CN106957092A - A kind of method that three-dimensional pulse electrolysis removes ammonia nitrogen - Google Patents

Abstract

The invention discloses a three-dimensional pulse electrolytic method for removing ammonia nitrogen, which is characterized in that it includes several sets of processing systems. A single treatment system includes: power supply, cathode and anode plates, particle electrodes, electrolyzer, constant current circulation pump and circulation water container. The electrolyzer, the constant-current circulating pump and the circulating water container are connected through relevant pipelines to form a closed loop. Several groups of cathode and anode plates are arranged inside the electrolytic cell. The anode plate of the cathode and anode plates is meshed titanium plated with ruthenium and iridium, and the cathode plate is meshed stainless steel. Both ends of the cathode and anode plates are respectively connected to the cathode and anode of the power supply. The power supply is a digitally controlled double-pulse electroplating power supply. Both sides of the cathode and anode plates are filled with particle electrodes. The electric energy is provided by the double-pulse electroplating power supply. Compared with the traditional DC power supply, it can reduce the concentration polarization caused by the difference between the ion concentration of the electrode interface layer solution and the bulk solution concentration, which causes the electrode potential to deviate from the equilibrium potential, and reduce it by 30% to 60%. % unit energy consumption.

Description

A method for three-dimensional pulse electrolytic removal of ammonia nitrogen

technical field

The invention relates to the field of wastewater treatment, in particular to a three-dimensional pulse electrolytic method for removing ammonia nitrogen.

Background technique

With the development of industry, agriculture, and animal husbandry, a large amount of untreated ammonia nitrogen wastewater is discharged into the environment indiscriminately, and the discharge is increasing year by year. The rapid growth and reproduction of plants leads to the production of organic matter in the water body faster than the speed of water consumption, resulting in eutrophication of the water body, destroying the ecological balance of the water body, further deteriorating the water quality, causing a large number of aquatic organisms to die, and even causing the lake to degrade or even disappear. On the other hand, ammonia nitrogen decomposes to produce nitrate and nitrite through the nitrification of nitrifying bacteria in the water body. Human beings drink drinking water containing nitrite for a long time, and there will be symptoms of hypoxia, and in severe cases, it will cause cancer and other hazards. . Therefore, the treatment of ammonia nitrogen in water has become an urgent problem for scientists today.

At present, the methods for treating ammonia nitrogen wastewater mainly include degassing method, ion exchange method, biological method, chemical precipitation method, break point chlorination method and so on. The degassing and degassing method is only suitable for the treatment of wastewater containing high concentration of ammonia nitrogen, and it is difficult to reach the standard, which is easy to cause air pollution; the adsorption capacity of the adsorbent in the ion exchange method is small, and it is not suitable for the treatment of wastewater with high salt content; biological method Not only does the reactor occupy a large area, but it also needs to provide additional organic matter as a carbon source for microorganisms, and the reaction cycle is longer; the price of ammonium magnesium phosphate precipitant in the chemical precipitation method is relatively high, and its economic benefit is not high when used for the removal of ammonia nitrogen ; Breakpoint chlorination requires a large amount of chlorine and high cost, and the formed chloramines and chlorinated organics are easy to pollute the environment, and the breakpoint in the operation is not easy to grasp.

In recent years, the electrochemical oxidation method has been widely used in various ammonia nitrogen wastewater treatment fields due to its unique advantages such as small equipment footprint, simple operation, and strong controllability. However, in the existing electrochemical research, the electrolyte system with high chloride ion concentration is generally used, and a large amount of "active chlorine species" is derived through the chlorine analysis of the anode to oxidize ammonia nitrogen. This system often produces excessive residual chlorine. Secondary pollution, and the corrosion of mechanical equipment by the high chloride ion system is also quite serious, which will greatly reduce the service life of equipment and plates in the factory.

Therefore, it is particularly important and urgent to reduce the added concentration of chloride ions in the treatment of ammonia nitrogen wastewater.

Contents of the invention

The purpose of the present invention is to solve the problem of corrosion of mechanical equipment caused by the use of a high chloride ion concentration system to remove ammonia nitrogen in wastewater in the prior art, and to reduce the energy consumption of ammonia nitrogen treatment by electrochemical oxidation.

The technical solution adopted to realize the object of the present invention is as follows, a method for removing ammonia nitrogen by three-dimensional pulse electrolysis, which is characterized in that it includes several groups of treatment systems. A single treatment system includes: power supply, cathode and anode plates, particle electrodes, electrolyzer, constant current circulation pump and circulation water container.

