CN113493239A

CN113493239A - Electrochemical treatment device, seawater desalination system and method

Info

Publication number: CN113493239A
Application number: CN202110970751.6A
Authority: CN
Inventors: 胡承志; 芦超杰; 孙境求; 曲久辉; 赵凯
Original assignee: Research Center for Eco Environmental Sciences of CAS
Current assignee: Research Center for Eco Environmental Sciences of CAS
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2021-10-12

Abstract

The invention provides an electrochemical treatment device, a seawater desalination system and a seawater desalination method, and relates to the field of water treatment. The electrochemical treatment device comprises an electrolytic bath, a power supply, a first electrode group and a second electrode group. In the first electrode group, the first anode comprises a dimensionally stable anode (DSA electrode) and the first cathode comprises a titanium electrode. After the power is switched on, the anode can directly oxidize organic matters and can generate strong oxidizing substances such as active chlorine, active oxygen and the like on line, so that the sterilization, algae removal, macromolecule organic matter destruction and membrane surface pollution alleviation can be realized effectively. In the second electrode group, the second anode/the second cathode comprises an iron electrode or an aluminum electrode, ions with complexing action such as iron ions or aluminum ions and the like can be generated on line, a series of polynuclear hydroxyl complexes and hydroxides are formed through hydrolysis and polymerization reaction and have flocculation action with suspended matters and pollutants in water, the pollutants are removed, and meanwhile, the flocculated matters can form a filter cake layer on the surface of the membrane, so that the membrane pollution is further reduced.

Description

Electrochemical treatment device, seawater desalination system and method

Technical Field

The invention relates to the technical field of water treatment, in particular to an electrochemical treatment device, a seawater desalination system and a seawater desalination method.

Background

At present, the situation of fresh water shortage generally exists in coastal and island regions of China, and with the rapid development of island economy, how to increase the development of water resources and enhance the water resource supply capacity becomes an important subject, wherein seawater desalination is an important means for providing fresh water resources. The seawater desalination, namely the seawater desalination is used for producing fresh water, is an open source increment technology for realizing the utilization of water resources, can increase the total amount of the fresh water, and provides guarantee for the water consumption of coastal residents.

Global seawater desalination technologies exceed more than 20, and are mainly divided into two main categories, namely distillation methods and membrane methods, wherein low-multiple-effect distillation methods, multi-stage flash evaporation methods and reverse osmosis membrane methods are global mainstream technologies. Generally speaking, the reverse osmosis membrane method has the advantages of low investment, low energy consumption and the like, is a seawater desalination method commonly used in China at present, but has higher requirements on seawater pretreatment because the reverse osmosis membrane is easily damaged by various substances in seawater.

The coagulating sedimentation pretreatment is a common pretreatment method of a reverse osmosis membrane method, and comprises the steps of adding a coagulant into seawater to precipitate suspended matters and partial organic matters so as to remove the suspended matters and the partial organic matters through filtration, and adding sodium hypochlorite, liquid chlorine and other chemical agents to carry out disinfection pretreatment on the seawater. For example, chinese patent document CN108483778A provides a seawater desalination process, which comprises the following steps: pretreatment of seawater: adding a flocculating agent to enable suspended matters in the seawater to form large flocs and then removing the large flocs; filtering the sand mud; purifying and sterilizing; ultrafiltration; reverse osmosis desalination treatment or pervaporation desalination treatment; and (4) condensing. For the coagulation sedimentation pretreatment method, a large amount of coagulant is needed to be added for removing suspended matters and partial organic matters, and meanwhile, the sedimentation time is long, the medicine consumption is high, and the occupied area of the device is large; in addition, chemical agents are utilized for purification and sterilization, the chemical agents are difficult to control the adding of the chemicals, the removal effect on bacteria, colloid and the like is poor, the water quality requirement of reverse osmosis inlet water cannot be met, and secondary pollution is easily caused. Most importantly, the conventional coagulating medicament and sodium hypochlorite or liquid chlorine sterilizing chemical medicament have a plurality of disadvantages due to the inconvenience of transportation and complicated transportation and medicament storage of part of islands and ships.

In the process of seawater desalination, the core unit is a membrane treatment unit, and membrane pollution damages the performance and the service life of the membrane, and increases the cost and the energy consumption of a seawater desalination system. Therefore, controlling membrane fouling and reducing energy consumption are key issues in the field of desalination treatment. The electrochemical technology is a green water treatment and purification technology, and because the main reaction reagent in the electrochemical reaction is electrons, the problem of secondary pollution can not be caused. The electrochemical technology comprises the following steps: electrocoagulation, electro-flotation, electro-oxidation, electrodialysis, etc., are commonly used for treating industrial wastewater. The application of electrochemical technology in seawater treatment has also been developed, for example, in the non-patent document "research on electric flocculation treatment of pollutants in seawater" in China, the use of iron and aluminum electrodes to study the removal efficiency of turbidity and chemical oxygen demand in the process of electric flocculation treatment of polluted seawater has been studied, and the test results show that: the electric flocculation seawater treatment process has a certain effect of removing turbidity, and the removal rate can reach more than 85%. The electric flocculation water treatment technology can effectively remove particulate matters and humic acid pollutants in raw water, and is often used as a pretreatment step of a membrane separation technology to control the membrane pollution problem. However, the existing electrochemical treatment device has limited functions, and subsequently needs to add medicaments to sterilize seawater and other treatments, which also causes the problems of more seawater pretreatment processes, large occupied area of equipment, high treatment cost, poor effect and the like. Therefore, the research on an electrochemical treatment device saves operations such as adding medicaments, simplifies the pretreatment process, reduces energy consumption, improves the treatment efficiency, slows down membrane pollution, prolongs the service life of the membrane, and becomes a technical problem to be solved in the field.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects of multiple seawater pretreatment processes, large equipment floor area, high treatment cost and poor effect caused by limited functions of the electrochemical treatment device in the prior art, so that a novel electrochemical treatment device, a seawater desalination system and a seawater desalination method are provided.

In a first aspect, the present invention provides an electrochemical processing apparatus comprising:

an electrolytic cell;

a first set of electrodes and a second set of electrodes, each disposed within the electrolytic cell, the first set of electrodes comprising a first anode comprising a dimensionally stable anode (DSA electrode), the first cathode comprising a titanium electrode, and a first cathode comprising a second anode comprising an iron electrode or an aluminum electrode, and a second cathode comprising an iron electrode or an aluminum electrode, the second cathode comprising an iron electrode or an aluminum electrode, at least one set of second electrode sets disposed between two adjacent sets of first electrodes, and/or at least one set of first electrode sets disposed between two adjacent sets of second electrodes;

and a power module, wherein the positive electrode of the power module is connected with the anodes of the first electrode group and the second electrode group, and the negative electrode of the power module is connected with the cathodes of the first electrode group and the second electrode group.

