CN105253991B - A kind of electromagnetic field couples desalter and method for having the dirty function of drop concurrently - Google Patents

Abstract

The invention discloses an electromagnetic field coupling desalination device and method with the function of reducing pollution. The device includes a reactor, and the reactor is sequentially divided into an anode chamber, an intermediate chamber and a cathode chamber; the anode chamber is equipped with a domestic sewage inlet and domestic sewage outlet, with built-in anode electrodes; the intermediate chamber has seawater inlet and fresh water outlet; the cathode chamber has acid waste water inlet and acid waste water outlet, and built-in cathode electrodes; the cathode electrode and the anode electrode are connected by wires connection; the reactor is also provided with a weak magnet providing a horizontal magnetic field for the anode chamber and a strong magnet providing a vertical magnetic field for the intermediate chamber. The domestic sewage is sent into the anode chamber, the acid waste water is sent into the cathode chamber, and the seawater is sent into the middle chamber, and the vertical magnetic field of the middle chamber and the horizontal magnetic field of the anode chamber are activated to carry out the electromagnetic field coupling desalination reaction, which can be used while treating domestic sewage. The electric field coupled with the magnetic field generated by the device removes the salt in the seawater.

Description

An electromagnetic field coupling desalination device and method with pollution reduction function

technical field

The invention relates to the field of seawater desalination and domestic sewage treatment, in particular to an electromagnetic field coupling desalination method and device with the function of reducing pollution.

Background technique

The lack of fresh water resources is one of the focal issues in the 21st century. According to statistics, the total amount of water resources on the earth is huge, about 1.38 billion cubic kilometers, but 97.5% of it is seawater (1.345 billion cubic kilometers), and fresh water only accounts for 2.5%, most of which are polar ice and snow glaciers and groundwater. Only 0.01% is really enjoyed by humans. Although China ranks sixth in the world in fresh water resources, the uneven distribution of water resources in space and time has led to China's per capita fresh water resources ranking 119 in the world, and 110 cities across the country are seriously short of water. Under this severe situation, It is imminent to develop seawater desalination technology industry to solve the problem of water scarcity.

Traditional seawater desalination technologies include distillation, freezing, electrodialysis, and membrane methods. The distillation method is relatively primitive. By heating seawater, the water is vaporized and then condensed to separate from the salt. However, distillation equipment has problems such as high cost, easy damage of accessories under high temperature and high pressure conditions, and huge energy consumption. Freezing is a method of separating salt from frozen seawater to obtain seawater. However, the process of freezing seawater also consumes a lot of energy, and the quality of the separated seawater is poor. Electrodialysis and membrane methods are two new directions for seawater desalination. Although electrodialysis solves the problems of high energy consumption, many chemical agents added, and complicated operations, the residual chemical agents added in the seawater desalination chamber make the effluent water unusable. Drinking water; and the membrane method has the disadvantages of high membrane cost and poor reusability.

Patent CN201510130271.3 discloses a seawater desalination system and seawater desalination method. The impurity particles in seawater undergo ion concentration polarization under the action of an electric field, and then the seawater is separated from the freshwater under the action of external pressure. . However, the system accessories are complex and require multiple processes, and the system is only suitable for a small amount of seawater desalination, and the energy consumption will increase during the expansion process, so the application prospect is relatively small. The invention of patent CN201210289714.X relates to a seawater desalination device, including an air humidification tower and an air dehumidification tower. The upper parts of the air humidification tower and the air dehumidification tower are connected to each other. Fresh water reduces the cost of seawater desalination, but due to this feature, seawater desalination is greatly restricted by region.

At the same time, with the acceleration of urbanization, the discharge of domestic sewage has increased dramatically. At present, the treatment of domestic sewage is aimed at removing COD, but research shows that COD is an inferior energy source with potential utilization value. On the other hand, using magnetic fields to concentrate and purify water is a technology with potential applications.

Therefore, it is necessary how to couple multiple directions of water treatment and multiple biophysical technologies to achieve the goals of energy saving, environmental protection and sustainability.

Contents of the invention

The invention provides an electromagnetic field coupling desalination device and method with pollution reduction function, which can desalinate seawater by using the electric field coupling magnetic field generated by the device itself while treating domestic sewage.

An electromagnetic field coupled desalination device with pollution reduction function, including a reactor, the reactor is divided into an anode chamber, an intermediate chamber and a cathode chamber in sequence;

The anode chamber has a domestic sewage inlet and a domestic sewage outlet, and a built-in anode electrode; the intermediate chamber has a seawater inlet and a fresh water outlet; the cathode chamber has an acidic wastewater inlet and an acidic wastewater outlet, and a built-in cathode electrode;

The cathode electrode and the anode electrode are connected by wires;

The reactor is also provided with a weak magnet providing a horizontal magnetic field for the anode chamber and a strong magnet providing a vertical magnetic field for the intermediate chamber.

