TW201934496A - A flowing capacitive method and its divice for desalination and disinfection of sea/waste waters - Google Patents

Abstract

A novel high-efficiency flowing capacitive method and device is invented for desalination and disinfection of metal-contaminated underground, waste, brine, and sea/salt waters. The flowing electrodes containing carbon slurry can effectively perform electrosorption and regeneration during the capacitive deionization process in a continuous operation mode. Moreover, additional disinfection function can be obtained in the desalination process as the core-shell particles (e.g., Ag@C) are dispersed on the carbon electrodes. It is worth to noting that chemicals are not used except the circulated carbon slurry during desalination/disinfection of sea/waste waters for water recycling/ reuse.

Description

High-efficiency flow capacitor method and device with sea / wastewater desalination and sterilization

The present invention relates to a novel and efficient method and device for deionizing capacitors with both sterilization and flow capacity. In particular, the invention relates to a rapid electrode adsorption and desorption (regeneration) of a flow type electrode with a carbon water slurry solution. Operation, and greatly improve the deionization / desalting efficiency of seawater or wastewater. In addition, nano metal core-shell particles are added to the flow-type carbon electrode to increase the disinfection and sterilization function to achieve the purpose of water recycling.

According to the industry's rapid development, the industrial water demand is increasing, but the development of new water sources is becoming more and more difficult, and clean water sources are facing serious shortages. For example, the island of Taiwan surrounded by the sea is mostly in the dry season in winter, and water resources are not distributed throughout the year. Uniformity underscores the importance of diversifying water resources.

Deionization / desalination of seawater or wastewater (sea / wastewater) can provide more efficient water resource selection. Contaminated surface water or groundwater, brine, wastewater, or seawater containing salt or metal ion pollutants can be removed by removing Salt or ionic pollutants can achieve the purpose of water recycling and reuse.

Capacitive deionization uses porous carbon materials as non-consumable electrodes. Microvolts are applied to the electrodes to form electricity on the electrode surface using the principle of electrosorption. Double layer to adsorb and remove charged pollutants or ions in water, such as the Republic of China Patent Publication No. I460135 capacitor desalination device.

In addition, the conventional fixed electrode desalination efficiency is relatively low, the equipment takes up a relatively large space, and it is impossible to desalinate high-concentration brine.

In addition, the traditional sea / wastewater desalination method lacks a disinfection and sterilization function, and an additional disinfection and sterilization unit is required to meet drinking water standards.

Therefore, it is necessary to provide an innovative and practical method and device for capacitive deionization of high-efficiency mobile electrodes and sterilization, which will contaminate surface water or groundwater, brine, wastewater or seawater containing salt or metal ionic pollutants. Removal of salt or ionic pollutants in water achieves the purpose of water recycling and reuse.

The invention provides a capacitor deionization method and device with high-efficiency flow-type electrode and sterilization. The implementation method includes: (1) a carbon water slurry solution flows between the electrodes to which a microvolt voltage is applied, so that the surface of the electrode forms an electric double layer ( electric double layer), the charged ions between the electrodes are electrostatically attracted, and they are separated through the anion and cation membranes, and migrate to the positive and negative electrodes on both sides of the electrode, so that the charged ions in the water can be separated to achieve deionization / desalination. Function; (2) This adsorption saturated carbon material water slurry solution flows into the regeneration tank, and it does not need to adjust the voltage for continuous operation. In addition, the flow rate of the carbon water slurry solution can be adjusted to desalinate seawater in response to high salinity; (3) Nano metal core-shell particles (such as silver or copper can be coated on the porous carbon layer (Ag @ C) Or Cu @ C)) Increase the function of disinfection and sterilization, which can block viruses, bacteria and parasites, and achieve the purpose of purifying water.

The reason is that the high-efficiency flow-type electrode of the present invention has a method and a device for sterilizing the capacitor deionization, and has the advantages of low energy consumption, high efficiency, low secondary pollution, and simple operation and maintenance. Can Contaminated surface water or groundwater, brine, wastewater, or seawater containing salt or ionic pollutants can achieve the purpose of water recycling and reuse by removing the salt or ionic pollutants in the water and increasing the disinfection and sterilization function.

FIG. 1 is a schematic diagram illustrating a highly efficient flow type capacitor deionization / desalination apparatus according to the present invention.

FIG. 2 is a schematic diagram illustrating continuous operation of the high-efficiency flow-type capacitor deionization in accordance with the present invention, which can be operated in parallel with two devices, such as a capacitor deionization / desalination and regeneration tank.

