Effect of PCB concentration on reductive dechlorination and dechlorination potential in natural sediments
Effect of PCB concentration on reductive dechlorination and dechlorination potential in natural sediments
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PCB浓度对天然沉积物还原脱氯及脱氯潜力的影响
DOI：
10.1016/0043-1354(94)00134-s
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发表时间：
1995
期刊：
影响因子：
12.8
通讯作者：
G. Rhee
中科院分区：
文献类型：
--
作者：
R. C. Sokol;C. M. Bethoney;G. Rhee
以2，3，4-和2，3，4，2 ′，4 ′，5 ′-氯联苯（CBP）为研究对象，在4 ~ 35 ppm的4种浓度下，研究了PCB浓度对微生物还原脱氯的影响。多氯联苯污染的河流沉积物中的脱氯潜力也被确定为在一个单一的同源物脱氯试验中使用受污染的沉积物作为接种物的滞后期的长度。2，3，4-CBP的脱氯具有浓度依赖性，在所有浓度下，14周后均发生脱氯，无论初始浓度如何，母体同系物的残留浓度似乎相同。相比之下，2，3，4，2 ′，4 ′，5 ′-CBP仅在23周后的最高浓度下显示脱氯。因此，浓度依赖性和滞后期是同源特异性的。脱氯潜力，作为3，4，5-CBP脱氯之前的滞后长度测量，似乎是较长的接种物制备的沉积物与较低的环境PCB浓度。综上所述，这些结果意味着，原位脱氯可能无法发生在低环境PCB水平的地区，因为脱氯率和脱氯潜力是浓度依赖性的。在不再被淹没的沉积物中，没有发现脱氯活性。
The effect of PCB concentration on microbial reductive dechlorination was examined using two individual congeners, 2,3,4- and 2,3,4,2′,4′,5′-chlorobiphenyl (CBP), at four concentrations ranging from 4 to 35 ppm. Dechlorination potential in PCB-contaminated river sediments was also determined as the length of the lag period in a single congener dechlorination assay using contaminated sediments as inocula. Dechlorination of 2,3,4-CBP was concentration-dependent and occurred at all concentrations by 14 weeks and the residual concentration of the parent congener appeared to be the same regardless of the initial concentrations. By contrast, 2,3,4,2′,4′,5′-CBP showed dechlorination only at the highest concentration after 23 weeks. The concentration dependence and the lag period thus were congener-specific. Dechlorination potential, measured as the length of the lag before dechlorination of 3,4,5-CBP, seemed to be longer with inocula prepared from sediments with lower ambient PCB concentrations. Taken together, these results imply that in situ dechlorination may not be able to occur in areas with low ambient PCB levels because both dechlorination rate and dechlorination potential are concentration-dependent. In sediments which are no longer submerged, dechlorinating activity was not found.