Determination of sixteen polycyclic aromatic hydrocarbons in aqueous and solid samples from an Italian wastewater treatment plant

Abstract

A robust procedure for the determination of 16 US EPA PAHs in both aqueous (e.g. wastewaters, industrial discharges, treated effluents) and solid samples (e.g. suspended solids and sludge) from a wastewater treatment plant (WWTP) is presented. Recovery experiments using different percentages of organic modifier, sorbents and eluting solvent mixtures were carried out in Milli-Q water (1000 mL) spiked with a mixture of the PAH analytes (100 ng/L of each analyte). The solid phase extraction (SPE) procedures applied to spiked waste water samples (1000 mL; 100 ng/L spiking level) permitted simultaneous recovery of all the 16PAHs with yields >70% (6-13% RSD). SPE clean up procedures applied to sewage and stabilized sludge extracts, showed percent recoveries in the range 73-92% (7-13% RSD) and 71-89% (7-12% RSD), respectively. The methods were used for the determination of PAHs in aqueous and solid samples from the WWTP of Fusina (Venice, Italy). Mean concentrations, as the sum of the 16PAHs in aqueous and suspended solid samples, were found to be approx. in the 1.12-4.62 microg/L range. Sewage and stabilized sludge samples contained mean PAH concentrations, as sum of 16 compounds, in the concentration range of 1.44-1.26 mg/kg, respectively. Extraction and clean up procedures for sludge samples were validated using EPA certified reference material IRM-104 (CRM No. 912). Instrumental analyses were performed by coupling HPLC with UV-diode array detection (UV-DAD) and fluorescence detection (FLD).

Occurrence, behavior and removal of typical substituted and parent polycyclic aromatic hydrocarbons in a biological wastewater treatment plant

“…As is known that PAH is a type of ubiquitous pollutant in WWTPs (Pham and Proulx, 1997;Manoli and Samara, 1999;Busetti et al, 2006;Vogelsang et al, 2006). Previous studies have well documented the removal efficiencies and potential mechanisms of PAHs during biological treatment processes.…”

The behaviors and fate of polycyclic aromatic hydrocarbons (PAHs) in a coking wastewater treatment plant

“…As a result, the behaviors and fate of these compounds in coking WWTPs have still not been adequately documented. Since 2000s, many efforts have been made to develop the effective sampling and/or analytical techniques for PAHs in the gas-phase (Bi et al, 2003;Chen et al, 2005), the liquid and solid-phase samples with the complicated matrix (Chen et al, 2005;Busetti et al, 2006;Guo et al, 2007). These newly developed techniques make the quantitative analyses possible for PAHs in various phase from coking WWTPs.…”

“…Among these available studies, the focuses were mainly on the occurrence and distribution of these compounds in coking wastewater, not including their behaviors and fate (e.g., the concentrations of PAHs in various phase states at different stages). It is mainly because of the difficulties in collecting sludge and gas samples and accurately quantifying PAHs in the complicated matrix (Busetti et al, 2006;Poster et al, 2006), so that the systematic balance of these PAHs is not available. As a result, the behaviors and fate of these compounds in coking WWTPs have still not been adequately documented.…”

“…The aim of the present study was to investigate the occurrence, behaviors and fate of PAHs in a coking WWTP, based on the sampling and analytical techniques developed recently (Bi et al, 2003;Busetti et al, 2006;Guo et al, 2007). Eighteen PAHs were identified and determined in coking wastewater as well as at particular points of the gas and sludge stream that well presented the process.…”

Quality assurance considerations in chemical analysis

“…It is therefore important to have several reference materials to choose from as well as reference materials that can be added unknown samples to control that the added compound can be recovered. The use of CRMs is applied in many fields of HPLC analysis such as drug monitoring [12,13], anti-doping analysis [14], ion chromatography [15] and pesticide analysis [16]. Applications of CRMs could also be found for other analytical techniques such as gas chromatography [17], infrared spectrometry [18] or atomic absorption spectroscopy [19].…”