Fig. 3 illustrates a method for synthesizing a porous carbon material with a high specific surface area by the biomass waste of the present invention.

Fig. 4 illustrates a method for synthesizing the composite nano metal core-shell particles and carbon material according to the present invention.

Fig. 5 illustrates a method for synthesizing the graphene oxide cation exchange membrane of the present invention.

Fig. 6 illustrates a method for synthesizing the quaternized polyvinyl alcohol / chitin composite anion exchange membrane of the present invention.

Fig. 7 illustrates a schematic diagram of a highly efficient flow-type capacitor deionized lithium ion recovery device of the present invention.

In order to make it easy to understand the technical means, inventive features, achieved objectives and effects of the present invention, the drawings and figures are described in detail as follows: Embodiment 1 of the present invention: a high-efficiency flow type capacitor deionization / desalination device.

Fig. 1 shows a schematic diagram of the device for efficient deionization / desalination of a capacitive capacitor of the present invention, including: a current collector (1), a flow electrode channel (cathode (2) / anode (3)), an ion exchange membrane (cation exchange membrane ( 4) / anion exchange membrane (5)), and sea / wastewater flow channel (6).

In this embodiment, a 5 to 60% porous carbon material slurry solution is uniformly mixed and dispersed in a flow-type electrode system. Activated carbon with high specific surface area and porous holes, carbon nanotubes, or graphene can be used as the carbon material. .

Graphite plates, titanium plates or other materials with good conductivity can be used as current collectors to transfer the applied electric type to the above-mentioned flowing electrodes.

First, the clean flowing electrode (carbon water slurry solution) (7) and the sea / wastewater inflow water (8) are pumped into the electrode channel (cathode (2) / anode (3)) and the water flow channel (6) respectively. ). The two ion exchange membranes (anion exchange membrane (5) / cation exchange membrane (4)) can select the migration of ions in the solution and isolate the flow electrode (7) and the inflow water (8).

Applying a microvolt electromotive force to the current collector, a voltage difference of 0.6 to 2.0 volts is generated for the capacitive deionization / desalting reaction at the electrodes on both sides.

The charged ions in the flowing water are electrostatically attracted to the electrodes on both sides, anions enter the anode (3) through the anion exchange membrane (5), and cations enter the cathode (2) through the cation exchange membrane (4). Anode and cathode of the flow electrode.

Remove the clean effluent water (9) of the charged ions, complete the deionization / desalting process, and the electro-saturated flow electrode (10) flows to the regeneration tank for backwash regeneration.

In addition, please refer to Figure 2. Two sets of devices can be connected in parallel for continuous operation. The inflow water (8) flows through the capacitor deionization / desalination device (12) for electro-adsorption to obtain clean effluent water (9). The electrode flows to the regeneration tank (13). The reverse or zero voltage opposite to the device (12) is applied for backwash regeneration. The ions attached to the mobile electrode are discharged from the brine (11) by the electrostatic repulsive force to complete the flow electrode. Backwash, the regenerated flow electrode can be returned to the capacitor deionization / desalination device (12) for electrosorption. This system combines capacitor deionization / desalination and backwash regeneration. It can be used for continuous operation of sea / wastewater desalination / deionization, and it can be modularized with multiple sets of devices in series or in parallel to improve the quality and quantity of sea / wastewater deionization / desalination, which is conducive to engineering enlargement according to practical needs .

Embodiment 2 of the present invention: Biomass waste is synthesized into a porous carbon material with a high specific surface area.

Biomass includes: coconut husk, rice husk, bamboo, bagasse, etc. This type of biomass waste is large in quantity and relatively simple in composition, with high carbon and low inorganic content. It is a suitable choice for activated carbon raw materials. It can solve the problem of waste disposal, and can also greatly reduce the dependence on petrochemical fuels. It is a relatively clean and recyclable substance.

Activated carbon developed using biomass waste is used in mobile capacitor deionization / desalination plants. Besides being environmentally friendly, it can also reduce costs.

Please refer to step S31 in FIG. 3, immerse the biomass waste in a chemical activator (for example: H ₃ PO4, ZnCl ₂ , or KOH, etc.) for 2 to 6 hours, and then dry at 60 to 150 ° C. (step S32) In addition to the dehydration effect, the carbonization process can also be changed, and the generation of char and volatile substances can be suppressed. Then, the precursors before activation and drying are completed by passing hypoxia gas at 400 ~ 800 ° C for pyrolysis. The reaction is performed for 1 to 3 hours (step S33), and the gas is released to form a porous structure carbon material.

