Book excerpt: The focus of Water-Energy Interactions in Water Reuse is to collect original contributions and some relevant publications from recent conference proceedings in order to provide state-of-art information on the use of energy in wastewater treatment and reuse systems. Special focus is given to innovative technologies, such as membrane bioreactors, high pressure membrane filtration systems, and novel water reuse processes. A comparison of energy consumption in water reuse systems and desalination will be also provided. Water-Energy Interactions in Water Reuse covers the use of energy in conventional and advanced wastewater treatment for various water reuse applications, including carbon footprint, energy efficiency, energy self-sufficient facilities and novel technologies, such as microbial fuel cells and biogas valorisation. It is of real value to water utility managers; policy makers for water and wastewater treatment; water resources planners, and researchers and students in environmental engineering and science. Editors: Valentina Lazarova, Suez Environnement, France, Kwang-Ho Choo, Kyungpook National University, Korea, Peter Cornel, Technical University of Darmstadt, Germany