The inside of the reactor is followed by an anode chamber, an intermediate chamber and a cathode chamber along the length direction, the anode chamber and the intermediate chamber are separated by an anion membrane, the intermediate chamber and the cathode chamber are separated by a cation membrane, the cathode electrode and the anode electrode They are connected by wires and connected to the battery. The electric energy generated during sewage treatment can offset part of the external power supply electric energy. On the basis of low energy consumption or even no energy consumption, the purpose of not only treating domestic sewage but also removing salt in seawater is achieved. At the same time, the photocatalytic cathode Under the catalysis of natural light, H ⁺ in acidic wastewater can be reduced, and anode electrons can be exported without secondary pollution.

In the present invention, a third chamber is added between the anode chamber and the cathode chamber to form a three-chamber system. The microorganisms attached to the carbon brush electrode on the anode degrade the COD in domestic sewage and generate additional electrons, while the presence of a weak horizontal magnetic field at the anode can greatly Improve the performance of the anode biofilm, lead the wire to the cathode to form a loop, and the generated electric energy is collected in the battery to supplement the electricity required for the water inflow of the device. Anions are diverted to the anode chamber and cations are diverted to the cathode chamber, thus achieving desalination. The cathode adopts photocatalytic silicon material, which can reduce H ⁺ in acidic wastewater under natural light conditions without cathode consumables or external potential, which greatly saves costs. More importantly, the process consumes less energy, and domestic sewage is treated without additional pollutant discharge. It is an environmentally friendly desalination design.

Preferably, the material of the anode electrode is carbon-based material. Such as graphite plate, carbon brush, carbon felt. It is further preferably a carbon brush, which is low in cost, large in specific surface area, has good electrical conductivity, facilitates electron export, and has good corrosion resistance, and can be widely used in practical applications. The anode electrode is first rinsed with a surfactant, such as sodium dodecylbenzenesulfonate, o-phenylphenol.

Preferably, the cathode electrode is a surface-treated photocatalytic silicon electrode. Photocatalytic silicon electrode and surface treatment itself can adopt prior art, preferably, photocatalytic silicon electrode surface treatment method and steps are as follows:

(1) Active ion etching of single crystal silicon slices, forming nanowire arrays on the surface of single crystal silicon;

(2) Then lightly doped p-Si nanowires modify a thin layer of highly doped n ⁺ layer to improve the photovoltage output;

(3) Modify the 30nm conformal coated titanium dioxide layer at a high temperature of 300°C to achieve a self-made atomic deposition layer to ensure long-term stable operation in a neutral pH electrolyte environment;

(4) Ni with a thickness of about 10 nm is modified on the electrode by quasi-conformal spraying.

Preferably, the anode chamber, the intermediate chamber and the cathode chamber are sequentially arranged along the length direction of the reactor, and the aspect ratio of the reactor is 1:10˜1:12. The desalination efficiency is further improved under this ratio condition. Still more preferably, the width of the reactor is more than 50 cm.

Preferably, the thickness of the intermediate chamber is 1mm-10mm. Further preferably, the thickness of the intermediate chamber is 5 mm.

The thickness here refers to the distance between the cationic membrane and the anionic membrane.

Preferably, the height of the reactor is 5cm-15cm, too thin, and the volume of the intermediate chamber is small. More preferably, it is 10 cm.

The present invention also provides a method for electromagnetic field coupling desalination, preferably carried out by using the device of the present invention, comprising the following steps:

The domestic sewage is sent into the anode chamber, the acidic waste water is sent into the cathode chamber, and the seawater is sent into the middle chamber, and the vertical magnetic field of the middle chamber, the horizontal magnetic field of the anode chamber and the internal electric field in the reactor are activated to carry out the electromagnetic field coupling desalination reaction and purify The final domestic sewage, acid wastewater and desalinated water are discharged out of the reactor.

After the analysis and calculation of the magnetic field force F=q×V×B and the friction coefficient f=6πηr (η is the viscosity of the liquid, r is the ion radius) of the water during ion movement, and combined with the condition screening of the device itself.

