CN114853122A - Magnetic assembly electrode and method for treating underground water by using peroxide flocculation technology - Google Patents
Magnetic assembly electrode and method for treating underground water by using peroxide flocculation technology Download PDFInfo
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Abstract
The invention relates to a magnetic assembly electrode and a method for treating underground water by using a peroxide flocculation technology. The method uses a magnetic assembly electrode comprising: a main electrode composed of dimensionally stable electrode, magnetic material at one side of the main electrode, and a heterogeneous auxiliary electrode at the other side of the main electrode, wherein the heterogeneous auxiliary electrode in the magnetic assembly electrode is over against the electrochemical reactionIn the process, the magnetic material in the magnetic assembly electrode and the region of the heterogeneous auxiliary electrode are completely immersed in the solution to be treated, the heterogeneous auxiliary electrode is uniformly dispersed at the bottom of the main electrode, one part of the main electrode is exposed in the solution to be treated, and the main electrode of the magnetic assembly electrode is connected with the positive electrode of a power supply. The main electrode can oxidize Cl existing in underground water during electrochemical treatment ‑ And the heterogeneous auxiliary electrode can separate out the Fenton catalyst under the action of current, and the Fenton catalyst and the heterogeneous auxiliary electrode can efficiently degrade pollutants in underground water under the combined action of the Fenton catalyst and the Fenton catalyst.
Description
Technical Field
The invention relates to the technical field of underground water treatment, in particular to a magnetic assembly electrode and a method for treating underground water by using a peroxide flocculation technology.
Background
Recently, as water quality and quantity problems have become more serious, it has become more and more complicated to provide drinking water to society. Widespread use of groundwater is now unavoidable for agricultural and industrial purposes, while nearly half of the world's population relies on groundwater for drinking water, the water quality safety of which is an important guarantee for human health. Chemical Oxygen Demand (COD) and ammonia Nitrogen (NH) 3 N) and Total Phosphorus (TP) are used as three indexes for evaluating the performance of the water body, and how to realize the synchronous removal of a plurality of pollutants is a great challenge at present. Among the existing technologies, bioremediation and adsorption are two common technologies for simultaneously removing COD and NH in groundwater 3 The method of-N and TP, but the former can not effectively remove the organic matter which is difficult to be biodegraded, and the chlorine ion which exists in the groundwater has the toxic action to the microorganism, and the latter needs to carry out post-treatment to the saturated adsorbent, which increases the operation and treatment cost. Therefore, it is urgent to develop a technology for treating groundwater economically and efficiently.
electro-Fenton as a novel electrochemical advanced oxidation water treatment technology generates strong oxidizing hydroxyl radicals ( ● OH) has a wide prospect in treating COD, ammonia nitrogen and other organic pollutants in groundwater, but TP cannot be oxidized and degraded. The electric flocculation has good effect on removing the total phosphorus, but is not beneficial to the degradation and removal of ammonia nitrogen due to the limitation on oxidation. In summary, the limitation of a single system is that it cannot effectively remove multiple pollutants from water. Therefore, a coupling system integrating multiple functions is developed, chloride ions existing in underground water are effectively utilized, and COD and NH are removed simultaneously 3 -N and TPHas great significance.
Disclosure of Invention
The invention aims to design a novel peroxide flocculation system, wherein a magnetic assembly electrode is formed by two materials (a main electrode and a heterogeneous auxiliary electrode) with different functions under the action of a magnetic field. The functions of the two materials are independent and do not influence each other. The main electrode can oxidize Cl existing in underground water during electrochemical treatment - The heterogeneous auxiliary electrode can separate out the Fenton catalyst under the action of current, and the heterogeneous auxiliary electrode and the Fenton catalyst can efficiently degrade pollutants in underground water under the combined action of the heterogeneous auxiliary electrode and the Fenton catalyst.
The purpose of the invention is realized by the following technical scheme:
a magnetic assembly electrode, comprising:
a main electrode consisting of dimensionally stable electrodes;
magnetic material, locate at one side of main electrode;
and the heterogeneous auxiliary electrode is positioned on the other side of the main electrode and is attached to the surface of the main electrode under the action of the magnetic material.