Further, the arrangement of the electrodes of the first electrode group and the second electrode group comprises a unipolar arrangement or a bipolar arrangement;

when the first electrode group and the second electrode group are arranged in a multi-pole mode, a first induction electrode is further arranged between the first anode and the first cathode, a second induction electrode is further arranged between the second anode and the second cathode, and the first induction electrode and the second induction electrode are not connected with the power supply assembly.

Further, the first and second sensing electrodes comprise iron electrodes and/or aluminum electrodes; the thickness of first response electrode and second response electrode is 2 ~ 8mm, and the area is 20000 ~ 60000mm²(ii) a The iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

Further, the arrangement of the first anode and the first cathode in the first electrode group is as follows: the titanium electrode, the dimension stable anode (DSA electrode) and the titanium electrode are arranged in sequence;

the number of the first electrode groups is 3-5, and the number of the second electrode groups is 4-8;

the first electrode groups are respectively arranged on the wall of the electrolytic tank close to the two end parts of the electrolytic tank, and the other first electrode group is arranged or not arranged in the middle of the electrolytic tank.

Further, the thickness of the first anode and the first cathode is 1.5-2.0 mm, and the thickness of the second anode and the second cathode is 2-8 mm; the area of the first anode, the first cathode, the second anode and the second cathode is 20000-60000 mm²(ii) a The distance between two adjacent electrodes is 10-20 mm; the dimension stable anode (DSA electrode) is a titanium plate plated with a rare metal oxide coating on the surface; the titanium electrode is a titanium plate, the iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

Further, the power supply assembly includes a first power supply connected to the first electrode set and a second power supply connected to the second electrode set.

Further, the voltage provided by the first power supply and the second power supply is 36V, and the current is 60A.

Further, the electrochemical processing apparatus further includes: and the water inlet pipe and the water outlet pipe are respectively communicated with the electrolytic cell.

In a second aspect, the invention provides the use of the electrochemical treatment device in a seawater desalination process.

In a third aspect, the invention provides a seawater desalination system comprising the electrochemical treatment device.

Further, the seawater desalination system comprises: the electrochemical treatment device comprises an electrochemical treatment unit and a membrane treatment unit which are connected in sequence, wherein the electrochemical treatment unit comprises the electrochemical treatment device.

Further, the seawater desalination system comprises: the device comprises an electrochemical treatment unit, an ultrafiltration membrane treatment unit and a reverse osmosis membrane treatment unit which are sequentially connected.

Furthermore, the ultrafiltration membrane treatment unit adopts an external immersed ultrafiltration membrane component, the outer diameter of the hollow fiber is 0.4-2.0 mm, and the inner diameter of the hollow fiber is 0.3-1.4 mm.

Further, the reverse osmosis membrane treatment unit adopts a Dow reverse osmosis membrane component.

Further, the seawater desalination system further comprises: and the sterilization unit is arranged on one side of the reverse osmosis membrane treatment unit, which is far away from the ultrafiltration membrane treatment unit.

Further, the seawater desalination system further comprises: the activated carbon filter and the security filter are arranged between the ultrafiltration membrane treatment unit and the reverse osmosis membrane treatment unit, the activated carbon filter is close to the ultrafiltration membrane treatment unit, and the security filter is close to the reverse osmosis membrane treatment unit.

Further, the seawater desalination system further comprises:

the monitoring unit comprises a residual chlorine on-line monitor and a turbidity on-line monitor, the residual chlorine on-line monitor is connected with the water outlet part of the membrane processing unit and is used for monitoring the residual chlorine content of the outlet water of the membrane processing unit on line, and the turbidity on-line monitor is connected with the electrochemical processing unit and is used for monitoring the turbidity of the seawater in the electrolytic bath of the electrochemical processing unit;

the PLC control unit is respectively connected with the monitoring unit and the electrochemical processing unit and is used for acquiring monitoring data signals of the residual chlorine on-line monitor and the turbidity on-line monitor, calculating current regulation and control data according to a preset program and outputting the current regulation and control data signals to the electrochemical processing unit so as to regulate and control the size of the electrified current of a first electrode group and a second electrode group in the electrochemical processing unit, thereby changing the chlorine yield and the flocculating agent yield of the electrochemical processing unit;

and the remote monitoring and control unit is respectively connected with the monitoring unit and the PLC control unit and is used for observing monitoring data and controlling the PLC control unit.

In a fourth aspect, the present invention provides a seawater desalination method, wherein the seawater desalination system is used for treating seawater.

The technical scheme of the invention has the following advantages:

1. the electrochemical treatment device provided by the invention comprises an electrolytic bath, a power supply, a first electrode group and a second electrode group, wherein the first electrode group and the second electrode group are arranged in the electrolytic bath. In the first electrode group, the first anode comprises a dimensionally stable anode, the first cathode comprises a titanium electrode, seawater to be treated is introduced into the electrolytic tank, after the power supply is switched on, the anode directly oxidizes organic matters and can generate active chlorine and active oxygen components on line at the same time, and the macromolecular organic matters are destroyed while sterilization and algae removal are carried out, so that membrane pollution is effectively slowed down; in the second electrode group, the second anode comprises an iron electrode or an aluminum electrode, the second cathode comprises an iron electrode or an aluminum electrode, after the power supply is switched on, the second electrode group can generate ions with complexing action such as iron ions or aluminum ions on line, the ions are hydrolyzed and polymerized into a series of polynuclear hydroxyl complexes and hydroxides, the polynuclear hydroxyl complexes and the hydroxides can flocculate with suspended matters and pollutants in water to remove the pollutants in water, besides, the floc generated by the electric flocculation has significant influence on the structure of a membrane cake layer and the pollution degree of the membrane, a loose and porous protective layer can be formed, the membrane pollution is further reduced by forming a dynamic membrane, and the service life of the membrane is prolonged.

