Dr. Chaker Ncibi obtained his PhD in Environmental Engineering in 2008 from the University of Sousse, Tunisia. He pursued his research activities as postdoctoral researcher in France, Guadeloupe, Germany and Finland. Currently, he is Assistant Professor in ‘circular economy in water treatment’ at the Department of Green Chemistry, School of Engineering Science, Lappeenranta University of Technology, Finland. His teaching and R&D focus areas include circular economy, bioeconomy, sustainability, green chemistry, advanced water and wastewater treatment technologies (adsorption, membrane bioreactor, AOPs and electrochemical processes), resources recovery from municipal and industrial side streams, and the thermochemical conversion of biomass and biowaste into materials, fuels and chemicals. Dr. Ncibi is the principal investigator of many projects, guest editor for several special issues in Elsevier journals, and has published more than 50 peer-reviewed articles and two books in the broad field of sustainability.