After the activated carbon is cooled, the remaining chemicals are removed by washing with dilute hydrochloric acid and water (step S34). Please refer to step S35. The completed biomass activated carbon is dispersed in fresh water to form a water slurry, which can be applied to flow-type capacitor deionization / desalination.

Embodiment 3 of the present invention: A novel composite nano metal core-shell / bio-active carbon electrode is synthesized.

By adding a core-shell material with adjustable particle size nano metal to the above bioactive Carbon can be used to prepare mobile electrodes (carbon water slurry solution) with disinfection and sterilization function.

Because copper or silver metal can destroy the protein and genetic material in microorganisms, make them inactivate and die, and achieve the purpose of disinfection and sterilization of water.

For the synthesis method, please refer to the description in FIG. 4. The sugar compound (for example, starch) is chelated to extract metal ions to form a complex (step S42), and dried at 40 to 150 ° C. for 24 to 72 hours (step S43).

The dry complex is uniformly mixed with the biomass activated carbon precursor (step S44), and carbonized with an oxygen-deficient gas at 400 to 600 ° C for 1 to 3 hours to generate nano metal core-shell particles and the biomass activated carbon composite material. (Step S45).

Core-shell particles with sterilization and bioactive activated carbon composite material (step S46) are applied to the flow capacitor deionization / desalination to achieve the purpose of high-efficiency sea / wastewater deionization / desalination with sterilization (> 90%).

Embodiment 4 of the present invention: Synthesis of a novel graphene oxide cation exchange membrane.

The negatively charged acidic active groups of graphene oxide, such as oxygen-containing functional groups and sulfonate groups, can selectively increase the permeability of cations, and at the same time block the transmission of anions.

Using graphene oxide with adjustable multifunctional functional groups and easy modification, graphene oxide can be modified by sulfonate. This kind of sulfonated graphene oxide is used as a cation exchange membrane of mobile capacitor deionization / desalination device, which can increase deionization / Desalination efficiency and reduce costs.

Referring to FIG. 5, first, the graphite sheet (S51) is chemically stripped (S52), and the product is washed with dilute hydrochloric acid and water to neutrality, and then graphene oxide (S53) is obtained after drying.

Disperse the graphene oxide in the aqueous solution and shake to homogeneity. Add aminobenzenesulfonic acid and nitrite at 50 ~ 70 ℃, and perform sulfonation reaction for 12 ~ 24 hours (step S54). Wash until neutral and dry.

Refer to step S55, disperse the sulfonated graphene oxide in a dilute polyvinyl alcohol solution, stir for 4-6 hours, coat on glass, and dry at 50-90 ° C for 12-24 hours to become cation exchange of graphene oxide. The membrane (step S56) can be applied to a flow-type capacitor deionization / desalination apparatus.

Embodiment 5 of the present invention: A novel composite anion exchange membrane is synthesized.

Modified polyvinyl alcohol and chitin basic functional groups can selectively increase the permeability of anions, and at the same time block the transmission of cations.

A new type of quaternized polyvinyl alcohol / chitin composite anion exchange membrane is applied to the flow type capacitor deionization / desalination device, which can increase the deionization / desalination efficiency of sea / wastewater and reduce the cost.

Please refer to step S61 in FIG. 6. First, polyvinyl alcohol is added to glycidyl trimethyl ammonium chloride and potassium hydroxide, and the reaction is performed at 50 to 80 ° C for 2 to 6 hours, and the product is washed with absolute alcohol to neutrality and dry.

Chitin is added to glycidyl trimethylammonium chloride and reacted at 50 ~ 80 ° C for 2 ~ 6 hours. The product is washed to be neutral and then dried (step S62).

Please refer to step S63. Dissolve the quaternized polyvinyl alcohol and chitin in water, add glutaraldehyde at 50 ~ 80 ℃ for 1 ~ 3 hours, and then coat the mixed solution on the glass at 50 ~ Dry at 70 ° C to produce a new composite anion exchange membrane (step S64), which can be applied to flow capacitor deionization / desalination.

Embodiment 6 of the present invention: Flow-type capacitive deionization / desalting of brine.

The implementation steps are as described in Example 1. The inflow water is brine ([NaCl] = 5000 (ppm), pass through the electrolytic capacitor deionization / desalting to perform the electro-adsorption reaction. After 12 groups of modules in series, most of the salt can be removed and clean water ([NaCl] <50ppm) can be obtained.

Embodiment 7 of the present invention: Flow-type capacitor deionization of RO wastewater from semiconductor processes.

The implementation steps are as described in Example 1. The influent water RO wastewater undergoes electro-adsorption reaction through flowing capacitor deionization. After 8 sets of series modules, metal salts can be further removed and pure water can be recovered.

