. The main body is connected to the first inflow pipeline, the second inflow pipeline, and the discharge pipeline to store and treat the waste water, so that the liquid oxidation promoter is mixed in the waste water, and the aeration and oxidation equipment is connected to the Adjust the bucket, and introduce the waste water from the adjusted bucket.

In one embodiment, the aeration and oxidation equipment further includes a sedimentation tank for recovering the catalysts.

In one embodiment, the aeration and oxidation equipment includes a catalyst aeration and oxidation tower, and the catalyst is provided in the catalyst aeration and oxidation tower, preferably. The aeration and oxidation equipment further includes an air aeration and oxidation tower, and the catalysts are not pre-installed in the air aeration and oxidation tower, and the catalysts are dispersed in the waste water and then introduced into the air aeration Oxidation tower.

In one embodiment, the aeration and oxidation equipment includes an air aeration and oxidation tower, and the catalysts are not pre-installed in the air aeration and oxidation tower, and the catalysts are dispersed in the wastewater before being introduced To the empty aeration oxidation tower.

In one embodiment, the precious metals are ruthenium, the transition metals are manganese, and the oxidation gas is air. In one embodiment, the activation liquid is a liquid containing ruthenium and a surfactant.

According to an embodiment of the present invention, a wastewater treatment method includes the following steps. A plurality of catalysts are provided, wherein the catalysts include a majority of activated carbon, a majority of transition metals, and a majority of noble metals, and the noble metals are bonded to the activated carbons via the transition metals. Provides hypochlorous acid. The catalysts, the hypochlorous acid, the gas for oxidation, and a waste water are introduced into an aeration oxidation device, and the catalysts are used to oxidize the waste water with the oxidation gas, thereby oxidizing the COD of wastewater. And, when the catalysts lose part of their activity, the catalysts are introduced into an activation tower, and an activation solution is used to activate the catalysts.

According to an embodiment of the present invention, a method for manufacturing hypochlorous acid includes the following steps. The salt and hydrochloric acid are placed in a reaction chamber, and most catalysts are added for reaction, wherein the catalysts include most activated carbon, most transition metals, and most noble metals, and the noble metals are separated by the transition metals. It is bonded to these activated carbons.

According to an embodiment of the present invention, a method for regenerating magnesium ammonium phosphate includes the following steps. The magnesium ammonium phosphate monophosphate is placed in a reactor, and NaOH is added to react to obtain Mg ₃ (PO ₄ ) ₂ , Na ₃ PO ₄ and NH ₃ . The Mg ₃ (PO ₄ ) ₂ and the Na ₃ PO ₄ are reacted with hydrochloric acid to prepare Mg ₃ HPO ₄ and NaCl. And, make Mg ₃ HPO ₄ react with NH ₃ to obtain regenerated magnesium ammonium phosphate.

In one embodiment, the steps of preparing Mg ₃ (PO ₄ ) ₂ , Na ₃ PO ₄ and NH ₃ are carried out according to the following formula 1, 3 MgNH ₄ PO ₄ ↓+3 NaOH ───→ Mg ₃ ( PO ₄ ) ₂ ↓+Na ₃ PO ₄ +3H ₂ O +3 NH ₃ ↑ Formula 1; the step of preparing Mg3HPO4 and NaCl is carried out in the following formula 2, Mg ₃ ( PO ₄ ) ₂ ↓+Na ₃ PO ₄ +3 HCl ───→3 MgHPO ₄ +3 NaCl formula 2; and the step of preparing regenerated magnesium ammonium phosphate is carried out in the following formula 3. 3 MgHPO ₄ +3 NH ₃ ───→3 MgNH ₄ PO ₄ ↓ Equation 3.

According to the wastewater treatment system and method according to an embodiment of the present invention, compared with the conventional biological pond treatment, the reaction speed is faster, and the construction space is small, and no sludge is generated. In one embodiment, in addition to reducing COD, it can also decolorize and reduce ammonia nitrogen to less than 1 PPM. In one embodiment, a new method for manufacturing hypochlorous acid can reduce the manufacturing cost and can be applied to the aforementioned wastewater treatment system and method. Preferably, the catalyst used in the method for producing hypochlorous acid is the same as the catalyst used in the wastewater treatment system and method, so that the loss of the catalyst can be reduced. In one embodiment, the new regeneration method of magnesium ammonium phosphate can further purify the magnesium ammonium phosphate, which is preferably applicable to the aforementioned wastewater treatment system and method, so that the aforementioned wastewater treatment system and method The obtained magnesium ammonium phosphate can be reused.

