Helmholtz Center for Environmental Research - UFZ, Department for Isotope Biogeochemistry, Permoserstrasse 15, 04318 Leipzig, Germany.
J Contam Hydrol. 2013 Oct;153:92-105. doi: 10.1016/j.jconhyd.2013.06.004. Epub 2013 Jul 16.
The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in ¹³C (<-60‰) suggesting production lines which have used depleted methane for synthesis. The other source had typical carbon isotope compositions of >-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, ¹³C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas.
氯代脂肪族化合物（如氯代甲烷、乙烷和乙烯）的稳定碳同位素组成可作为分配来源的固有指纹进行检查。为了评估污染来源，研究了位于意大利费拉拉的一个具有 50 多年使用氯代脂肪族化合物历史的复杂现场。在靠近波河的复杂冲积砂质多含水层系统中发现了几个污染羽流；污染源包括未受限制的前工业和市政垃圾场以及工业区域的溢油事件。碳稳定同位素特征允许区分 2 种主要的污染物来源。一种氯代脂肪族污染物的来源在 ¹³C 中强烈贫化（<-60‰），表明使用贫化甲烷进行合成的生产线。另一个来源具有典型的碳同位素组成，大于>-40‰，这在最近的氯代溶剂生产中很常见。通过分别解释母体和子体化合物的同位素富集和贫化，可以追踪羽流中的降解过程。我们证明，在特定的生产条件下，即在氯甲烷生产过程中产生高度氯化的乙烯作为副产物时，可以获得¹³C 贫化的污染物指纹，并且可以利用这种指纹来追踪来源并确定城市地区污染的责任方。