Embodiment 8 of the present invention: Flow-type capacitor deionization / desalting of seawater.

The implementation steps are as described in Example 1. The inflow water seawater ([NaCl] = 35,000ppm) was passed in, and the electro-adsorption reaction was carried out through the flow capacitor deionization / desalting. After 30 series modules, most of the salt could be removed and clean water ([NaCl] < 50ppm).

Embodiment 9 of the present invention: Flow-type capacitor deionization of heavy metal contaminated groundwater.

The implementation steps are as described in Example 1. The inflow water flows into the groundwater contaminated with heavy metals and undergoes an electro-adsorption reaction through mobile capacitor deionization. After 8 sets of series modules, metal salts can be removed and clean water can be recovered.

Embodiment 10 of the present invention: Flow-type capacitor deionization of heavy metal-contaminated wastewater.

The implementation steps are as described in Example 1. The influent water is passed in as heavy metal-contaminated wastewater, which is subjected to electro-adsorption reaction through mobile capacitor deionization. After 10 sets of series modules, metal salts can be removed and clean water can be recovered.

The eleventh embodiment of the present invention: Flow type capacitor deionized lithium ion recovery.

The applications of lithium compounds are quite extensive, such as: rechargeable batteries, nuclear fusion, and alloys for aircraft casings, leading to a significant increase in the demand for lithium in recent years.

The land lithium mine that can be mined is about 16.7GT, but the lithium concentration in seawater is low (0.17mg / L), and the total lithium amount is as high as 230GT. Due to the high demand, the technology of recovering lithium from seawater has gradually received attention.

The traditional method uses lithium manganese oxide as an adsorbent, but the poor efficiency results in long time consumption, and it must be back-extracted with an acid solution, which may cause environmental pollution problems.

The use of an electrostatic field assisted with a flow-type capacitive deionization device can effectively improve the adsorption efficiency of lithium ions, and the reverse or zero voltage can be applied to desorb lithium ions from the carbon material, reducing the concerns of secondary pollution.

In this embodiment, as shown in FIG. 7, the anode is a mobile porous carbon material (18), and the cathode is a mobile lithium manganese oxide (17) as an adsorbent for lithium ions.

First, the carbon material water slurry solution (mobile electrode) and seawater or lithium-containing wastewater (8) are pumped into the electrode channel (cathode (2) / anode (3)) and the water flow channel (8), respectively. The carbon material water slurry solution (mobile electrode) of the cathode (2) electrode channel is additionally added with 10 to 60% of manganese oxide (for example: H ₂ TiO ₃ ), and the manganese hydrogen oxide can also be formed without adsorbing trace lithium ions in seawater. Lithium manganese oxide. The ion exchange membrane (anion exchange membrane (5) / cation exchange membrane (4)) can limit the migration of ions in the solution and isolate the suspended electrode solution and lithium-containing inflow water.

An electromotive force is applied to the current collector, and a voltage difference of 0.6 to 2.0 volts is generated at the electrodes on both sides for ion electrosorption.

The charged ions in seawater migrate to the electrodes on both sides due to electrostatic attraction, and lithium manganese oxide can selectively adsorb lithium ions, so that the recovery rate of lithium ions is much larger than the other positively charged ions.

Clean adsorption water (9) is obtained by electro-adsorption; the flow-type electrode saturated with adsorption flows to the regeneration tank, and reverse reverse or zero voltage is applied for backwash regeneration. The ions attached to the flow-type electrode are discharged by brine by electrostatic repulsion. The backwashing of the flow-type electrode is completed, and the regenerated flow-type electrode can be returned to the capacitor deionization / desalination device for electrosorption.

The adsorption-saturated lithium manganese oxide flows into the lithium recovery tank, and reverse or zero voltage is applied to desorb lithium ions from the carbon material and pass into CO ₂ to generate Li ₂ CO ₃ precipitates to complete the separation and recovery of lithium ions.

To sum up, the embodiments of the present invention can indeed achieve the expected effects, and the specific functions shown by them are not only not seen in similar products, nor disclosed before the application, and they have fully complied with the provisions and requirements of the Patent Law. I filed an application for an invention patent in accordance with the law, and I urge you to examine it and grant the patent.

