Electro-Fenton technology based on ion exchange resin and application

Abstract

The invention belongs to the technical field of organic wastewater treatment, and particularly relates to an electro-Fenton technology based on ion exchange resin and application. The graphite felt is etched at a high temperature by adopting a transition metal oxide to prepare an efficient cathode material; ion exchange resin is used as a solid electrolyte to replace a traditional liquid electrolyte, a novel electro-Fenton technology is constructed to eliminate secondary pollution caused by the liquid electrolyte, and a conductive material is loaded on the surface of the ion exchange resin to improve the conductivity and reduce the wastewater treatment energy consumption. The electro-Fenton technology has the advantages of good treatment effect, no secondary pollution, wide pH application range, simple process, recyclability and environmental friendliness, and has a wide application prospect in the field of organic wastewater treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of organic wastewater treatment, and particularly relates to an electro-Fenton technology based on ion exchange resin and its application. Background Art

[0002] Organic wastewater in the environment mainly comes from industrial production, agricultural activities and daily life. If it is discharged directly into the environment without treatment or inadequate treatment, it will cause a series of hazards to water bodies, soil, ecosystems and human health. Common treatment methods include physical, chemical and biological methods. However, these methods generally have disadvantages such as low treatment efficiency, large limitations, possible secondary pollution and high treatment costs.

[0003] In recent years, electro-Fenton technology, as an advanced oxidation treatment method, has gradually become an emerging technology for treating organic wastewater because it can generate active components with strong oxidizing properties. Compared with traditional Fenton technology, electro-Fenton technology overcomes the problem of using a large amount of Fe in the reaction. 2+ , low H2O2 utilization rate, narrow applicable pH range, and large amounts of iron-containing sludge generated after the reaction. Therefore, electro-Fenton technology has shown good application prospects in the field of organic wastewater treatment.

[0004] Electro-Fenton technology usually uses carbon materials with stable chemical properties, long service life, excellent durability, large specific surface area and low cost as electrodes, such as carbon felt, activated carbon, graphene and graphite felt. Choosing carbon materials etched with transition metal oxides as cathode materials can not only increase the specific surface area of ​​carbon materials, make their surfaces rougher, and provide more active sites, but also promote oxygen adsorption and active oxygen formation, which is beneficial to the oxidative degradation of organic pollutants. When using electro-Fenton technology to treat organic wastewater, it is usually necessary to add liquid electrolytes to reduce resistivity and voltage, which not only increases operating costs, but may also cause secondary pollution.

[0005] The present invention uses ion exchange resin as a solid electrolyte instead of a traditional liquid electrolyte to construct a new type of electro-Fenton technology to eliminate secondary pollution caused by the electrolyte and is applied to the treatment of organic wastewater. Graphite felt is etched at high temperature by transition metal oxides to prepare a high-efficiency cathode material; conductive materials such as graphene and multi-walled carbon nanotubes are loaded on the surface of the ion exchange resin to increase its conductivity and reduce the energy consumption of wastewater treatment. Therefore, the present invention has broad application prospects in the field of organic wastewater treatment. Summary of the invention

[0006] The purpose of the present invention is to establish an electro-Fenton technology based on ion exchange resin and apply it to a method for degrading organic wastewater in view of the shortcomings of the prior art. The electro-Fenton technology has the advantages of excellent treatment effect, no secondary pollution, wide pH range, simple process, recyclability and environmental friendliness.

[0007] The technical solution of the present invention is: using graphite felt etched by transition metal oxide as cathode material; selecting ion exchange resin as solid electrolyte, and adding conductive material to adjust its conductive performance; constructing a new type of ion exchange resin-based electro-Fenton technology system, and applying it to treat organic wastewater.

[0008] The present invention relates to an electro-Fenton technology based on ion exchange resin and application thereof, comprising the following steps:

[0009] (1) A graphite felt with a thickness of 2 to 5 mm was washed with ethanol and deionized water, respectively, and dried. Then, it was immersed in an acetate solution of a transition metal with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. The graphite felt was taken out and dried naturally, then placed in a muffle furnace and calcined at 200 to 300 °C for 0.5 to 2.0 h, and then heated to 300 to 600 °C and calcined for 0.5 to 2.0 h to obtain a transition metal oxide-etched graphite felt cathode material.

