In Memoriam: Dion Dionysiou, PhD

Environmental engineering professor was renowned water quality researcher

Dionysios Dionysiou was a world-renowned researcher lauded for his work developing technologies and strategies to identify, monitor and treat water pollutants and toxins.

Dionysiou, a professor of environmental engineering in the University of Cincinnati College of Engineering and Applied Science, died Nov. 20. He was 57 years old. 

headshot of Dionysios Dionysiou, professor of environmental engineering

Dion Dionysiou, environmental engineering professor for 23 years at UC, died Nov. 20, 2023. Photo/Andrew Higley/UC Marketing + Brand

He joined UC’s faculty in 2000 in the Department of Chemical and Environmental Engineering.

Dionysiou was a true leader in his field. In 2022, he was named a Highly Cited Researcher by Clarivate for the fifth consecutive year. Dionysiou had more than 600 publications, which have been cited 68,000 times in other papers. His research has been supported by more than $8 million in grant funding. 

Dionysiou and his students were awarded the prestigious Prince Sultan Bin Abdulaziz International Prize for Water in 2022. The University of Cincinnati named him 2022 Distinguished Research Professor. 

Dionysiou's research centered on innovative technologies for removing difficult-to-treat water pollutants, addressing regional concerns like harmful algae blooms, and removal of emerging contaminants such as pharmaceuticals and personal care residues. 

Soryong R. Chae, associate professor in UC’s Department of Chemical and Environmental Engineering, was a frequent collaborator of Dionysiou and they were friends for more than 15 years.

“Dion possessed a giant reservoir of energy for knowledge and curiosity that could never be filled,” Chae said. “Dion was one of the reasons I joined UC from Australia in 2015. I will miss my esteemed colleague and best friend at UC.”

UC College of Engineering and Applied Science professor Dionysios Dionysiou was recognized by Saudi Arabia for his nanotechnology water research. Shown here with UC College of Engineering and Applied Science graduate Abdulaziz Al Anazi, who will be honored as part of Dr. Dionysiou's team.

UC graduate Abdulaziz Al Anazi, left, and UC College of Engineering and Applied Science professor Dionysios Dionysiou talk in an environmental engineering lab. Photo/Andrew Higley/UC Marketing + Brand

Dionysiou attributed his success to joint efforts with students and collaborators, valuing creativity and a passion for research. He consistently embraced new ideas from his students, encouraged risk-taking in unexplored research domains, and maintained a dynamic approach to scientific exploration.

“He was a consummate professional who demonstrated exceptional care for his students. His passing affected us all deeply,” said Anastasios Angelopoulos, professor and head of the Department of Chemical and Environmental Engineering. 

Dionysiou provided opportunities and support to his students by promoting their work for recognition and awards whenever there was an opportunity. As a result, his students received over 130 university, state, national and international awards. In 2021, Dionysiou received the W. Wesley Eckenfelder Graduate Research Faculty Adviser Award for Outstanding Lifetime Achievements for Advancement of Environmental Protection for his mentor role.

Katie Weitzel has been a PhD student on Dionysiou’s research team for the last four years. 

“Dr. Dion challenged me and pushed me harder than anyone had before. He showed me I was capable of great things. I would not be the person or scientist I am today without him,” Weitzel said. 

He was well-known and highly regarded among peers in his field – and went out of his way to connect with colleagues around the world. 

“At every conference, when people learned Dr. Dion was my adviser, they would launch into a story about how they knew him – which would usually end in laughter,” Weitzel said. 

He was known for his affable personality as much as he was for his impressive body of research. Weitzel recalls how he would stop by her office to chat and share funny stories about his pet chinchilla or his crazy travel adventures. 

“Dr. Dion was always able to make people laugh and he genuinely cared for the people around him. He dedicated his life to his work and his students,” Weitzel said. “Dr. Dion was always looking out for his students and making sure he was helping them achieve their goals and make connections that would set them up for success both in research and their future careers.”

professor Dionysiou in a white coat holding a tray of small vials in a lab

UC environmental engineering professor Dionysios Dionysiou pictured in the lab, where he and his students have developed innovative water monitoring systems. Photo/Andrew Higley/UC Marketing + Brand

Throughout his career, Dionysiou served on numerous research, educational and outreach committees, and held many leadership roles. As a testament to his contribution at the international level, he was elected academician of the European Academy of Sciences and a fellow of four other professional societies (International Water Association, American Chemical Society, Royal Society of Chemistry, and Association of Environmental Engineering and Science Professors). 

He organized numerous conferences, including symposia, to highlight the pioneering work of women in environmental engineering and science. Dionysiou received more than 50 awards, including the ARCADIS Frontier in Research Award, the Outstanding Publication Award from the Association of Environmental Engineering and Science Professors, and the Sustainable Water Award from the Royal Society of Chemistry. 

Dionysiou’s childhood inspired his work in water quality. He grew up in Cyprus, where water scarcity was an ongoing issue. After earning his BS degree in chemical engineering at the National Technical University of Athens, Greece, and his master's in chemical engineering at Tufts University, Dionysiou came to UC for his doctoral studies in environmental engineering in the field of water treatment using sustainable technologies. 

Makram Suidan, UC professor emeritus, was Dionysiou’s mentor while he was a doctoral student. Recognizing Dionysiou’s commitment and intellectual leadership to his research, Suidan knew the impact Dionysiou could make in the environmental engineering program and thus advocated for the college to hire him as a faculty member. 

“Dion was highly respected among his peers and left an indelible mark at UC. He will always be remembered as a gentle person who loved his extended family of graduate students,” Suidan said. “He will be deeply missed by those of us who were fortunate enough to get to know him and call him a colleague and a friend.”

Dionysiou is survived by his wife of 32 years, Paula; daughters, Marianna and Stella; and his parents.

Visitation is 9 to 11 a.m. Tuesday, Dec. 5, at St. Nicholas Greek Orthodox Church, 7000 Winton Road, Cincinnati. Read the full obituary

In lieu of flowers, the family requests that donations be made to the Professor Dion Dionysiou Memorial Fund (8002746) at the UC Foundation website.

Related Stories


Faculty Awards 2021: Peter Smirniotis

April 8, 2021

University of Cincinnati chemical engineering professor Peter Smirniotis honored as 2020 recipient of George Rieveschl Jr. Award for Distinguished Scientific Research.