The heterogeneous auxiliary electrode is a substance containing zero-valent iron, other auxiliary substances such as ferroferric oxide, copper and the like can be added, and the heterogeneous auxiliary electrode can be divided into powder, blocks and any other shapes under different conditions.
The mass of zero-valent iron on the heterogeneous auxiliary electrode is obtained by the formula (1)
In the formula: m: mass g of iron dissolved out under a certain current intensity;
i: current intensity, a;
t: energization time, s;
z: number of electrons per iron atom;
f: faraday constant, 96490C/mol.
Different electrifying time and current intensity can be set according to the concentration of the pollutants, and the longer the electrifying time is, the higher the current is, the higher the pollutant removing efficiency is.
The heterogeneous auxiliary electrode is pure zero-valent iron powder which is uniformly distributed on the main electrode and occupies 1/3 the effective area of the main electrode immersed in the groundwater to be treated.
A method for treating underground water by using a peroxide flocculation technology is characterized by comprising the following steps: the heterogeneous auxiliary electrode in the magnetic assembly electrode is over against a cathode in an electrochemical reaction process, a magnetic material in the magnetic assembly electrode and the area of the heterogeneous auxiliary electrode are completely immersed in a solution to be treated, the heterogeneous auxiliary electrode is uniformly dispersed at the bottom of a main electrode, a part of the main electrode is exposed in the solution to be treated, the main electrode of the magnetic assembly electrode is connected with a power supply anode, hydrogen peroxide can be efficiently generated in situ by the cathode in an electrolysis process, and Fe can be precipitated in situ by iron powder at the bottom of one side of the magnetic assembly electrode 2+ ，Fe 2+ Reacting with hydrogen peroxide to generate hydroxyl free radical with strong oxidizing property and Fe 3+ Hydroxyl free radical high-efficiency degradation of organic pollutant Fe in underground water 2+/ Fe 3+ Removing total phosphorus in the groundwater by flocculation; meanwhile, Cl in groundwater - Oxidized to active chlorine on the surface of the main electrode, and the active chlorine combines with hydroxyl radicals to generate active chlorine species (Cl) ● And ClO ● ) Removing ammonia nitrogen;
the method for treating underground water by the peroxide flocculation technology forms a novel peroxide flocculation system.
The invention has the following outstanding characteristics:
(1) the magnetic assembly electrode designed by the invention has the advantages that each assembly is independent, and the advantages of the magnetic assembly electrode are fully exerted. During the electrochemical treatment, Cl can be enabled - Active chlorine is formed on the surface of the magnetic assembly anode (main electrode) through oxidation, and Fe can be separated out from the heterogeneous auxiliary electrode under the action of current 2+ Several systems are coupled into one-step reaction, chloride ions in underground water are utilized to remove various pollutants simultaneously, DSA is connected with the anode of a power supply, and Cl is greatly improved under the action of current - The efficiency of oxidation.
(2) The invention utilizes magnetic material to assist electricityThe electrode is fixed on the other side of the main electrode and Fe is separated out under the action of current 2+ Compared with the traditional iron plate anode, on the premise of not influencing the pollutant removal efficiency, the yield of ferrous iron is obviously reduced, the generation of sludge is reduced, and the solid-liquid separation cost and the sludge treatment cost are saved.
(3) The method is suitable for removing various pollutants in underground water, the zero-valent iron powder is fixed on one side of the main electrode, the catalyst required by Fenton reaction is generated in situ under the action of current, and the external addition of the catalyst is avoided.
(4) The main electrode has certain oxidation function and can oxidize Cl existing in underground water - Oxidation to active chlorine (HClO/ClO) - ) And combines with hydroxyl radical generated by Fenton reaction to generate active chlorine species (Cl) with oxidation function ● And ClO ● ) And further degradation of ammonia nitrogen is promoted. The method is obtained through three-dimensional fluorescence analysis, and the combined action of various oxidizing free radicals and active chlorine has a good removal effect on various organic matters existing in underground water, and can also remove organic matters which are difficult to degrade.
(5) The invention adopts the magnetic assembly anode formed by combining the heterogeneous auxiliary electrode and the main electrode to replace an iron plate in the traditional peroxide flocculation system, thereby solving the problem that the iron plate of the traditional peroxide flocculation anode is easy to passivate.
