Grantee Research Project Results
2023 Progress Report: Elucidating the occurrence of known and emerging chemical contaminants in wastewater biosolids and the influence of treatment and management processes on their fate, mobility and bioavailability
EPA Grant Number: R840248Title: Elucidating the occurrence of known and emerging chemical contaminants in wastewater biosolids and the influence of treatment and management processes on their fate, mobility and bioavailability
Investigators: Hale, Robert C. , Song, Bongkeun , Guardia, Mark La , Luellen, Drew
Institution: Virginia Institute of Marine Science , Hampton Roads Sanitation District
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2021 through July 31, 2024 (Extended to July 31, 2026)
Project Period Covered by this Report: September 1, 2022 through August 31,2023
Project Amount: $1,486,562
RFA: National Priorities: Evaluation of Pollutants in Biosolids (2020) RFA Text | Recipients Lists
Research Category: Water Quality , Water , Water Treatment
Objective:
1) Advance understanding of the composition, bioaccessibility, persistence, toxicity and mobility of chemical pollutants in wastewater sludges, biosolids and receiving soils; 2) Evaluate the influence of wastewater source and treatment choice on these; and 3) Assess sludge pollutant effects on critical wastewater treatment and soil microbial processes.
Progress Summary:
Issues with some project-critical instrumentation have been encountered, specifically the laser direct infrared (LDIR) imaging system and the UPLC-time of flight mass spectrometer. These occurred despite the instruments being recent acquisitions and covered under warranty or service contracts. Both issues were beyond the capabilities of the vendor dispatched service engineers and required return of instrumentation to the manufacturer. In the case of the LDIR this was in Australia.
A temperature/pressure reactor, capable of maintaining conditions used in the thermal hydrolysis process (THP; used to treat wastewater sludge to destroy pathogens, degrade natural polymeric substances and facilitate sludge dewatering) was acquired by our HRSD partner (using non-EPA funds). It was installed at their Norfolk VA facility in 2022. The PhD student who was to work with the system changed degree programs in January 2023. We thus investigated the use of an accelerated solvent extractor (ASE) present at VIM, instead. This system can dispense both aqueous and organic solvents and reach temperatures and pressures comparable to THP. It also incorporates stainless steel frits in the extraction vessels, which remove, inline, particulates from the extracts. Trials to extract both synthetic organic pollutants, polymer additives and endotoxins from sludge samples have been performed and are promising. An endotoxin analysis system for their determinations was also acquired and is being evaluated for endotoxin analysis.
Future Activities:
In the coming project year we will complete validation of mass spectrometric methods for detecting targeted and non-targeted chemical contaminants (including contaminants of emerging concern (CECs)) in wastewater/sludge matrices. We are investigating HLB columns for the retention and purification of biosolid extracts for CECs, as well as validate methods for the LDIR determination of microplastics (once it is returned from the manufacturer). The influence of elevated temperature, pressure and dissolved organic carbon (encompassing conditions encountered during THP) on the physical conformation of microplastics and chemical additive mobilities will be investigated. Also, we will evaluate the influence of weathering on the melting point and glass transition temperature of polymers commonly found in biosolids.
Journal Articles:
No journal articles submitted with this report: View all 10 publications for this projectSupplemental Keywords:
wastewater residuals, environmental chemistry, toxicsProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.