Department of Biology and Chemistry, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region, People's Republic of China.
Environ Sci Technol. 2014 May 6;48(9):4724-31. doi: 10.1021/es4053818. Epub 2014 Apr 8.
The fate of BDE-153 (BDE = brominated diphenyl ethers) in different mangrove, fresh water pond, and marine subsurface sediments collected from Hong Kong SAR was investigated. Under anaerobic conditions, all sediments showed good intrinsic abilities to reductively debrominate BDE-153, producing debromination products ranging from hexa- to mono-BDEs in 90 days. The half-lives of BDE-153 in eight different sediments varied from 7.6 to 165 days, with higher debromination in mangrove than marine and fresh water pond sediments. All sediments exhibited the preference in removing the bromine in para, followed by meta, and the lowest in ortho positions; however, fresh water pond sediments had relatively higher fractions of meta (BDE-99) and ortho substitution (BDE-118) of the three penta-BDE products. Mai Po mangrove and fresh water pond subsurface sediments were also capable of debrominating BDE-47 in 90 days of anaerobic incubation with half-lives of 76.2 and 56.9 days, respectively; but not BDE-209. BDE-47, -153, and -209 in Mai Po surface sediment were not transformed under 30 day aerobic incubation. This study demonstrated that the microbial-mediated debromination of BDE-47 and -153 occurred in natural subsurface sediments under anaerobic conditions although the rates and pathways varied among the sediment types.
本研究考察了香港不同红树林、淡水池塘和海洋底栖沉积物中 BDE-153 的命运。在厌氧条件下，所有沉积物均表现出良好的内在还原脱溴能力，可在 90 天内将 BDE-153 脱溴生成六溴至单溴代产物。八种不同沉积物中 BDE-153 的半衰期在 7.6 至 165 天之间，红树林沉积物的脱溴率高于海洋和淡水池塘沉积物。所有沉积物均优先去除对位的溴，其次是间位，而邻位的去除率最低；然而，淡水池塘沉积物中五溴代产物的间位（BDE-99）和邻位取代（BDE-118）比例相对较高。在 90 天的厌氧培养中，米埔红树林和淡水池塘底栖沉积物也能够脱溴 BDE-47，半衰期分别为 76.2 和 56.9 天；但不能脱溴 BDE-209。在 30 天的好氧培养中，米埔表层沉积物中的 BDE-47、-153 和 -209 没有发生转化。本研究表明，尽管在不同沉积物类型中脱溴速率和途径有所不同，但微生物介导的 BDE-47 和 -153 在自然底栖沉积物中的脱溴作用是在厌氧条件下发生的。
