On the level of a textbook a self-consistent approach to liquid separations with membranes is presented, contrasting equilibrium separations with the rate-controlling effects of barrier interference on mass transfer. As a corollary objective, an effort is made to observe context, factual and historical, when introducing concepts and applications of membrane separation science. Ordering principle is the formal structure of mass transfer across barriers, being construed of a driving force (allocated to the condition of the mixtures to be separated) and a barrier permeability (holding the keys to membrane selectivity). The membranes, by this approach, appear by way of the mass transport demands which they are to meet, or else by way of the separation effects which they inspire. Learning by principles and context - exploiting barrier interference is the challenge of membrane separation science and technology. This book is about the principles behind.

Karl W. Böddeker became Professor at Technical University Hamburg (TUHH) while he already was well known as an expert on desalination and pervaporation in the scientific community, both in EMS and NAMS. He retired from GKSS Research in 2005 but is still active as lecturer at TUHH. He served as an editor for the Journal of Membrane Science and still is an active editor for Membrane News, the quarterly newsletter of the European Membrane Society (EMS).