Modification And Application Of Glycyrrhiza Biochar In Adsorption Field

Biochar has high surface area,high porosity and rich functional groups,and has good adsorption effect on a variety of pollutants.Glycyrrhiza is commonly used in clinical medicine,and its waste residual can be used to prepare biochar.In this paper,the preparation,modification and application of biochar in pollutant adsorption.1.Licorice cellulose was obtained from licorice residue at 180°C under hydrothermal conditions.Licorice fiber carbon material（named T-800-K₂CO₃）was obtained by carbonizing both licorice cellulose and the activator potassium carbonate.A variety of glycyrrhiza biochar materials were prepared by changing the amount and type of activator.The materials obtained were characterized,among which T-800-K₂CO₃ had high specific surface area（1769.84 m²/g）,high porosity and high stability.It was used for the adsorption of 6 kinds of organic small molecular pollutants,and the adsorption conditions were optimized with 2,4-D as the representative.T-800-K₂CO₃ also shows strong adsorption capacity for the above-mentioned other pollutants.2.The adsorption of heavy metal ions and anions was studied with the above material.It was found that T-800-K₂CO₃ had a good adsorption effect on mixed heavy metal ions,especially on Cr（VI）,and the adsorption capacity could reach 315.9 mg/g,however,it shows no capacity to adsorb any anion studied.3.The UIO-66 was further in-situ modified on T-800-K₂CO₃ to change its surface properties and for adsorption of small molecular pollutants（T-800-K₂CO₃@UIO-66）.The uncarbonized glycyrrhiza cellulose T was also used as the substrate to modify the framework materials（T@UIO-66）.T-800-K₂CO₃@UIO-66 and T@UIO-66 were characterized,T-800-K₂CO₃@UIO-66is characterized by high specific surface area（576.71 m²/g）,high porosity,and abundant functional groups.Both modified materials were used to adsorb the above 6cited organic pollutes.It was found that T-800-K₂CO₃@UIO-66 material had the best adsorption effect on 2,4-D.The adsorption conditions were optimized with 2,4-D as the representative.T-800-K₂CO₃@UIO-66 also shows strong adsorption capacity for other pollutants mentioned above.