Summer 2024 Undergraduate Research Program: Electro-Enhanced Conversion of Wet Waste to Products Beyond Methane

Introduction

Each year, the US produces >77 million tons of wet organic waste, including food waste and manure. Most of this waste is landfilled but some of this waste is processed in anaerobic digestion (AD) units, in which complex microbial communities hydrolyze and convert the carbon-containing molecules in waste to methane and CO2. This can be an effective means of reducing organic waste volume and generating methane. However, while there are more than 16,000 AD units in the US, fewer than 1000 capture the methane because of its low market value.

The goal of this project is to re-engineer the AD process into a sequence of electro-biochemically enhanced processes that convert wet organic waste to higher-value products to displace petroleum-based products and reduce CO2 and methane emissions.

This Department of Energy-funded research project is a collaboration among researchers at Colorado State University, South Dakota School of Mines & Technology, University of California – Irvine, and the National Renewable Energy Laboratory.

Opportunity

Several paid summer research experiences are available for undergraduate students to work on different aspects of this overall project. Descriptions of the specific projects are listed on the following page, along with their locations. There will be a stipend of $7,000 for each student participant.

Application Deadline: April 14, 2024 11:59pm MST

To apply for the Summer 2024 edition of this program, submit the following in a single pdf file:

A. Resume

B. Cover letter with your background and statements of why you’re interested in this research

C. Ranked list of your top two projects with a paragraph to explain your choices

For questions, contact Dr. Ken Reardon at kenneth.reardon@colostate.edu

Projects

1. Economic and Environmental Assessment 

Location: Colorado State University, Fort Collins, CO

The work will focus on techno-economic analysis and life-cycle assessment to determine the associated cost and emissions of a process that converts organic wastes to chemical feedstocks, for example diesel and aviation fuel. There is flexibility in the research tasks based on personal interest. Generally, the work will focus on process design and mass balance.

2. Electron-Supplemented Fermentation of Wet Wastes for Enhanced VFA Production

Location: Colorado State University, Fort Collins, CO

Electron-supplemented fermentation, or electro-fermentation, of pure cultures has been shown to alter microbial metabolism and increase yields of more reduced metabolites. Similarly, some studies have shown that supplementation of electrons in anaerobic digestion (electro-AD) of wet wastes may lead to enhanced production of volatile fatty acids (VFAs). This project will investigate the behavior of microbial communities involved in this electro-AD process and the effect of different electron-supplementation conditions on VFA production.

3. Modeling Anaerobic Digestion Kinetics

Location: Colorado State University, Fort Collins, CO

In anaerobic digestion, various microorganisms interact to convert waste into products such as methane and volatile fatty acids. You will work with other students to model and optimize anaerobic digestion with a focus of integrating metagenomic data of microbial communities. This includes fitting parameters in an anaerobic digestion kinetic model using experimental data and suggesting conditions and microbial community compositions that maximize desired products. The intern will learn basic concepts and computational workflows for DNA sequence analysis and kinetic modeling using high-performance computing clusters, command-line tools, and Python programming.

4. Agitation and Scale-Up Effects on Anaerobic Digestion for Volatile Fatty Acids Production 

Location: South Dakota School of Mines & Technology, Rapid City, SD

While anaerobic digestion is less sensitive to scale-up effects compared to aerobic fermentations, our AD studies at the 2-L scale indicate that agitation level has a significant impact on volatile fatty acid (VFA) profiles. Although agitation minimizes mass transfer limitations, higher power per unit volume levels may disrupt critical biofilms on solid substrates, and good mixing becomes more difficult as the digester size increases. You will assist graduate students with 2- and 20-L fermentations designed to understand the multiple effects of agitation and scale on food waste/manure digestion. You will also learn how to start-up and operate a pilot-scale (2000 L) anaerobic digestion system. 

5. Bioconversion of Volatile Fatty Acids to Valuable Alcohols

Location: UC-Irvine, Irvine, CA

Our work focuses on the bioconversion of volatile fatty acids in the anaerobic digestion to valuable alcohols by utilizing our metabolically engineered microbe. To improve productivity and efficiency of our process, we employ cell immobilization. Alginate cell immobilization offers enhanced stability and productivity while requiring little effort and resources. You will have a chance to work on both the immobilization and bioconversion.

Colorado State University may conduct background checks on final candidates.

Employee benefit information can be found on HR’s Website at https://hr.colostate.edu/current-employees/benefits/

Payrate: $7,000 stipend

Start Date: May 28, 2024

Hours: variable, see details in project description

Job Roles: Mathematicians, Microbiologists, University Student Researchers