Preferably, the magnetic field strength of the intermediate chamber is 6000Gs-12000Gs. The horseshoe-shaped NdFeB strong magnet with a magnetic field strength of 10000Gs is optimally selected. The vertical magnetic field applied to the intermediate chamber is perpendicular to the bottom surface of the intermediate chamber, that is, the vertical magnetic field in the present invention is a vertical magnetic field.

The increase of the magnetic field strength is conducive to greater deflection of moving anions and cations, and the work done by the Loren magnetic force component is greater to overcome the frictional resistance to water.

Preferably, the magnetic field strength of the anode chamber is 1500Gs-2500Gs. The best choice is a weak magnet with a magnetic field strength of 2000Gs.

Preferably, the seawater flow velocity in the intermediate chamber is 0.5m/s-2m/s. Considering energy saving and ion deflection force, the optimal value is 1m/s. If the deflection is too slow, the deflection effect is poor, and if the ion is too fast, it will flow out of the water outlet before it can pass through the membrane.

Preferably, during a treatment process, the residence time of the seawater in the intermediate chamber is 3-6 hours. After one cycle of treatment with a cycle of 3 hours, the salinity of seawater will drop below 1.5g/L, and the desalination rate will reach more than 95%.

Preferably, the water temperature in the intermediate chamber is controlled at 25-35°C. More preferably, it is 30°C.

Preferably, the feed water to the cathode chamber is weakly acidic wastewater with a pH of 5-6.

Most preferably, during the start-up phase of the device, the cathode chamber is filled with M9 electrolyte, and the anode chamber is inoculated with bacterial liquid, which is composed of domestic sewage containing 2000 mg/L of organic matter and electricity-producing mixed bacterial liquid of 1:2 (volume ratio), and the intermediate chamber is filled with The salinity of the static state is about 30% of seawater, the reactor is started at 30°C, and the start-up time is about 1 day; the magnetic field strength of the middle chamber is 10000Gs, and the magnetic field strength of the anode chamber is 2000Gs;

After the device is running stably, domestic sewage with a COD of 300mg/L is sent into the anode chamber at a flow rate of 4.6t/(m ³ d), so that the microorganisms on the anode electrode can obtain sufficient carbon sources, and at the same time, the sewage COD is effectively degraded; In the cathode chamber, the water flow rate is 9.2m ³ /(m ³ ·d) to send weakly acidic wastewater;

After the device runs stably, raw seawater enters the intermediate chamber at a flow rate of 1m/s, and the water flowing out of the seawater outlet is combined with the raw water through the pipeline and then pumped into the intermediate chamber, thus forming a cycle, with 6h as a cycle.

After one cycle, the COD of domestic sewage effluent is reduced to below 80mg/L, the concentration of seawater is reduced to about 1g/L, and the desalination rate reaches above 96.7%.

The present invention adds a strong magnet in the middle chamber to the structure of the device, uses the Loren magnetic force of charged particles to couple the electric field force of the inner circuit to strengthen the desalination effect; adds a common magnet outside the anode, and uses the effect of a weak magnetic field on microorganisms to increase the output current, thereby further Improve desalination efficiency. In terms of processing technology, the present invention essentially utilizes the coupling of the internal circuit electric field and the external enhanced magnetic field to act on anions and cations; the cathode adopts surface-treated photocatalytic silicon electricity, which can reduce H+ under sunlight conditions.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The weak electric field at the anode level improves the performance of the biofilm and increases the power production.

(2) The surface-treated photocatalytic silicon electrode can reduce the weakly acidic electrolyte under sunlight conditions, solve the problem of cathode consumables, and greatly save costs.

(3) The weak electric field of the anode improves the performance of the biofilm, increases the electric field of the internal circuit, couples the strong magnetic field, and achieves the desalination effect enhanced by the electric field and magnetic field.

(4) The surface-treated photocatalytic cathode electrode can additionally treat weakly acidic wastewater, achieving the four-in-one effect of electricity generation, enhanced desalination, domestic sewage treatment and weakly acidic wastewater treatment, and there is no secondary pollution and no cathode consumption. Realize low-cost operation.

(5) The desalination time is short and the efficiency is high. After a treatment cycle of 3 hours, the COD of domestic sewage effluent is reduced to 100mg/L, the salinity of seawater is reduced to below 1.5g/L, and the desalination rate reaches more than 95%.

Description of drawings

Fig. 1 is a three-dimensional schematic diagram of the device of the present invention.

Fig. 2 is a schematic top view of the device of the present invention.