Drawings
FIG. 1 is a schematic structural and schematic diagram of a novel peroxygen flocculation system according to one embodiment of the present invention;
FIG. 2 is a graph comparing the degradation performance of COD, ammonia nitrogen and total phosphorus in groundwater based on traditional and novel peroxygen flocculation;
FIG. 3 shows pH vs. COD and NH of novel peroxygen flocculation system in groundwater 3 N, degradation Performance influence Pattern of Total phosphorus
FIG. 4 is a graph comparing the accumulation of active chlorine and hydroxyl radicals in groundwater based on conventional and novel peroxygen flocculation;
figure 5 is a graph based on the change over time of iron ions, hydrogen peroxide and active chlorine in a novel peroxygen flocculation system.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
A magnetic assembly electrode, characterized in that the magnetic assembly electrode comprises:
a main electrode consisting of dimensionally stable electrodes;
magnetic material, locate at one side of main electrode;
and the heterogeneous auxiliary electrode is positioned on the other side of the main electrode and is attached to the surface of the main electrode under the action of the magnetic material.
The heterogeneous auxiliary electrode is a substance containing zero-valent iron, other auxiliary substances such as ferroferric oxide, ferroferric oxide and copper can be added, the heterogeneous auxiliary electrode can be divided into powder, blocks and any other shapes under different conditions, and the form of micron zero-valent iron powder (mZVI) is selected to be presented in the following examples.
The zero-valent iron used according to this example was obtained by the formula (1)
In the formula: m: mass g of iron dissolved out under a certain current intensity;
i: current intensity, a;
t: energization time, s;
z: the number of electrons per iron atom transferred, under experimental conditions, is 2;
f: faraday constant, 96490C/mol.
The iron powder can continuously separate out Fe under the action of current 2+ According to different experimental conditions, different iron powder qualities are selected, and the situation that the iron powder is too fast in dissolving rate due to overlarge current and is not enough to participate in subsequent reactions is avoided. If the area of the zero-valent iron powder in the main electrode is too large, the active area of the main electrode is reduced, and Cl is affected - Oxygen of (2)Therefore, the zero-valent iron powder is uniformly distributed and occupies less main electrode area as much as possible. The proportion of 1/3 in which the zero-valent iron powder occupies the effective area of the main electrode (immersed in the groundwater to be treated) can be adjusted properly by different experimental conditions.
The main electrode is a ruthenium-series, iridium-series, platinum-series and other titanium electrode, has good chlorine evolution performance in an electrochemical system, has relatively flat two surfaces, and is beneficial to the adhesion of a magnetic material and a heterogeneous auxiliary electrode. The magnetic material is generally a substance that contains at least one of metals such as iron, cobalt, nickel, rare earth elements, manganese, and metal alloys containing the above elements and that can react to a magnetic field. The heterogeneous auxiliary electrode is made of magnetizable materials and can be fixed on one side of the main electrode under the action of the magnetizable materials. In the following examples, a titanium electrode (DSA) with ruthenium iridium coated on the surface was selected as the main electrode.
The magnetically assembled electrode is used in groundwater treatment or as a sacrificial anode in the field of electroflocculation.
The invention also provides a novel method for treating underground water by using the peroxide flocculation technology, wherein a heterogeneous auxiliary electrode in a magnetic assembly electrode is right opposite to a cathode in an electrochemical reaction process, a magnetic material in the magnetic assembly electrode and the area of the heterogeneous auxiliary electrode are completely immersed in a solution to be treated, the heterogeneous auxiliary electrode is uniformly dispersed at the bottom of a main electrode, a part of the main electrode is exposed in the solution to be treated, the main electrode of the magnetic assembly electrode is connected with a power supply anode, in an electrolysis process, hydrogen peroxide can be efficiently generated in situ by the cathode, and Fe can be precipitated in situ by iron powder at the bottom of one side of the magnetic assembly electrode 2+ ，Fe 2+ Reacting with hydrogen peroxide to generate hydroxyl free radical with strong oxidizing property and Fe 3+ Hydroxyl free radical high-efficiency degradation of organic pollutant Fe in underground water 2+/ Fe 3+ Removing total phosphorus in the groundwater by flocculation; meanwhile, Cl in groundwater - Oxidized to active chlorine on the surface of the main electrode, and the active chlorine combines with hydroxyl radicals to generate active chlorine species (Cl) ● And ClO ● ) And removing ammonia nitrogen.
