Degradation And Mechanism Characteristics Of Polybrominated Diphenyl Ethers (PBDEs)

A review of degradation of non-biodegradable persistent organic compounds and technique of photocatalysis or electron beam was firstly presented. And then the research aim was proposed. There are two parts in this paper: BDE-3 degradation by photocatalysis of UV irradiation or electron beam processes, proposed pathway of BDE-3 degradation by the process; BDE-209 degradation by photocatalysis of UV irradiation or electron beam processes, proposed pathway of BDE-209 degradation by the process.(1) The experiment of BDE-3 degradation, by photocatalsis of UV irradiation, shows that the synergistic effect exists on the decomposition of BDE-3 by EB. The effects of operating parameters, i.e. initial pH value, concentration of BDE-3, energy of UV, were also investigated. It is found that the structure of BDE-3 is destroyed and its biodegradability is improved.(2) The experiment of BDE-209 degradation, by photocatalsis of UV irradiation, shows that the synergistic effect exists on the decomposition of BDE-209 by EB. The effects of operating parameters, i.e. initial pH value, concentration of BDE-209, energy of UV, were also investigated. It is found that the structure of BDE-209 is destroyed and its biodegradability is improved.(3) Intermediates of BDE-3 and BDE-209 degradation by photocatalysis of UV irradiation were analyzed by some analytic technologies (UV-vis, pH value, GC, LC, GC-MS). Three products were identified: diphenylether, o-hydroxyphenyl, p-hydroxyphenyl. The pathway of BDE-3 degradation was discussed.