Photodegradation of decabromodiphenyl ether adsorbed onto clay minerals, metal oxides, and sediment
Photodegradation of decabromodiphenyl ether adsorbed onto clay minerals, metal oxides, and sediment
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DOI：
10.1021/es051415t
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发表时间：
2006-01-01
影响因子：
11.4
通讯作者：
Bezares-Cruz, J
中科院分区：
文献类型：
--
作者：
Ahn, MY;Filley, TR;Bezares-Cruz, J
在阳光下和350 +/- 50 nm灯（四盏灯，每盏24 W）照射下，研究了吸附在六种不同固体基质上的十溴二苯醚（BDE-209）的光脱溴作用。经过14天的灯照射后，BDE-209在蒙脱石或高岭石上的降解半衰期分别为36天和44天，而在富含有机碳的天然沉积物上吸附时，降解速度要慢得多（t（1/2）= 150天）。在夏末和秋季的阳光下（北纬40.5度，海拔600英尺），吸附在蒙脱石和高岭石上的BDE-209的半衰期分别为261天和408天。在这两种辐照方案下，BDE-209在吸附到氢氧化铝、氧化铁（水铁矿）或二氧化锰（水钠锰矿）上时均未发生重大损失。在接触到灯光和太阳光以及存在蒙脱石和高岭石的情况下，会产生许多溴化程度较低的同系物（三溴二苯醚至九溴二苯醚）。在蒙脱石和高岭石上几乎相同的产物分布是明显的。对每种矿物进行的黑暗控制实验表明，BDE-209没有消失，也没有出现降解产物。这些结果表明，BDE-209在远距离大气迁移过程中在矿物气溶胶上的光降解可能是BDE-209在环境中的一个重要归宿过程。
The photodebromination of decabromodiphenyl ether (BDE-209) adsorbed onto six different solid matrixes was investigated in sunlight and by irradiation with 350 +/- 50 nm lamps (four lamps at 24 W each). After 14 days of lamp irradiation, BDE-209 degraded with a half-life of 36 and 44 days, respectively, on montmorillonite or kaolinite, with much slower degradation occurring when sorbed on organic carbon-rich natural sediment (t(1/2) = 150 days). In late summer and fall sunlight (40.5 degrees N, elevation 600 ft), the half-lives of BDE-209 sorbed on montmorillonite and kaolinite were 261 and 408 days, respectively. Under both irradiation schemes, no significant loss of BDE-209 occurred when sorbed to aluminum hydroxide, iron oxide (ferrihydrite), or manganese dioxide (birnessite). Upon exposure to both lamp and solar light and in the presence of montmorillonite and kaolinite, numerous lesser brominated congeners (tri- to nonabromodiphenyl ethers) were produced. Nearly identical product distribution was evident on montmorillonite and kaolinite. Dark control experiments for each mineral showed no disappearance of BDE-209 or appearance of degradation products. These results suggest that photodegradation of BDE-209 on mineral aerosols during longrange atmospheric transport may be an important fate process for BDE-209 in the environment.