In the electrolytic process, the heterogeneous auxiliary electrode fixed on the magnetic assembly electrode is opposite to the cathode, and the main electrode is a ruthenium-series, iridium-series, platinum-series and other titanium electrode; the cathode is made of carbon materials, such as carbon felt, graphite felt and activated carbon fiber, the oxygen of which can be reduced to hydrogen peroxide water on the surface.
FIG. 1 is a schematic and schematic diagram of the structure of a novel peroxygen flocculation system, in which H is generated at the cathode 2 O 2 Fe dissolved with anode 2+ Fenton reaction generation takes place ● OH and Fe 3+ . Generated by ● OH reacts with generated active chlorine in groundwater to generate a large amount of active chlorine species (Cl) ● And ClO ● ) In various oxidizing agents (e.g. ClO) ● 、 ● OH, active chlorine), organic pollutants in the groundwater can be oxidized and degraded, and finally, the mineralization is caused to generate CO 2 And H 2 And O. Generated ClO ● And NH 3 Reaction of-N to chloramine (NH) 2 Cl、NHCl 2 And NCl 3 ) The chloramine is further oxidized to N 2 At the same time due to ● OH extraction of NH 3 H in-N, to form hydroxylamine (NH) step by step 2 OH) may be further converted to N 2 The removal of ammonia nitrogen is realized; phosphate can react with ferrous ions dissolved in the anode to form precipitates, hydrogen phosphate and phosphate can also react with ferric iron to form precipitates, and the synergistic effect is realized to remove TP; excess Fe produced at the anode 3+ With Fe (OH) 3 The form of the sludge is separated out for flocculation, organic matters with certain content, nitrogen-containing pollutants and phosphorus are coagulated, and the total amount of phosphorus and ammonia nitrogen in the system is further reduced. Therefore, under the same system, the removal of COD and NH is realized simultaneously 3 The effects of N and TP.
The carbon black modified carbon felt is selected as a cathode, and the preparation process is as follows: cutting a carbon felt with a proper size, soaking the carbon felt by PTFE, drying the carbon felt, calcining the carbon felt for half an hour at 360 ℃, and forming a stable air diffusion layer on the surface of the electrode; then, carbon black and PTFE are uniformly mixed as a catalytic layer according to the mass ratio of 1.7, and then coated on one side of a carbon felt, and then calcined at 360 ℃ for half an hour to obtain the catalyst.
According to the method for treating the underground water by using the peroxide flocculation technology, the pH (3-9) of the underground water to be treated, heterogeneous auxiliary electrodes (zero-valent iron powder) (0.1-0.4 g), the current (100-400 mA) and the electrolysis time can be regulated to realize efficient and simultaneous removal of various pollutants. The specific DSA plate size, reactor size and the like can be adjusted according to actual conditions.
The method is suitable for treating the underground water with high COD (500-2500 mg/L), high ammonia nitrogen (50-400 mg/L) and high total phosphorus (20-200 mg/L). According to the national standard of the people's republic of China-the standard of water quality for sewage discharged into town sewers (GB/T31962-.
Example 1:
the method for treating groundwater by using the peroxide flocculation technology of the embodiment compares the treatment effect of a traditional peroxide flocculation system and a novel peroxide flocculation system on groundwater. The anode of the peroxide flocculation system adopts an iron plate; the novel peroxide flocculation system adopts DSA as a main electrode, and the heterogeneous auxiliary electrode adopts pure micron-sized zero-valent iron powder, is uniformly adsorbed on the main electrode under the action of a magnetic material, and is just opposite to a cathode. Both systems use modified carbon felt as the cathode.
Reaction conditions are as follows: 200mL of underground water to be treated, 0.05mol/L of sodium sulfate (electrolyte), 300mA of current, 6.8 of initial pH of the underground water to be treated, 0.4g of iron powder, and carbon black modified carbon felt as a cathode. COD in the groundwater to be treated: 910 plus or minus 20 mg/L; ammonia nitrogen: 72 plus or minus 3 mg/L; total phosphorus: 35 plus or minus 3 mg/L; chloride ion: 1320 plus or minus 30 mg/L.
