Rooney Kim Lazcano
Rooney Kim Lazcano is a doctoral student in Ecological Sciences and Engineering Interdisciplinary Program and Department of Agronomy at Purdue University. Her research addresses beneficial use of waste residuals and associated environmental assessment, which includes leachability and uptake of contaminants of concern. Specifically, her research is focus on the environmental fate of trace organic contaminants including pharmaceutical and personal care products and per/polyfluorinated compounds in commercial biosolids-based fertilizer. She received a B.S. in Environmental Toxicology from the University of California-Davis in Davis, CA, and a M.S. from Molecular Sciences and Bioengineering from University of Hawaii-Manoa in Honolulu, HI.
Per- and Polyfluoroalkyl Acids in Composted Wastes: Commercial Biosolids-based and Nonbiosolid-based Fertilizers
Biosolids are nutrient-rich organic materials that have been applied to agricultural land as a fertilizer to enhance agricultural production while maintaining soil quality. More recently, commercially available biosolids-based fertilizers (CBFs) have gained popularity for personal use in urban and sub-urban gardens. However, recent studies showed that per- and polyfluoroalkyl substances are frequently detected in biosolids, which is due to their widespread use and persistence. Application of CBFs in urban and sub-urban gardens can lead to potential risks of transfer and accumulation of PFASs in food crops. The objective of this study was to quantify and compare the concentration of PFASs in different types of CBFs (e.g., composted and heat-treated) versus in non-biosolids based fertilizers (NBFs) (e.g., composted animal manure, composted food and yard wastes, composted food service-ware products, etc.). We hypothesized that PFAS concentrations in CBFs would be higher than NBFs. CBFs and NBFs were extracted with a methanol/ammonium hydroxide solution using sonication followed by a 2-h end-over-end rotation. Prior to analysis, all solvent extracts were concentrated under nitrogen, and cleaned with ENVI-carb to reduce matrix effects that may affect quantitation. All extracts were analyzed for 17 perfluoroalkyl acids (PFAAs) of which 13 were perfluoroalkyl carboxylic acids (PFCAs) from C4-C18 chain length and 4 were perfluoroalkyl sulfonates (PFSAs, C4, C6, C8, and C10) using a Shimadzu liquid chromatography system coupled to a Sciex quadrupole time of flight. Both PFCAs and PFSAs were found in both CBFs and NBFs, but as hypothesized, concentrations are generally much lower in NBFs. Also all samples except those containing domestic sewage sludge contained had higher levels of PFCAs (>50% to 97%) relative to total PFAAs. Domestic sewage sludge samples contained as much as 80% PFSAs. Although CBFs had much less PFASs compare to municipal biosolids, future studies are needed to address if levels are low enough to remove concerns with regards to PFAA bioaccumulation in food crops, leaching to water sources, and potential adverse effects on human and ecological health at the concentrations detected. Currently, leaching of PFAAs from a subset of CBFs and NBFs are being evaluated and will be discussed relative to PFAA loads and starting materials in the various fertilizers.