Anaerobic Digestion and Composting Treatment Efficiency of Cephalosporins

EPA Grant Number: FP917144
Title: Anaerobic Digestion and Composting Treatment Efficiency of Cephalosporins
Investigators: Mitchell, Shannon Mary
Institution: Washington State University
EPA Project Officer: Lee, Sonja
Project Period: August 23, 2010 through August 22, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Pesticides and Toxic Substances


Human and veterinary antibiotic excretion and the subsequent release of un-metabolized antibiotics into the environment following different waste management practices is a human and environmental health concern. Several studies have identified antibiotics in surface water and groundwater, but antibiotic quantification in environmental matrices such as biosolids, manure, compost, and anaerobic digestion effluent has been performed to a lesser extent. This research project will investigate antibiotic presence in processed and unprocessed solid waste products and analyze antibiotic persistence during composting and anaerobic digestion. It will also investigate antibiotic chemical behaviors in soil and water systems.


Trace antibiotic levels in the environment are an increasing public health concern, as these pharmaceutical compounds have been linked to the promotion of antibiotic resistant bacteria. Moreover, their impacts on ecosystem functions remain unknown. This project studies antibiotic presence in environmental samples such as manure, compost, anaerobic digestion effluent and biosolids. It also analyzes antibiotic dissipation mechanisms in soil and water systems.


The first step in quantifying antibiotic presence from manure, compost, anaerobic digestion effluent, and biosolids will be to determine appropriate antibiotic extraction and sample clean-up methods. Then, environmental samples will be collected around Washington State and analyzed for selected human and veterinary antibiotics. By examining samples before and after waste treatment using scaled-down treatment units, antibiotic treatment efficiencies will be identified. Antibiotic dissipation mechanisms will also be tested under laboratory conditions by controlling for chemical degradation, biological degradation, and sorption.

Expected Results:

Processed and unprocessed solid waste products are land applied as fertilizer, and in many confined animal feeding operations compost is used for cattle bedding. This is concerning because antibiotic presence promotes antibiotic resistance. This research will quantify antibiotic presence in compost and other land-applied solids, and the results will be provided to resource managers, which will help facilitate antibiotic exposure evaluation and risk assessments in confined animal feeding operations.

Potential to Further Environmental/Human Health Protection:

Antibiotics that are more mobile in soil may contaminate drinking water; however, less mobile antibiotics may persist in soils, where bioaccumulation and antibiotic resistance in soil bacteria are promoted. Antibiotic resistance has been increasing, and critically important medicines may no longer be first-line agents due to developed antibiotic resistance in pathogens. This project has the potential to further human and environmental health protection by identifying antibiotic presence in environmental samples, investigating antibiotic persistence during waste treatment, and analyzing the compound mobility in soil and water systems.

Supplemental Keywords:

antibiotic, biosolids, compost, anaerobic digestion waste, manure, treatment, soil, water, degradation, sorption, waste management practices, contaminant, fate and transport, antibiotic resistance, health risk,

Progress and Final Reports:

  • 2011
  • 2012
  • Final