Preparing a carbon black modified carbon felt: cutting a carbon felt with a size suitable for the main electrode, impregnating with PTFE, drying, calcining at 360 ℃ for half an hour, and forming a stable air diffusion layer on the surface of the electrode; then, carbon black and PTFE are uniformly mixed as a catalytic layer according to the mass ratio of 1.7, and then coated on one side of a carbon felt, and then calcined at 360 ℃ for half an hour to obtain the catalyst.
To reveal the potential advantages of the novel peroxygen flocculation system, the performance of the conventional peroxygen flocculation with iron as anode and the novel peroxygen flocculation system with magnetic assembly electrode as anode were compared. The novel peroxygen battings are evident from FIGS. 2 (a) and (b)Condensate system to COD and NH 3 The concentration of-N decays more efficiently. Using the conventional peroxygen flocculation system as an example, COD and NH 3 The degradation rate of-N after 4h treatment was only 46.5% and 14.2%, respectively, while the removal efficiency of both increased to 89.5% and 100% when the mZVI/DSA replaced the Fe anode, respectively. It can be seen in fig. 2 (c) that both systems are characterized by rapid and complete removal in terms of TP processing.
In conclusion, the novel peroxygen flocculation system is difficult to separate from the traditional peroxygen flocculation in the aspect of degrading TP, however, COD and NH 3 The degradation performance of the-N is obviously improved, so that the novel peroxygen flocculation system has wide prospect in treating various pollutants in underground water.
Example 2:
the magnetic assembly electrode of the embodiment is used in groundwater treatment, the specific process of groundwater treatment is the same as that of the embodiment 1, and the reaction conditions are as follows: 200mL of underground water to be treated, 0.05mol/L of sodium sulfate concentration and 300mA of current, wherein a carbon black modified carbon felt is selected as a cathode, an mZVI/DSA is selected as an anode, the mass of iron powder is 0.3g, and the COD: 910 plus or minus 20 mg/L; ammonia nitrogen: 72 plus or minus 3 mg/L; total phosphorus: 35 plus or minus 3 mg/L; chloride ion: 1320 plus or minus 30 mg/L.
The COD degradation curve in figure 3 shows that the combination of hydroxyl radical, oxychlorination and flocculation works best at pH3, next to pH6.8, 5 and 9. And NH 3 The removal rate of-N increases with increasing pH and the removal rate of TP decreases with increasing pH. For example, when the initial pH is decreased from 9 to 3, the time for complete phosphorus removal is shortened from 50 minutes to 30 minutes. Under the condition that the pH value of underground water is 6.8, the attenuation efficiency of three parameters achieves good effect, the pH value of the underground water does not need to be additionally adjusted, and the cost of underground water treatment is reduced, so that the novel peroxygen flocculation system has good prospect in the aspect of practical application.
Example 3:
in the method for treating groundwater by using the peroxide flocculation technology, compared with the traditional peroxide flocculation system and the novel peroxide flocculation system, the accumulation amount of active chlorine and hydroxyl free radicals is 4 hours after the groundwater is treated, and the specific process of groundwater treatment is the same as that in example 1. Reaction conditions are as follows: 200mL of underground water to be treated, 0.05mol/L of sodium sulfate concentration, 300mA of current and 6.8 of initial pH. A peroxide flocculation system: the iron plate is used as an anode; novel peroxygen flocculation system: the anode was a DSA electrode, and the mass of iron powder was 0.4 g. The cathodes of the two systems are carbon black modified carbon felts, COD: 910 plus or minus 20 mg/L; ammonia nitrogen: 72 plus or minus 3 mg/L; total phosphorus: 35 plus or minus 3 mg/L; chloride ion: 1320 plus or minus 30 mg/L.