The electrolyzer, the constant-current circulating pump and the circulating water container are connected through relevant pipelines to form a closed loop. The constant current circulation pump is connected with the water inlet end of the electrolytic cell. The circulating water container is connected with the water outlet of the electrolytic cell.

Several groups of cathode and anode plates are arranged inside the electrolytic cell. The cathode and anode plates are perpendicular to the water inlet direction and the water outlet direction of the electrolytic cell. The anode plate of the cathode and anode plates is meshed titanium plated with ruthenium and iridium, and the cathode plate is meshed stainless steel. The distance between adjacent cathode and anode plates is 2-5 mm.

Both ends of the cathode and anode plates are respectively connected to the cathode and anode of the power supply.

The power supply is a numerical control double pulse electroplating power supply.

Both sides of the cathode and anode plates are filled with particle electrodes.

Use the above system for the following steps:

1) adding chlorine salt in ammonia nitrogen wastewater;

The concentration of chloride ion in the chlorine salt is 20～140mg/L;

2) Send the ammonia nitrogen waste water in the circulating water container into the electrolytic cell continuously through the constant current circulating pump;

The flow range of the constant flow circulating pump is 200-1000mL/h;

3) Start the power supply to load pulse current; carry out electrolysis in the electrolyzer;

The pulse frequency provided by the power supply is 5-5000HZ, and the duty cycle is 1-100%;

The current density of the cathode and anode plates is 50-150 mA/cm ² .

Further, the particle electrode includes coconut shell activated carbon, natural clinoptilolite and biological ceramsite; the particle diameter of the coconut shell activated carbon is 2-10mm, the particle diameter of the natural clinoptilolite is 2-10mm, and the living The particle size of ceramsite is 2-10mm.

Further, the pore diameter of the titanium ruthenium-coated iridium stencil is 2-10 mm; the pore diameter of the stainless steel stencil is 2-10 mm.

Technical effect of the present invention is beyond doubt, and the present invention has the following advantages:

1) The present invention adopts the numerical control double-pulse electroplating power supply to provide electric energy. Compared with the traditional DC power supply, it can reduce the concentration difference caused by the difference between the ion concentration of the electrode interface layer solution and the bulk solution concentration in the electrolytic cell, which causes the electrode potential to deviate from the equilibrium potential. and reduce the unit energy consumption by 30% to 60%;

2) The present invention adopts a plurality of sets of pole plates placed at intervals of 2-5 mm, the anode is a net-shaped titanium plate with ruthenium and iridium, and the cathode is a net-shaped stainless steel pole plate. The waste water flow in the electrolytic cell is in contact with the front of the mesh plate and flows vertically, which improves the mass transfer intensity of pollutants;

3) The present invention uses coconut shell activated carbon, biological ceramsite and other particle electrode materials as the refolding electrode. Compared with most three-dimensional electrode researches that only use natural zeolite, the raw material has wide sources, low price and high economic benefit.

4) the present invention adopts the electrochemical method of low chloride ion concentration system, compares with traditional electrochemical method adopting high chloride ion concentration system, has the effect of reducing the corrosion of pole plate and equipment, prolongs the service life of equipment and pole plate, realizes simultaneously High efficiency removal of ammonia nitrogen.

Description of drawings

Figure 1 is a schematic diagram of the device structure of a single three-dimensional pulse electrolytic removal of ammonia nitrogen.

In the figure: power supply 1, cathode and anode plates 2, particle electrodes 3, electrolytic tank 4, constant current circulation pump 5 and circulation water container 6.

detailed description

The present invention will be further described below in conjunction with the examples, but it should not be understood that the scope of the subject of the present invention is limited to the following examples. Without departing from the above-mentioned technical ideas of the present invention, various replacements and changes made according to common technical knowledge and conventional means in this field shall be included in the protection scope of the present invention.

Example 1:

A method for removing ammonia nitrogen by three-dimensional pulse electrolysis is characterized in that it includes several sets of processing systems.

A single processing system as shown in FIG. 1 includes: a power source 1 , cathode and anode plates 2 , particle electrodes 3 , electrolytic tank 4 , constant current circulation pump 5 and circulation water container 6 .

The electrolytic cell 4, the constant-current circulating pump 5 and the circulating water container 6 are connected through relevant pipelines to form a closed loop. The constant current circulation pump 5 is connected to the water inlet end of the electrolytic cell 4 . The circulating water container 6 is connected with the water outlet of the electrolytic cell 4 .

Several groups of cathode and anode plates 2 are arranged inside the electrolytic cell 4 . The cathode and anode plates 2 are perpendicular to the water inlet direction and the water outlet direction of the electrolytic cell 4 . The anode plate of the cathode and anode plates 2 is mesh-shaped titanium plated with ruthenium iridium, and the cathode plate is mesh-shaped stainless steel. The distance between adjacent cathode and anode plates 2 is 2-5 mm.

