Study On Preparation Of Mycelium-based Biochar Materials And Mycelium-based Composite Carbon Materials And Their Adsorption Properties

With the rapid development of industries such as industry,animal husbandry,and medicine,the overuse of dyes and antibiotics has led to their residues in the environment,posing a threat to the ecological environment and human health.Therefore,how to abate the pollutants in the environment is one of the scientific problems that researchers are always concerned about.As a kind of adsorbent,biochar has the advantages of abundant oxygen-containing functional groups,high specific surface area,and strong adsorption effect on pollutant molecules,and has wide application potential in pollutant and wastewater treatment.Biochar adsorption is the most effective method for pollutant and wastewater treatment.How to obtain new biomass carbon adsorption materials with better adsorption performance and reusability has become the key issue.Compared with other biochar material structures,hyphae has a unique fibrous mesh structure making its structure more fluffy and higher specific surface area,and hyphae has the advantages of a short growth cycle,abundant source,and low price.The study of hyphae and its composite material of biomass carbon material is of great significance and prospect for the study of high adsorption performance biomass carbon material and its application.In this study,hyphae-based carbon materials and hyphae-based composite carbon materials were prepared from hyphae and hyphae medium through the charring and chemical activation process,and the effects of chemical activation conditions（activation time,activation temperature,alkali-carbon ratio）on the activation effect were investigated.The char materials were characterized by TGA,SEM,N₂ adsorption-desorption test,FT-IR,XRD,Raman,XPS,and zeta potential.The performance of hyphae-based biochar and hyphae-based composite biochar in adsorption was evaluated and the adsorption mechanism was preliminarily investigated using the synthetic dye brilliant Green（BG）and the antibiotic tetracycline hydrochloride（THC）as contaminant models.The results of the study were as follows.1.The specific surface area of the hyphae-based biochar material（BCFF）prepared from Fomes fomentarius（FF）at a charring temperature of 600°C,optimal activation conditions of Na OH as an activator and the alkali-to-carbon ratio of 4:1,activation temperature of 700°C,and activation time of 60 min was 3352 m² g^-1,and the total pore volume was 2.29 cm³ g^-1.When the model pollutant was BG,the adsorption process was chemisorption with multilayer adsorption,and the maximum adsorption capacity was 3361.43 mg g^-1.2.The hyphae-based composite carbon materials HCAFF,HCAAN,and HCAMV were prepared from Fomes fomentarius（FF）,Aspergillus nige（AN）and Myrothecium verrucaria（MV）under the conditions of a charring temperature of 500°C,activation temperature of 700°C,activation time of 60 min and the alkali-carbon ratio of 3:1,respectively,were greener and more environmentally friendly compared with the activation conditions of BCFF.Moreover,HCAFF and HCAAN have super high specific surface areas of 4357.6 and 3410.1 m² g^-1,respectively,which is significantly higher than BCFF.3.The results of the structure and adsorption performance of hyphae-based biochar materials and hyphae-based composites showed that the hyphae-based carbon materials and hyphae-based composite carbon are mainly composed of C and O elements,and there are a large number of carbon and oxygen-containing functional groups on the surface,and the presence of these functional groups can improve the adsorption performance.With the increase of solution p H,the surface of hyphae-based biochar materials and hyphae-based composites are full of negative charges,which is more favorable for their adsorption of cationic dyes in printing and dyeing wastewater.4.The adsorption kinetics,adsorption isotherms,and adsorption thermodynamic properties of hyphae-based composite biochar were investigated using synthetic dyestuff BG and antibiotic THC as contaminant models.The adsorption processes of HCAFF,HCAAN,and HCAMV on BG and THC were by the proposed secondary adsorption kinetic model,Freundlich isotherm,and Temkin isotherm.It indicates that the adsorption of BG and THC by biochar is mainly chemisorption and multilayer adsorption.The adsorption thermodynamic results indicated that the adsorption process was spontaneous and exothermic.The maximum adsorption capacities of HCAFF,HCAAN,and HCAMV on BG were as high as 3384.36,3139.97,and 2315.76 mg g^-1at p H 9.The maximum adsorption capacity of HCAFF on BG was higher than that of BCFF(3166.43 mg g^-1).The adsorption mechanism can be attributed to pore filling,π-πinteractions,hydrogen bonding interactions,and electrostatic attraction.5.The results of the recycling study of its adsorbent with the adsorption capacity of dyes as well as antibiotics showed that after 5 cycles,the adsorption capacity of HCAFF,HCAAN,and HCAMV for BG could still reach more than 90%of the original value,and the adsorption capacity of THC could still reach more than 80%of the original value,which proved that the hyphae-based composite biochar prepared in this paper has a high recycling capacity.