In addition, at least one second electrode group is arranged between two adjacent first electrode groups, and/or at least one first electrode group is arranged between two adjacent second electrode groups. Through the cross arrangement of the first electrode group and the second electrode group, the coupling effect of electric flocculation and electric oxidation is realized, the membrane pollution can be effectively slowed down, and the life cycle of the membrane is prolonged. The first electrode group directly oxidizes organic matters on the surface of the anode and indirectly oxidizes the organic matters by electrolyzing chloride ions in seawater, and the generated effective components have strong oxidizing property, so that natural organic matter molecules in the seawater can be destroyed while sterilization and algae removal are carried out, the molecular weight of the organic matters is reduced, and the organic matters are removed. In addition, in the field of membrane pollution control, oxidation is a good supplement to flocculation, an electric field promotes flocculation by utilizing polarization, the flocculation of a second electrode group can be further promoted after electrooxidation, and the second electrode group play a synergistic role in water pretreatment. 2. The electrochemical treatment device provided by the invention can be used for pretreatment of seawater desalination or brackish water desalination, and can also be applied to the fields of life and special industrial water supply. Particularly, when the electrochemical treatment device is used for pretreatment of seawater desalination, the flocculating agent and the disinfectant can be generated in situ on line under the condition of low energy consumption by utilizing the advantage of high conductivity of seawater, the traditional chemical dosing flocculation and chemical dosing disinfection and sterilization are replaced, the dosage of the medicament in the seawater pretreatment process can be reduced, a green pretreatment mode is formed, and the medicament cost is reduced; the reaction condition is mild, and is generally normal temperature and normal pressure; the controllability is strong, the electrochemical reaction process can be controlled by adjusting the current and the voltage, the reaction selectivity is improved, and side reactions are prevented; meanwhile, both the electric flocculation and the electric oxidation can effectively slow down membrane pollution, and the flocculation and the oxidation can further cooperate to control the membrane pollution under the action of an electric field, so that the service life of the membrane can be prolonged, and the operation and maintenance cost can be reduced; the electric flocculation and the electric oxidation are coupled into one device, the occupied area is small, no medicament is used, the flow is short, two kinds of treatment can be realized by one-step operation, the process is flexible, the device can be used as a single water treatment process, and can also be used as a pretreatment or advanced treatment process to be combined with other treatment technologies, the process flow of the seawater desalination process is favorably shortened, the comprehensive cost of the treatment process is fully reduced, the seawater desalination project is more economical, and the device is particularly suitable for pretreatment of the small-scale seawater desalination project.

3. In the electrochemical treatment device provided by the invention, the electrode arrangement mode of the first electrode group and the second electrode group comprises a unipolar arrangement mode or a bipolar arrangement mode. When the first electrode group and the second electrode group are arranged in a multi-pole type, the induction electrodes which are not connected with the power supply are arranged between the anode and the cathode, so that the flocculation effect generated by the induction electrodes can be exerted, and simultaneously, under the action of a strong oxidizing substance, the induction electrodes are coupled with the generated polynuclear hydroxyl complexes and hydroxides to play a role in oxidation-flocculation synergy.

4. In the electrochemical processing apparatus of the present invention, the first anode and the first cathode in the first electrode group are preferably arranged in the following manner: the titanium electrode, the dimension stable anode and the titanium electrode are arranged in sequence. Because the two surfaces of the anode with stable size are both provided with oxide coatings, the titanium electrode, the anode with stable size and the titanium electrode are sequentially arranged according to the cross sequence, which is beneficial to fully utilizing the anode with stable size and improving the utilization efficiency of the anode.

5. According to the electrochemical treatment device provided by the invention, the first electrode groups are respectively arranged on the wall of the electrolytic tank close to the two end parts of the electrolytic tank, the other first electrode group is arranged in the middle of the electrolytic tank, so that the generated effective chlorine is uniformly distributed, the effective chlorine content is in a low concentration level through reasonable design and regulation, and the subsequent membrane treatment is damaged due to overhigh chlorine generating concentration, so that the post-treatment load is increased. The power supply is monitored and intelligently regulated on line, the number of the electrodes of the first electrode group and the second electrode group, the arrangement sequence of the electrodes and the like are further adjusted, and the concentration and the speed of chlorine production and flocculant production are controlled, so that the pretreatment step is flexibly adjusted.

6. In the electrochemical treatment apparatus according to the present invention, the power supply module preferably includes a first power supply connected to the first electrode group and a second power supply connected to the second electrode group. The pretreatment can be more flexible through the independent power supply arrangement of the first electrode group and the second electrode group. Further preferably, the electrochemical treatment device further comprises a monitoring unit, a PLC control unit and a remote monitoring and control unit, and the concentration of the chlorine generating agent and the concentration of the flocculant generating agent in the electrolytic cell are monitored and controlled in real time, so that a user can control substances generated in the electrolytic cell in real time according to actual needs, the flexibility of pretreatment steps is further increased, and low-maintenance and intelligent operation is realized.

7. The seawater desalination system provided by the invention comprises an electrochemical treatment unit and a membrane treatment unit which are sequentially connected, and further preferably comprises the electrochemical treatment unit, an ultrafiltration membrane treatment unit and a reverse osmosis membrane treatment unit which are sequentially connected. The electrochemical treatment unit can be used for pretreating seawater to remove suspended matters, partial pollutants, bacteria, algae and other microorganisms, so that the load of ultrafiltration membrane pollution can be relieved, and the inflow water quality of the reverse osmosis membrane can be ensured.

The electrochemical and membrane separation method is organically combined by adopting a mature, advanced and stable unit technology and utilizing the combination of the electrochemical and membrane separation water treatment technology to show a good synergistic effect, an electrochemical-double-membrane process is taken as a core, the problems of high drug consumption and high energy consumption of the existing double-membrane method are solved, the traditional pretreatment dosing mode is replaced, the pretreatment cost is reduced, and meanwhile, the synergistic effect of the electrooxidation and the electrocoagulation is utilized to slow down membrane pollution and prolong the service life of the membrane, so that the treatment process is advanced, efficient and stable.

The low-maintenance sea-fresh water integrated equipment is developed, the effluent can reach the standards of drinking water and various domestic water, and the equipment can be used for different environmental conditions, such as various special working environments of islands, ships, offshore drilling, disaster areas and the like, and is not limited by the water quality of water source areas. The seawater desalination treatment system has the characteristics of simple assembly, flexible assembly, simple and convenient management and operation and high treatment efficiency, and has good development and market prospects.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a first electrode set of an electrochemical processing apparatus according to the present invention;

FIG. 2 is a schematic view of the structure of an electrochemical processing apparatus provided in example 1 of the present invention;

FIG. 3 is a schematic diagram of the connection relationship of the seawater desalination system provided in embodiment 2 of the present invention;

fig. 4 is a schematic connection diagram of the intelligent seawater desalination system provided in embodiment 3 of the present invention.

