Occurrence and Fate of Polycyclic Aromatic Hydrocarbons in Sewage Treatment Plants Using Microwave-Assisted Extraction Followed by Liquid Chromatography Coupled with Fluorescence Detector

Polycyclic aromatic hydrocarbons (PAHs) are highly persistent compounds in the environment, recalcitrant to biodegradation and highly lipophilic, while some of them cause acute carcinogenic and mutagenic toxicity. Due to the risk of soil contamination whenever sewage sludge is disposed to agricultural land, the investigation of their presence in sewage sludge is a priority need.This work concerns the occurrence of five PAHs, selected from the priority list of the US Environmental Protection Agency (phenanthrene, fluoranthene, pyrene, benzo[b]flouranthene, and benzo[a]pyrene), in municipal sewage sludge and to assess their fate in a sewage treatment plant. An analytical method based on microwave-assisted extraction (MAE), followed by HPLC-UV coupled with a fluorescent detector (FD) was used for their measurement. The method efficiency was evaluated as to its linearity, repeatability, accuracy and sensitivity.The contamination levels of the PAHs were determined in sludge from the sewage treatment plants of three main Greek cities: Athens, Patras and Heraklion. PAHs ranged from 0.2 to 4 mg kg(-1) d.m for each PAH in mixtures of primary and secondary sludge, while they were significantly lower in secondary sludge (less than 0.1 mg kg(-1) d.m).