Fate of polycyclic aromatic hydrocarbons during composting of activated sewage sludge with green waste

摘要: Abstract The level and fate of 16 polycyclic aromatic hydrocarbons (PAHs), targeted by the US Environmental Protection Agency (USEPA), has been studied over 90 days composting activated sludge with green waste, under a semi-arid climate. total PAH calculated from sum amounts PAHs in initial mixture was lower than accepted European Union cut-off limits about 0.48 mg kg−1. treatment led to decrease all mainly stabilization phase, but some differences could be observed between three or fewer rings (N ⩽ 3) those four more (N ⩾ 4). former (except phenanthrene) exhibited continuous decrease, while latter N phenanthrene showed increases intermediate stages (30–60 days). This indicates high potential sorption molecular weight (N ⩾ 4) plus phenanthrene, their tight adsorption makes them inaccessible for microbial attack. greater reduction bioavailability low weight. Naphthalene, lowest weight, smallest (about 67.8%) compared other higher (decrease reaching 100%). is agreement fact that less reversible increased numbers fused an increase hydrophobicity.