Reference numerals:

1-an electrolytic cell; 2-water inlet pipe; 3-water outlet pipe; 4-titanium plate; 5-iron plate; 6-DSA electrode plate; 7-power supply components; 100-raw water pump; 200-an electrochemical processing unit; 300-folded plate reaction zone; 400-ultrafiltration membrane treatment unit; 401-an ultrafiltration membrane module; 402-an ultrafiltration membrane water production zone; 500-a booster pump; 600-an activated carbon filter; 700-cartridge filter; 800-reverse osmosis membrane treatment unit; 801-reverse osmosis membrane module; an 802-RO water tank; 900-a sterilization unit; 1100-a monitoring unit; 1101-residual chlorine on-line monitor; 1102-turbidity on-line monitor; 1200-a PLC control unit; 1300-remote monitoring regulation unit.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "left", "right", "front", "back", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The examples do not show the specific experimental steps or conditions, and can be performed according to the conventional experimental steps described in the literature in the field. The raw materials or equipment used are all conventional products which can be obtained commercially, including but not limited to the raw materials or equipment used in the examples of the present application.

an electrolytic cell;

a first electrode set and a second electrode set, both arranged in the electrolytic cell, the first electrode set comprising a first anode and a first cathode, the first anode comprising a dimensionally stable anode (DSA electrode), the first cathode comprising a titanium electrode, the second electrode set comprising a second anode and a second cathode, the second anode comprising an iron electrode or an aluminum electrode, the second cathode comprising an iron electrode or an aluminum electrode, at least one second electrode set arranged between two adjacent first electrode sets, and/or at least one first electrode set arranged between two adjacent second electrode sets;

and the positive electrode of the power supply component is connected with the anodes of the first electrode group and the second electrode group, and the negative electrode of the power supply component is connected with the cathodes of the first electrode group and the second electrode group.

The operation principle of the electrochemical treatment apparatus according to the present invention will be described below.

(1) The working principle of the first electrode group is as follows:

the invention provides an electrochemical treatment deviceThe first electrode group is used for generating electrooxidation reaction to achieve the purpose of sterilization and algae removal. As shown in fig. 1, the first electrode group is formed by coating a coating layer of noble metal oxide such as ruthenium and iridium on a surface of a titanium plate or a titanium rod, which is a dimensionally stable anode (also called DSA electrode) as an anode. The DSA electrode has strong capability of catalyzing and generating bactericidal active substances, does not dissolve in the electrolytic process and has long service life. On one hand, the organic matter is directly oxidized by the anode, on the other hand, the indirect oxidation is carried out, and on the other hand, the characteristic of high conductivity of the seawater is utilized, a large amount of chloride ions in the seawater are electrolyzed under the action of an electric field to generate chlorine, HClO and HClO₃The three are strong oxidants, can kill bacteria, algae and organic matters in seawater, and effectively slow down membrane pollution. Meanwhile, the titanium electrode is used as the cathode in the first electrode group, and the cathode mainly generates hydrogen evolution reaction while the anode generates oxidation reaction, so that OH in water is generated^-Rising and mixing with Mg in seawater²⁺The combination may be such that flocculation occurs simultaneously, with synergy with the second electrode set. The induction electrode (iron electrode) is corroded to generate Fe in the electrolytic process³⁺、Fe²⁺In water, a series of hydrolysis and polymerization occur to form hydroxyl complexes, polynuclear hydroxyl complexes and hydroxide flocculants, which also produce flocculation. The electrode group plays a role in oxidation and provides good supplement for controlling membrane pollution through cooperation of electric flocculation.

(2) The working principle of the second electrode group is as follows:

in the electrochemical treatment device provided by the invention, the second electrode group is used for generating an electric flocculation reaction to remove colloid and suspended impurities in seawater. The electroflocculation technique uses consumable metals (such as aluminum, iron, etc.) as electrodes, and under the action of direct current, the anode is corroded and electrolytically oxidized into metal cation Al³⁺、Fe³⁺、Fe²⁺After being mixed with water to be treated uniformly, colloidal impurities and suspended impurities in the water are destabilized and condensed to be removed; in addition, floc substances generated under the action of electric flocculation can be on the surface of the membraneA loose and porous filter cake layer is formed on the surface, so that the membrane pollution is effectively slowed down; meanwhile, under the electrochemical action, the gas generated by the anode and the cathode forms tiny bubbles and is adsorbed on the flocculating constituent, so that the flocculating constituent floats upwards and achieves the separation effect.

In addition, the first electrode group and the second electrode group are arranged in a crossed manner, so that the coupling effect of electric flocculation and electric oxidation is realized, and the membrane pollution can be effectively reduced under the action of an electric field. The electrochemical method is adopted to generate metal cations and form metal oxides on line, replaces flocculating agents and bactericides, does not introduce other ions, and does not influence pH. Magnesium hydroxide and other flocs generated by the first electrode group and iron and aluminum complexes generated by the second electrode group can synergistically adsorb organic particles, colloids and fine suspended solids in seawater, and the pollutant removal efficiency and the turbidity removal efficiency are improved. The two have synergistic effect on the pretreatment of water, and compared with the single treatment, the method can obviously reduce the content and turbidity of pollutants in water, effectively reduce membrane pollution, prolong the service life of the membrane and reduce the comprehensive cost of seawater desalination.

As an alternative embodiment of the present invention, the electrode arrangement of the first electrode group and the second electrode group includes a unipolar arrangement or a bipolar arrangement;

when the first electrode group and the second electrode group adopt a multi-pole arrangement mode, a first induction electrode is further arranged between the first anode and the first cathode, a second induction electrode is further arranged between the second anode and the second cathode, and the first induction electrode and the second induction electrode are not connected with a power supply. Preferably, the first and second sensing electrodes comprise at least one of iron electrodes, aluminum electrodes; the thickness of first response electrode and second response electrode is 2 ~ 8mm, and the area is 20000 ~ 60000mm²(ii) a The iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

It should be noted that the selection of the types and arrangement manners of the electrodes in the first electrode groups and the second electrode groups may be the same or different, that is, a unipolar arrangement manner or a bipolar arrangement manner may be adopted, or the arrangement manners of different electrode groups may be different; the first electrode group or the second electrode group can be selected from the same kind of electrodes, or different kinds of electrodes are selected among different electrode groups, for example, one first electrode group is selected from the arrangement of titanium electrode-dimensionally stable anode-titanium electrode, and the other first electrode group is selected from the arrangement of titanium electrode-inductive electrode-dimensionally stable anode-inductive electrode-titanium electrode; for another example, one second electrode group is selected from the iron electrode-sensing electrode-iron electrode arrangement, and the other second electrode group is selected from the iron electrode-sensing electrode-aluminum electrode arrangement.

As an alternative embodiment of the present invention, the first anode and the first cathode in the first electrode group are arranged in the following manner: the titanium electrode, the dimension stable anode and the titanium electrode are arranged in sequence.

