Green solutions for treating wastewater

Professor Ochieng Aoyi, director of the Centre for Renewable Energy and Water at the Vaal University of Technology

Professor Ochieng Aoyi, director of the Centre for Renewable Energy and Water at the Vaal University of Technology

It’s stating the obvious to say that we cannot survive without water. However, unlike many of the other things we need, water cannot be manufactured nor imported should we run out of it. This is why Professor Ochieng Aoyi believes that scientists and leaders have a moral obligation to provide clean water. For this reason his career has focused on water research and building capacity in the engineering field to broaden studies into water use and management.

He is director: Centre for Renewable Energy and Water (Crew) at the Vaal University of Technology (VUT) and head of the VUT’s department of chemical engineering. He is also a consultant in wastewater management and renewable energy, disciplines in which he has more than 23 years of research and teaching experience.

Aoyi’s particular focus in the last 10 years has been on the application of green technology in municipal wastewater treatment plants, seeking the sustainable management of water and energy, and building research capacity in these fields.

“These are issues of national and international interest, and our work aims to improve environmental cleanliness and quality of life,” he says.

Aoyi and his team have developed novel low-cost wastewater treatment techniques that integrate solar photodegradation with anaerobic digestion. The processes improve the production rate and quality of biogas, which is subsequently employed to generate electricity. Implementing this technique requires the participation of microbiologists, chemists and chemical engineers.

The team is working with Johannesburg Water, and has one doctoral and three intern master’s students conducting research with pilot and plant scale systems with different companies.

“The uniqueness of this approach is that we have a consolidated body of research anchored on three pillars: desktop experimental data capturing and analysis; the application of computational fluid dynamics; and the implementation of the processes at plant scale,” he explains.

“In this way, I try to solve real industrial problems, working with companies and organisations such as Eskom, Talbot & Talbot Ltd, Rand Water, Local Government Sector Education and Training Authority, Johannesburg Water and Mintek.”

For the last three years, he has organised two international conferences through Crew; team members and students present their work to delegates from industry and other academic institutions. The conferences are heavily subsidised so that students don’t pay to attend, even if not presenting.

These events build strong collaboration between industry and academia, and give young researchers who may not be able to travel abroad the opportunity to present their work to peers and international experts. Crew has six bilateral research collaboration projects, facilitating the sharing of information between researchers in different countries.

Aoyi has worked tirelessly to create this globally impactful research facility. When he joined VUT in 2009 as an associate professor, there was no active research lab at the university in this field and only part-time B-Tech courses available to students. By 2013, he was co-supervising or supervising six DTech/PhD, 12 MTech/MSc and 52 BTech students, and the facility continues to grow.

From a zero-funding base, he has attracted R30-million in research funding in five years. He has also accelerated the process of collaborating with other institutions to expand the pool of supervisors and equipment available to researchers.

“The most rewarding thing in my life is to see my former students become professors, work with them and learn with and from them, as we provide some solutions to problems in our community,” says Aoyi.