100‧‧‧Processing system

120‧‧‧Adjusting barrel

121‧‧‧The first inflow pipeline

122‧‧‧Second inflow pipeline

123‧‧‧Ontology

125‧‧‧Exhaust pipe

130‧‧‧Revitalizing Tower

131‧‧‧Pipe

132‧‧‧Pipe

140‧‧‧Catalyst aeration and oxidation tower

140a‧‧‧Air Aeration Oxidation Tower

141‧‧‧Pipe

142‧‧‧Pipe

143‧‧‧Exhaust pipe

143a‧‧‧Exhaust pipe

144‧‧‧Pipe

161‧‧‧The first intermediate barrel

162‧‧‧Second intermediate barrel

181‧‧‧Aeration tank

182‧‧‧Sedimentation tank

211‧‧‧First filter

212‧‧‧Second filter

Fig. 1 is a schematic diagram of an adjustment barrel according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a wastewater treatment system according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a wastewater treatment system according to another embodiment of the present invention.

Fig. 4 is a schematic diagram of a wastewater treatment system according to another embodiment of the present invention.

Fig. 5 is a schematic diagram of a wastewater treatment system according to another embodiment of the present invention.

According to the wastewater treatment of an embodiment of the present invention, the activated carbon catalyst and hypochlorous acid are used to oxidize COD in a fixed-bed oxidation adsorption tower. Hereinafter, the manufacturing method of the activated carbon catalyst will be described.

[Example 1]: Catalyst manufacturing method.

More specifically, ruthenium oxide, manganese dioxide, and 5L of activated carbon catalyst are used to synthesize by a high-pressure hydrothermal method to synthesize a COD removal catalyst. The method for manufacturing a catalyst in an embodiment of the present invention includes the following steps S11 to S39. Step S11: Add 3000 ml of pure water to 1000 ml of activated carbon, and wash with water at 60°C for more than three times until the upper layer is clear. Step S12: Add 3000 ml of 1% sodium bicarbonate aqueous solution and continue stirring to adjust the solution to alkaline. Step S13: Take 20 grams of manganese sulfate, dissolve it in 500 ml of pure water, and slowly drop it into the lower layer for about 60 minutes. Because precious metals are not easy to live As for the carbon, it is necessary to use a transition metal such as magnesium zinc copper manganese tin to connect a precious metal such as ruthenium to the activated carbon via the transition metal. For the purpose of the lowest cost and the easiest to manufacture, manganese is preferably selected (that is, manganese sulfate is used as a raw material).

Step S14: After dropping, the temperature is raised to 160°C for 60 minutes, and after the reaction is completed, the temperature is cooled to 40°C, and the upper layer liquid is drawn out. This step is a crystal growth step. Step S15: Add 3000ml of pure water and wash with water at room temperature for more than three times until the upper layer is clear. Step S16: Add 3000 ml of 0.5% sodium bicarbonate aqueous solution and continue stirring. Step S17: Take 3.0 g of ruthenium chloride, dissolve it in 500 ml of pure water, and slowly drop it into the lower layer for about 60 minutes. Step S18: After dripping, continue to stir and raise the temperature to 160°C, react for 1 hour, cool to 40°C before decompression, and extract the upper layer liquid. Step S19: Add 3000ml of pure aqueous solution, wash with water at room temperature for more than three times, until the upper layer is clear, that is, a catalyst for COD removal can be prepared.

According to the above catalyst manufacturing method, manganese is first grown on activated carbon, and then ruthenium is connected to manganese, so that ruthenium is bonded to the activated carbon via manganese. In detail, ruthenium cannot be oxidized and easily reduced. Therefore, ruthenium oxide is oxidized to ruthenium oxide through manganese dioxide, and the ruthenium oxide is bonded to the OH group on the activated carbon.

The catalyst of this embodiment can use activated carbon to adsorb organic matter, and then use precious metals to oxidize organic matter. After the organic matter is oxidized into carbon dioxide and water, it can adsorb organic matter again. Repeat this process until the activity of activated carbon disappears. Better oxidation effect and speed. In addition, when the activated carbon activity disappears, an activation solution or an activator can be added to perform an activation reaction. After the activation is completed, the catalyst can be reactivated and can be used continuously.

In addition, in other embodiments, the ruthenium catalyst may be an organic ruthenium catalyst. In one embodiment, the organic ruthenium catalyst has _{the general formula Ru(CO)HA(Z) 3} , wherein A is preferably a halogen atom Ground is chlorine; or hydrogen atom. Z is PR ¹ R ² R ³ , which may be the same or different, and are selected from alkyl groups and aryl groups, and preferably all are phenyl groups. In an embodiment, the organic ruthenium catalyst can also have _{the general formula Ru(CO)XY(Z) 2} , and X is a carboxylate group, especially _{ClCH 2} COO-, Cl ₂ CHCOO-, Cl ₃ CCOO- , F ₃ CCOO-, CH ₃ COO-, C ₆ H ₅ COO- or p-ClC ₆ H ₄ COO-, y is a halogen atom, preferably a chlorine atom or a bromine atom, or a hydrogen atom or a carboxylate group , Z is as defined above.