As an optional embodiment of the invention, the number of the first electrode groups is 3-5 groups, and the number of the second electrode groups is 4-8 groups.

In an alternative embodiment of the present invention, the first electrode groups are provided on the wall of the electrolytic cell near both ends of the electrolytic cell, and the other first electrode group is provided or not provided in the middle of the electrolytic cell.

As an optional embodiment of the invention, the thickness of the first anode and the first cathode is 1.5-2.0 mm, and the thickness of the second anode and the second cathode is 2-8 mm; the area of the first anode, the first cathode, the second anode and the second cathode is 20000-60000 mm²(ii) a The distance between two adjacent electrodes is 10-20 mm; the anode with stable size is a titanium plate plated with rare metal oxide on the surface; the titanium electrode is a titanium plate, the iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

As an alternative embodiment of the invention, the power supply assembly comprises a first power supply and a second power supply, the first power supply being connected to the first electrode set and the second power supply being connected to the second electrode set.

As an alternative embodiment of the present invention, the first power supply and the second power supply provide a voltage of 36V and a current of 60A.

As an alternative embodiment of the present invention, the electrochemical processing apparatus further comprises: the water inlet pipe and the water outlet pipe are respectively communicated with the electrolytic bath.

As an alternative embodiment of the invention, the electrolytic cell is made of polyvinyl chloride (PVC) or polypropylene (PP) material that is very resistant to corrosion by sodium hypochlorite.

In a second aspect, the invention provides the use of an electrochemical treatment device in a desalination process.

It should be noted that the electrochemical treatment device provided by the invention is not only limited to be applied to seawater desalination treatment, but also can be used for treating other water with higher salt content.

In a third aspect, the present invention provides a seawater desalination system, comprising the aforementioned electrochemical treatment apparatus.

As an alternative embodiment of the present invention, a seawater desalination system comprises: an electrochemical processing unit and a membrane processing unit which are connected in sequence. Still further preferably, the seawater desalination system comprises: the device comprises an electrochemical treatment unit, an ultrafiltration membrane treatment unit and a reverse osmosis membrane treatment unit which are sequentially connected.

The electrochemical treatment unit can be used for pretreating seawater to remove suspended matters, partial pollutants, bacteria, algae and other microorganisms, so that the load of ultrafiltration membrane pollution can be relieved, and the inflow water quality of the reverse osmosis membrane can be ensured. The electrochemical and membrane separation method is organically combined by adopting a mature, advanced and stable unit technology and utilizing the combination of the electrochemical and membrane separation water treatment technology to show a good synergistic effect, an electrochemical-double-membrane process is taken as a core, the problems of high drug consumption and high energy consumption of the existing double-membrane method are solved, the traditional pretreatment dosing mode is replaced, the pretreatment cost is reduced, the membrane pollution can be effectively reduced, the life cycle of the membrane is prolonged, and the treatment process is advanced, efficient and stable. The low-maintenance sea-fresh water integrated equipment is developed, the effluent can reach the standards of drinking water and various domestic water, and the equipment can be used for different environmental conditions, such as various special working environments of islands, ships, offshore drilling, disaster areas and the like, and is not limited by the water quality of water source areas. The seawater desalination treatment system has the characteristics of simple assembly, flexible assembly, simple and convenient management and operation and high treatment efficiency, and has good development and market prospects.

As an optional embodiment of the invention, the ultrafiltration membrane treatment unit adopts an external immersed ultrafiltration membrane component, the outer diameter of the hollow fiber is 0.4-2.0 mm, and the inner diameter is 0.3-1.4 mm.

As an optional embodiment of the invention, the reverse osmosis membrane treatment unit adopts a Dow reverse osmosis membrane module.

As an optional embodiment of the present invention, the seawater desalination system further comprises: and the sterilization unit is arranged on one side of the reverse osmosis membrane treatment unit, which is far away from the ultrafiltration membrane treatment unit.

As an optional embodiment of the present invention, the seawater desalination system further comprises: the activated carbon filter and the security filter are arranged between the ultrafiltration membrane treatment unit and the reverse osmosis membrane treatment unit, the activated carbon filter is close to the ultrafiltration membrane treatment unit, and the security filter is close to the reverse osmosis membrane treatment unit.

As an optional embodiment of the present invention, the seawater desalination system further comprises:

The intelligent operation of the seawater desalination system is realized by arranging the detection unit, the PLC control unit and the remote monitoring and control unit. The specific working principle is as follows:

on one hand, the electrochemical processing unit generates active chlorine and enters a subsequent membrane processing unit, the residual chlorine on-line monitor is connected with a water outlet part of the membrane processing unit, the residual chlorine content of outlet water of the membrane processing unit is monitored on line to form a related monitoring data signal, the PLC control unit obtains the signal, whether the residual chlorine content of the outlet water exceeds the standard is judged according to a set value, a current regulation and control data signal is output to the electrochemical processing unit after calculation, the current of the first electrode group is adjusted in time to control the chlorine yield, meanwhile, the remote monitoring and control unit can observe residual chlorine data on line, and an on-line regulation and control model can be formed according to regulation and control historical data to regulate and control the PLC control unit.

On the other hand, the electrochemical processing unit produces the flocculating agent in order to reduce the sea water turbidity in the electrolysis trough, turbidity on-line monitoring appearance is connected with the electrochemical processing unit, the sea water turbidity in the monitoring electrochemical processing unit electrolysis trough forms relevant monitoring data signal, the PLC the control unit obtains above-mentioned signal, through calculating back output current regulation and control data signal to the electrochemical processing unit according to preset program, in time adjust the second electrode group current control and produce flocculating agent quantity, turbidity data can be observed on line to remote monitoring regulation and control unit simultaneously, and can form on-line regulation and control model in order to regulate and control PLC the control unit according to regulation and control historical data.

The units form an internet of things system, and the content of effective chlorine and effective flocculating agent generated by the electrochemical treatment unit is dynamically regulated and controlled by a closed loop mode of data acquisition, signal feedback, simulation model, signal output and current regulation and control, so that the water quality is ensured to be stable and reach the standard, and the intelligent regulation and control of the seawater desalination treatment system are realized.

In a fourth aspect, the present invention provides a seawater desalination method, which uses the aforementioned seawater desalination system to process seawater.

The technical solution provided by the present invention will be further explained with reference to specific embodiments.

