Boise State University researchers recently presented their work at the Asia Conference on Environment and Sustainable Development, held at Kyushu University in Fukuoka, Japan. Graduate student Gregor Posadas from the Department of Civil Engineering, along with Associate Professor Sondra Miller, shared findings from their study titled “Dissolved Oxygen Influences on Sludge Settleability: Mediating Role of the Volatile-to-Total Suspended Solids Ratio.”
The research is part of Posadas’ master’s thesis and examines how dissolved oxygen levels affect sludge settling in full-scale wastewater treatment plants, such as the facility in Greenleaf, Idaho. The team’s findings could help plant operators improve treatment processes.
“We were studying a wastewater treatment plant that started experiencing sludge bulking, and we wanted to understand why,” Posadas said. “We found that higher dissolved oxygen levels were strongly linked to poorer settling performance. By connecting those results to previous research, we could explain what was happening at the microbial level. That connection between data, science and real-world operation is what makes this work useful, because it gives plant operators a measurable warning sign they can use to catch problems early.”
The conference brings together experts from around the world to discuss developments in environmental engineering and sustainable solutions for global challenges.
“It is critical we continually explore innovations that lower costs and improve treatment performance outcomes for modern water and wastewater infrastructure,” Miller said. “This research has a direct impact on rural states, like Idaho, as utilities prepare for new regulations targeting contaminants such as PFAS and pharmaceuticals.”
Miller and Posadas engaged with international scholars during the event and highlighted Boise State’s focus on research with practical applications.