Taking 1000 tons/day of industrial wastewater as an example, the wastewater treatment method according to an embodiment of the present invention will be described. The wastewater treatment method according to an embodiment of the present invention includes a pre-treatment step for adjusting the pH value of the wastewater in the adjustment barrel 120; a catalyst activation step for activating the catalyst in the activation tower 130; and an oxidation The step is to oxidize COD in the wastewater in the activation tower 130.

Fig. 1 is a schematic diagram of an adjustment barrel according to an embodiment of the present invention. The adjustment barrel 120 is used to perform the pre-treatment steps of oxidation and adsorption wastewater treatment. More specifically, as shown in FIG. 1, the adjustment barrel 120 includes a first inflow pipe 121 for inflow of hypochlorous acid; a second inflow pipe 122 for inflow of waste water; and a discharge pipe 125 for The adjusted waste water is discharged; and a body 123 is connected to the first inflow pipe 121, the second inflow pipe 122, and the discharge pipe 125 to store and treat the waste water.

In one embodiment, a 20M ³ adjustment barrel 120 can be built, waste water is added to the adjustment barrel 120, bleach water is added, the pH value is adjusted to pH 7-9, and air is stirred at room temperature. When the acid-base value reaches pH 7~9, the catalyst activity is relatively strong. In one embodiment, the component of the bleaching water may be sodium hypochlorite, calcium hypochlorite (Ca(ClO) ₂ ), calcium hypochlorite chloride (Ca(ClO)Cl), or the like.

Fig. 2 is a schematic diagram of a wastewater treatment system according to an embodiment of the present invention. As shown in FIG. 2, according to an embodiment of the present invention, the wastewater treatment system 100 includes an adjustment barrel 120, an activation tower 130 and a catalyst aeration and oxidation tower 140. In one embodiment, a first filter 211 is further included. In another embodiment, a second filter 212 may be further included. Preferably, the first filter 211 or the second filter 212 may be a fiber filter cloth rotating disc filter; or it may contain glass sand for filtering. Taking 1000 tons/day of industrial waste water as an example, for industrial waste water with COD less than 500 ppm, a 25-ton catalyst aeration oxidation tower 140 and a 2.5-ton activation tower 130 can be installed. More specifically, this embodiment can build a 25M ³ catalyst aeration oxidation tower 140 and a 3M ³ or 2.5M ³ activation tower 130, and combine the 5M ³ activated carbon catalyst and the initial activation liquid , Placed in the catalyst aeration oxidation tower 140 in batches to make the wastewater undergo oxidation and adsorption reactions.

According to the catalyst of this embodiment, the activated carbon can be used to adsorb organic matter, and ruthenium is used to oxidize the organic matter. After the organic matter is oxidized into carbon dioxide and water, the organic matter can be adsorbed again. This is repeated until the activity of the activated carbon catalyst disappears. When the activated carbon activity disappears, an activation solution or an activator can be added to activate the reaction. After the activation is completed, the catalyst can recover its activity and can be used continuously. The activation liquid is a liquid containing ruthenium and a surfactant to increase the life of the catalyst.

In this embodiment, since the wastewater treatment is a continuous operation, the activated carbon catalyst is about to In the case of loss of activity, an activation step is required for the catalyst. The catalyst activation step of the wastewater treatment method will be described below. In this embodiment, in the adjustment barrel 120, 500 ppm of bleach water is added to waste water with a COD of 500 ppm. The adjusted waste water first passes through the glass sand of the first filter 211 and then is introduced into the activation tower 130. Add the activation solution to the activation tower 130, heat it to 80° C. and pass air into it for batch reaction for two hours, and then cool down to complete the activation of the activated carbon catalyst. Finally, the activated activated carbon catalyst can be introduced into the catalyst aeration and oxidation tower 140 in the next stage. In this embodiment, using air as the oxidizing gas can reduce the processing cost. However, it is not limited by the present invention, and it can also be oxygen or odor.

In addition, as shown in FIG. 2, the activation tower 130 further includes a pipeline 131 and a pipeline 132. The pipeline 131 is used to introduce air into the activation tower 130, and the pipeline 132 is used to discharge the catalyst (catalyst), which is then introduced into the sedimentation tank for recovery of the sedimentation tank.