Example 1

As shown in fig. 2, the present embodiment provides an electrochemical processing apparatus, which comprises the following components:

(1) an electrolytic cell 1: the utility model is used for water treatment provides the space, the cell body of electrolysis trough 1 is the cuboid shape, polypropylene (PP) material is made, the size of cell body is 690mm x 550mm x 615mm (length x width x height), the thickness of cell wall is 15mm, corresponding set up the trench on preceding, back cell wall and bottom cell wall, form the draw-in groove corresponding with plate electrode shape and thickness, be used for pegging graft the plate electrode, the interval between the adjacent draw-in groove is 20mm, the distance between draw-in groove and the cell wall at both ends about is 12 mm. The electrolytic tank 1 is also connected with a water inlet pipe 2 and a water outlet pipe 3 which are respectively used for leading water to be treated into the electrolytic tank 1 or discharging the treated water from the electrolytic tank 1.

(2) Electrode plate: all set up in electrolysis trough 1, peg graft and fix in the draw-in groove, set up 3 first electrode groups of group and 2 second electrode groups altogether, the arrangement order of electrode group: the electrode plate comprises a first electrode group, a second electrode group, a first electrode group, a second electrode group and a first electrode group, wherein the electrode plates are arranged in sequence from left to right: titanium plate 4 (first cathode) -iron plate 5 (induction electrode) -DSA electrode plate 6 (first anode) -iron plate 5 (induction electrode) -titanium plate 4 (first cathode) -iron plate 5 (second cathode) -iron plate 5 (induction electrode) -iron plate 5 (second anode) -titanium plate 4 (first cathode) -iron plate 5 (induction electrode) -DSA electrode plate 6 (first anode) -iron plate 5 (induction electrode) -titanium plate 4 (first cathode) -iron plate 5 (second cathode) -iron plate 5 (induction electrode) -iron plate 5 (second anode) -titanium plate 4 (first cathode) -iron plate 5 (induction electrode) -DSA electrode plate 6 (first anode) -iron plate 5 (induction electrode) -titanium plate 4 (first cathode).

The size of the titanium plate 4 is 800mm × 500mm × 2mm (length × width × thickness), and is provided by Shanxi Youguan environmental protection science and technology Limited;

the DSA electrode plate 6 has the size of 800mm multiplied by 500mm multiplied by 2mm (length multiplied by width multiplied by thickness), is provided by Shanxi Youguan environmental protection technology GmbH, and is a ruthenium yttrium coating titanium anode series YC-L1, DSA oxidation electrode;

the iron plate 5 has dimensions of 800mm × 500mm × 8mm (length × width × thickness), and is provided by yixing shun morning environmental protection equipment limited.

(3) The power supply component 7: the anode of the first power supply is respectively connected with the anode (DSA electrode plate) of each first electrode group, and the cathode of the first power supply is respectively connected with the cathode (titanium plate) of each first electrode group; the positive electrode of the second power supply is respectively connected with the positive electrode (iron plate) of each second electrode group, and the negative electrode of the second power supply is respectively connected with the negative electrode (iron plate) of each second electrode group; the induction electrode (iron plate) between the anode and cathode of each electrode group is not connected with the power supply.

A first power supply: the direct current power supply DH-17996 is provided by Dahua electronic group, the working voltage is 30V, the current is 60A, can pulse and reverse the pole, there is PLC programming function;

a second power supply: the direct current power supply RD-S30100G is provided by Vanderda electric company Limited, Suzhou, has the working voltage of 30V and the current of 60A, can pulse the pole, and has the PLC programming function.

In the electrochemical treatment device provided in example 1, the raw water quality may be seawater or brackish water, wherein the seawater generally requires an electrical conductivity higher than 30000 μ s/cm, and the brackish water generally has an electrical conductivity higher than 1500 μ s/cm.

The yield of the flocculant is 10mg/L (calculated by the effective components of the flocculant generated per unit volume of seawater); the active chlorine yield was 1kg/h (in terms of active chlorine yield per unit operating time).

Example 2

As shown in fig. 3, the present embodiment provides a seawater desalination system, which comprises the following components:

(1) the raw water pump 100: for pumping the seawater to the next unit.

(2) Electrochemical processing unit 200: the electrochemical treatment apparatus provided in example 1 has an inlet pipe connected to the raw water pump 100, and seawater is electro-oxidized and electro-flocculated in the electrochemical unit 200.

(3) Flap reaction area 300: is connected with a water outlet pipe of the electrochemical treatment device, and discharges the sludge sediment in the seawater treated by the electrochemical treatment unit 200.

(4) Ultrafiltration membrane treatment unit 400:

external submerged ultrafiltration membrane module 401: the model ES-18M provided by the Water technology holdings group, Inc. has the following specific information:

the outer diameter of the hollow fiber is 0.4-2.0 mm, and the inner diameter is 0.3-1.4 mm;

membrane area: 25-40m²；

The material of the film is as follows: polyvinylidene fluoride (PVDF);

operating pressure: 0.5-1 bar;

temperature and pH: the pH is 2-11 at 60 deg.C or below.

The seawater treated by the folded plate reaction zone 300 enters the ultrafiltration membrane treatment unit 400, is treated by the ultrafiltration membrane module 401 and then enters the ultrafiltration water production zone 402, and the water entering the ultrafiltration water production zone 402 can also backwash the ultrafiltration membrane module 401. Most of the particles, colloids, bacteria and high molecular organic substances in the seawater are removed by the ultrafiltration membrane treatment unit 400.

(5) 500 parts of a booster pump: the seawater treated by the ultrafiltration membrane treatment unit 400 is pressurized by the booster pump 500 and then pumped into the subsequent units.

(6) Activated carbon filter 600: booster pump 500 pumps seawater into activated carbon filter 600 to filter out organics and quench active chlorine.

(7) Cartridge filter 700: the water filtered by the activated carbon filter 600 enters the security filter 700 for further filtration to ensure the water quality entering the reverse osmosis membrane treatment unit 800 and avoid damage to the reverse osmosis membrane.

(8) Reverse osmosis membrane treatment unit 800:

a high-pressure pump: danfoss APP-W7.2, Q ═ 6m³H, h 600m, operating pressure: 5-6 MPa;

the dow reverse osmosis membrane module 801: the model SW30-8040 provided by the Water technology holdings group, Inc., has the following specific information:

the membrane pore size is about 0.1 nm;

the material of the film is as follows: a spiral wound polyamide composite film element;

the material of the film frame: SUS304 or SUS 316;

operating pressure: 10-15 bar.

The seawater treated by the cartridge filter 700 enters the reverse osmosis membrane treatment unit 800, the high pressure pump provides sufficient water inflow and water inflow pressure, and the reverse osmosis membrane module 801 intercepts various inorganic ions, colloidal substances and macromolecular solutes in the water, thereby obtaining high-quality pure water, which enters the RO water tank 802 for storage.

