Research On The Functionalization Of Biomass Materials And Its Application In The Field Of Environmental Pollutant Removal

With the rapid development of industrialization worldwide,the problem of environmental pollution has become more and more serious,which has caused great harm to the ecological environment and human health.Therefore,the tre atment of environmental pollution has become one of the important issues that urgently need to be resolved.Based on the current problems of environmental pollution,this paper has c arried out the following three parts:?1?Sawdust is a by-product of the wood processing industry and low-cost biomass materials.Biomass sawdust are formed by disordered accumulation of natural wood cells with micron or millimeter scales.Sawdust has the unique microstructure,which is composed of a zigzag container channel formed when sawing natural wood in a natural or radial direction,and many pits and microp ores are distributed on the entire surface of the container channel.Sawdust wit h such a unique three-dimensional?3D?layered porous structure are attractive candidates for scalable and cost-effective water filtration.The main component of sawdust is cellulose,which is rich in hydroxyl groups and can be modified by grafting functional groups to expand the application range of the material.We grafted?-cyclodextrin to cellulose of sawdust by organic reaction,and furt her designed an assembly-based?-cyclodextrin polymer functionalized sawdust??-CD/WS?filter.In this way,the drug contaminants can be fully contacted wi th the?-CD grafted on the wood fiber,thereby enhancing the water treatment performance of the assembled?-CD/WS.Therefore,the removal efficiency of?-CD/WS for propranolol,amitriptyline,chlortetracycline,diclofenac and levoflox acin was still as high as 97.5%when the contact time was about 90 seconds,and the saturated adsorption amounts were 170 156,257,159 and 185 mg g^-1,respectively.This high-performance cross-flow filtration method based on?-C D/WS solves the current balance between processing efficiency and processing speed in the field of water treatment.?2?The main chemical component of biomass sawdust is cellulose,with a content of about 40-50%.Cellulose is rich in large of hydroxyl-active functio nal groups which can form weak coordination bonds with pollutants.Hence,w e further explored the removal of small molecule environmental pollutants by b iomass sawdust.Because of its advantages of green initiative and low energy c onsumption,photocatalysis is used in the field of environmental pollutant remo val.The lignin component in the sawdust is removed by chemical oxidation,a nd it is prepared into a transparent biomass film.Compared with untreated wo od chips,the transparent biomass film is more conducive to photocatalysis.As a new type of photocatalytic material,bismuth tungstate?Bi₂WO₆?has a narro w band gap,high photochemical stability,strong oxidation ability,and low cost.It can be excited under visible light.It has the advantages of high utilization rate,and has a wide range of uses in catalytic degradation of pollutants.In ad dition,wood sawdust is rich in hydroxyl functional groups,which have a good adsorption and enrichment effect on pollutants.Therefore,we have physically mixed bismuth tungstate and wood sawdust to prepare a transparent film?Bi₂W O₆/WS?for the degradation of indoor formaldehyde pollutants.Under the sunlig ht,formaldehyde pollutant was completely degraded by Bi₂WO₆/WS transparent film.The transparent film containing bismuth tungstate has advantages of low cost,simple preparation,and green sustainability.The design and synthesis of the transparent film material provides a new scientific idea for the removal of indoor pollutants.?3?The leakage of oil/organic solvents has caused serious pollution to the environment,a large amount of oil pollution and oil waste,and required a lar ge amount of energy.In recent years,materials with super wettability such as super hydrophobicity and super lipophilicity have been used to separate oil/orga nic solvents and water-based solutions due to their selective repellency?or affin ity?for water or oil/organic solvents.We designed and synthesized CaCO₃/woo d film material through mineralization for separation of oil and water.Wood w ith unique three-dimensional linear channel structure can realize the transportati on of oil.At the same time,CaCO₃ with micro-nano structure on the channel has a certain repellent effect on water,and the oil-water mixture is separated b y lipophilic and hydrophobic.In addition,we also prepared the SF-CaCO₃/woo d film material through secondary mineralization in order to achieve better oil-water separation effect.The film prepared by mineralization using wood as a s ubstrate has the advantages of simple synthesis,low cost,and scale-up.