Reductive dechlorination of polychlorinated biphenyls: Threshold concentration and dechlorination kinetics of individual congeners in aroclor 1248
Reductive dechlorination of polychlorinated biphenyls: Threshold concentration and dechlorination kinetics of individual congeners in aroclor 1248
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DOI：
10.1021/es034600k
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发表时间：
2003-12-15
影响因子：
11.4
通讯作者：
Rhee, GY
中科院分区：
文献类型：
--
作者：
Cho, YC;Sokol, RC;Rhee, GY
利用来自圣劳伦斯河（NY）的沉积物微生物研究了Aroclor 1248中单个PCB同源物的还原脱氯。当Aroclor浓度低于40 ppm [137 nmol （g沉淀物）[-1]时，未观察到脱氯现象。超过这个阈值，同类物可分为三类：A组，脱氯超过40 ppm的同类物；B组，仅在高于60 ppm [206 nmol （g沉淀物）（-1）]的高浓度下脱氯的同系物；C组，低氯同系物浓度增加。A组和B组同系物的脱氯速率是其初始沉积物浓度的线性函数。对于A组同系物，该线性函数的浓度截距与阈值浓度下它们在Aroclor中的浓度相同，因此这些代表阈值。然而，B组同系物的截距值明显高于Aroclor阈值浓度，与Aroclor 1248中75 ppm [258 nmol （g沉积物）[-1]的浓度相当。无论初始浓度如何，脱氯结束时A组和B组同系物的终浓度相同。这些最终浓度明显低于其阈值。C族同系物的积累速率与其初始浓度成线性关系，沉积物中Aroclor浓度越高，总积累量越大。
Reductive dechlorination of individual PCB congeners in Aroclor 1248 was investigated using sediment microorganisms from the St. Lawrence River (NY). No dechlorination was observed at Aroclor concentrations below 40 ppm [137 nmol (g of sediment)(-1)]. Above this threshold, congeners could be divided into three categories: group A, congeners that dechlorinated above 40 ppm; group B, congeners that dechlorinated only at high concentrations above 60 ppm [206 nmol (g of Sediment)(-1)]; and group C, lower chlorinated congeners that increased in concentration. The dechlorination rate of congeners in groups A and B was a linear function of their initial sediment concentration. For group A congeners, the concentration intercepts of this linear function were the same as their concentrations in the Aroclor at the threshold concentration, and these therefore represented the threshold values. However, the intercepts of group B congeners were significantly higher than their levels at the threshold Aroclor concentration and were equivalent to their concentrations in Aroclor 1248 at about 75 ppm [258 nmol (g of sediment)(-1)]. The final concentrations of group A and group B congeners at the end of dechlorination were the same, regardless of their initial concentrations. These final concentrations were significantly lower than their threshold values. The accumulation rate of group C congeners was a linear function of their initial concentrations, and the total accumulation was greater at higher Aroclor concentrations in sediments.