(9) The sterilization unit 900: the pure water in the RO water tank 802 is subjected to ultraviolet sterilization by the sterilization unit 900, thereby completing seawater desalination.

Example 3

The embodiment provides an intelligent seawater desalination system, as shown in fig. 4, the following units are further added on the basis of the components provided in embodiment 2:

(1) the monitoring unit 1100: the on-line monitoring device comprises an on-line residual chlorine monitor 1101 and an on-line turbidity monitor 1102, wherein the on-line residual chlorine monitor 1101 is connected with a water outlet part of a membrane processing unit and is used for monitoring the residual chlorine content of outlet water of the membrane processing unit on line, and the on-line turbidity monitor 1102 is connected with an electrochemical processing unit 200 and is used for monitoring the seawater turbidity in an electrolytic bath of the electrochemical processing unit 200. The on-line monitor for residual chlorine/total chlorine-HachCL 17Dsc and the on-line monitor for turbidity-Hach 1720E are all provided by Water technologies, Inc.

(2) PLC control unit 1200: the monitoring unit is respectively connected with the monitoring unit 1100 and the electrochemical processing unit 200 and is used for acquiring monitoring data signals of the residual chlorine on-line monitor 1101 and the turbidity on-line monitor 1102, calculating current regulation and control data according to a preset program, and outputting the current regulation and control data signals to the electrochemical processing unit 200 so as to regulate and control the sizes of the electrified currents of the first electrode group and the second electrode group in the electrochemical processing unit 200, thereby changing the chlorine yield and the flocculating agent yield of the electrochemical processing unit 200. The PLC control unit 1200 selects the PLC control cabinet SYDZ-ST01, which is provided by water technology stock group, ltd.

(3) The remote monitoring and controlling unit 1300: respectively connected with the monitoring unit 1100 and the PLC control unit 1200 for observing the monitoring data and regulating the PLC control unit 1200. The unit belongs to a platform for data acquisition, statistics, modeling and regulation of the Internet of things, adopts a water technology data Internet of things platform SYWL-ST01 and is provided by water technology stock group, Inc.

Example 4

The embodiment provides a seawater desalination method, which is performed by using the seawater desalination system provided in embodiment 2, and includes the following steps:

(1) electrochemical treatment: pumping seawater to be treated to an electrochemical treatment unit through a water inlet pipe by a raw water pump to generate electrooxidation and electroflocculation, killing microorganisms such as bacteria and algae in the seawater and generating flocculation with pollutants in the water;

(2) and (3) precipitation: discharging the water treated in the step (1) into a folded plate reaction area through a water outlet pipe, and discharging sludge sediment in seawater;

(3) and (3) ultrafiltration membrane treatment: introducing the water treated in the step (2) into an ultrafiltration membrane treatment unit for treatment, removing most particles, colloids, bacteria and high molecular organic substances in seawater, and introducing the treated water into an ultrafiltration water production area;

(4) and (3) filtering: pressurizing the water treated in the step (3), and then sequentially introducing an activated carbon filter and a security filter, filtering to remove organic matters and quench active chlorine, and ensuring the water quality entering a reverse osmosis membrane treatment unit;

(5) reverse osmosis membrane treatment: and (4) introducing the water treated in the step (4) into a reverse osmosis membrane treatment unit for treatment, intercepting various inorganic ions, colloidal substances and macromolecular solutes in the water, thus obtaining high-quality pure water, and introducing the treated water into an RO water tank.

(6) And (3) sterilization: and (4) performing ultraviolet sterilization on the water treated in the step (5), and enabling the sterilized water to enter a clear water facility or a water storage facility and a pipe network.

Comparative example 1

The present comparative example provides a seawater desalination system, which is different from example 3 only in that all the first electrode groups are omitted from the electrochemical treatment apparatus, the anodes and cathodes of the second electrode groups are made of iron plates and connected in a single-stage arrangement manner, and the number of the second electrode groups is 4.

Comparative example 2

The present comparative example provides a seawater desalination system, which is different from example 3 only in that all second electrode sets are omitted from the electrochemical treatment apparatus, the anodes of the first electrode sets are DSA electrode plates, the cathodes of the first electrode sets are titanium plates, and the first electrode sets are connected in a single-stage arrangement manner, and the number of the first electrode sets is 3.

Comparative example 3

This comparative example provides a seawater desalination system which differs from example 3 only in that the arrangement order of the electrode groups in the electrochemical treatment apparatus is: the first electrode group, the second electrode group and the second electrode group are connected in a single-stage arrangement mode, and specifically, the arrangement sequence of the electrode plates from left to right is as follows: titanium plate (first cathode) -DSA electrode plate (first anode) -iron plate (second cathode) -iron plate (second anode).

Examples of the experiments

The seawater desalination system provided in example 3 was used to treat seawater to verify the desalination effect, and the seawater desalination systems provided in comparative examples 1-3 were used as controls. The experimental site is island of Taizhou Zhejiang, the conductivity of the seawater to be treated is 35000 mu s/cm, the inlet water turbidity is 60NTU, and the current density between each pair of polar plates is 20A/m²And the seawater treatment capacity is 50 t/d.

(1) Detecting the effluent quality of an electrochemical treatment unit of a seawater desalination system:

firstly, detecting the content of available chlorine in water, wherein the detection method adopts a spectrophotometry method and utilizes a real-time residual chlorine monitoring instrument hach-cl17 for online detection.

Secondly, detecting the organic matter content and turbidity of the effluent, and calculating the organic matter removal rate and turbidity removal rate, wherein the calculation formula is as follows:

organic matter removal rate (COD)_{Go out}-COD_Into)/COD _Into100% of the total of all the total of all the total_{Go out}The effluent water of the electrochemical treatment unit has organic matter content, COD_IntoIs the influent organic matter content of the electrochemical treatment unit;

turbidity removal rate (raw water turbidity-effluent turbidity)/raw water turbidity 100%.

The method for detecting the content of the organic matters adopts a rapid digestion test method, and COD (hach-DR2800) rapid digestion instruments and COD rapid measuring instruments are used for measuring COD of a water sample;

the turbidity detection method refers to 2.1 section scattering method-formalin standard in national standard GB/T5750.4-2006 'standard sensory properties and physical indexes of standard test method for drinking water for life', and the instrument is as follows: hash DR1900 turbidimeter.

(2) Detecting the quality of the effluent water after the seawater desalination system is subjected to ultraviolet sterilization:

detecting the conductivity of the produced water, and calculating the desalination rate by the following calculation formula:

salt rejection rate (TDS)_{Original source}-TDS_{Product produced by birth})/TDS _{Original source}100% of, wherein TDS_{Original source}Is the conductivity, TDS, of raw water of a seawater desalination system_{Product produced by birth}Is the conductivity of the produced water of the seawater desalination system.

