Research in this line focuses on improving sewer systems and wastewater treatment plants to optimise wastewater treatment within the framework of the circular economy. It investigates the mitigation of hydrogen sulfide emissions that cause odours and the transformation of emerging contaminants during the transport of water to treatment plants. Work is also being done on resource recovery—such as energy, nutrients, and water—through emerging treatments that enable the production of value-added products like biopolymers and proteins.