The oxidation step of the wastewater treatment method is explained below. In an embodiment, the catalytic aeration and oxidation tower 140 may include a pipeline 141 and a pipeline 142. The pipeline 141 is connected between the first filter 211 (or the adjustment barrel 120) and the catalytic aeration and oxidation tower 140. The pipeline 142 is connected between the activation tower 130 and the catalytic aeration and oxidation tower 140. In the initial state, the 5M ³ activated carbon catalyst and the initial activation liquid are placed in the catalyst aeration oxidation tower 140 in batches. The waste water with a COD of 500 ppm is introduced from the adjustment tank 120 through the pipeline 142 to the catalyst aeration oxidation tower 140. Add 50 ppm of hypochlorous acid to wastewater as a liquid oxidation promoter. In addition, air was introduced into the catalyst aeration oxidation tower 140, and the room temperature aeration treatment was performed for 30 minutes. That is, the waste water is preferably retained in the tower for 30 minutes. Subsequently, the COD of the wastewater after the reaction can be reduced from 500 ppm to 200 ppm. In an embodiment, the catalyst aeration and oxidation tower 140 may further include a discharge pipe 143 connected to the second filter 212. The reaction waste water is discharged through the discharge pipe 143, and after the second filter 212 is filtered and treated with glass sand, the waste water without catalyst is discharged as the discharge water, and the catalyst obtained from the glass sand is introduced through the pipe 144 to The catalyst aeration oxidation tower 140 is used to recover the catalyst.

In one embodiment, the activation liquid is a liquid containing ruthenium and a surfactant to increase the use time of the catalyst.

Hypochlorous acid, which is a liquid oxidation accelerator, can oxidize COD and is equivalent to hexavalent chromium, so it can be used instead of hexavalent chromium. In addition to the activated carbon, the catalyst also coats a layer of precious metal on the activated carbon. More specifically, the trivalent ruthenium (which is not easily soluble in water) in the catalyst can be oxidized by hypochlorous acid to hexavalent ruthenium (which is easily soluble in water), so the amount of ruthenium used can be reduced.

In one embodiment, the oxidation step can also be performed in the following manner. Add 50ppm of hypochlorous acid to the wastewater with a COD of 500ppm, and filter it through glass sand, and then introduce it into the 25-ton catalyst aeration oxidation tower 140, and add 20% of the activated catalyst, with regular temperature aeration Treatment, the residence time is 30 minutes, so that the COD of the industrial wastewater after the reaction is reduced from 500ppm to 200ppm, and finally the catalyst is recovered through glass sand treatment.

In one embodiment, in the initial state, it is not necessary to add 5M ³ activated carbon catalyst. Fig. 3 is a schematic diagram of a wastewater treatment system according to another embodiment of the present invention. The structure of the embodiment in FIG. 3 is similar to the structure of the embodiment in FIG. 2, so the same elements use the same symbols and their related descriptions are omitted. Only at least one difference between the two will be described below. In this embodiment, the wastewater treatment system 100 includes an air aeration and oxidation tower 140 a instead of a catalytic aeration and oxidation tower 140. No activated carbon catalyst is specially added to the air aeration oxidation tower 140a, but only the catalyst originally present in the activation liquid is used as the catalyst. In this embodiment, since the amount of activated carbon catalyst used is small, a relatively large volume of air aeration oxidation tower 140a and activation tower 130 are required for wastewater treatment. Taking 1000 tons/day of industrial wastewater as an example, a 50M ³ air aeration oxidation tower 140a and a 10M ³ activation tower 130 can be set up to perform the oxidation step of the wastewater treatment method.

Fig. 4 is a schematic diagram of a wastewater treatment system according to another embodiment of the present invention. The structure of the embodiment in FIG. 4 is similar to the structure of the embodiment in FIG. 2, so the same elements use the same symbols and their related descriptions are omitted. Only at least one difference between the two will be described below. In this embodiment, in addition to the catalytic aeration and oxidation tower 140, the wastewater treatment system 100 further includes an air aeration and oxidation tower 140a. No activated carbon catalyst is specially added to the air aeration oxidation tower 140a, but only the catalyst originally present in the activation liquid is used as the catalyst. Taking 1000 tons/day of industrial wastewater as an example, 15M ³ catalyst aeration oxidation tower 140, 30M ³ air aeration oxidation tower 140a, and 2M ³ activation tower 130 can be installed to perform the oxidation step of the wastewater treatment method. In this embodiment, the air aeration and oxidation tower 140 a is provided between the catalyst aeration and oxidation tower 140 and the second filter 212.

In the initial state, the 5M ³ activated carbon catalyst and the initial activation liquid are placed in the catalyst aeration oxidation tower 140 in batches. The waste water with a COD of 500 ppm is introduced from the adjustment tank 120 through the pipeline 142 to the catalyst aeration oxidation tower 140. Add 50 ppm of hypochlorous acid to wastewater as a liquid oxidation promoter. In addition, air is introduced into the catalyst aeration oxidation tower 140, and the room temperature aeration treatment is performed for 10 to 30 minutes to perform the first oxidation reaction. The pipeline 132 is connected to the pipeline 141 for introducing the activated catalyst and wastewater from the activation tower 130 to the catalyst aeration oxidation tower 140 when the catalyst activation step of the wastewater treatment method is performed. The discharge pipe 143 is connected between the catalytic aeration and oxidation tower 140 and the air aeration and oxidation tower 140a, so that after the first oxidation reaction, the waste water is introduced to the air aeration and oxidation tower 140a, and air is introduced to treat the waste water. Secondary oxidation reaction. Subsequently, the waste water after the second oxidation reaction is discharged through the discharge pipe 143a, and after the second filter 212 is filtered with glass sand, the waste water without catalyst is discharged as the discharge water, and the catalyst obtained from the glass sand is discharged. The medium is introduced into the catalyst aeration oxidation tower 140 through the pipeline 144 to recover the catalyst.