The detection method of the conductivity refers to section 6.1 of national standard GB/T5750.4-2006 ' standard test method for drinking water sensory properties and physical indexes ' of the people's republic of China, and a DDS-307 conductivity meter of the Remamoto corporation is adopted to measure the conductivity.

(3) The quality of the effluent water after the seawater desalination system is subjected to ultraviolet sterilization is detected, and whether the effluent water meets the sanitary standard for drinking water (GB5749-2006) is determined.

The results of the three tests are shown in table 1.

TABLE 1 seawater desalination treatment Effect

As can be seen from Table 1, after electrochemical treatment, the content of available chlorine in comparative example 1 is low, only 0.2mg/L, the turbidity removal rate is 70%, and the organic matter removal rate is 50%, so that the comparative example 1 causes the problems of excessive microorganism content and serious subsequent membrane pollution, and in the experimental process, the flocs generated in an electrolytic bath are large, but the effluent chromaticity is excessive; comparative example 2 generates higher effective chlorine of 2.5mg/L, the removal rate of organic matters is 80%, the removal rate of turbidity is only 30%, the yield of the effective chlorine is far higher than the design requirement, but the treatment load of the subsequent reverse osmosis membrane is increased, fewer floccules are generated in the experimental process, floccules are generated around the cathode only, the turbidity of the outlet water does not meet the water inlet requirement of membrane treatment, and the subsequent membrane is seriously polluted; comparative example 3, the content of available chlorine in water is 1.5mg/L, the removal rate of organic matters is 82%, and the removal rate of turbidity is 75%, in the experimental process, the comparative example 3 can generate higher available chlorine and generate more flocs, but the available chlorine and the flocs in the water are not uniformly distributed, so that the treatment effect is influenced, in addition, the connection mode enables the operation voltage to be increased, the total voltage is about 20V, the energy consumption is higher, which is about 60% higher than that of example 3, and the defect that the second anode is consumed too fast exists; the electrolytic cell of the embodiment 3 has the advantages of uniform distribution of the effective chlorine and flocs, proper content of the effective chlorine, high removal rate of organic matters and turbidity, effluent meeting the requirement of subsequent membrane treatment, low energy consumption and total voltage of only 8V.

Because the seawater desalination systems of the embodiment and the comparative example are provided with the ultrafiltration membrane treatment unit and the reverse osmosis membrane treatment unit, the difference of final desalination rate is not large, but after the electrochemical treatment unit of the embodiment 3 is used for treatment, the membrane pollution degree of the ultrafiltration unit is minimum, the water production flux is maximum, the overall removal effect is better than that of other three modes, and the energy consumption is minimum.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. An electrochemical processing apparatus, comprising:

an electrolytic cell;

a first set of electrodes and a second set of electrodes, both disposed within the electrolytic cell, the first set of electrodes comprising a first anode and a first cathode, the first anode comprising a dimensionally stable anode, the first cathode comprising a titanium electrode, the second set of electrodes comprising a second anode and a second cathode, the second anode comprising an iron or aluminum electrode, the second cathode comprising an iron or aluminum electrode, at least one set of second electrode sets disposed between two adjacent sets of first electrodes, and/or at least one set of first electrode sets disposed between two adjacent sets of second electrodes;

2. The electrochemical processing apparatus according to claim 1,

the arrangement mode of the electrodes of the first electrode group and the second electrode group comprises a unipolar arrangement mode or a bipolar arrangement mode;

when the first electrode group and the second electrode group are arranged in a multi-pole mode, a first induction electrode is arranged between the first anode and the first cathode, a second induction electrode is arranged between the second anode and the second cathode, and the first induction electrode and the second induction electrode are not connected with the power supply assembly;

preferably, the first and second sensing electrodes comprise iron electrodes and/or aluminum electrodes; the thickness of first response electrode and second response electrode is 2 ~ 8mm, and the area is 20000 ~ 60000mm²(ii) a The iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

3. The electrochemical processing apparatus according to claim 1,

the arrangement mode of the first anode and the first cathode in the first electrode group is as follows: the titanium electrode, the dimension stable anode and the titanium electrode are arranged in sequence;

4. The electrochemical processing apparatus according to claim 1,

the thickness of the first anode and the first cathode is 1.5-2.0 mm, and the thickness of the second anode and the second cathode is 2-8 mm; the area of the first anode, the first cathode, the second anode and the second cathode is 20000-60000 mm²(ii) a The distance between two adjacent electrodes is 10-20 mm; the anode with stable size is a titanium plate plated with a rare metal oxide coating on the surface; the titanium electrode is a titanium plate, the iron electrode is an iron plate, and the aluminum electrode is an aluminum plate.

5. The electrochemical processing apparatus according to claim 1,

the power supply assembly comprises a first power supply and a second power supply, the first power supply is connected with the first electrode group, and the second power supply is connected with the second electrode group;

preferably, the voltage provided by the first power supply and the second power supply is 36V, and the current is 60A.

6. Use of an electrochemical treatment device according to any one of claims 1 to 5 in a desalination process.

7. A seawater desalination system comprising the electrochemical treatment apparatus according to any one of claims 1 to 5.

8. The seawater desalination system of claim 7, comprising: the electrochemical treatment unit and the membrane treatment unit are connected in sequence, and the electrochemical treatment unit comprises the electrochemical treatment device;

preferably, the seawater desalination system comprises: the electrochemical treatment unit, the ultrafiltration membrane treatment unit and the reverse osmosis membrane treatment unit are sequentially connected;

more preferably, the ultrafiltration membrane treatment unit adopts an external immersed ultrafiltration membrane component, the outer diameter of the hollow fiber is 0.4-2.0 mm, and the inner diameter is 0.3-1.4 mm;

the reverse osmosis membrane treatment unit adopts a Dow reverse osmosis membrane component;

the seawater desalination system further comprises: the sterilization unit is arranged on one side of the reverse osmosis membrane treatment unit, which is far away from the ultrafiltration membrane treatment unit;

the seawater desalination system further comprises: the activated carbon filter and the security filter are arranged between the ultrafiltration membrane treatment unit and the reverse osmosis membrane treatment unit, the activated carbon filter is close to the ultrafiltration membrane treatment unit, and the security filter is close to the reverse osmosis membrane treatment unit.

9. The seawater desalination system of claim 8, further comprising:

10. A method for desalinating seawater, characterized in that the seawater is treated by using the seawater desalination system according to any one of claims 7 to 9.