Themistokles Lekkas is Professor (e) of Environmental Engineering at Department of Environment, University of the Aegean (Greece). He is a graduate of Chemical Engineering from the NTU of Athens and holds an MSc (Mark of Distinction) and a Ph.D. from the Imperial College London. He has extensive industrial experience and has held various managerial positions. He is the founder of the Global Nest Journal. Professor Lekkas has conducted extensive research and has published research papers in the areas of water filtration, fluidisation, disinfection by-products, priority substances, emerging pollution and solid waste management.