CN-121972156-A - Modified biochar catalyst and preparation method and application thereof

Abstract

The invention discloses a modified biochar catalyst and a preparation method and application thereof, and belongs to the technical field of industrial wastewater treatment. The catalyst comprises a carrier, biochar and an active component, wherein the biochar has a porous structure, and the active component is an oxide containing a plurality of cerium and is loaded on the carrier. The catalyst is favorable for generating oxygen vacancies and has the capability of storing/releasing oxygen, thereby catalyzing ozone to directionally generate singlet oxygen active species and improving the oxidation selectivity of pollutants. The catalyst is used for treating complex electroplating wastewater containing heavy metal complexes, can realize high-selectivity oxidation and vein breaking and heavy metal synchronous adsorption recovery, and simultaneously has high catalytic activity in a wider pH range, reusability and strong capability of resisting complex water interference.

Inventors

• HUANG XIANFENG
• XU WENMIN
• FANG YUQI
• Cai Anhong

Assignees

• 温州大学

Dates

Publication Date

20260505

Application Date

20260402

Claims (10)

1. 1. A modified biochar catalyst, comprising: The carrier is biochar with a porous structure; an active component supported on a carrier and containing an oxide of cerium; The oxide of cerium includes ceria, and non-stoichiometric ceria; the load capacity of the active component on the carrier is 1 wt% -10 wt%.
2. 2. The modified biochar catalyst according to claim 1, wherein the ceria has a cubic fluorite structure.
3. 3. The modified biochar catalyst according to claim 1, wherein the non-stoichiometric ceria is present in the surface layer, grain boundaries and defects of ceria; the ceria is present in non-stoichiometric ceria and ceria surface active sites.
4. 4. The modified biochar catalyst according to claim 1, wherein the carrier is biochar comprising one or more of coconut shell charcoal, walnut shell charcoal, apricot kernel charcoal, and/or, The average pore diameter of the carrier is 3-5nm, and the porosity is 0.25-0.6cm 3 /g.
5. 5. A method for preparing the modified biochar catalyst according to any one of claims 1 to 4, comprising the steps of: Step S1, soaking, namely dissolving a cerium source to obtain a metal cerium salt solution, adding a biological carbon source into the metal cerium salt solution, carrying out ultrasonic treatment for a plurality of hours, standing overnight, and then carrying out drying treatment; and S2, pyrolysis and calcination treatment to obtain the modified biochar catalyst.
6. 6. The method for producing a modified biochar catalyst according to claim 5, wherein in step S1, The cerium source comprises one or more of cerium nitrate, cerium chloride, cerium sulfate, ammonium cerium nitrate and cerium carbonate, and/or, The concentration of the metal cerium salt solution is 0.1-0.15M, and/or, The ultrasonic treatment time is 4-5h, and the drying temperature is 120-130 ℃.
7. 7. The method for producing a modified biochar catalyst according to claim 6, wherein in step S2, the calcination temperature is 400 to 500 ℃ and the calcination time is 4 to 5 hours, and the calcination atmosphere is an air atmosphere.
8. 8. The use of the modified biochar catalyst according to any one of claims 1 to 4, wherein the modified biochar catalyst is used for catalyzing ozone oxidation to degrade complex heavy metal wastewater in complex water bodies.
9. 9. The use of the modified biochar catalyst according to claim 8, wherein the method comprises the steps of adding the catalyst into complex heavy metal wastewater, adjusting the pH to 5-8, adjusting the ozone concentration to 5-15 mg/L, and degrading.
10. 10. The use of a modified biochar catalyst according to claim 8, wherein the complex heavy metal wastewater comprises a heavy metal complex comprising one or more of Cu, zn, ni, co, wherein the complex comprises one or more of ‌ ethylenediamine tetraacetic acid, citric acid, tartaric acid, nitrilotriacetic acid, and inorganic ions comprising one or more of Cl - 、CO 3 2- and NO 3 - .

