Dr. Maarten Biesheuvel is principal scientist at Wetsus, European Centre for Sustainable Water Technology, The Netherlands. He is the author of two textbooks on electrochemical processes and 160 scientific publications in the field of the theory of transport processes and physical chemistry, including theory for capacitive deionization, electrodialysis, and reverse osmosis. He is in editorial board member of the journals Desalination and J. Membrane Science Letters. He is regularly invited to give tutorial lectures on transport theory and chemical equilibrium, specifically on reverse osmosis and electrodialysis, as well as on the history of theory for activity coefficients of ions. Other highly acclaimed tutorial lectures provide students (BSc to PhD level) with useful insights in data analysis and graphical presentations of data.