CN114538575B - Electrochemical reduction device and method for high-nitrate nitrogen wastewater - Google Patents
Electrochemical reduction device and method for high-nitrate nitrogen wastewater Download PDFInfo
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
- C02F1/4676—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electroreduction
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- C02F2101/00—Nature of the contaminant
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- C02F2201/46—Apparatus for electrochemical processes
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- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
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- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
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- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
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- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Abstract
An electrochemical reduction device for high nitrate nitrogen wastewater, comprising: the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system; the cathode chamber and the anode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank; the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel; the reference electrode is fixed in the cathode chamber; the power supply system is respectively connected with the cathode and the platinum anode; the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber. The invention satisfies the requirement and stably obtains 1 by adjusting the reaction voltage and the running time: the ammonia nitrogen and nitrite nitrogen in the 1 are used as reaction substrates in the anaerobic ammonia oxidation process, so that the method has high flexibility and high catalytic efficiency, and has important significance for realizing the advanced denitrification of the anaerobic ammonia oxidation subsequently.
Description
Technical Field
The invention relates to the technical field of electrochemical reduction of nitrate nitrogen, in particular to an electrochemical reduction device and an electrochemical reduction method for high-nitrate nitrogen wastewater.
Background
When the nitrogen content of the water body exceeds an environmental threshold (TN is more than 0.2 mg/L), blue algae burst in a large amount, so that the water body is eutrophicated. The drinking water with high nitrate nitrogen threatens human health, and induces a plurality of diseases such as blue infant syndrome, infant hemorrhagic erythrosinesis, adult gastric cancer, methemoglobin and the like. Excessive nitrate nitrogen in the water body can also induce poisoning symptoms such as rapid breathing, middle wind and the like of livestock.
Biological nitrification/denitrification processes are most widely used as traditional denitrification techniques, wherein the nitrification is energy intensive, and the subsequent denitrification often requires an external organic carbon source to completely reduce the nitrate nitrogen. The removal of nitrate nitrogen requires a suitable carbon to nitrogen ratio (C/N) of 2.7 to 3. For low C/N ratio wastewater, the need for additional organic carbon addition results in a dramatic increase in cost.
The anaerobic ammonia oxidation denitrification technology is a novel energy-saving and consumption-reducing sewage biological treatment technology, and autotrophic denitrification is realized by oxidizing ammonia nitrogen by nitrite nitrogen. The denitrification technology based on anaerobic ammonia oxidation is paid attention to because of the advantages of no need of additional carbon source, low sludge yield, low energy consumption, low cost, high denitrification rate, no greenhouse gas emission and the like.
The electrochemical nitrogen reduction method is a nitrate nitrogen reduction method with high catalytic efficiency, strong flexibility and high selectivity, and uses electrons provided by a power supply (serving as a green reducing agent) to selectively reduce nitrate nitrogen into ammonia nitrogen, nitrite nitrogen, nitrogen and the like. Therefore, providing an electrochemical reduction device and method for high nitrate nitrogen wastewater is a technical problem to be solved urgently by those skilled in the art.
Disclosure of Invention
In view of the above, the present invention aims to provide an electrochemical reduction device and method for high nitrate nitrogen wastewater, which can stably obtain 1 by adjusting the reaction voltage and the operation time to meet the requirements: the ammonia nitrogen and nitrite nitrogen are used as reaction substrates in the anaerobic ammonia oxidation process, the method has high flexibility and high catalytic efficiency, and the direct current power supply is used for providing electrons (used as a green reducing agent) and is simple and easy to operate, so that the method has great significance for realizing the advanced denitrification of the anaerobic ammonia oxidation subsequently, and is more suitable for actual wastewater treatment.
The invention provides an electrochemical reduction device for high nitrate nitrogen wastewater, which comprises:
the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system;
the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank;
the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel;
the reference electrode is fixed in the cathode chamber;
the power supply system is respectively connected with the cathode and the platinum anode;
the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber.
Preferably, the reaction volume of the anode chamber is 300 mL-500 mL, the inner diameter is 60 mm-80 mm, and the effective height is 110 mm-150 mm; the reaction volume of the cathode chamber is 300-500 mL, the inner diameter is 60-80 mm, and the effective height is 110-150 mm.