In this embodiment, due to the secondary oxidation reaction, COD can be further reduced. In addition, since there is an empty aeration oxidation tower 140a after the catalyst aeration oxidation tower 140, the recovery of the catalyst is more efficient, and the loss of the catalyst can be further reduced, so the catalyst can be further reduced. the cost of.

The foregoing is a wastewater treatment system capable of treating industrial wastewater. Hereinafter, the wastewater treatment method according to an embodiment of the present invention will be described with respect to an embodiment during the experiment.

[Example 2]

Example 2 is: using a catalyst containing ruthenium, manganese, and activated carbon to perform oxidation and activation reaction steps on 250L of low-concentration wastewater in a continuous manner. The wastewater treatment method of this embodiment includes a catalyst activation step and an oxidation step. The catalyst activation step includes the following steps S21 and S22. The oxidation step includes S23, S24 and S25.

Step S21: Place 100L of activated carbon catalyst containing ruthenium, manganese and activated carbon in a 500L activation tank, and add 399L of low-concentration wastewater containing 500ppm of bleach, the COD of which is about 200ppm to adjust the PH value Between 7 and 9, add 1L of activation solution, add air, and then increase the temperature to 80°C for 120 minutes.

Step S22: After the reaction of step S21 is completed, cool to 40°C and let it stand for 30 minutes to form an upper layer and a lower layer. 30ml of the upper layer is sampled for COD analysis, and 250L of activated catalyst solution, or 50L of activated catalyst solution The catalyst is transferred to the 250L continuous oxidation tower.

Step S23: In the continuous oxidation tower, air is introduced for room temperature reaction, and low-concentration wastewater containing 50ppm hypochlorous acid is introduced, the COD concentration is about 200ppm, the flow rate is about 500L per hour, and sampling every two hours 30ml analysis COD concentration.

Step S24: Perform the reaction in a continuous 24-hour operation, and discharge 25L of catalyst liquid every day for activation reaction, and replenish 25L of activated catalyst liquid or 5L of activated catalyst.

Step S25: Repeat step S23 and step S24 for hundreds of days until the COD concentration in the wastewater sampled in step S23 exceeds 80 ppm or more. This situation indicates that the activated carbon catalyst is about to lose its activity (for example, 50% to 80% of its activity is lost) At this time, it is changed to release 50L of catalyst liquid every day for activation, and add 50L of activated catalyst liquid or 10L of activated catalyst.

[Example 3]

Example 3 is: using a catalyst containing ruthenium, manganese, and activated carbon to perform oxidation and activation reaction steps on 500 mL of low-concentration wastewater in a batch manner. The wastewater treatment method of this embodiment includes a catalyst activation step and an oxidation step. The catalyst activation step includes the following steps S31 and S32. Oxidation step Including S33, S34 and S35.

Step S31: Put 75ml of activated carbon catalyst containing ruthenium, manganese and activated carbon into a 500ml reactor, and then add 300ml of low-concentration wastewater containing 500ppm of bleach, the COD concentration of which is about 200ppm to adjust the PH value Between 7 and 9, and then add 3ml of activation solution, pass in air, and then increase the temperature to 80°C and react for 120 minutes.

Step S32: After the reaction of step S31 is completed, cool it to 40°C and let it stand for 30 minutes to form an upper layer liquid and a lower layer liquid, and then drain the upper layer liquid and sample 30 ml to analyze its COD concentration.

Step S33: Add 300ml of low-concentration waste water containing 50ppm hypochlorous acid to the obtained lower layer, and its COD is about 200ppm to adjust the PH value to around 5, and pass air in the reactor to react at room temperature for 30 minutes .

Step S34: After the reaction of step S33 is completed, let it stand for 30 minutes to form an upper layer liquid and a lower layer liquid, and then drain the upper layer liquid and sample 30 ml to analyze the COD concentration.

Step S35: Repeat Step S33 and Step S34 dozens of times until the COD of the upper layer liquid in Step S34 exceeds 80 ppm or more, and then perform an activation reaction of an activated carbon catalyst containing ruthenium, manganese, and activated carbon.

