Study On The Preparation And Adsorption Properties Of Diatomite Modified Woodceramics

Wood ceramic is a new type of porous carbon material,which is made of wood(other wood materials)impregnated with thermosetting resin after the vacuum(nitrogen protection)carbonization.In this study,a new kind of environmental functional material was prepared through the modification of diatom soil by using the agricultural waste straw and phenolic resin as the main raw material.It was used in the treatment of polluted wastewater and opened a new direction for the research of wood ceramics.The diatomite modified woodceramics were prepared by adding diatomite to modify it,combined with heat pressing,and firing at high temperature in vacuum.The effects of different ratio and process parameters on the properties of wood ceramics were investigated by orthogonal and single factor tests.The structure and properties of the prepared wood ceramics were characterized by SEM,XRD,FI-TR,mercury intrusion porosimetry and three point bending.The results show that the best methods for preparing diatomite modified wood ceramics are:straw powder 125g,diatomite100g,phenol formaldehyde resin 80g,the grinding time of diatomite and straw powder mixture is 20min,the hot pressing temperature is 150?,the holding time is 30min,the calcining temperature is 1100?,and the heat preservation time 60min.The pore size of woodceramics is mainly 1500~2800nm,the porosity is about 28.3%,the specific surface area is about 7.83m~2/g,and the ultimate strength is 87N.The removal of tetracycline showed that the adsorption effect was better pH between 3~4,and the adsorption was basically balanced after 6 hours.The quasi two stage kinetic model was more suitable for describing the adsorption of tetracycline to wood ceramics.Liquid membrane diffusion was the main control rate step of the adsorption process.The fitting results of adsorption thermodynamics show that the fitting degree of Freundlich,Redlich-pereeson and Koble-Corrigan models is high,indicating that the adsorbed tetracycline is a composite adsorption system with uneven adsorption,which is also related to the composite properties of the material itself.The removal of tetracycline by diatomaceous modified wood ceramics and Fenton method was synergistic,and the adsorption effect was improved by 47.3%compared with the single use of wood ceramics.The quasi two stage kinetics and Freundlich are also suitable for describing the process of adsorbing hydroquinone in wood ceramics.The adsorption process includes liquid film diffusion,particle diffusion and chemical reaction.Adsorption exists in multi molecular layer adsorption,while adsorption heat decreases linearly with the adsorption amount.