As can be clearly observed in fig. 4, the concentration of the two active substances of the novel PC (peroxygen flocculation) system is significantly higher than that of the conventional PC system. After the traditional PC is used for treating underground water for 4 hours, the accumulation amounts of active chlorine and hydroxyl radicals are respectively 0.70mg/L and 35.8 mu M, and the concentrations of the active chlorine and the hydroxyl radicals are respectively improved by 20 times and 6 times after the mZVI/DSA treatment. This result confirmed that oxygen evolution reaction mainly occurred on the surface of the iron anode, and Cl - And the iron anode surface is difficult to oxidize. Therefore, mZVI/DSA has significant advantages in treating a variety of pollutants.
Example 4:
the specific process of groundwater treatment was the same as in example 1. Reaction conditions are as follows: 200mL of underground water to be treated, 0.05mol/L of sodium sulfate concentration, 300mA of current and 6.8 of initial pH, wherein a carbon black modified carbon felt is selected as a cathode, an mZVI/DSA is selected as an anode, the mass of iron powder is 0.2g, and the COD: 910 plus or minus 20 mg/L; ammonia nitrogen: 72 plus or minus 3 mg/L; total phosphorus: 35 plus or minus 3 mg/L; chloride ion: 1320 plus or minus 30 mg/L.
As can be seen from FIG. 5, the iron ion concentration is between 3.2 and 3.8mg/L in the first 30min, the iron ion concentration sharply decreases to 0.9mg/L due to partial consumption of the ZVI particles at 40min, and then gradually increases with acidification of the solution pH. The hydrogen peroxide shows an ascending trend 2 hours before electrolysis and then tends to be flat, and H in the underground water 2 O 2 May assist in the purification of the solution. It is worth noting that the accumulation concentration of active chlorine in the new PC system increases slowly first, and then the rate of increase increases significantly, which can be explained by the increase in the active area of DSA and the increase in the rate of oxidation of chloride ions to active chlorine with the gradual consumption of zero-valent iron powder. Reaction of active chlorine with hydroxyl radicals to produce active chlorine species (Cl) ● And ClO ● ) And is beneficial to removing ammonia nitrogen.
The pH of the groundwater used in the invention is close to neutral (pH 6.8), so the experiment is mainly developed around a neutral environment, and the three pollutants can be well removed under the pH condition of 6.8, i.e. without adjusting the pH.
However, according to the experimental results, the application can obtain good removal effect on three pollutants under the pH condition of 3-9. The three figures show that at pH3, 5,6.8,9, COD, NH 3 -removal effects of N and TP. When the pH value is reduced from 9 to 3, the degradation effect of ammonia nitrogen is gradually inhibited, but the ammonia nitrogen in the solution can still be completely removed after 4 hours of treatment. The degradation effect of the total phosphorus is improved, and the time for completely descaling is shortened from 50 minutes to 30 minutes. The COD degradation rate was the highest at pH3, reaching 90%, and the COD degradation rate was the worst as pH increased to 9, but 72% degradation was also obtained. Therefore, the application can obtain satisfactory degradation effect under the pH condition of 3-9.
However, the content of zero-valent iron affects the removal efficiency of contaminants. The three pollutants COD and NH mentioned in the invention 3 N and TP, the pollutant removing effect of the zero-valent iron is as follows, and the dosage range of the zero-valent iron is 0.1 g-0.4 g. The removal efficiency of TP is improved along with the increase of the dosage of zero-valent iron, Fe 2+ The precipitation amount is increased, and the flocculation effect is obvious. NH (NH) 3 The decay law of-N is opposite to that of TP, and the removal efficiency is inversely related to that of zero-valent iron. The increase in the zero-valent iron content causes a decrease in the active area of the DSA anode, Cl - Decrease in oxidizing power of, NH 3 The degradation rate of-N decreases. The degradation efficiency of COD is reduced along with the increase of the dosage of the zero-valent iron powder, and 0.3g of the zero-valent iron is the optimal value for removing the COD under the condition of the embodiment. When the dosage of the zero-valent iron powder is 0.1-0.3 g, the content of dissolved iron is increased, and the Fenton reaction and flocculation rate are accelerated. On the contrary, when the zero-valent iron powder exceeds 0.3g, Fe is excessively increased 2+ Can cause a series of side reactions ● Partial consumption of OH with reduced active area leading to Cl - The weak oxidation ability is also one of the factors for reducing the COD degradation rate.