Preferably, the proton exchange membrane is a Nafion 117 membrane;
the proton exchange membrane is arranged at the middle end of the anion-cation exchange tank and fixed by a fixing clamp, so that the tightness of the device is ensured.
Preferably, the cathode is a brass mesh deposited Cu cathode or a stainless steel mesh deposited Cu cathode;
the brass net is an H65 brass net with 50-150 meshes, the wire thickness is 0.1-0.15 mm, and the aperture is 0.1-0.2 mm;
the stainless steel net is a 304 stainless steel net with 50-150 meshes, the wire thickness is 0.1-0.15 mm, and the aperture is 0.1-0.2 mm.
Preferably, the deposited Cu cathode is between 0.4M and 0.6M CuSO 4 、pH<3, depositing for 20 to 40 minutes under the condition that the cathode potential is controlled to be-2V and 300 to 500rpm by an electrochemical workstation.
Preferably, the distance between the cathode and the platinum anode is 4.5 cm-5.5 cm.
Preferably, the power supply system is a direct current power supply, and the applicable voltage is 15V-25V.
The invention also provides a high nitrate nitrogen wastewater electrochemical reduction method, which adopts the high nitrate nitrogen wastewater electrochemical reduction device adopting the technical scheme, and comprises the following steps:
a) Placing the high nitrate nitrogen wastewater in a cathode chamber of a built-in rotor, and adding electrolyte into an anode chamber; washing the surface of the cathode with ethanol, drying with inert gas, weighing, fixing in a cathode chamber, and introducing inert gas for deoxidization; placing a platinum anode in the anode chamber, placing a reference electrode in the cathode chamber, and opening a magnetic stirrer;
b) Connecting the positive electrode of the power supply system with the anode of the platinum sheet, connecting the negative electrode of the power supply system with the cathode, and starting to operate after adjusting the reaction voltage; after the reaction is operated to a specific reduction ratio of nitrite nitrogen and ammonia nitrogen, terminating the reaction, and completing electrochemical reduction of the high-nitrate nitrogen wastewater; the specific reduction ratio is: NO (NO) 3 - -N/NH 4 + -N≈1。
Preferably, the water quality of the high nitrate nitrogen wastewater in the step a) is as follows: NO (NO) 3 - -n=100 mg/L to 500mg/L, conductivity 20mS/cm to 100mS/cm;
the conductivity of the electrolyte is 30 mS/cm-80 mS/cm;
the rotating speed of the magnetic stirrer is 200 rpm-600 rpm.
Preferably, the reaction voltage in step b) is 15V to 25V; the running time is 3.5-7 h.
The invention provides an electrochemical reduction device and method for high nitrate nitrogen wastewater; the device comprises: the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system; the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank; the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel; the reference electrode is fixed in the cathode chamber; the power supply system is respectively connected with the cathode and the platinum anode; the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber. According to the electrochemical reduction device and method for the high-nitrate nitrogen wastewater, provided by the invention, the reaction voltage and the running time are regulated to meet the requirements, and the stable acquisition of 1: the ammonia nitrogen and nitrite nitrogen are used as reaction substrates in the anaerobic ammonia oxidation process, the method has high flexibility and high catalytic efficiency, and the direct current power supply is used for providing electrons (used as a green reducing agent) and is simple and easy to operate, so that the method has great significance for realizing the advanced denitrification of the anaerobic ammonia oxidation subsequently, and is more suitable for actual wastewater treatment.
Drawings
Fig. 1 is a schematic structural diagram of an electrochemical reduction device for high nitrate nitrogen wastewater provided in embodiment 1 of the present invention.
Detailed Description
The technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention provides an electrochemical reduction device for high nitrate nitrogen wastewater, which comprises:
the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system;
the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank;
the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel;
the reference electrode is fixed in the cathode chamber;
the power supply system is respectively connected with the cathode and the platinum anode;
the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber.
In the invention, the electrochemical reduction device for the high nitrate nitrogen wastewater comprises: the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system.
