ORGANIC WASTEWATER CONTAMINANTS IN BIOSOLIDS AND BIOSOLID-DERIVED PRODUCTS

Numerous organic compounds are known to be present in wastewater streams. Some of the compound classes present include pharmaceuticals, personal-care products, endocrine disruptors, industrial chemicals, and pesticides. Components of each of these classes consist of a broad group of compounds defined as organic wastewater contaminants (OWCs), which may be useful as chemical tracers of wastewater components. The solid byproducts of wastewater treatment, known as biosolids, are disposed of in many ways, including land application as soil supplements. Biosolids also are used to produce composts and fertilizers that are available for public or commercial use. Traditionally concern about land application of biosolids has focused on metals, nutrients, and selected organic compounds; however, the presence and environmental fate of OWCs that may be present in biosolids has not been evaluated, particularly as a source to surface or ground water. This is because of the analytical challenges posed by organic-rich matrices, such as biosolids and products derived from biosolids. This study examined biosolids and biosolid-derived products from multiple sources to determine the compositions and concentrations of OWCs present in biosolids and biosolids-derived products. More than 35 OWC’s were identified and quantified in biosolid matrices, including pharmaceuticals, fragrances, sterols, and other industrial chemicals. Concentrations of the OWCs ranged between less than 1 ng/g and greater than 100 ng/g. Future research will include field sampling of locations receiving land-applied biosolids in order to assess the fate and transport of OWCs in the soil environment, and to evaluate the potential for OWCs from biosolids to reach groundwater.