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DEVELOPMENT AND VALIDATION OF ANALYTICAL METHODS FOR ENUMERATION OF FECAL INDICATORS AND EMERGING CHEMICAL CONTAMINANTS IN BIOSOLIDS
Citation:
MECKES, M. C., S. FOUT, T. L. JONES, AND W. BRUMLEY. DEVELOPMENT AND VALIDATION OF ANALYTICAL METHODS FOR ENUMERATION OF FECAL INDICATORS AND EMERGING CHEMICAL CONTAMINANTS IN BIOSOLIDS. Presented at 2006 Water Quality BOSC Review, Cincinnati, OH, January 25 - 27, 2006.
Description:
In 2002 the National Research Council (NRC) issued a report which identified a number of issues regarding biosolids land application practices and pointed out the need for improved and validated analytical techniques for regulated indicator organisms and pathogens. They also called out the need for developing methods for detection and quantification of pharmaceuticals and personal care products (PPCP) in biosolids. Analysis of sludges or biosolids poses unique challenges due to the potential for sorption of contaminants to solids and in the case of untreated sludges and class B biosolids the potential for high densities of microorganisms, including those that are pathogenic.
EPAs Office of Research and Development (ORD) in cooperation with the Office of Water (OW) developed standardized methods for the analysis of indicator bacteria (fecal coliform) and a pathogenic bacteria (Salmonella sp.) and worked with volunteer laboratories throughout the United States to validate these methods by common analysis of shared samples. EPA is currently working with the University of Cincinnati to develop improved techniques for elutriation, detection, and identification of enteric viruses in biosolids. The improved techniques will be able to detect many enteric virus types that are not detected by the current analytical method. Upon completion of this effort, a standardized protocol will be developed and, if funding is available, multilab validation testing will be conducted similar to the approach used for fecal coliform and Salmonella.
EPA also has plans to begin research to optimize the improved methods for isolating and identifying viable ova of the parasitic helminth (worm), Ascaris lumbricoides in biosolids. PPCPs are part of waste streams entering publicly owned treatment works and may concentrate in sludges.
EPA is currently developing methods for the detection and quantification of specific PPCPs in biosolids. Using a previously developed analytical method for synthetic musk compounds, extraction techniques were carried out to determine the most efficient extraction method. A pressurized liquid extraction technique (PLE) was adopted. The objective was to develop a higher percentage recovery (close to 100%) of synthetic musk compounds in Class A biosolids. Although the method has been developed, details of the analytical work have not been presented. Method developments for recovery and detection of fluoroquinone and macrolide antibiotics are underway. Both sonication, liquid-liquid, and accelerated solvent extraction (ASE) are being investigated as possible extraction techniques. High performance liquid chromatography (HPLC) with fluorescence and HPLC with mass spectroscopy (MS) are being investigated as detection techniques.