Activated Sludge - 100 Years and Counting covers the current status of all aspects of the activated sludge process and looks forward to its further development in the future. It celebrates 100 years of the Activated Sludge process, from the time that the early developers presented the seminal works that led to its eventual worldwide adoption. The book assembles contributions from renowned world leaders in activated sludge research, development, technology and application.  The objective of the book is to summarise the knowledge of all aspects of the activated sludge process and to present and discuss anticipated future developments. The book comprises invited papers that were delivered at the conference "Activated Sludge…100 Years and Counting!", held in Essen, Germany, June 12th to 14th, 2014. Activated Sludge - 100 Years and Counting is of interest to researchers, engineers, designers, operations specialists, and governmental agencies from a wide range of disciplines associated with all aspects of the activated sludge process. Authors: David Jenkins, University of California at Berkeley, USA, Jiri Wanner, Institute of Chemical Technology, Prague, Czech Republic.