CN-121972134-A - Ion-compounded graphene-activated carbon adsorbent and preparation method and application thereof

Abstract

The invention discloses an ion-compounded graphene-activated carbon adsorbent, a preparation method and application thereof, and belongs to the technical field of pollutant adsorption; the activated carbon is subjected to acid catalytic treatment to increase the phenolic hydroxyl density of the activated carbon and form electronegative activated carbon, and finally, the two carbon material suspensions are reacted to generate the composite carbon adsorption material connected by N + and O ‑ , the prepared adsorbent has larger adsorption capacity and excellent conventional pollutant adsorption performance, and when the adsorbent is used for treating papermaking wastewater, the alkaline pH environment of the papermaking wastewater can enable the adsorbent to release oxygen anions and nitrogen cations, the cellulose colloid steady state of the papermaking wastewater is broken through surface charges, and residual pollutants in sewage are captured, so that the adsorption effect is further enhanced, and the problems that the traditional carbon-based adsorption material is single in electrical property and difficult to cope with high-alkalinity papermaking machine pulp wastewater with complex components are solved.

Inventors

• LIU BO
• Xia Longyi
• XU YAXIANG
• YANG JIALE

Assignees

• 南京大学

Dates

Publication Date

20260505

Application Date

20260123

Claims (10)

1. 1. The ion-composited graphene-activated carbon adsorbent is characterized in that graphene oxide is composited on the surface of activated carbon through ionic bonds formed by electrostatic adsorption of quaternary ammonium groups and oxygen anions, and the graphene oxide forms a multi-layer folding structure on the surface of the activated carbon.
2. 2. The ion-composited graphene-activated carbon adsorbent according to claim 1, wherein the adsorbent has a microporous and mesoporous structure.
3. 3. The ion-composited graphene-activated carbon adsorbent according to claim 1 or 2, wherein the adsorbent structure is: 。
4. 4. The preparation method of the ion-composited graphene-activated carbon adsorbent is characterized by comprising the following steps of: adjusting the graphene oxide suspension to a strong alkali environment, and adding glycidol trimethyl ammonium chloride to catalyze ring opening to form quaternized graphene oxide; Soaking and catalyzing the activated carbon with nitric acid and hydrogen peroxide to form electronegative activated carbon with high phenolic hydroxyl density; Mixing the obtained quaternized graphene oxide with electronegative activated carbon, and performing ultrasonic reaction to form ion-compounded graphene oxide-activated carbon suspension; And extracting and centrifuging the obtained graphene oxide-activated carbon suspension, repeating the operation for three times, freezing to form a solid, volatilizing and drying the solid at normal temperature and normal pressure to obtain the ion-compounded graphene-activated carbon powder adsorbent.
5. 5. The method for preparing an ion-composited graphene-activated carbon adsorbent according to claim 4, wherein the pH of the graphene oxide suspension is adjusted to 11-13 in a strong alkaline environment.
6. 6. The preparation method of the ion-composited graphene-activated carbon adsorbent disclosed in claim 4 or 5, wherein the mass ratio of graphene oxide to glycidol trimethyl ammonium chloride in the reaction of catalyzing ring opening to form quaternized graphene oxide is 1 (40-60), and the catalysis reaction condition is that the reaction is carried out for 12 hours at 50-60 ℃.
7. 7. The preparation method of the ion-composited graphene-activated carbon adsorbent is characterized in that in the electronegative activated carbon reaction for forming high phenolic hydroxyl group density, the mass ratio of activated carbon, nitric acid and hydrogen peroxide is (5-10): 10-20, and the reaction condition is that the reaction is carried out for 6 hours at 50-60 ℃.
8. 8. The preparation method of the ion-composited graphene-activated carbon adsorbent, which is disclosed in claim 4, is characterized in that the mass ratio of quaternized graphene oxide to electronegative activated carbon is 1 (200-500), and the ultrasonic reaction condition is that the ultrasonic frequency is 40kHz and the reaction is carried out for 2 hours at 30 ℃.
9. 9. The method for preparing the ion-composited graphene-activated carbon adsorbent according to claim 4, wherein the extraction process adopts tertiary butanol for extraction, and the volume ratio of the graphene oxide-activated carbon suspension to the tertiary butanol is 1:1.
10. 10. The use of the ion-composited graphene-activated carbon adsorbent according to any one of claims 1-3 for advanced treatment of papermaking machine pulp wastewater, wherein ionic bonds in high-alkalinity wastewater are broken to release positive and negative polar groups, so that the adsorbent has two electrical adsorption capacities at the same time, and the types of adsorbed pollutants are increased.