The reference signs shown in the figure are as follows:

1-cathode electrode 2-cathode chamber 3-domestic sewage inlet

4-Sea water inlet 5-Anode chamber 6-Anode electrode

7-Fresh water outlet 8-Vertical magnetic field 9-Internal electric field

10-Domestic sewage outlet 11-Intermediate room 12-Strong magnet

13-anion membrane 14-cation membrane 15-acid wastewater inlet

16- Acid waste water outlet. 17-weak magnet 18-water pump

19 - Water storage tank.

detailed description

Example 1

As shown in Figure 1 and Figure 2, an electromagnetic field coupled desalination device with the function of reducing pollution includes reactors, several water pumps and batteries.

Inside the reactor along the length direction are cathode chamber 2 , intermediate chamber 11 and anode chamber 5 . The cathode chamber and the intermediate chamber are separated by a cationic membrane 14, and the anode chamber and the intermediate chamber are separated by an anionic membrane 13, so that each chamber is independent.

A cathode electrode 1 is arranged in the cathode chamber, and the cathode electrode is a photocatalytic silicon electrode. An acid waste water inlet 15 and an acid waste water outlet 16 are arranged on the side wall of the cathode chamber. The cathode chamber 2 is composed of a cathode electrode, a cationic membrane 14, an acid waste water inlet 15 and an acid waste water outlet Composed of 16; the anode chamber is provided with an anode electrode 6, and the anode adopts a carbon brush electrode. The side wall of the anode chamber is provided with a domestic sewage inlet 3 and a domestic sewage outlet 10. It is composed of domestic sewage outlet 10 and anion exchange membrane; between cation membrane 14 and anion membrane 13 is an intermediate chamber 11, and seawater inlet 4 and fresh water outlet 7 are provided on the side wall of the intermediate chamber.

Weak magnets 17 are set outside the anode chamber 5, and the weak magnets are common magnets that provide a horizontal magnetic field for the anode chamber; strong magnets 12 are set outside the middle room, and the strong magnets are horseshoe-shaped NdFeB strong magnets that provide vertical magnetic fields 8 for the middle chamber. An internal electric field 9 is formed between the electrodes and the cathode electrode.

The anode electrode and the cathode electrode are connected by wires and connected to the storage battery, and the storage battery is connected to various water pumps 18 to provide part of the electric energy for the water pumps.

The aspect ratio of the reactor is 1:10-1:12. The width of the reactor is 50 cm or more (preferably 100 cm in this embodiment). The height is 5cm-15cm (preferably 10cm in this embodiment), and the thickness of the intermediate chamber is 1mm-10mm (preferably 2mm in this embodiment).

The specific operation process of the desalination device is as follows:

During the start-up phase of the device, the cathode chamber is filled with M9 electrolyte, and the anode chamber is inoculated with bacterial solution. The bacterial solution is composed of domestic sewage containing 2000 mg/L of organic matter and electrogenic mixed bacterial solution (conventional electrogenic bacteria) at a ratio of 1:1 (volume ratio). The chamber is filled with seawater with a salinity of about 3% in a static state, and the reactor is started at 30°C for about 2 days. During the process, the vertical magnetic field strength in the intermediate chamber is 10000Gs, and the horizontal magnetic field strength in the anode chamber is 2000Gs.

After several cycles of stable operation of the device, the anode chamber is replaced by a peristaltic pump and the domestic sewage with a COD ^of 500mg/ ^L is controlled to enter the water inlet. The carbon source is sufficient, and the COD of the sewage is effectively degraded; the cathode chamber is replaced by a peristaltic pump and the water flow rate of the weakly acidic wastewater entering the water inlet is controlled to be 9.2m ³ /(m ³ ·d).

After several cycles of stable operation of the device, the seawater raw water enters the seawater inlet through the water pump at a flow rate of 1m/s, and the water flowing out from the seawater outlet is combined with the raw water through the pipeline and then pressed into the middle chamber through the water pump, thus forming a cycle, which takes 1.5h for a cycle.

After one cycle, the COD of domestic sewage effluent is reduced to 200mg/L, the salinity of seawater is reduced to below 10g/L, and the desalination rate reaches above 66.7%.

Example 2

The overall structure of the device is the same as in Example 1.

During the start-up phase of the device, the cathode chamber is filled with M9 electrolyte, and the anode chamber is inoculated with bacterial solution. The bacterial solution is composed of domestic sewage containing 2000mg/L of organic matter and electrogenic mixed bacterial solution (conventional electrogenic bacteria) at a volume ratio of 1:2. The chamber is filled with seawater with a salinity of about 3% in a static state, and the reactor is started at 30°C for about 1 day. During the process, the vertical magnetic field strength in the intermediate chamber is 10000Gs, and the horizontal magnetic field strength in the anode chamber is 2000Gs.

