A changing paradigm

“Wastewater treatment technologies are being driven towards a new paradigm due to rapid increases in energy costs and ongoing environmental challenges, with trends emerging towards a major transition,” said Jurg Keller, conference keynote speaker and the director of the Advanced Water Management Centre at the University of Queensland.

Keller presented some of the key urban water management transitions underway in Australia that are influencing and reflecting global trends for wastewater treatment.

“Cities and towns of the future need to be more sustainable, productive, resilient and livable, but different cities have different visions and needs,” he said. “However, all cities need safe water supplies. We need to create ‘water-sensitive cities’ through the use of tools that allow cities to transition from where they are now to where they want to be in the future. Getting their populations to invest in these trends is just as important as investing in the technology.”

Conference speaker Amy Pruden, a professor from Virginia Tech, echoed his remarks, noting, “Water treatment can be very expensive, so ideally we need to tailor it to be less expensive. In designing wastewater treatment systems, we need to stay in harmony with water and other sustainability efforts.”

The future of microalage

Ana Otero, associate professor at the University of Santiago de Compostela, discussed microalgal biotechnology used for wastewater treatment in her conference presentation. This technology has experienced major growth in the last decade due to an increased interest in microalgae.

“The field of microalgae has been completely reimagined since 2006,” Otero noted. “Microalgae are now being integrated into the wastewater treatment process as part of the microalgal biorefinery concept.

“Preliminary results from studies demonstrate the efficacy and versatility of microalgae-based nutrient filtering units to provide tailored solutions for specific industrial effluents. However, further studies must be carried out to fully assess the feasibility of this application.”

Jeremy Guest, an assistant professor from the University of Illinois at Urbana-Champaign, outlined the use of microalgal bioprocesses for nutrient recovery from wastewater in his talk.

“Microalgal treatment systems could significantly advance nutrient recovery from wastewater, but the successful implementation of algae for nutrient recovery requires intensification of algal unit processes and a mechanistic understanding of how design and operational decisions influence treatment system performance and reliability,” he said. “We need to embrace these microalgal technologies, and we hope they will take off soon.”

Averting the next public health crisis

A number of conference speakers discussed the public health component of wastewater treatment and changes and innovations in this field.

“We need to think beyond just disinfecting water to managing its microbial ecology—this is a probiotic approach to encouraging good microbes and combatting the next public health crisis,” said Celia Manaia, an assistant professor at the Portuguese Catholic University.

Manaia spoke about antibiotic resistance in treated wastewater and how to mitigate the risks from this, noting, “Antibiotic resistance is considered a major threat to human and animal health worldwide. Environmental reservoirs and human practices are potential enhancers for the propagation of antibiotic resistant bacteria and genes (ARB&ARG). To reduce the risks associated with ARB&ARG in wastewater discharge and reuse, further investigation, policy implantation and the development of technical solutions are required.”

“Water is one of the most important habitats in which we can study antibiotic resistance,” she continued. “Wastewater treatment plants discharge a huge number of antibiotic resistance genes every minute, but we don’t know the fate of these genes—although some of them are successful in being transmitted to other bacteria.

“We need to find a way to measure the dynamics of antibiotic resistance so we can figure out the full implications of this in the environment. Water disinfection remains one of the most crucial strategies to reduce the spread of antibiotic resistance today.”
Poster prize competition


The conference’s poster prize competition featured three Ph.D. student winners from KAUST: Hong Cheng (first prize); David Mantilla Calderon (second prize); and Dario Rangel Shaw (third prize).

In his closing remarks, conference organizer and KAUST Associate Professor of Environmental Science and Engineering Pascal Saikaly noted, “Our event’s many talks and presentations showed us the many facets of wastewater treatment processes and their applications. Many future outcomes are possible with microbial technology, and we should continue to think about niche-specific technologies for next-generation wastewater treatment.”

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- By Caitlin Clark, KAUST News