Analysis of organic compounds in an urban wastewater treatment plant effluent

Abstract

In the present work we fractioned the effluent water from an urban sewage treatment plant (USTP) of Ribarroja (Valencia, Spain) using the conventional protocol based on DAX8 and XAD4 resins. The fractions were analyzed by elemental analysis, FT–IR, ¹H‐NMR, COSY‐NMR, HSQC‐NMR, FAB⁺‐MS and also by derivatization with bis(trimethylsilyl)trifluoroacetamide with 10% of trimethylchlorosilane. The four fractions obtained have common spectroscopic features and individual compounds indicating that the fractioning procedure is inefficient at separating different families of compounds. Gas chromatography/mass spectrometry (GC–MS) analysis of the derivatized fractions allowed identification of many individual compounds. The main classes of organic compounds present in the effluent are saccharides, amino acids, fatty acids, hydroxyacids, aromatic compounds and steroids. Also we were able to identify in the effluent the emerging pollutants paracetamol and ketoprofen – two best‐selling anti‐inflammatory drugs used in humans.

Keywords:

• urban wastewater effluent
• dissolved organic matter analysis
• NMR spectroscopy
• mass spectroscopy
• emergent pollutants

Acknowledgements

Financial support from the Spanish DGI (CTQ 2009‐11583) is gratefully acknowledged. S. Navalon thanks the Technical University of Valencia for a postgraduate research contract (Cantera Programme). We are indebted to the staff in charge of the Ribarroja del Turia urban wastewater treatment plant (belonging to the Entidad Pública de Saneamiento de Aguas Residuales de la Comunidad Valenciana) for providing samples and analytical data available for the influent and effluent water.