Brown Derick G, Gupta Lovleen, Kim Tae-Hyung, Keith Moo-Young H, Coleman Andrew J
Department of Civil and Environmental Engineering, Lehigh University, 13 East Packer Avenue, Bethlehem, PA 18015, USA.
Chemosphere. 2006 Nov;65(9):1562-9. doi: 10.1016/j.chemosphere.2006.03.068. Epub 2006 May 15.
A comparative analysis was performed on eleven coal tars obtained from former manufactured gas plant sites in the eastern United States. Bulk properties analyzed included percent ash, Karl Fisher water content, viscosity and average molecular weight. Chemical properties included monocyclic- and polycyclic-aromatic hydrocarbon (PAH) concentrations, alkylated aromatic concentrations, and concentrations of aliphatic and aromatic fractions. It was found that there was at least an order-of-magnitude variation in all properties measured between the eleven coal tars. Additionally, two coal tars obtained from the same manufactured gas plant site had very different properties, highlighting that there can be wide variations in coal tar properties from different samples obtained from the same site. Similarities were also observed between the coal tars. The relative chemical distributions were similar for all coal tars, and the coal tars predominantly consisted of PAHs, with naphthalene being the single-most prevalent compound. The C(9-22) aromatic fraction, an indicator of all PAHs up to a molecular weight of approximately 276 gmole(-1), showed a strong power-law relationship with the coal tar average molecular weight (MW (ct)). And the concentrations of individual PAHs decreased linearly as MW (ct) increased up to ca. 1000 gmole(-1), above which they remained low and variable. Implications of these properties and their variation with MW (ct) on groundwater quality are discussed. Ultimately, while these similarities do allow generalities to be made about coal tars, the wide range of coal tar bulk and chemical properties reported here highlights the complex nature of coal tars.
对从美国东部以前的煤气厂场地获取的11种煤焦油进行了对比分析。分析的总体性质包括灰分百分比、卡尔费休水分含量、粘度和平均分子量。化学性质包括单环和多环芳烃（PAH）浓度、烷基化芳烃浓度以及脂肪族和芳香族馏分的浓度。结果发现，在测量的所有性质方面，这11种煤焦油之间至少存在一个数量级的差异。此外，从同一煤气厂场地获取的两种煤焦油具有非常不同的性质，这突出表明从同一地点获取的不同样品的煤焦油性质可能存在很大差异。在煤焦油之间也观察到了相似之处。所有煤焦油的相对化学分布相似，且煤焦油主要由多环芳烃组成，其中萘是最主要的单一化合物。C(9 - 22)芳香族馏分是分子量高达约276 g/mol的所有多环芳烃的一个指标，它与煤焦油平均分子量（MW(ct)）呈现出很强的幂律关系。并且，各个多环芳烃的浓度随着MW(ct)增加至约1000 g/mol时呈线性下降，超过该值后它们保持在较低水平且变化不定。讨论了这些性质及其随MW(ct)的变化对地下水质量的影响。最终，虽然这些相似性确实使得能够对煤焦油做出一些一般性结论，但此处报道的煤焦油总体性质和化学性质的广泛范围突出了煤焦油的复杂性质。
