Grantee Research Project Results

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: R840248
Title: 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 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:

The goals of this research are to: 1) Advance understanding of the composition, bioaccessibility/bioavailability, 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.

Approach:

This research addresses each of the Research Area 1 questions, using a series of controlled lab experiments and field investigations. Objectives include: 1) Validate a broad spectrum analytical method to identify diverse chemical pollutants in sludge, biosolids and soils (including targeted and non-targeted contaminants); 2) Validate a method for endotoxin quantitation in these matrices. Endotoxins are liberated from bacterial cell walls/debris during treatment. Exposure to these is a health concern to communities near application sites; 3) Develop novel Raman and laser-directed infrared (LDIR) micro-spectroscopic methods to chemically image and characterize biogenic/organic particulates (which affect pollutant fate and can be modified by sludge treatment choice) and microplastics (an emerging biosolids concern); 4) Compare differences in sludge pollutants arising from municipal-dominated, mixed sources and those receiving storm water runoff; 5) Investigate the effects of wastewater treatment plant (WWTP)-based anaerobic digestion (AD) and the thermal hydrolysis process (THP) on the composition/degradation of sludge and associated contaminants; 6) In controlled experiments, apply chemical analysis and spectroscopic micro-imaging to evaluate consequences of AD, THP, liming and thermal drying on sludge pollutants and the associated biogenic matrix; 7) Using actual WWTP sludge matrices, assess the impact of THP on bioaccessibility of polymer additives and other pollutants; 8) Under controlled conditions, evaluate the influence of temperature, pressure and dissolved organic carbon conditions on surface-sorbed pollutants and additive leaching from polymers; 9) Assess the impact of THP-treated sludge leachates on processes critical to proper WWTP function and soil health, i.e. nitrification and denitrification; 10) Evaluate the effects of sludge treatment choice on biosolid pollutant mobility and persistence in field-applied soils.

Expected Results:

Pollutant profiles in sludge will vary as a function of influent source and sludge treatment; hitherto unreported pollutants will be identified; THP will increase pollutant mobility and bioaccessibility; THP-treated sludge leachates will impact nitrification and denitrification processes. Outcomes will facilitate improved strategies for monitoring sludge-related pollutants, selecting optimal treatment processes and reducing contaminant levels in U.S. biosolids and receiving soils. These improvements, in turn, will decrease associated public health and ecosystem risks.

Publications and Presentations:

Publications have been submitted on this project: View all 6 publications for this project

Supplemental Keywords:

wastewater residuals, environmental chemistry, toxics

Progress and Final Reports:

The 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.