In the invention, the anode chamber and the cathode chamber are connected through the anion-cation exchange tank, and an H-shaped electrolytic cell is integrally formed and is the main body structure of the high-nitrate nitrogen wastewater electrochemical reduction device; the cathode chamber is internally provided with a columnar cavity, one side below the cavity is connected with an anion-cation exchange tank, the top end of the cavity is provided with a sealing cover, and the sealing cover is provided with two air ports and two electrode ports; the inside of the anode chamber is a columnar cavity, one side below the cavity is connected with an anion-cation exchange tank, the top end of the cavity is provided with a sealing cover, and the sealing cover is provided with two air ports and an electrode port; the inside of the anion-cation exchange tank is a columnar cavity, the middle is separated by a proton exchange membrane, and the tightness of the device is ensured by a fixing clamp. In the present invention, the reaction volume of the anode chamber is preferably 300 mL-500 mL, more preferably 400mL, the inner diameter is preferably 60 mm-80 mm, more preferably 70mm, the effective height is preferably 110 mm-150 mm, more preferably 130mm; the reaction volume of the cathode chamber is preferably 300 mL-500 mL, more preferably 400mL, the inner diameter is preferably 60 mm-80 mm, more preferably 70mm, and the effective height is preferably 110 mm-150 mm, more preferably 130mm.
In the invention, the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank. In the present invention, the proton exchange membrane is preferably a Nafion 117 membrane; commercially available products known to those skilled in the art may be used. In the invention, the proton exchange membrane is preferably arranged at the middle end of the anion-cation exchange tank and is fixed by a fixing clamp, so that the tightness of the device is ensured.
In the present invention, the cathode is fixed in the cathode chamber, preferably by an electrode clip; the platinum anode is fixed in the anode chamber, preferably by an electrode clamp; the electrode clamps are preferably platinum electrode junctions; the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel; it is seen that the cathode and the platinum anode approach the proton exchange membrane from both sides of the proton exchange membrane, respectively. In the present invention, the distance between the cathode and the platinum anode is preferably 4.5cm to 5.5cm.
In the present invention, the cathode is preferably a brass mesh deposited Cu cathode or a stainless steel mesh deposited Cu cathode, more preferably a brass mesh deposited Cu cathode. In the invention, the brass net is preferably a 50-150 mesh H65 brass net, more preferably a 100 mesh H65 brass net, the wire thickness is preferably 0.1-0.15 mm, the aperture is preferably 0.1-0.2 mm, more preferably 0.15mm; the stainless steel mesh is preferably a 304 stainless steel mesh of 50-150 meshes, more preferably a 304 stainless steel mesh of 100 meshes, the wire thickness is preferably 0.1-0.15 mm, and the aperture is preferably 0.1-0.2 mm, more preferably 0.15mm.
In the present invention, the deposited Cu cathode is preferably between 0.4M and 0.6M CuSO 4 、pH<3, and depositing for 20min to 40min in an electro-deposition solution under the condition that the cathode potential is controlled to be-2V, 300rpm to 500rpm by an electrochemical workstation, and more preferably 0.5M CuSO 4 、pH<2, and depositing the mixture in the electro-deposition solution for 30min under the condition that the cathode potential is controlled to be-2V and 400rpm by an electrochemical workstation. In the preferred embodiment of the invention, a pretreated brass or stainless steel mesh is fixed by a platinum electrode clamp, and is electrodeposited with a platinum sheet electrode and a reference electrode in a 500mL single-chamber electrochemical cell to obtain a deposited Cu cathode.
In the present invention, the reference electrode is fixed to the cathode chamber, and the present invention is not particularly limited thereto.
In the present invention, the power supply system is connected to the cathode and the platinum anode, respectively, preferably by electrode clamps.
In the present invention, the power supply system is preferably a dc power supply, such as a dc capacitor of model VC3003 (30V/5A single-pass), which is well known to those skilled in the art, and the applicable voltage is preferably 15V to 25V.
In the invention, the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom outside a cathode chamber, and the rotor is arranged at the bottom inside the cathode chamber.
The electrochemical reduction device for the high-nitrate nitrogen wastewater is suitable for treating the high-nitrate nitrogen wastewater, and has the characteristics of stable accumulation of ammonia nitrogen and nitrite nitrogen, saving of additional carbon sources and easy flexible regulation and control.
