The webinar on “Wastewater to Resource Water” by invited speaker Prof Dr Ronald Droste from the University of Ottawa, Canada on 2 February 2023 enlightened participants on ways to turn wastewater into resource water.

The webinar, organised by the Division of Community and International Networking (DCInterNet) via Zoom, was moderated by Department of Environmental Engineering Head Prof Dr Mohammed J. K. Bashir from the Faculty of Engineering and Green Technology (FEGT). The speaker shared on water, energy, nutrients, and other constituents and divided them into two aspects, which were recoverable and problematic.

He shared about the lifecycle assessment framework that looks into net energy balance, resources consumption, risk and damage to human well-being and ecosystems, as well as labour and costs. Participants also learnt that wastewater sludges consisted of waste-activated sludge or fixed film sludge.

On water security, he explained, “Over 260 river basins are shared by two or more countries. There is a need for well-defined water-sharing agreements and a need to look into challenges such as water shortages. Water stress results from an imbalance between water use and water resources. The water stress indicator in the following map measures the proportion of water withdrawal with respect to total renewable resources.

Prof Droste also spoke about factors that affect water resources, namely climate change, anthropogenic influence, and pollution in rivers and oceans. He further elucidated, “The minimum amount of water required to meet the basic needs varies from 20 to 50 litre per day, depending on the sources, and environmental conditions. The United Nations (UN) has estimated that more than 1 in 6 people in the world is currently water stress, referring to physical water scarcity. The current world population has reached 8 billion and we need to consider this as the population will grow another 40% to 50% in the next 50 years. Physical water scarcity refers to inadequate natural water resources to supply a region’s demand, while economic water scarcity refers to the poor management of sufficient available water resources.”

He highlighted that one of the methods to reduce water scarcity is by turning wastewater into safe drinking water. He said, “In Windhoek Namibia, they have been reusing wastewater as safe drinking water for 50 years, as well as in Singapore, which reclaims about 30% of its waster for water supply since 2002. To ensure that wastewater is properly treated and made into safe drinking water, we need to carefully look into the hazards, including pathogens, metals, emerging contaminants, and even salts.” Towards the end, he elaborated on the ways to treat wastewater, the processes involved, and ways to incorporate some nutrients into the water. The webinar then ended with an interactive Q&A session.