In the following, the actual industrial wastewater is used to illustrate the test treatment process. It uses hypochlorous acid and manganese ruthenium catalysts as catalyst catalysts to treat different industrial wastewaters. The industrial wastewater may be, for example, ammonia-nitrogen-containing discharge water, Tetramethylammonium Hydroxide (TMAH) wastewater, biochemical wastewater, and the like. In addition, the treatment system and method of this case will be evaluated for the removal effect of ammonia nitrogen, total nitrogen and COD in the water. The test flow chart is as follows. Figure 5 is a waste of another embodiment of the present invention Schematic diagram of water treatment system. As shown in FIG. 5, according to an embodiment of the present invention, the wastewater treatment system 100 includes an aeration tank 181, a sedimentation tank 182, a first filter 211, a first intermediate tank 161, and a catalyst aeration and oxidation tower 140. An activation tower 130, a second intermediate barrel 162, and a second filter 212.

Taking 1000 tons/day of industrial waste water as an example, the waste water is aerated in the aeration tank 181, settled in the sedimentation tank 182 to remove large garbage or particles, and then introduced into the first filter 211 after being filtered with glass sand, and then introduced to the first filter 211. A middle barrel 161. After the pretreatment, the waste water is introduced from the first intermediate tank 161 to the catalytic aeration oxidation tower 140 for oxidation reaction. The reacted waste water is discharged through the discharge pipe 143 and is filtered and treated with glass sand in the second filter 212. The waste water without catalyst is discharged as discharge water, and the catalyst obtained from the glass sand is introduced into the catalyst aeration oxidation tower 140 through the pipeline 144 to recover the catalyst.

In one embodiment, the catalyst aeration and oxidation tower 140 includes a small sedimentation tank, and the catalyst is precipitated in the small sedimentation tank in the form of a catalyst or a catalyst liquid. When the catalyst needs to be activated, the wastewater can be introduced from the first intermediate tank 161 to the activation tower 130, and the catalyst liquid can be introduced from the catalyst aeration and oxidation tower 140 to the activation tower 130. After air is introduced, the catalyst can be used for catalytic oxidation. The activation reaction of the medium. After the activated catalyst or catalyst liquid is introduced into the second intermediate tank 162, the activated catalyst or catalyst liquid is introduced to the catalyst aeration oxidation tower 140 when necessary.

According to this test, a catalyst catalyst with a waste water treatment capacity of 500 L/hr is used and placed in the catalyst aeration oxidation tower 140. Pre-treat waste water and collect the waste water in the first intermediate barrel 161, The waste water is transported to the catalyst aeration oxidation tower 140 by the transport pump, and hypochlorous acid is added for the reaction at the same time. After the end, the gravity flows into the sedimentation tank, so that the larger particle catalyst is precipitated, and then transported to the activation when necessary. The tower 130 is activated. In addition, the upper layer liquid is introduced into the second filter 212 by a transfer pump and filtered with an active sand tank, and the remaining catalyst suspended in the suspension is recovered into the catalyst aeration and oxidation tower 140. Below, the test results are recorded in Table 1 and Table 2 below.

Table II

According to an embodiment of the present invention, to treat wastewater with a COD of less than 500 ppm and 1,000 tons of wastewater per day as an example, a 25-ton catalyst aeration oxidation tower 140 and a 2.5-ton activation tower 130 are required, and the required catalyst catalyst is about 5 Tons, that can reduce COD from 500ppm to 200ppm. If the COD is to be reduced below 50 ppm, it is only necessary to double the volume of the catalytic aeration oxidation tower 140 and the activation tower 130. In addition, the activation tower 130 can be operated in batches. Raise the temperature from room temperature to 80°C, carry out the activation reaction for two hours, then lower the temperature to 40°C for crystallization for half an hour, and let it stand for ten minutes to complete the activation reaction.

In addition, according to another embodiment of the present invention, taking the treatment of wastewater with COD greater than 500 ppm or difficult-to-treat wastewater, such as dyeing and finishing wastewater or TMAH and other toxic wastewater, treating 1,000 tons of wastewater per day as an example, A 50-ton catalyst aeration oxidation tower 140 and a 5-ton activation tower 130 are needed. The catalyst catalyst required is about 10 tons, which can reduce COD from 1000 ppm to 200 ppm. If the COD is to be reduced below 50 ppm, it is only necessary to double the volume of the catalytic aeration oxidation tower 140 and the activation tower 130. In addition, the activation tower 130 can be operated continuously. From the bottom of the activation tower 130, the catalyst is transferred to the catalyst aeration and oxidation tower 140. The sedimentation tank of the catalyst aeration oxidation tower 140 is very small, and only needs to stay for ten minutes.

The present invention proposes a new low-cost method for manufacturing hypochlorous acid. The manufacturing method is as follows. The salt (sodium chloride, NaCl) and hydrochloric acid (HCl) are placed in the reaction chamber, and the aforementioned manganese ruthenium catalyst is added and reacted to produce hypochlorous acid. The reaction formulas are as follows.