The invention also provides a high nitrate nitrogen wastewater electrochemical reduction method, which adopts the high nitrate nitrogen wastewater electrochemical reduction device adopting the technical scheme, and comprises the following steps:
a) Placing the high nitrate nitrogen wastewater in a cathode chamber of a built-in rotor, and adding electrolyte into an anode chamber; washing the surface of the cathode with ethanol, drying with inert gas, weighing, fixing in a cathode chamber, and introducing inert gas for deoxidization; placing a platinum anode in the anode chamber, placing a reference electrode in the cathode chamber, and opening a magnetic stirrer;
b) Connecting the positive electrode of the power supply system with the anode of the platinum sheet, connecting the negative electrode of the power supply system with the cathode, and starting to operate after adjusting the reaction voltage; after the reaction is operated to a specific reduction ratio of nitrite nitrogen and ammonia nitrogen, terminating the reaction, and completing electrochemical reduction of the high-nitrate nitrogen wastewater; the specific reduction ratio is: NO (NO) 3 - -N/NH 4 + -N≈1。
According to the electrochemical reduction device for the high-nitrate nitrogen wastewater, which is disclosed by the technical scheme, firstly, the high-nitrate nitrogen wastewater is placed in a cathode chamber of a built-in rotor, and electrolyte is added into an anode chamber; washing the surface of the cathode with ethanol, drying with inert gas, weighing, fixing in a cathode chamber, and introducing inert gas for deoxidization; the anode chamber is filled with platinum anode, the cathode chamber is filled with reference electrode, and the magnetic stirrer is turned on.
In the invention, the water quality of the high nitrate nitrogen wastewater is preferably: NO (NO) 3 - -n=100 mg/L to 500mg/L, more preferably: NO (NO) 3 - -n=300 mg/L; the conductivity of the high nitrate nitrogen wastewater is preferably 20mS/cm to 100mS/cm, more preferably 50mS/cm to 70mS/cm.
In the present invention, the conductivity of the electrolyte is preferably 30mS/cm to 80mS/cm, more preferably 50mS/cm to 60mS/cm, and an aqueous potassium sulfate solution well known to those skilled in the art may be used.
In the invention, the process of placing the high nitrate nitrogen wastewater in a cathode chamber of a built-in rotor and adding electrolyte in an anode chamber is preferably realized by a pump outside the device; in addition, after the reaction is terminated, the cathode chamber effluent is also pumped by the pump, and the invention is not particularly limited thereto.
In the present invention, the rotational speed of turning on the magnetic stirrer is preferably 200rpm to 600rpm, more preferably 400rpm.
Then, the anode of the power supply system is connected with the anode of the platinum sheet, the cathode of the power supply system is connected with the cathode, and the operation is started after the reaction voltage is regulated; and after the reaction is operated to a specific reduction ratio of nitrite nitrogen and ammonia nitrogen, terminating the reaction, and completing the electrochemical reduction of the high-nitrate nitrogen wastewater.
In the present invention, the reaction voltage is preferably 15V to 25V; the running time is preferably 3.5 to 7 hours.
In the present invention, the specific reduction ratio is: NO (NO) 3 - -N/NH 4 + -N≈1。
The electrochemical specific reduction method for the high-nitrate nitrogen wastewater provided by the invention has the advantages of high reaction rate, high treatment efficiency and large reaction scale, and is more suitable for wastewater treatment; the areas of the cathode electrode plate and the anode electrode plate are increased, so that the activation point positions are increased; the cathode is modified simply, the specific surface area is enlarged, the electron transfer rate is accelerated, the electrode surface reduction reaction is promoted, the cathode deposition material can effectively control the required product, and the nitrite nitrogen and ammonia nitrogen with the required proportion can be obtained by simply adjusting the voltage and the reaction time; the direct current power supply control is more convenient to be applied to wastewater treatment, and is simple and easy to regulate and control.
The invention provides an electrochemical reduction device and method for high-nitrate nitrogen wastewater, which are used for solving the problems that the high-nitrate nitrogen wastewater is difficult to stably reach the standard in the current stage and the bottleneck problem that the anaerobic ammonia oxidation is difficult to stably obtain the 1:1 ratio of ammonia nitrogen to nitrite nitrogen; the device comprises: the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system; the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank; the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel; the reference electrode is fixed in the cathode chamber; the power supply system is respectively connected with the cathode and the platinum anode; the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber. According to the electrochemical reduction device and method for the high-nitrate nitrogen wastewater, provided by the invention, the reaction voltage and the running time are regulated to meet the requirements, and the stable acquisition of 1: the ammonia nitrogen and nitrite nitrogen are used as reaction substrates in the anaerobic ammonia oxidation process, the method has high flexibility and high catalytic efficiency, and the direct current power supply is used for providing electrons (used as a green reducing agent) and is simple and easy to operate, so that the method has great significance for realizing the advanced denitrification of the anaerobic ammonia oxidation subsequently, and is more suitable for actual wastewater treatment.