Description

Modified biochar catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a modified biochar catalyst and a preparation method and application thereof. Background The electroplating industry is an important component in national economy, but a large amount of wastewater generated in the production process contains various heavy metals (such as Zn, fe, cr, ni, cd, au and Cu) and organic pollutants, which poses serious threat to the environment. Heavy metals in electroplating wastewater mainly exist in a stable complexing form, and the ideal treatment effect is often difficult to achieve by the traditional treatment method. In recent years, advanced oxidation technology has received a great deal of attention in the field of electroplating wastewater treatment due to its high efficiency and thorough characteristics. In advanced oxidation techniques, selective oxidation of the catalyst is an important issue. Selective oxidation refers to preferential oxidation of target contaminants with a catalyst that is less affected by other co-existing components. In the treatment of electroplating wastewater, selective oxidation is particularly important due to the complex composition of the wastewater. Currently, most of the optimization of selective oxidation is achieved by regulating the composition, structure and surface properties of the catalyst. For example, in photocatalytic oxidation, the energy band structure of the catalyst is modulated by doping specific elements or constructing a heterojunction, thereby improving the selectivity for degradation of the target contaminant. In Fenton oxidation, the oxidizing power of a specific organic matter is enhanced by introducing a ligand or using a supported catalyst. In recent years, the ozone oxidation technology has been widely used in electroplating wastewater treatment due to the advantages of strong oxidizing property, no secondary pollution and the like. However, the problems of low selectivity in the ozone oxidation process due to complex components of the electroplating wastewater, firstly, the complex components of the electroplating wastewater, the possibility of competing reactions between different pollutants to influence the selectivity, secondly, the problem of stability of the catalyst is not completely solved, the selectivity can be reduced due to long-term operation, and furthermore, when the selectivity is pursued, the oxidation efficiency can be reduced, so that the balance of the selectivity and the oxidation efficiency is a difficult problem. Therefore, development of efficient catalysts and breaking of complex heavy metals have become one of the important points of research in the environmental field. Through searching, patent CN117339562A discloses a preparation method and application of cerium modified coconut shell biochar. The method comprises the steps of S1, preparing cerium modified biochar, namely adding the biochar into cerium chloride solution for soaking, stirring, adding sodium hydroxide for regulating pH to obtain cerium hydroxide precipitate, centrifuging, cleaning and drying, S2, adsorbing, namely weighing the cerium modified biochar, adding KH 2PO4 solution, and oscillating for 24 hours to adsorb phosphorus in the solution. However, cerium exists in the cerium-modified biochar in the form of cerium hydroxide, and is only used for physical adsorption treatment, so that complex heavy metals are difficult to remove. Patent CN118253307A discloses an iron-magnesium modified biochar catalyst and a preparation method and application thereof, wherein the preparation method comprises the following steps of stirring and dissolving an iron source, a magnesium source and a cerium source, adding a biomass carbon source, heating and stirring to obtain a paste, and drying and oxygen-limited roasting to obtain the catalyst, wherein the catalyst is used for activating persulfate to degrade tetracycline. Patent CN119080205A discloses an ozone catalytic oxidation wastewater treatment device and method, the treatment device is filled with a catalyst, the catalyst comprises a catalytic carrier, an active component and an adsorption component, the catalytic carrier is a molecular sieve, the active component comprises one or more of Fe, ru, mn, cu, ni, zn, co, ce and La oxide, the adsorption component comprises active carbon, and the active carbon comprises at least two or more of coal active carbon, coconut shell active carbon and fruit shell active carbon. The patent blends a catalytic carrier, an active component and an adsorption component to form a precursor, and then the precursor is subjected to integral molding calcination to obtain the catalyst, wherein the active component comprises Fe 2O3, cuO, ruO and ZnO, and the active component is blended with the rest of components in the form of oxide and then is subjected to calcinat