Both ends of the cathode and anode plates 2 are respectively connected to the cathode and anode of the power supply 1 .

The power supply 1 is a digitally controlled double-pulse electroplating power supply.

Both sides of the anode and cathode plates 2 are filled with particle electrodes 3 .

Example 2:

A method for three-dimensional pulse electrolytic removal of ammonia nitrogen, characterized in that, using the system in Example 1, the following steps are carried out:

1) Configure simulated ammonia nitrogen wastewater: the concentration range of ammonium sulfate is 318.6g/L, the concentration range of sodium sulfate is 10g/L, and the concentration range of sodium chloride is 125mg/L;

2) The distance between the plates in the electrolytic cell 4 is 5mm, the total filling capacity of coconut shell activated carbon is 130g, the current density is 109.65mA/cm ² , the flow rate of the constant current pump is in the range of 500-1000mL/h, and the simulation in measurement step 1) 650mL of water was prepared, pulsed current electrolysis was applied for 300 minutes, and the removal rate of ammonia nitrogen in the simulated distribution water reached 78.11%;

The anode plate is reticulated titanium plated ruthenium iridium (size: 57mm*76mm*1mm), and the cathode plate is reticulated stainless steel (size: 57mm*76mm*1mm); the pulse frequency in the pulse current is 5000HZ, accounting for The empty ratio is 50%.

In this embodiment, the electric energy is provided by the double-pulse electroplating power supply. Compared with the traditional DC power supply, it can reduce the ion concentration of the electrode interface layer solution in the electrolytic cell 4 and the concentration of the bulk solution, which causes the electrode potential to deviate from the equilibrium potential. Poor polarization and lower unit energy consumption. In this embodiment, the concentration of sodium chloride added is low, which reduces the corrosion effect on the plates and devices, and at the same time achieves the purpose of removing ammonia nitrogen.

Example 3:

A method for three-dimensional pulse electrolytic removal of ammonia nitrogen, characterized in that, using the system in Example 1, the following steps are carried out:

1) Configure simulated ammonia nitrogen wastewater: the concentration range of ammonium sulfate is 318.6g/L, the concentration range of sodium sulfate is 10g/L, and the concentration range of sodium chloride is 155mg/L;

2) The distance between the plates in the electrolytic cell 4 is 5mm, the total filling capacity of coconut shell activated carbon is 130g, the current density is 109.65mA/cm ² , the flow rate of the constant current pump is in the range of 500-1000mL/h, and the simulation in measurement step 1) With 650mL of water, load pulse current electrolysis for 300min, the removal rate of ammonia nitrogen in simulated water reaches 98.01%;

The anode plate is reticulated titanium plated ruthenium iridium (size: 57mm*76mm*1mm), and the cathode plate is reticulated stainless steel (size: 57mm*76mm*1mm); the pulse frequency in the pulse current is 5000HZ, accounting for The empty ratio is 50%.

In this embodiment, the electric energy is provided by the double-pulse electroplating power supply. Compared with the traditional DC power supply, it can reduce the ion concentration of the electrode interface layer solution in the electrolytic cell 4 and the concentration of the bulk solution, which causes the electrode potential to deviate from the equilibrium potential. Poor polarization and lower unit energy consumption.

In this embodiment, the concentration of sodium chloride added is low, which reduces the corrosion effect on the plates and devices, and at the same time achieves the purpose of removing ammonia nitrogen.

Example 4:

A method for three-dimensional pulse electrolytic removal of ammonia nitrogen, characterized in that, using the system in Example 1, the following steps are carried out:

1) Configure simulated ammonia nitrogen wastewater: the concentration range of ammonium sulfate is 350.8g/L, the concentration range of sodium sulfate is 10g/L, and the concentration range of sodium chloride is 155mg/L;

2) The distance between the plates in the electrolytic cell 4 is 2mm, the total filling amount of natural clinoptilolite is 110g, the current density is 109.65mA/cm ² , the flow rate of the constant current pump is in the range of 500-1000mL/h, measure the The simulated distribution water is 600mL, and the pulse current electrolysis is applied for 300min, and the removal rate of ammonia nitrogen in the simulated distribution water reaches 98.13%;

The anode plate is reticulated titanium plated ruthenium iridium (size: 57mm*76mm*1mm), and the cathode plate is reticulated stainless steel (size: 57mm*76mm*1mm); the pulse frequency in the pulse current is 5000HZ, accounting for The empty ratio is 50%.

