This volume contains the papers presented at the Sixth International Ion Exchange Conference organised by the SCI and held at Churchill College, Cambridge, UK, in July 1992. As on previous occasions, most recently in 1988, the organising committee did not engage plenary speakers but decided to solicit state-of-the-art contributions from the ion exchange community. This book contains the refereed papers presented at the meeting, whether in poster or oral form. Extra papers were presented at the meeting as posters because they were not available in time for refereeing purposes. The subject matter of the meeting and therefore the contents of the book is subdivided into seven separate topic areas as follows: resin developments; water treatment; fundamentals; biotechnology, food and pharmaceuticals; environmental and pollution control; membranes, inorganic materials and nuclear; and hydrometallurgy. The coverage of the meeting is similar to 1988 although there are fewer subdivisions on this occasion. The more restricted coverage this time reflects the smaller number of papers offered by authors. This is probably due to the world wide industrial recession which has affected commercial development and exploitation of the technology and restricts the ability of practitioners and academics to contribute to and attend international meetings. Nevertheless, the advances in biotechnology, growing concern about the environment and the. need for novel separation processes have provided sufficient impetus to stimulate a sufficient number of workers in the field.