WELLS LAB - Key Persons


Ahmed AlSayed

Ahmed AlSayed is an NSERC postdoctoral fellow working in the Department of Civil and Environmental Engineering, Northwestern University. He is interested in investigating and developing energy-efficient and resources recovery processes for wastewater treatment (i.e., A-stage process, short-cut N removal, High-rate P-removal). His research at Northwestern University mainly focuses on developing and demonstrating data-driven process models and controls for water resource recovery facility (WRRF) full-scale process technologies like the dynamic A-stage process. Prior to joining Northwestern, Ahmed worked on investigating the effect of operational and microbial parameters on the A-stage process, developing stable low DO nitrite-shunt process, and using methanotrophic bacteria for resources recovery from wastewater and biogas valorization.

Bill Yen

Bill is an undergraduate student in the Department of Mechanical Engineering and the Department of Civil and Environmental Engineering who joined the Wells Lab in 2020. He is interested in environmental sensing and monitoring, agriculture, and smart urban systems. His research project focuses on leveraging soil microbial fuel cells as long-term renewable energy supplies for low-powered sensors in green infrastructures, and he is currently designing cells with alternative geometries for maximum power generation. Outside of the lab, he serves as the Co-President for NU's chapter of Engineers for a Sustainable World and practices Brazilian jiu jitsu.

Daniel Stockard

Job Titles:
  • Graduate Student

Emily Kin


Esther Nehmad Karasik


George Wells

Job Titles:
  • Associate Professor

Hannah Schmitz

Hannah is a graduate student in the Department of Civil and Environmental Engineering who joined the Wells Lab in 2021. She earned her undergraduate degree in biomedical engineering from the University of Arizona in 2018. Between grad school and undergrad, she worked at Baxter on research and development of infusion pumps. She is currently researching imaging techniques to quantify the mechanical properties of biofilms. Her research has been recognized with an NSF GRFP.

Hau Truong

Job Titles:
  • Graduate Student

Heather Nielsen


Laura Jaliff

Laura is a PhD student in the Department of Civil and Environmental Engineering who joined the Wells lab in 2021. She graduated from the California Institute of Technology with a B.S. in Physics in 2020. Her research focuses on the development of microbially catalyzed electrochemical technologies to extract electricity from soil and as soil quality sensors. She is currently exploring the effects of duty cycling on electron storage mechanisms in the anodic biofilms of lab-based soil microbial fuel cells as well as working on constraining the role of soil texture and composition on microbial fuel cell performance in the field.

McKenna Farmer

McKenna is a PhD student in the Department of Civil and Environmental Engineering and joined the Wells Lab in 2019. She graduated from the University of Wisconsin-Platteville with a B.S. in Civil Engineering. Her research interests center on biological nutrient removal and recovery. She is currently operating a lab-scale CANDO+P process for simultaneous phosphorus and nitrogen recovery from wastewater. She is also researching biological phosphorus removal and nitrogen recovery metabolisms using 16S and metagenomic sequencing. Outside of the lab, she is an Outreach Committee Member for Northwestern GradSWE.

Stefanie Huttelmaier

Stefanie is a PhD student in the Department of Civil and Environmental Engineering working under the guidance of both the Hartmann and Wells Labs. She received her B.A. in Biology and Environmental Science at Carthage College in 2018. Her research interests revolve around the potential to manipulate microbial communities in engineered systems to mitigate environmental impacts of human activity. She is currently exploring the use of bacteriophage as process control for nutrient removal systems in wastewater treatment and the potential applications of wastewater-based epidemiology as an early detection method for the outbreak of infectious disease.

Thomas Lippert

Thomas Lippert is a postdoctoral scholar in the Department of Civil and Environmental Engineering at Northwestern University and Argonne National Laboratory. He is interested in valorizing organic waste materials into valuable products such as energy-rich biomethane using anaerobic digestion and biogas upgrading. Thomas is co-advised by Dr. George Wells at Northwestern University and Dr. Yupo Lin at Argonne National Laboratory. His research mainly focuses on the development and operation of electrochemical and biological reactor systems for biomethane generation and their translation from lab- into pilot-scale applications. Before coming to Northwestern, Thomas worked as a PhD student on ultrasonic sewage sludge pre-treatment for enhanced anaerobic digestion performance and as a postdoc for industrial wastewater treatment at Technical University of Munich, Germany.

Tyler Pozan

Job Titles:
  • Graduate Student

Zhen Jia

Zhen is a PhD student in the Department of Civil and Environmental Engineering, and he joined the Wells Lab in 2018. His research interests include the improved biological processes for cost-effective nutrients removal and recovery from wastewater. His previous works focused on the development of integrated PN/A + EBPR processes in a mainstream bench scaled reactor and community analysis of PAOs in a sidestream enhanced biological phosphorus reactor. He is currently investigating the feasibility of developing state-of-art partial denitrification/anammox (PdN/A) concepts using denitrifying PAOs to accomplish the mainstream deammonification incorporated with biological phosphorus removal.