In order to further illustrate the present invention, the following examples are provided.
Example 1
The schematic structural diagram of the electrochemical reduction device for high nitrate nitrogen wastewater provided by the embodiment 1 of the invention is shown in fig. 1, wherein 1 is an anode chamber, 2 is a cathode chamber, 3 is an anion-cation exchange tank, 4 is a proton exchange membrane, 5 is a brass mesh (or stainless steel mesh) deposited Cu cathode, 6 is a platinum sheet anode, 7 is a reference electrode, 8 is a direct current power supply, and 9 is a stirring system.
The working process of the electrochemical reduction device for the high-nitrate nitrogen wastewater is as follows:
the method comprises the steps that a double-chamber H-type electrolytic cell with the effective volume of an anode chamber 1 and a cathode chamber 2 of 400mL is adopted, and the middle of a cation exchange tank 3 is separated by a proton exchange membrane 4 and fixed by a fixing clamp; depositing Cu by using a brass mesh (or a stainless steel mesh) with the thickness of 4cm multiplied by 6cm as a cathode 5, using a platinum sheet with the thickness of 2.5cm multiplied by 2.5cm as an anode 6, and using a saturated calomel electrode (model-232) as a reference electrode 7; the platinum electrode clamp for fixing the cathode plate is used for connecting an external circuit; a direct current power supply 8 with an external voltage of 15V-25V; the cathode chamber houses a rotor which is placed on a magnetic stirrer 9.
The potassium nitrate solution was used to simulate high nitrate nitrogen wastewater (2.166 g/L potassium nitrate, 43.565g/L potassium sulfate) as feed water.
A100 mesh H65 brass mesh (4 cm. Times.6 cm) was used as a substrate at 0.5M CuSO 4 、pH<2. In 500mL of electrodeposited liquid, applying-2V voltage by an electrochemical workstation and depositing for 30 minutes at 400 rpm; the material was weighted from the initial 1.1569g to 2.5079g.
400mL of electrolysis was introduced into the cathode chamberLiquid (300 mg/L NO) 3 - -N、0.25M K 2 SO 4 ) 400mL of electrolyte (0.25. 0.25M K) was introduced into the anode chamber 2 SO 4 ) The conductivity is about 55mS/cm; under the conditions of 15V of external voltage of direct current power supply and 400rpm of rotating speed, the current is 0.157A and the current density is 6.54mA/cm 2 。
Taking a water sample every half hour, and testing the nitrogen conversion condition; when the reaction is carried out for the 2h, a small amount of ammonia nitrogen begins to appear in the water sample, and the nitrite nitrogen reaches 140mg/L; along with the increase of the reaction time, the nitrite nitrogen is still rapidly increased, the ammonia nitrogen concentration is slowly increased, and the nitrite nitrogen concentration reaches the peak value of 190mg/L at the time of 4.5 hours, and the ammonia nitrogen is increased to 70mg/L at the moment; then the nitrate nitrogen and nitrite nitrogen concentration are synchronously reduced, and the concentration ratio of ammonia nitrogen to nitrite nitrogen reaches about 1 in 7 hours: 1, both about 130mg/L, the residual nitrate nitrogen concentration is about 40mg/L.
Example 2
The working procedure provided in example 1 was followed using the high nitrate nitrogen wastewater electrochemical reduction apparatus provided in example 1, except that: under the condition that the external voltage of the direct current power supply is increased to 25V and the rotating speed is 400rpm, the current is 0.282A, and the current density is 11.75mA/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the When the reaction occurs to the 1 st hour, a small amount of ammonia nitrogen begins to appear in the water sample, and nitrite nitrogen is accumulated to 100mg/L at the moment; then at 2.5h, the nitrite nitrogen concentration reaches a peak value of 175mg/L, and the ammonia nitrogen concentration reaches 82mg/L; along with the synchronous reduction of the nitrate nitrogen and the nitrite nitrogen, the ammonia nitrogen and the nitrite nitrogen reach the same concentration at 3.5h, both are about 130mg/L, and the residual nitrate nitrogen concentration is about 40mg/L.