In this embodiment, the electric energy is provided by the double-pulse electroplating power supply. Compared with the traditional DC power supply, it can reduce the ion concentration of the electrode interface layer solution in the electrolytic cell 4 and the concentration of the bulk solution, which causes the electrode potential to deviate from the equilibrium potential. Poor polarization and lower unit energy consumption.

In this embodiment, the concentration of sodium chloride added is low, which reduces the corrosion effect on the plates and devices, and at the same time achieves the purpose of removing ammonia nitrogen.

Example 5:

A method for three-dimensional pulse electrolytic removal of ammonia nitrogen, characterized in that, using the system in Example 1, the following steps are carried out:

1) Configure simulated ammonia nitrogen wastewater: the concentration range of ammonium sulfate is 350.8g/L, the concentration range of sodium sulfate is 10g/L, and the concentration range of sodium chloride is 160mg/L;

2) The distance between the plates in the electrolytic cell 4 is 2mm, the total filling amount of natural clinoptilolite is 110g, the current density is 109.65mA/cm ² , the flow rate of the constant current pump is in the range of 500-1000mL/h, measure the The simulated distribution water is 600mL, and the pulse current electrolysis is applied for 300min, and the removal rate of ammonia nitrogen in the simulated distribution water reaches 98.68%;

The anode plate is reticulated titanium plated ruthenium iridium (size: 57mm*76mm*1mm), and the cathode plate is reticulated stainless steel (size: 57mm*76mm*1mm); the pulse frequency in the pulse current is 5000HZ, accounting for The empty ratio is 50%.

In this embodiment, the electric energy is provided by the double-pulse electroplating power supply. Compared with the traditional DC power supply, it can reduce the concentration difference caused by the difference between the ion concentration of the electrode interface layer solution and the bulk solution concentration in the electrolytic cell, which causes the electrode potential to deviate from the equilibrium potential. Polarization, and reduce unit energy consumption. In this embodiment, the concentration of sodium chloride added is low, which reduces the corrosion effect on the plate and the device, and at the same time achieves the purpose of removing ammonia nitrogen.

Claims (3)

1. a kind of method that three-dimensional pulse electrolysis removes ammonia nitrogen, it is characterised in that including some groups of processing systems；Single processing system Including：Power supply (1), cathode-anode plate (2), granule electrode (3), electrolytic cell (4), constant current cycle pump (5) and circulating water container (6)；

The electrolytic cell (4), constant current cycle pump (5) are connected with circulating water container (6) by associated conduit, constitute closed-loop path； The constant current cycle pump (5) is connected with the water inlet end of electrolytic cell (4)；The circulating water container (6) and the water side of electrolytic cell (4) It is connected；

The electrolytic cell (4) is internally provided with some groups of cathode-anode plates (2)；The cathode-anode plate (2) is perpendicular to electrolytic cell (4) Intake direction and water outlet direction；The positive plate of the cathode-anode plate (2) is that netted titanium plates ruthenium iridium, and minus plate is netted stainless steel； The spacing of adjacent cathode-anode plate (2) is 2~5mm；

The two ends of the cathode-anode plate (2) are connected with the negative electrode and anode of power supply (1) respectively；

The power supply (1) is numerical control Double-pulse Plating Power Source；

The both sides of the cathode-anode plate (2) are filled with granule electrode (3)；

Followed the steps below using said system：

1) villaumite is added in ammonia nitrogen waste water；

The concentration of chlorion is 20~140mg/L in the villaumite；

2) in the feeding electrolytic cell (4) continuously circulated the ammonia nitrogen waste water in circulating water container (6) by constant current cycle pump (5)；

The range of flow of the constant current cycle pump (5) is 200~1000mL/h；

3) startup power supply (1) load pulses electric current；It is electrolysed in the electrolytic cell (4)；

The pulse frequency that the power supply (1) provides is 5~5000HZ, and dutycycle is 1~100%；

The current density of the cathode-anode plate (2) is 50~150mA/cm²。

2. the method that a kind of three-dimensional pulse electrolysis according to claim 1 removes ammonia nitrogen, it is characterised in that：The granule electrode (3) cocoanut active charcoal, natural clinoptilolite and biological ceramic particle are included；The particle diameter of the cocoanut active charcoal is 2~10mm, the day The particle diameter of right clinoptilolite is 2~10mm, and the particle diameter of the life haydite is 2~10mm.

3. the method that a kind of three-dimensional pulse electrolysis according to claim 1 removes ammonia nitrogen, it is characterised in that：The titanium plates ruthenium iridium Web plate mesh aperture is 1~10mm；The stainless (steel) wire plate mesh aperture is 1~10mm.