Trace Analysis of Pharmaceutical Residues in Wastewater Treatment Plants in Rio de Janeiro, Brazil

Abstract

The occurrence and fate of trace-level contamination of pharmaceuticals in theaquatic environment has been recognized as one of the emerging issues in environmentalchemistry. The effluents of wastewater treatment plants, usually directly emitted to theenvironment, often contain the anti-inflammatory drug diclofenac. Diclofenac was chosen becauseit is of high consumption; by background literature indicate toxic effects on biota and the lack ofprofile in sewage removal provided by the city. For this purpose, a survey on the presence ofdiclofenac in urban wastewater of Rio de Janeiro was carried out. It were evaluated diclofenacconcentration in the affluent and effluent from wastewater treatment plant (WWTP) Penha and Ilhado Governador, Rio de Janeiro, Brazil. Samples were collected along the line of treatment of eachWWTP, and for clean up the samples were solid phase extraction (SPE), analysed by highperformance liquid chromatography (HPLC), assisted by diode array detector (DAD) techniques.The removal efficiency of pharmaceuticals in the wastewater treatment plants was roughlyevaluated. Diclofenac was detected in all samples analysed wastewater (treated and raw), whichconfirms the low removal efficiency of conventional treatment systems, aerobes and anaerobes.