After several cycles of stable operation of the device, the peristaltic pump is used to replace and control the domestic sewage with a COD of 500mg/L to enter the water inlet, and the inflow flow rate is 2.3t/(m ³ ·d), so that the microorganisms on the anode electrode can obtain sufficient carbon source At the same time, the sewage COD is effectively degraded; the cathode chamber is replaced by a peristaltic pump and the water flow rate of weakly acidic wastewater entering the water inlet is controlled to 9.2m ³ /(m ³ ·d).

After several cycles of stable operation of the device, the seawater raw water enters the seawater inlet through the water pump at a flow rate of 1m/s, and the water flowing out of the seawater outlet is combined with the raw water through the pipeline and then pressed into the middle chamber by the water pump, thus forming a cycle, which takes 3 hours A cycle.

After one cycle, the COD of domestic sewage effluent is reduced to 100mg/L, the salinity of seawater is reduced to below 1.5g/L, and the desalination rate reaches more than 95%.

Example 3

The overall structure of the device is the same as in Example 1.

During the start-up phase of the device, the cathode chamber is filled with M9 electrolyte, and the anode chamber is inoculated with bacterial solution. The bacterial solution is composed of domestic sewage containing 2000mg/L of organic matter and electrogenic mixed bacterial solution (conventional electrogenic bacteria) at a volume ratio of 1:2. The chamber is filled with seawater with a salinity of about 3% in a static state, and the reactor is started at 30°C for about 1 day. During the process, the vertical magnetic field strength in the intermediate chamber is 10000Gs, and the horizontal magnetic field strength in the anode chamber is 2000Gs.

After several cycles of stable operation of the device, the peristaltic pump is used to replace and control domestic sewage with a COD of 300mg/L to enter the water inlet, and the inflow flow rate is 4.6t/(m ³ ·d), so that the microorganisms on the anode electrode can obtain sufficient carbon sources At the same time, the sewage COD is effectively degraded; the cathode chamber is replaced by a peristaltic pump and the water flow rate of weakly acidic wastewater entering the water inlet is controlled to 9.2m ³ /(m ³ ·d).

After several cycles of stable operation of the device, the seawater raw water enters the seawater inlet through the water pump at a flow rate of 2m/s, and the water flowing out from the seawater outlet is combined with the raw water through the pipeline and then pressed into the middle chamber by the water pump, thus forming a cycle, which takes 6 hours as A cycle.

After one cycle, the COD of domestic sewage effluent is reduced to below 80mg/L, the salinity of seawater is reduced to about 1g/L, and the desalination rate reaches above 96.7%.

Claims (5)

1. a kind of method for carrying out desalination using the electromagnetic field couples desalter for having the dirty function of drop concurrently, it is characterised in that including Following steps：

In sanitary sewage feeding anode chamber, in acid waste water feeding cathode chamber, in seawater feeding medial compartment, start hanging down for medial compartment Internal electric field in straight magnetic field, the horizontal magnetic field of anode chamber and reactor, carries out electromagnetic field couples desalination reaction, the life after purification Outside sewage living, acid waste water and desalination water discharge reactor；The magnetic field intensity 6000Gs-12000Gs of medial compartment, the magnetic of anode chamber Field intensity is 1500Gs-2500Gs；The seawater velocity of medial compartment is 0.5m/s-2m/s；The water inlet of cathode chamber is the weak of pH5~6 Acid waste water；

The electromagnetic field couples desalter includes being divided into anode chamber, medial compartment and the moon successively in reactor, the reactor Pole room；

The anode chamber is exported with sanitary sewage import and sanitary sewage, built-in anode electrode；The medial compartment carries seawater Import and water outlet；The cathode chamber is exported with acid waste water import and acid waste water, built-in cathode electrode；

Connected between the cathode electrode and anode electrode by wire；The cathode electrode is electric for the photocatalysis silicon of surface treatment Pole；

Be additionally provided with outside the reactor in anode chamber provide horizontal magnetic field weak magnetic iron and be that vertical magnetic field is provided in medial compartment Strong magnet.

2. method according to claim 1, it is characterised in that the coolant-temperature gage of medial compartment is controlled at 25~35 DEG C.

3. method according to claim 1, it is characterised in that the material of the anode electrode is carbon-based material.

4. method according to claim 1, it is characterised in that the length of the anode chamber, medial compartment and cathode chamber along reactor Degree direction is arranged successively, and the depth-width ratio of the reactor is 1:10~1:12.

5. method according to claim 1, it is characterised in that the thickness of the medial compartment is 1mm-10mm.