Na O Cl +HC l ───→HO Cl + NaCl formula 1-2

According to the aforementioned method, hypochlorous acid can be manufactured with low cost. In addition, in one embodiment, a hypochlorous acid generator (not shown) can also be added to the aforementioned wastewater treatment system 100, and the hypochlorous acid generator can be connected to the catalyst aeration oxidation tower 140, if necessary Directly introduce the produced hypochlorous acid into the catalyst aeration oxidation tower 140. In one embodiment, the catalyst used in the method for producing hypochlorous acid is preferably the same as the catalyst used in the wastewater treatment system and method, so that the loss of the catalyst can be reduced.

In addition, the aforementioned wastewater treatment mainly describes the COD degradation method. When the wastewater contains high concentration of ammonia, the ammonia nitrogen can be removed in advance before the wastewater enters the adjustment tank 120 or the catalytic aeration oxidation tower 140. The treatment method is as follows.

Lead the wastewater into a magnesium ammonium monophosphate (MAP) sedimentation tank (not shown), add sodium hydroxide to adjust the pH to 9~10, and then press Mg ²⁺ ：NH ⁴⁺ ：PO ₄ ^3- =1~ 1.6:1: 1~1.6 Add magnesium salt (such as magnesium chloride, MgCl) and phosphate (MgHPO ₄ ), stir and react for 30 minutes, then let it settle for 1 to 1.5 hours, and the resulting precipitate is magnesium ammonium phosphate (MAP). The reaction formula is shown in the following formula 2-1. According to the aforementioned process, the ammonia nitrogen in wastewater can be reduced. In addition, magnesium ammonium phosphate is commonly known as struvite, which can be used as a fertilizer. It is only slightly soluble in water or in a wet soil environment, so its nutrient release rate is slower than other soluble fertilizers and can be used as slow-release fertilizers (SRFs). However, in this embodiment, the purity of the magnesium ammonium phosphate is relatively impure, contains impurities or heavy metals in industrial wastewater, and therefore cannot be reused. Therefore, additional treatment of the magnesium ammonium phosphate is required.

Mg ²⁺ +NH ₄ ⁺ +PO ₄ ^3- =MgNH ₄ PO ₄ ↓ Equation 2-1

According to an embodiment of the present invention, a brand-new regeneration method of magnesium ammonium phosphate is proposed. With this regeneration method, the magnesium ammonium phosphate can be purified to remove impurities or heavy metals. The regeneration method is as follows, and the reaction formula is as follows: 3-1 to 3-3. Put the prepared magnesium ammonium phosphate in a reactor, add NaOH, adjust the PH value to greater than 10, preferably greater than 11, increase the temperature to 70°C, preferably to 80°C, and carry out the reaction by blowing method (Formula 3-1 ), while collecting NH _{3 in the} gas phase. _{The Mg 3} (PO ₄ ) ₂ and Na ₃ PO ₄ obtained in the previous step are added to hydrochloric acid to react (Equation 3-2). _{The Mg 3} HPO ₄ obtained in Formula 3-2 is reacted with NH ₃ to regenerate magnesium ammonium phosphate (Formula 3-3). In one embodiment, preferably NH ₃ in Formula 3-3 to Formula 3-1 employed _an NH ₃ collected thus manufacturing cost can be reduced.

The so-called stripping method or stripping method is used to remove dissolved gases and certain volatile substances in water. That is to pass the gas (carrier gas) into the water to make them fully contact each other, so that the dissolved gas and volatile substances in the water pass through the gas-liquid interface and transfer to the gas phase, so as to achieve the purpose of removing pollutants. Air or water vapor is commonly used as carrier gas. The former is called stripping and the latter is called stripping.

Below, the equipment and processing cost required by an embodiment of the present invention are listed in Table 3 below. From the following Table 3, it can be known that the wastewater treatment system and method of an embodiment of the present invention can greatly reduce the wastewater treatment cost and treatment time due to the improved oxidation efficiency.

According to an embodiment of the present invention, the advanced oxidation method has advantages including at least one of the following.

1. The fast reaction speed takes about 0.5-2hr, which can effectively shorten the processing time. Compared with this, the conventional biological pond processing time takes about 24-48hr. Therefore, the reaction speed of an embodiment of the present invention is more than 10 times faster.

2. The equipment construction space occupies a small area, only 10 points 1 of the traditional manufacturing process, the cost is relatively cheap, and there is no civil construction problem.

3. No sludge output, no need to deal with secondary pollutants.

4. In addition to reducing COD, it can also decolorize and reduce ammonia nitrogen to below 1PPM.

5. The oxidation reaction is stable, easy to control, and there is no problem of excessive value.

In summary, according to the wastewater treatment method of an embodiment of the present invention, compared with the conventional biological pond treatment, the reaction speed is faster, and the construction space is small, and no sludge is generated. Compared to the conventional The wet oxidation treatment method does not need to be carried out under high pressure and high temperature, but can carry out wastewater treatment under normal pressure and temperature of 80°C. In one embodiment, in addition to reducing COD, it can also decolorize and reduce ammonia nitrogen to below 1 PPM.

