Occurrence and removal of fungicides in municipal sewage treatment plant.

This work reports the occurrence and the removal of widely used fungicides, in municipal sewage treatment plant receiving combined sewage discharges and operating with primary (mechanical), secondary (activated sludge) and tertiary (sand filtration and chlorination) treatments that are commonly applied in Greece. Target analytes included compounds belonging to triazoles and anilino-pyrimidines. Analytical determination in wastewaters and river water samples was carried out by means of solid-phase extraction followed by gas chromatography equipped with flame thermionic and mass spectrometric detection. The fungicides tebuconazole and cyproconazole were more frequently detected in influent and effluent samples at concentrations up to 1893 and 1735 ng L(-1), respectively. Effluent concentrations were below 691.1 ng L(-1) recorded for tebuconazole. With the exception of triadimefon, all the azole fungicides and pyrimethanil showed relatively low removal efficiencies after secondary and tertiary treatments. Mean removal rates of the fungicides after secondary treatment ranged between 31% for pyrimethanil and 65% for triadimefon. Mean overall removal efficiencies after tertiary treatment ranged between 46% for pyrimethanil and 93% for triadimefon. The findings demonstrate that significant levels of fungicides enter river waterways and that only some of these compounds are being reduced in low levels by municipal wastewater treatment processes. (c) 2009 Elsevier B.V. All rights reserved.