The dissertation explores the integration of electromicrobiology in nature-based solutions to treat wastewater

Amanda Prado de Nicolás has defended at the University of Alcalá the doctoral thesis entitled Exploring METland Technology: treating wastewater by integrating electromicrobiology into Nature-based Solutions. The work has been directed by Professor Abraham Esteve Núñez within the Doctoral Programme in Hydrology and Management of Water Resources. Dr. Prado was a predoctoral researcher at IMDEA Agua between 2015 and 2017.The study is framed in the field of electromicrobiology, a discipline that studies the interaction between electroactive microorganisms and electrically conductive materials. Its applied aspect is represented by Microbial Electrochemical Technologies (MET). These systems take advantage of the extracellular electron transfer (EET) mechanism of electroactive bacteria to convert the chemical energy present in water pollutants into electrical current.

The METland® technology is a wastewater treatment system that belongs to the so-called nature-based solutions. The term was born from the incorporation of MET to treatment wetlands with the aim of intensifying this technology; that is, to increase the efficiency of wastewater pollutant treatment per unit area.

The thesis examines the role of each of the three determining elements of a METland® –vegetation, bed material, and microbial communities–, and how they affect wastewater treatment. As a result of the research, a new configuration has been developed, called e-sink, or electron sink, patented by the Bioe group, led by Esteve Núñez. This mechanism contributes to increasing the efficiency of wastewater treatment.

METland® technology is a reality in the wastewater treatment market for small urban agglomerations, given its high efficiency and versatility. This solution is respectful of the environment, minimizes the costs of operation and maintenance, and allows an effective treatment of wastewater in decentralized locations.