Claims (10)

High-efficiency flow-type capacitor deionization / desalting and sterilization method and device, including the following steps: (a) The carbon material water slurry solution and inflow water are pumped into the electrode channel and the water flow channel respectively, and the solution is restricted by an anion / cation exchange membrane The migration of ions, and the carbon water slurry solution and the inflow water are isolated. (b) Applying a voltage difference of 0.6 to 2.0 volts to the electrodes on both sides for capacitive deionization and desalination. The charged ions in the flowing water are electrostatically attracted and migrate to the electrodes on both sides. The anions enter the anode through the anion exchange membrane, the cations enter the cathode through the cation exchange membrane, and the anions and cations are adsorbed on the carbon water solution of the anode and the cathode, respectively. (c) Recover clean water, complete the deionization / desalination process, and adsorb the saturated carbon material back to the regeneration tank for backwash regeneration. The high-efficiency flow type capacitor deionization / desalination device and method according to claim 1, wherein, in step (a), the carbon material uses the high specific surface area, porous carbon material synthesized by the biomass waste as the capacitor deionization / desalination. The mobile electrode material is applied to the flow capacitor deionization / desalination. Besides being environmentally friendly, it can also reduce costs. The device and method for high-efficiency flow-type capacitor deionization / desalination according to claim 1, wherein, in step (a), composite nano-metal core-shell particles and carbon material are used as the flow electrode material, and sugar compounds and metal ions are used. After chelating extraction, it is mixed with carbon materials and carbonized at 400 ~ 600 ° C for 1 ~ 3 hours to produce composite nano-metal core-shell carbon materials, which are applied to the flow type capacitor deionization, which can achieve the purpose of high efficiency desalination and sterilization. The device and method for high-efficiency flow-type capacitor deionization / desalination according to claim 1, wherein, in step (a), the cation exchange membrane uses a sulfonated graphene oxide cation exchange membrane as the capacitor removal Cation exchange membrane. Graphene oxide is sulfonated by a simple chemical method. Polyvinyl alcohol and dilute solution of sulfonated graphite oxide are prepared. After drying, it is applied to the cation exchange membrane of the flow capacitor deionization device, which can increase the selectivity and permeability of cations. And can block the transmission of anions. The high-efficiency flow type capacitor deionization / desalting device and method according to claim 1, wherein in step (a), the anion exchange membrane uses a quaternized polyvinyl alcohol / chitin composite anion exchange membrane as the capacitor deionization Anion exchange membrane. Modified polyvinyl alcohol and chitin with glycidyl trimethyl ammonium chloride, the positively charged functional group can increase the selectivity and permeability of anions, and can block the transmission of cations. Perform quaternization of polyvinyl alcohol and chitin, and react at 50 ~ 80 ℃ for 2 ~ 6 hours. After washing and drying, crosslink with glutaraldehyde at 50 ~ 80 ℃ for 1 ~ 3 hours. After drying, a quaternized polyvinyl alcohol / chitin composite anion exchange membrane is generated and applied to the anion exchange membrane of the flow type capacitor deionization / desalination device, which can increase the selectivity and permeability of anions, and can block Cation transport. As described in the first to fifth items in the scope of the patent application, the high-efficiency flow type capacitor deionization / desalting and sterilization method and device, wherein the high-efficiency flow type capacitor deionization / desalting device can be applied to desalination from brine and recover clean water. . As described in the first to fifth items in the scope of the patent application, the high-efficiency flow type capacitor deionization / desalting and sterilization method and device, wherein the high-efficiency flow type capacitor deionization / desalting device can be applied to the deionization and recovery of RO wastewater in the semiconductor process. Clean water. As described in the first to fifth items of the scope of the patent application, the high-efficiency flow type capacitor deionization / desalting and sterilization method and device, wherein the high-efficiency flow type capacitor deionization / desalting device can be applied to seawater desalination and recover clean water. As described in the first to fifth items in the scope of the patent application, the high-efficiency flow type capacitor deionization / desalting and sterilization method and device, wherein the high-efficiency flow type capacitor deionization / desalting device can be used for deionization and recovery of groundwater containing heavy metal pollution. Clean water. As described in the first to fifth items of the patent application scope, the high-efficiency flow type capacitor deionization / desalting and sterilization method and device, wherein in step (a), the cathode flow type suspension solution selects lithium manganese oxide for lithium ion adsorption Agent. Lithium manganese oxide can selectively adsorb lithium ions, so that the recovery rate of lithium ions is much larger than that of other positively charged ions. The adsorption-saturated lithium manganese oxide is flowed into another series of devices, and the delithium ions are desorbed from the ion oxide into the solution with secondary water to complete the lithium ion concentration recovery. The cathode suspension solution applied to the flow-type capacitor deionization device can effectively improve the adsorption efficiency of lithium ions, and can apply reverse or zero voltage to desorb the lithium ions from the carbon material without the concern of secondary pollution.