Example 3
The working procedure provided in example 1 was followed using the high nitrate nitrogen wastewater electrochemical reduction apparatus provided in example 1, except that: 100 mesh H65 brass mesh (4 cm. Times.6 cm) substrate was replaced with 100 mesh 304 stainless steel mesh (4 cm. Times.6 cm) substrate at 0.5M CuSO 4 、pH<2, applying-2V voltage by an electrochemical workstation and depositing for 30 minutes at 400 rpm; the material was weighted from the initial 1.1231g to 2.4653g. Strip with 25V applied voltage and 400rpm rotation speed on DC power supplyUnder the element, the current was 0.281A, and the current density was 11.71mA/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the The phenomenon of slow accumulation of ammonia nitrogen still occurs after the reaction is carried out for 1h, and the concentration of nitrite nitrogen is 105mg/L; after 2 hours, the nitrite nitrogen content begins to drop, at this time, the nitrite nitrogen concentration is 150mg/L, and the ammonia nitrogen concentration reaches 60mg/L; at 3.5h, the ammonia nitrogen concentration had exceeded 150mg/L of nitrite nitrogen, which was 100mg/L, with the remainder of nitrite nitrogen being approximately 50mg/L.
Experimental results show that the required reaction time is between 3 and 3.5 hours, which is the shortest, in the experimental example 3, but compared with the experimental example 2, the residual concentration of nitrate nitrogen in the reaction system using the cathode material with the stainless steel mesh as the substrate is slightly higher than that in the reaction system using the cathode material with the brass mesh as the substrate; the stainless steel net has better selectivity to ammonia nitrogen due to the fact that the stainless steel net mainly contains substances such as iron and nickel, and the phenomenon is characterized by high ammonia nitrogen accumulation rate; the stability of the two substrate materials is relatively consistent, and the uniformity and the deposition amount of Cu on the electrodeposition under the same condition are relatively consistent; the conductivity of the two materials is relatively consistent, and the current density can reach 11mA/cm under the voltage of 25V below zero 2 The above.
In summary, the reaction voltage and reaction time can be adjusted according to the ratio of the required products to promote the conversion of nitrate nitrogen into ammonia nitrogen and nitrite, and the concentration ratio is close to 1, and the reaction conditions in example 2 more satisfy the requirements.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (5)
1. The electrochemical reduction method for the high-nitrate nitrogen wastewater is characterized by adopting an electrochemical reduction device for the high-nitrate nitrogen wastewater, and comprises the following steps of:
a) Placing the high nitrate nitrogen wastewater in a cathode chamber of a built-in rotor, and adding electrolyte into an anode chamber; washing the surface of the cathode with ethanol, drying with inert gas, weighing, fixing in a cathode chamber, and introducing inert gas for deoxidization; placing a platinum anode in the anode chamber, placing a reference electrode in the cathode chamber, and opening a magnetic stirrer; the water quality of the high nitrate nitrogen wastewater is as follows: NO (NO) 3 - -n=100 mg/L to 500mg/L, conductivity 20mS/cm to 100mS/cm;
the conductivity of the electrolyte is 30 mS/cm-80 mS/cm;
the rotating speed of the magnetic stirrer is 200 rpm-600 rpm;
b) Connecting the positive electrode of the power supply system with the anode of the platinum sheet, connecting the negative electrode of the power supply system with the cathode, and starting to operate after adjusting the reaction voltage; after the reaction is operated to a specific reduction ratio of nitrite nitrogen and ammonia nitrogen, terminating the reaction, and completing electrochemical reduction of the high-nitrate nitrogen wastewater; the specific reduction ratio is: NO (NO) 3 - -N/NH 4 + -n≡1; the reaction voltage is 15V-25V; the running time is 3.5-7 hours;
the electrochemical reduction device for the high nitrate nitrogen wastewater comprises:
the device comprises an anode chamber, a cathode chamber, an anion-cation exchange tank, a proton exchange membrane, a cathode, a platinum anode, a reference electrode, a power supply system and a stirring system;
the anode chamber and the cathode chamber are connected through an anion-cation exchange tank and are separated by a proton exchange membrane fixed in the middle of the anion-cation exchange tank;
the cathode is fixed in the cathode chamber, the platinum anode is fixed in the anode chamber, and the cathode and the platinum anode are arranged on two sides of the proton exchange membrane in parallel;
the reference electrode is fixed in the cathode chamber;
the power supply system is respectively connected with the cathode and the platinum anode;
the stirring system comprises a magnetic stirrer and a rotor, wherein the magnetic stirrer is arranged at the bottom of the outside of the cathode chamber, and the rotor is arranged at the bottom of the inside of the cathode chamber;
the cathode is a stainless steel mesh deposited Cu cathode;
the stainless steel mesh is a 304 stainless steel mesh with 50-150 meshes, the wire thickness is 0.1-0.15 mm, and the aperture is 0.1-0.2 mm;
the deposition Cu cathode is formed by 0.4M-0.6M CuSO 4 、pH<3, depositing for 20-40 min in the electro-deposition solution under the condition that the cathode potential is controlled to be-2V and 300-500 rpm by an electrochemical workstation.
