Book Review: Osmosis Engineering

Editors: Nidal Hilal, Ahmad Ismail, Mohamed Khayet Souhaimi, Daniel Johnson; ISBN: 9780128210161; Elsevier; 2021; €170.04

If I were to carry whisky in a hip flask when out walking, and I were to consume it quickly, it would make me tipsy. The whisky has the power to do something, but the power is only made manifest if it is consumed. Likewise, the osmotic pressure of a solution contained in a beaker open to the atmosphere is not a pressure that is exerted. Osmosis only emerges in the presence of a suitable membrane and these membranes are absolutely key to the various osmosis processes. Thus, readers of Osmosis Engineering might well expect to find more about membrane development than is provided. What the book offers instead, it is an introductory chapter on the basic principles of osmosis, and then an initial focus on reverse osmosis and nanofiltration, two well-established commercially successful processes in which the osmotic pressure has to be overcome though elevation of the feed pressure. The main part of the book then covers processes in which the difference in osmotic pressure is itself the driving force.

Processes covered include those that employ forward osmosis, pressure-retarded osmosis (PRO), osmotic distillation, and thermo-osmosis. The last process is little known, and the authors inform us that in over 100 years only 169 papers have been published on this topic. Should we applaud such comprehensive coverage, or wonder why it has been included? As the stated aim in the preface was to cover the family of technologies best able to deal with large-scale water production, the inclusion of this esoteric process is discordant.