[0010] The transition metal acetate is any one or two of iron acetate, cobalt acetate or manganese acetate;

[0011] (2) Add ion exchange resin and conductive material to ethanol, stir at room temperature for 24 h, filter and dry;

[0012] The ion exchange resin is any one or two of a sulfonic acid ion exchange resin, a carboxylic acid ion exchange resin, a quaternary ammonium ion exchange resin or a tertiary amine ion exchange resin, and the particle size of the ion exchange resin ranges from 0.05 to 2.0 mm;

[0013] The conductive material is any one of graphene, multi-walled carbon nanotubes or conductive carbon black, and the mass ratio of the ion exchange resin to the conductive material is 375-200;

[0014] (3) At room temperature, graphite felt etched with transition metal oxides was used as the cathode, ruthenium-coated titanium plate was used as the anode, and ion exchange resin loaded with conductive materials was used as the solid electrolyte. An electro-Fenton wastewater treatment device was assembled, and a certain current was applied to treat organic wastewater. Samples were taken for analysis at regular intervals, and the degradation rate of organic pollutants in the wastewater was calculated.

[0015] The advantages of the present invention over the prior art are mainly reflected in:

[0016] (1) The present invention selects transition metal oxide-etched carbon materials as cathode materials, which promotes the formation of surface defects and porous structures of carbon materials, provides more active sites, and can also promote oxygen adsorption and active oxygen formation, thereby facilitating the oxidative degradation of organic pollutants.

[0017] (2) Use ion exchange resin as solid electrolyte instead of traditional liquid electrolyte to construct a new type of electro-Fenton technology to eliminate the secondary pollution caused by liquid electrolyte and apply it to the treatment of organic wastewater.

[0018] (3) By loading conductive materials such as graphene and multi-walled carbon nanotubes on the surface of ion exchange resin, the conductivity and ion migration rate can be improved, thereby reducing the energy consumption of wastewater treatment.

[0019] (4) The electro-Fenton technology system based on ion exchange resin constructed in the present invention has the advantages of low cost, no secondary pollution, good recycling capacity, simple operation and high organic wastewater degradation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a scanning electron microscope photograph of the graphite felt etched by cobalt tetroxide in Example 1.

[0021] Figure 2 Schematic diagram of the assembled electro-Fenton device. DETAILED DESCRIPTION

[0022] The following examples are only used to illustrate the specific application of the present invention and are not intended to be limiting. Example 1

[0023] The graphite felt with a thickness of 3 mm was washed with ethanol and deionized water respectively, and dried, then immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L, and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace, calcined at 300 °C for 1.0 h, and then heated to 400 °C for 1.0 h to obtain a graphite felt cathode material etched with cobalt tetroxide.

[0024] 1.5 g of sulfonic acid ion exchange resin with a particle size of 0.05 mm and 0.004 g of multi-walled carbon nanotubes were added to 10 mL of ethanol, stirred at room temperature for 24 h, filtered, and dried;

[0025] An electro-Fenton water treatment device was assembled with etched graphite felt as cathode, ruthenium-coated titanium plate as anode and sulfonic acid ion exchange resin loaded with multi-walled carbon nanotubes as solid electrolyte. At room temperature, a current of 45 mA was applied to treat 100 mL of oxytetracycline organic wastewater with a concentration of 20 mg / L. Samples were taken every 10 min to determine the oxytetracycline concentration. After 90 min of reaction, the degradation rate of oxytetracycline was 79.2%. Example 2

[0026] The graphite felt with a thickness of 3 mm was washed with ethanol and deionized water respectively, and dried, then immersed in a 5.0 mmol / L ferric acetate solution, and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace, calcined at 300 °C for 2.0 h, and then heated to 600 °C for 1.0 h to obtain the graphite felt cathode material etched with iron oxide.

[0027] Take 1.5 g of sulfonic acid ion exchange resin with a particle size of 1.0 mm and 0.004 g of graphene and add them to 10 mL of ethanol, stir at room temperature for 24 h, filter and dry;

[0028] An electro-Fenton water treatment device was assembled with etched graphite felt as cathode, ruthenium-coated titanium plate as anode, and graphene-loaded sulfonic acid ion exchange resin as solid electrolyte. At room temperature, a current of 45 mA was applied to treat 100 mL of oxytetracycline organic wastewater with a concentration of 20 mg / L. Samples were taken every 10 min to determine the oxytetracycline concentration. The degradation rate of oxytetracycline was 86.5% after 90 min of reaction. Example 3

[0029] The graphite felt with a thickness of 2 mm was washed with ethanol and deionized water respectively, and dried, then immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L, and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace, calcined at 200 °C for 0.5 h, and then heated to 600 °C for 2.0 h to obtain a graphite felt cathode material etched with cobalt tetroxide.