In conclusion, the invention develops a novel method for treating underground water by using a peroxide flocculation system and has obvious advantages compared with the traditional peroxide flocculation system. The efficient degradation of various pollutants in the underground water is realized by utilizing the Cl & lt- & gt in the underground water and cooperating with the hydroxyl free radical generated in the Fenton reaction through the oxidation function of the anode. The method can realize the in-situ release of the Fenton catalyst, and avoids the external addition of the catalyst.
Nothing in this specification is said to apply to the prior art.
Claims (9)
1. A method for treating underground water by using a peroxide flocculation technology is characterized by comprising the following steps: the method uses a magnetic assembly electrode comprising: the magnetic assembly electrode comprises a main electrode consisting of a dimensionally stable electrode, a magnetic material positioned on one side of the main electrode and a heterogeneous auxiliary electrode positioned on the other side of the main electrode, wherein the heterogeneous auxiliary electrode is attached to the surface of the main electrode under the action of the magnetic material, the heterogeneous auxiliary electrode in the magnetic assembly electrode is right opposite to a cathode in an electrochemical reaction process, the magnetic material in the magnetic assembly electrode and the area of the heterogeneous auxiliary electrode are completely immersed in a solution to be treated, the heterogeneous auxiliary electrode is uniformly dispersed at the bottom of the main electrode, one part of the main electrode is exposed in the solution to be treated, the main electrode of the magnetic assembly electrode is connected with a power supply anode, hydrogen peroxide can be efficiently generated in situ by the cathode in an electrolysis process, and Fe can be separated out in situ by iron powder at the bottom of one side of the magnetic assembly electrode 2+ ，Fe 2+ Reacting with hydrogen peroxide to generate hydroxyl free radical with strong oxidizing property and Fe 3+ Hydroxyl free radical high-efficiency degradation of organic pollutant Fe in underground water 2+/ Fe 3+ Removing total phosphorus in the groundwater by flocculation; meanwhile, Cl in groundwater - Oxidized to active chlorine on the surface of the main electrode, and the active chlorine combines with hydroxyl radicals to generate active chlorine species (Cl) ● And ClO ● ) And removing ammonia nitrogen.
2. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the heterogeneous auxiliary electrode is a substance containing zero-valent iron, and the heterogeneous auxiliary electrode is in the form of powder, block or any other shape under different conditions.
3. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the mass of zero-valent iron on the heterogeneous auxiliary electrode is obtained by the formula (1)
In the formula: m: mass of iron dissolved at current intensity I, g;
i: current intensity, a;
t: energization time, s;
z: number of electrons per iron atom;
f: faraday constant, 96490C/mol.
4. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the heterogeneous auxiliary electrode is pure zero-valent iron powder which is uniformly distributed on the main electrode and occupies 1/3 the effective area of the main electrode immersed in the groundwater to be treated.
5. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the main electrode is a ruthenium-series, iridium-series or platinum-series titanium electrode, and the magnetic material is at least one of metal containing iron, cobalt, nickel, rare earth elements or manganese and metal alloy containing the elements; the heterogeneous auxiliary electrode is made of magnetizable materials and can be fixed on one side of the main electrode under the action of the magnetizable materials.
6. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the principle process of the peroxide flocculating body is as follows: h formed at cathode 2 O 2 Fe dissolved with anode 2+ Fenton reaction generation takes place ● OH and Fe 3+ Generated by ● OH undergroundReacting with generated active chlorine in water to generate a large amount of active chlorine species (Cl) ● And ClO ● ) In various oxidizing agents (e.g. ClO) ● 、 ● OH, active chlorine), organic pollutants in the groundwater can be oxidized and degraded, and finally, the mineralization is caused to generate CO 2 And H 2 O; generated ClO ● And NH 3 Reaction of-N to chloramine (NH) 2 Cl、NHCl 2 And NCl 3 ) The chloramine is further oxidized to N 2 At the same time due to ● OH extraction of NH 3 H in-N, to form hydroxylamine (NH) step by step 2 OH) is further converted into N 2 The removal of ammonia nitrogen is realized; phosphate reacts with ferrous ions dissolved in the anode to form precipitates, hydrogen phosphate and phosphate can also react with ferric iron to form precipitates, and the TP is removed through synergistic effect; excess Fe produced at the anode 3+ With Fe (OH) 3 The organic matters, the nitrogen-containing pollutants and the phosphorus are coagulated to further reduce the total phosphorus and ammonia nitrogen in the system, thereby realizing the simultaneous removal of COD and NH in the same system 3 The effects of N and TP.
