Mary Luz Barrios-Hernandez received her BS in Environmental Engineering from the Technological Institute of Costa Rica (TEC) in 2011. There she worked as a lecturer and researcher at the Environmental Protection Research Centre (CIPA) of the School of Chemistry in on-site sanitation-related projects (2012-2014). She obtained her MSc in Urban Water Sanitation at UNESCO-IHE (2016) where she participated in the development of a microwave-based technology for faecal sludge sanitation. She obtained her doctoral degree at IHE Delft and Delft University of Technology (TU-Delft). Her research focused on faecal indicator removal mechanisms involving aerobic granular sludge (AGS) systems. She is interested on biological wastewater treatment systems for organic matter, nutrient and pathogen removal, including faecal sludge treatment and decentralized sanitation. She has experience with bacterial and viral indicators, identifying microbial communities with molecular techniques including FISH, qPCR and next-generation sequencing (16S and 18S rRNA genes), and with optical, fluorescence and scanning electron microscopy (SEM).