Fly ashes generated from coal-fired thermoelectric power plants on the Balkan Peninsula – Organic geochemical study

Organic matter (OM) presence in fly ashes (FA) might be a serious obstacle towards their utilization or beneficial use. Though, it is imperative to enhance the knowledge of FA geochemical composition and environmental impact. Feed coals and FA from thermoelectric power plants (TPP) in Bulgaria (Maritza East 2 TPP), Greece (Megalopolis TPP and Agios Dimitrios TPP) and Serbia (TENT A, Nikola Tesla A TPP and TENT B, Nikola Tesla B TPP) were comparatively studied by geochemical proxies. Extractable organic matter, 0.45–6.10% for the feed coals and 0.013–0.025% for the FA, was subjected to extensive chromatographic separation and species in different chemical series were GC–MS identified and quantified. Changes in the biomarker assemblages triggered by combustion in the pairs feed coal/FA were picked up, series of chemical classes quantified and subsequently alterations in chemical series were expressed in rel. %.