Degradation Of Decabromodiphenyl Ether By Nanoscale Zero-valent Iron Immobilized In Carbon Microspheres

Decabromodiphenyl ether(DBDE)commonly used in many commercial products for brominated flame retardant has raised a big concern for public safety.Nanoscale zero valent iron(NZVI)is a versatile environmental remediation material for various pollutants with high removal efficiency,deca-BDE is one of them.However,the nano scale zero valent iron has a strong tendency to be oxidized and aggregate.In order to overcome the drawbacks of nanoscale zero valent iron in the remediation of environmental contaminants,we chose carbon microspheres as the carrier of nanoscale zero valent iron.In this work,carbon microsphere supported NZVI were synthesized by immobilizing NZVI on carbon microsphere and used to remove DBDE rapidly.The characteristics of carbon microsphere supported NZVI(C-NZVI)were analyzed by XRD?TEM?SEM?XPS and BET,which showed that,the carbon microspheres were in the size range of about 10 ?m an average pore size of 2.046 nm,and a specific surface area of 495.9 m2/g.Nanoscale zero valent iron loaded on the surface and inside of carbon microspheres having a particle size of about 50 nm.Based on XRD and XPS results,we found the existence of oxygen in the material because of,oxidation of NZVI.Promise own existence carried out a peak position of nanoscale zero valent iron correct,consistent with the expected thought.The degradation mechanism of DBDE by C-NZVI were explored.We investigated influence factors,such as C-NZVI dosage,initial concentration and affect DBDE solvent(water and THF)conditions.The results showed that,the removal of DBDE followed pseudo-first-order kinetics,and C-NZVI prepared in this study had high removal efficiency than that of carbon microspheres,and conventional zero valent iron.In addition,it was showed that the removal of DBDE increased with the increase of C-NZVI dosage,increasing with the decrease of initial concentration of DBDE,,and the presence of tetrahydrofuran(THF)as a cosolvent at a volume fraction of 50%was appropriate for the removal of DBDE by C-NZVI.