Removal Of Polybrominated Diphenyl Ethers From Water And Soil By Sepiolite-supported Nanoscale Zerovalent Iron

Pollution and remediation of polybrominated diphenyl ethers (PBDEs) has become a hotspot of the current environmental protection research because of its difficult degradability, biological accumulation, and long-distance transmission. This study was proceeded to discuss the feasibility of the removal of decabromodiphenyl ether (BDE-209) from water and soil by sepiolite-supported nanoscale zerovalent iron.Sepiolite-supported nanoscale zerovalent iron was successfully synthesized based on the hydrochloric acid modified sepiolite which acted as the carrier. Batchs of experments were conducted to remove BDE-209 from water, and the sepiolite-supported nanoscale zerovalent iron showed good removal effect on BDE-209 from water mainly through degradation and adsorption. After a 24 h reaction, the ultimate removal efficiency of BDE-209 was almost 100%. The experimental results indicated that the higher dosage of sepiolite-supported nanoscale zerovalent iron, the lower of the initial BDE-209 concentration, and reduction of the initial solution pH could increase the degradation efficiency of BDE-209. The degradation of BDE-209 is a progressive debromination process, and the process of sepiolite-supported nanoscale zerovalent iron to remove BDE-209 from water was in accordance with the pseudo-first-order kinetics model.Experments were also proceeded to remove BDE-209 from soil and the results showed that the sepiolite-supported nanoscale zerovalent iron had good removal efficiency. After reaction 16 d, the removal rate of BDE-209 from soil by sepiolite-supported nZVI was 29.44%. Higher dosage of sepiolite-supported nanoscale zerovalent iron or decrease of the initial soil solution pH could increase the removal efficiency of BDE-209. Soil organic matter reduced the migration rate of BDE-209 from soil phase to sepiolite phase, which lead to the lower removal efficiency of BDE-209 from soil by sepiolite supported nZVI.