100‧‧‧Processing system

120‧‧‧Adjusting barrel

130‧‧‧Revitalizing Tower

131‧‧‧Pipe

132‧‧‧Pipe

140‧‧‧Catalyst aeration and oxidation tower

141‧‧‧Pipe

142‧‧‧Pipe

143‧‧‧Exhaust pipe

144‧‧‧Pipe

211‧‧‧First filter

212‧‧‧Second filter

Claims (12)

A waste water treatment system, comprising: hypochlorous acid to promote oxidation reaction; most catalysts, including most activated carbon, most transition metals and most precious metals, wherein the precious metals are bonded to each other through the transition metals On the activated carbon; and an activation tower for activating the catalysts with an activation solution when the catalysts lose part of their activity; an aeration oxidation device connected to the activation tower, and The catalysts, the hypochlorous acid, the gas for oxidation, and a waste water are introduced, and the catalysts are used to oxidize the waste water with the oxidation gas, thereby reducing the COD concentration of the waste water. The wastewater treatment system according to claim 1 further includes: an adjustment barrel, wherein the adjustment barrel includes: a first inflow pipeline for flowing bleach water; a second inflow pipeline for flowing wastewater; A discharge pipe for discharging the adjusted waste water; and a body connected to the first inflow pipe, the second inflow pipe, and the discharge pipe for storing and processing the waste water to mix the bleaching water In the waste water, the aeration oxidation device is connected to the adjustment barrel, and the waste water is introduced from the adjustment barrel. The wastewater treatment system according to claim 2, wherein the aeration and oxidation equipment further includes a sedimentation tank for recovering the catalysts. The wastewater treatment system according to claim 1 or 2, wherein the aeration and oxidation equipment includes a catalyst aeration and oxidation tower, and the catalysts are provided in the catalyst aeration and oxidation tower. The wastewater treatment system according to claim 1 or 2, wherein: The aeration oxidation equipment includes an air aeration oxidation tower, and the catalysts are not pre-installed in the air aeration oxidation tower, and the catalysts are dispersed in the waste water and then introduced into the air aeration oxidation tower. The wastewater treatment system according to claim 4, wherein the aeration and oxidation equipment further includes an air aeration and oxidation tower, and the catalysts are not pre-installed in the air aeration and oxidation tower, and the catalysts are After being dispersed in the wastewater, it is introduced into the air aeration oxidation tower. The wastewater treatment system according to claim 1, wherein the precious metals are ruthenium, the transition metals are manganese, and the oxidation gas is air. The wastewater treatment system according to claim 1, wherein the activation liquid is a liquid containing ruthenium and a surfactant. A wastewater treatment method includes: providing a plurality of catalysts, wherein the catalysts include a plurality of activated carbon, a plurality of transition metals, and a plurality of noble metals, and the noble metals are bonded to the activated carbons via the transition metals On; provide hypochlorous acid; introduce the catalysts, the hypochlorous acid, the gas for oxidation, and a waste water into an aeration oxidation device, and use the catalysts to make the oxidizing gas The wastewater is oxidized to oxidize the COD of the wastewater; and when the catalysts lose part of their activity, the catalysts are introduced into an activation tower, and an activation solution is used to activate the catalysts. A method for manufacturing hypochlorous acid includes: placing salt and hydrochloric acid in a reaction chamber, and adding a plurality of catalysts to react, wherein the catalysts include most activated carbon, most transition metals and most precious metals, And that The precious metals are bonded to the activated carbon via the transition metals. A method for regenerating magnesium ammonium phosphate, comprising: placing magnesium ammonium phosphate in a reactor, adding NaOH, and reacting to obtain Mg ₃ (PO ₄ ) ₂ , Na ₃ PO ₄ and NH ₃ ; ₃ (PO ₄ ) ₂ and the Na ₃ PO ₄ are reacted with hydrochloric acid to obtain Mg ₃ HPO ₄ and NaCl; and Mg ₃ HPO _{4 is} reacted with NH ₃ to obtain regenerated magnesium ammonium phosphate. The method for regenerating magnesium ammonium phosphate according to claim 11, wherein the step of preparing Mg ₃ (PO ₄ ) ₂ , Na ₃ PO ₄ and NH ₃ is carried out according to the following formula 1, 3 MgNH ₄ PO ₄ ↓ +3 NaOH ───→ Mg ₃ ( PO ₄ ) ₂ ↓+Na ₃ PO ₄ +3H ₂ O +3 NH ₃ ↑ Formula 1; the step of preparing Mg3HPO4 and NaCl is carried out in the following formula 2, Mg ₃ ( PO ₄ ) ₂ ↓+Na ₃ PO ₄ +3 HCl ───→3 MgHPO ₄ +3 NaCl formula 2; and the step of preparing regenerated magnesium ammonium phosphate is carried out in the following formula 3, 3 MgHPO ₄ +3 NH ₃ ───→3 MgNH ₄ PO ₄ ↓ Formula 3.

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