Preparation of @COFs from maple fruit shells for oil-water separation and iodine adsorption
A large amount of oily wastewater produced by the development of the petroleum industry and radioactive iodine discharge from the development of nuclear energy poses a threat to human health and the environment.The treatment of oily wastewater and adsorption of iodine are imminent and have become the focus of attention in the world.In recent years,the preparation of multifunctional adsorption materials for effective separation of oil and water and iodine adsorption has been a hot topic.Covalent organic framework(COFs)has advantages of large specific surface area and good adsorption effect,but its powdery structure is difficult to recover and usually causes secondary pollution to the water body.Amblygum(Liquidambar formosana Hance)is an excellent fast-growing tree in China.Its fruit has a natural porous structure and a large amount of amblygum is used for the treatments of agricultural and forestry waste every year.The dried and mature fruit consists of a large number of small capsules,spherical in shape,2-3 cm in diameter.The highly lignified shell forms a bark-shaped frame,with excellent mechanical properties,high porosity,and large specific surface area.Therefore,it can be used as a good carrier for COFs grafting.In this study,on the basis of the takeoff lignin pretreatment by amino propyl(3-)triethoxy silane,maple fruit shells were utilized as a basal material for maple fruit shell amination and the Schiff base reaction was used to covalent organic framework(COFs)grafted on the surface maple fruit shell,generating maple fruit shell@COFs composite materials.The properties of the developed composite were characterized by N2 adsorption-desorption experiment,organic solvent adsorption experiment and iodine adsorption experiment.The experimental results showed that the composite material maintained the original spherical and pore structure and had good oil-water separation ability and iodine adsorption performance.The specific surface area of the composite was 190 m2/g,showing good adsorption capacity and cycling performance in 13 organic solvents,among which the adsorption capacity of trichloromethane can reach up to 5 841 mg/g,and the adsorption capacity still maintained 90％after 20 cycles.In addition,the adsorption capacity in iodine vapor reached 1 180 mg/g and remained above 50％after five cycles.The composite material not only has advantages of low cost,natural environmental protection,but also has excellent recyclability and recyclability.In this study,a simple scheme for preparing@COFs of maple fruit hulls was proposed,which is expected to provide a new utilization idea for this kind of agricultural and forestry waste and a new scheme for wastewater treatment.
maple fruit shellcovalent organic frameworkseparation of oil and wateriodine adsorptionrecyclability
万方数据
维普