Description

Ion-compounded graphene-activated carbon adsorbent and preparation method and application thereof Technical Field The invention belongs to the technical field of pollutant adsorption, and particularly relates to an ion-composited graphene-activated carbon adsorbent, and a preparation method and application thereof. Background The pollutant adsorption technology is a technology which is a focus in the field of environmental protection, is an effective means for advanced sewage treatment, and has very important effect in wastewater treatment due to the advantages of simple operation of the adsorption technology and no need of complex facilities. The adsorbent is mainly used for removing pollutants, and is mainly used for realizing hydrophobic adsorption, adsorbing substances with low hydrophobicity or low polarity by adsorption potential energy provided by the complex surface of the adsorbent, pore filling, sealing the pollutants with proper size by the complex pore channel structure of the adsorbent, and chemically adsorbing, so that chemical groups on the surface of the adsorbent react with the pollutants, the pollutants are fixed on the surface of the adsorbent, and the pollutants are removed from a water body. The industrial adsorbents practically applied to water pollution adsorption mainly comprise resin, zeolite and active carbon. The zeolite is a three-dimensional grid formed by connecting silicon (aluminum) oxide tetrahedrons, the structure is mainly micropores, the pore size distribution is most uniform, the adsorption resin is a high molecular polymer which has a porous structure and can selectively adsorb specific substances, the structure of the activated carbon is mainly micropores, the specific surface area is large, the applicability is wide, and the activated carbon has the advantages of being relatively cheap and easy to obtain, and has a high specific surface area, rich mesoporous structure and various surface functional groups, so that the application is most extensive. However, the adsorption effect on paper machine pulp wastewater is very limited. The chemical mechanical pulping method is adopted in paper mill in China, the produced waste water is chemical pulp waste water, which is different from chemical pulp waste water, and the chemical pulp waste water pollutant composition mainly comprises lignin, cellulose and derivatives thereof. Lignin is a polymer composed of three aromatic propane derivative monomers, has a complex structure and large molecular weight in chemical pulp wastewater, is difficult to adsorb by an adsorbent, forms electronegative colloid due to the alkaline environment of the chemical pulp wastewater, and cannot be effectively treated no matter by means of hydrophobic effect or gap filling, and is dissolved in water in a protonated manner. Therefore, how to effectively adsorb cellulose colloid and macromolecular lignin at the same time is the key for treating papermaking machine pulp wastewater. To treat electronegative cellulose gums, positive electricity is needed for neutralization, breaking the steady state structure of the cellulose gum, while to treat lignin, not only the surface electropositive functional groups of the adsorbent are needed, but also more mesoporous and macroporous structures of the adsorbent are needed. Patent CN119569053a discloses an activated carbon for treating organic wastewater, which has the advantages of high specific surface area, abundant pores, large average pore diameter, developed mesopores and capability of adsorbing part of lignin by virtue of a void structure, but is difficult to treat for colloidal cellulose. The quaternary ammonium modified activated carbon disclosed in the patent CN115193410A, although the surface of the activated carbon is loaded with positive functional groups to damage the colloid structure of cellulose, can not effectively treat macromolecular lignin. Thus, the deep adsorption treatment of papermaking machine pulp wastewater faces a dilemma. Disclosure of Invention The invention provides an ion-compounded graphene-activated carbon adsorbent, a preparation method and application thereof, and the prepared novel adsorption material has good adsorption performance in papermaking machine pulp wastewater, can adsorb macromolecular lignin and break cellulose colloid steady state of the papermaking wastewater, and greatly improves COD removal capacity of the papermaking machine pulp wastewater. In order to achieve the above purpose, the present discovery adopts the following technical scheme: The ionic composite graphene-activated carbon adsorbent is characterized in that graphene oxide is compounded to the surface of activated carbon through ionic bonds formed by electrostatic adsorption of quaternary ammonium groups and oxygen anions, the graphene oxide forms a multi-layer folding structure on the surface of the activated carbon, the adsorbent has a micropore and mesopore structure, and the adsorbent has the