Does Circularizing Source-Separated Food Waste Present A Risk To Our Food?

Author

Astha Thakali, University of Maine, OronoFollow

Date of Award

Fall 5-8-2020

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Department

Civil Engineering

Advisor

Jean D. MacRae

Second Committee Member

Cindy Isenhour

Third Committee Member

Travis Blackmer

Abstract

About a third of the food produced annually is wasted. Food waste recycling can be a way to close the loop and attain a more sustainable food system, however, the system must be carefully monitored and managed to avoid the introduction and build-up of contaminants. To study the potential presence of contaminants in food waste, source-separated food waste was collected and screened for five classes of contaminants (physical contaminants, heavy metals, halogenated organic contaminants, pathogens, and antibiotic resistance genes) from two separate regulatory environments (voluntary vs mandated food separation). The regulatory environment did not affect the level of contamination, except there was more physical contamination in Maine, where food waste diversion is not mandated. Fifty-seven percent of samples had some form of non-compostable waste. Most of the heavy metals tested were not detected. Copper and zinc were detected in most samples but were always below the most stringent global standards for compost. Some samples had detectable halogenated organics, which is cause for concern because some are known to accumulate in the food chain. Foodborne pathogens were seldom detected and should be killed during treatment, but this could pose a risk to collectors and haulers. Antibiotic resistance genes were detected in most samples. This could jeopardize the utility of antibiotics used to fight infections. More research is needed to determine the fate of antibiotic resistance genes and halogenated organics during treatment, and the risk of their accumulation in a circular food system.

Recommended Citation

Thakali, Astha, "Does Circularizing Source-Separated Food Waste Present A Risk To Our Food?" (2020). Electronic Theses and Dissertations. 3438.
https://digitalcommons.library.umaine.edu/etd/3438