7. A method of treating groundwater using a peroxygen flocculation technique as claimed in claim 1, wherein: the pH value range of the underground water is 3-9, the COD range is 500-2500 mg/L, the ammonia nitrogen content range is 50-400 mg/L, the total phosphorus content range is 20-200 mg/L, the chloride ion content in the underground water is more than 350mg/L, the mass of zero-valent iron powder on the heterogeneous auxiliary electrode is 0.1-0.4 g, and the current is 100-400 mA; the pollutants are efficiently removed by regulating and controlling the content of the heterogeneous auxiliary electrode, the electric field intensity, the pH value and the electrolysis time.
8. A magnetic assembly electrode, comprising:
a main electrode consisting of dimensionally stable electrodes;
magnetic material, locate at one side of main electrode;
the heterogeneous auxiliary electrode is positioned on the other side of the main electrode and is attached to the surface of the main electrode under the action of the magnetic material;
the mass of zero-valent iron on the heterogeneous auxiliary electrode is obtained by the formula (1)
In the formula: m: mass of iron dissolved at current intensity I, g;
i: current intensity, a;
t: energization time, s;
z: number of electrons per iron atom;
f: faraday constant, 96490C/mol.
9. The magnetically assembled electrode of claim 8, wherein the anode is a titanium electrode of ruthenium, iridium, platinum, or the like; the cathode is made of carbon materials, such as carbon felt, graphite felt, carbon black modified carbon felt, activated carbon fiber and the like, of which oxygen can be reduced into hydrogen peroxide on the surface; the process of modifying the carbon felt by the carbon black comprises the following steps: cutting a carbon felt, soaking the carbon felt by PTFE, drying the carbon felt, and calcining the carbon felt at 360 ℃ for half an hour to form a stable air diffusion layer on the surface of the electrode; then, carbon black and PTFE are uniformly mixed as a catalytic layer according to the mass ratio of 1.7, and then coated on one side of a carbon felt, and then calcined at 360 ℃ for half an hour to obtain the catalyst.
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| CN115520939A (en) * | 2022-10-11 | 2022-12-27 | 西安交通大学 | Multipole type electric control coupling ozone air flotation water treatment device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09155392A (en) * | 1995-12-06 | 1997-06-17 | Kyodo Kumiai Akuteibu Sci | Apparatus for removing nitrogen and phosphorus in drainage |
| CN106915802A (en) * | 2017-04-12 | 2017-07-04 | 哈尔滨工业大学 | The integral type electrochemical reaction appts and processing method of organic wastewater with difficult degradation thereby treatment |
| CN110357217A (en) * | 2019-06-19 | 2019-10-22 | 浙江理工大学 | A kind of application of the fixed iron powder electrode of magnetic force in the treatment of waste water |
| CN111422953A (en) * | 2020-04-01 | 2020-07-17 | 北京林业大学 | In-situ flocculation-Fenton coupling electrochemical method for advanced treatment of high-salinity wastewater |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09155392A (en) * | 1995-12-06 | 1997-06-17 | Kyodo Kumiai Akuteibu Sci | Apparatus for removing nitrogen and phosphorus in drainage |
| CN106915802A (en) * | 2017-04-12 | 2017-07-04 | 哈尔滨工业大学 | The integral type electrochemical reaction appts and processing method of organic wastewater with difficult degradation thereby treatment |
| CN110357217A (en) * | 2019-06-19 | 2019-10-22 | 浙江理工大学 | A kind of application of the fixed iron powder electrode of magnetic force in the treatment of waste water |
| CN111422953A (en) * | 2020-04-01 | 2020-07-17 | 北京林业大学 | In-situ flocculation-Fenton coupling electrochemical method for advanced treatment of high-salinity wastewater |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115520939A (en) * | 2022-10-11 | 2022-12-27 | 西安交通大学 | Multipole type electric control coupling ozone air flotation water treatment device |
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