2. The electrochemical reduction method for the high-nitrate nitrogen wastewater according to claim 1, wherein the reaction volume of the anode chamber is 300-500 mL, the inner diameter is 60-80 mm, and the effective height is 110-150 mm; the reaction volume of the cathode chamber is 300-500 mL, the inner diameter is 60-80 mm, and the effective height is 110-150 mm.
3. The electrochemical reduction method of high nitrate nitrogen wastewater according to claim 1, wherein the proton exchange membrane is a Nafion 117 membrane;
the proton exchange membrane is arranged at the middle end of the anion-cation exchange tank and fixed by a fixing clamp, so that the tightness of the device is ensured.
4. The electrochemical reduction method of high nitrate nitrogen wastewater according to claim 1, wherein the distance between the cathode and the platinum anode is 4.5 cm-5.5 cm.
5. The electrochemical reduction method of high nitrate nitrogen wastewater according to claim 1, wherein the power supply system is a direct current power supply, and the applicable voltage is 15-25 v.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107180987A (en) * | 2017-05-13 | 2017-09-19 | 华南理工大学 | Couple the negative electrode efficient denitrification type microbiological fuel cell of Anammox technology |
| CN110436583A (en) * | 2019-08-27 | 2019-11-12 | 辽宁拓启环保科技有限公司 | A kind of depth removes the electrochemical appliance and its application method of nitrate in water removal |
| CN111360279A (en) * | 2020-03-22 | 2020-07-03 | 华南理工大学 | Preparation method and application of monoatomic copper material |
| CN111392822A (en) * | 2020-04-13 | 2020-07-10 | 上海交通大学 | Method for reducing nitrate nitrogen into ammonia nitrogen |
| CN112779557A (en) * | 2019-11-07 | 2021-05-11 | 韩国科学技术研究院 | Method for modifying electrode for electrochemical reaction |
-
2022
- 2022-02-18 CN CN202210151874.1A patent/CN114538575B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107180987A (en) * | 2017-05-13 | 2017-09-19 | 华南理工大学 | Couple the negative electrode efficient denitrification type microbiological fuel cell of Anammox technology |
| CN110436583A (en) * | 2019-08-27 | 2019-11-12 | 辽宁拓启环保科技有限公司 | A kind of depth removes the electrochemical appliance and its application method of nitrate in water removal |
| CN112779557A (en) * | 2019-11-07 | 2021-05-11 | 韩国科学技术研究院 | Method for modifying electrode for electrochemical reaction |
| CN111360279A (en) * | 2020-03-22 | 2020-07-03 | 华南理工大学 | Preparation method and application of monoatomic copper material |
| CN111392822A (en) * | 2020-04-13 | 2020-07-10 | 上海交通大学 | Method for reducing nitrate nitrogen into ammonia nitrogen |
Non-Patent Citations (1)
| Title |
|---|
| Nitrate Reduction at Electrodeposited Copper on Copper Cathode;Rajmohan K.S.等;《ECS Transactions》;20141231;第59卷(第1期);第397-497页 * |
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