It is often said, quite correctly, that to really learn a foreign language one needs to immerse oneself in it. For me, getting to grips with chemical and process engineering requires the same degree of immersion. It means formulating lots of problems using the core engineering skills of material and energy balancing. It also means using key mathematical and computational techniques on a regular basis. Having taught on an interdisciplinary degree programme for more than 20 years, it is clear to me that very few students can cope with doing a relatively small amount of engineering while at the same time studying lots of biology, or some other, less quantitative, subject. For most people, constant practice of engineering skills is required. The late and great golfer, Seve Ballesteros, once said: To give yourself the best possible chance of playing to your potential, you must prepare for every eventuality. That means practice. Engineering is similar to golf; the more time students spend solving practice problems, the better they become at doing engineering.

This book is all about immersing the reader in the field of membrane filtration. To use a football term, it is about encouraging the reader to ‘get stuck into’ quantitative aspects of membrane process design and analysis. As a consequence, the book is somewhat ‘equation heavy’ but that is the nature of engineering. In any event, none of the mathematics used is beyond what an undergraduate engineering student should be able to cope with.