[0030] Take 1.5 g of 0.1 mm carboxylic acid-based ion exchange resin and 0.006 g of multi-walled carbon nanotubes and add them to 10 mL of ethanol, stir at room temperature for 24 h, filter and dry;

[0031] An electro-Fenton water treatment device was assembled with etched graphite felt as cathode, ruthenium-coated titanium plate as anode, and carboxylic acid-based ion exchange resin loaded with multi-walled carbon nanotubes as solid electrolyte. At room temperature, a current of 45 mA was applied to treat 100 mL of oxytetracycline organic wastewater with a concentration of 20 mg / L. Samples were taken every 10 min to determine the oxytetracycline concentration. The degradation rate of oxytetracycline was 75.0% after 90 min of reaction. Example 4

[0032] The graphite felt with a thickness of 5 mm was washed with ethanol and deionized water respectively, and dried, then immersed in a solution of 5.0 mmol / L cobalt acetate and 5.0 mmol / L manganese acetate, and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace, calcined at 200 °C for 2.0 h, and then heated to 300 °C for calcination for 2.0 h to obtain a graphite felt cathode material etched with cobalt tetroxide and manganese dioxide.

[0033] Take 1.5 g of 2.0 mm quaternary ammonium ion exchange resin and 0.0075 g of multi-walled carbon nanotubes and add them to 10 mL of ethanol, stir at room temperature for 24 h, filter and dry;

[0034] An electro-Fenton water treatment device was assembled with etched graphite felt as cathode, ruthenium-coated titanium plate as anode and quaternary ammonium ion exchange resin loaded with multi-walled carbon nanotubes as solid electrolyte. At room temperature, a current of 45 mA was applied to treat 100 mL of oxytetracycline organic wastewater with a concentration of 20 mg / L. Samples were taken every 10 min to determine the oxytetracycline concentration. The degradation rate of oxytetracycline was 88.1% after 90 min of reaction. Example 5

[0035] The graphite felt with a thickness of 3 mm was washed with ethanol and deionized water respectively, and dried, then immersed in a cobalt acetate solution with a molar concentration of 5.0 mmol / L, and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace, calcined at 300 °C for 1.0 h, and then heated to 600 °C for 0.5 h to obtain a graphite felt cathode material etched with cobalt tetroxide.

[0036] Take 1.0 g of sulfonic acid ion exchange resin with a particle size of 0.05 mm, 0.5 g of tertiary amine ion exchange resin with a particle size of 0.1 mm, and 0.006 g of conductive carbon black and add them to 10 mL of ethanol, stir at room temperature for 24 h, filter, and dry;

[0037] An electro-Fenton water treatment device was assembled with etched graphite felt as cathode, ruthenium-coated titanium plate as anode, sulfonic acid ion exchange resin and tertiary amine ion exchange resin loaded with conductive carbon black as solid electrolytes. At room temperature, a current of 45 mA was applied to treat 100 mL of oxytetracycline organic wastewater with a concentration of 20 mg / L. Samples were taken at intervals of 10 min to determine the oxytetracycline concentration. The degradation rate of oxytetracycline was 81.0% after 90 min of reaction.

Claims

1. An electro-Fenton technique based on ion exchange resin, characterized in that: Follow the steps below, (1) A graphite felt with a thickness of 2 to 5 mm was washed with ethanol and deionized water, respectively, and dried. Then, it was immersed in an acetate solution of a transition metal with a molar concentration of 5.0 mmol / L and ultrasonically treated for 30 min. The taken-out graphite felt was naturally dried and placed in a muffle furnace for calcination at 200 to 300 °C for 0.5 to 2.0 h, and then the temperature was raised to 300 to 600 °C for calcination for 0.5 to 2.0 h to obtain a transition metal oxide-etched graphite felt cathode material. (2) Add ion exchange resin and conductive material to ethanol, stir at room temperature for 24 h, filter and dry; The transition metal acetate in step (1) is any one or two of ferric acetate, cobalt acetate or manganese acetate; The ion exchange resin in step (2) is any one or two of a sulfonic acid ion exchange resin, a carboxylic acid ion exchange resin, a quaternary ammonium ion exchange resin or a tertiary amine ion exchange resin, and the particle size of the ion exchange resin is in the range of 0.05 to 2.0 mm; The conductive material in step (2) is any one of graphene, multi-walled carbon nanotubes or conductive carbon black, and the mass ratio of the ion exchange resin to the conductive material is 375-200.

2. The application of an ion exchange resin-based electro-Fenton technique obtained by the method according to claim 1, characterized in that: At room temperature, graphite felt etched with transition metal oxides is used as the cathode, ruthenium-plated titanium plate is used as the anode, and ion exchange resin loaded with conductive materials is used as the solid electrolyte. An electro-Fenton wastewater treatment device is assembled, a certain current is applied, and organic wastewater is treated. Samples are taken and analyzed at regular intervals to calculate the degradation rate of organic pollutants in the wastewater.

Images