Quantitative analysis of plasticizers in a wastewater treatment plant: Influence of the suspended solids parameter

Abstract

This study investigated the occurrence of di(2-ethylhexyl)phthalate (DEHP) and bisphenol A (BPA) in the wastewater treatment plant of the University of Caxias do Sul (WWTP-UCS). During five months, five wastewater samples from the inflow and outflow points were collected and submitted to liquid-liquid extraction (LLE). The organic extracts were analyzed by gas chromatography with flame ionization detection (GC/FID). The removals grades were 37.79 and 19.90% for BPA and DEHP, respectively. The average concentrations at the outflow points were 52.52, and 20.00 mg L-1, for BPA and DEHP, respectively. These high target compound contents at the exit point may be due to the low removal of suspended solids from the raw samples (only 42.72% removal). To confirm this hypothesis, other five samples also from the inflow and out flow points were submitted to LLE extraction with and without the prefiltration step. The DEHP removal in the filtered samples was 74.44% and the median DEHP concentration at the outflow point was 6.01 mg L-1. For the unfiltered samples, the DEHP removal was 40.96% and the median DEHP concentration at the outfilow point was 17.04 mg L-1. © 2011 Sociedade Brasileira de Química.