It was intended to return with the International Gothenburg Symposia every other time to the birthplace of these events, Gothenburg in Sweden. But instead the 8th symposium has been invited to be organized and held in Prague, i. e. in the midst of Central and Eastern Europe a region now keen on intensified environmental control. This attests that the symposia have attained such standing in the interna tional world of operators, designers, officers and researchers in water treatment technology that their presence in various parts of the world has been requested. And this ever growing significance, in short the success of this conference series, stems form the fact that the symposia offer a unique platform for the exchange of ideas and experiences on all aspects of water and wastewater treatment between administrators, engineers and scientists. The content of this book, i. e. the schedule of the symposium lectures, results for the most part from a vast response to an international call for papers. Many excellent contributions are included in this volume but at the same time many outstanding ones could not be included for lack of time and space. The total sum of these contributions document again the development in the field, both in terms of new technological (and other) developments as well as public and administrative acceptance and approval of solutions offered."

This seventh symposium in the series of biennial Gothenburg Symposia, taking place in Edingburgh 1996 continues to bring together research scientists, designing and operating engineers and funding and supervising administrators. It also has enlarged the scope of its platform by bringing together concerned specialists from Western countries and Central and Eastern Europe and furthermore attempts to bridge the gap between developing and industrialized countries. The traditionally presented topics, such as treatment of potable water and wastwater predominantly by chemical means are of utmost importance for those that need immediate action at reasonable costs. It is particularly noteworthy that an increasing number of contributions address these problems of the emerging need for environmental protection. And more and more presentations are delivered by experts from Central and Eastern Europe and from developing countries. Again the proceedings of this seventh symposium indicate and demonstrate new developments that advance the field of water and wastewater treatment. Be sides the ever present topics there is now a whole section on automation and control, a highly significant topic for water technology that so far has not received too much attention in symposia of this kind addressing theoreticians and prac titioners at the same time."

For the ninth Gothenburg Symposium time design and operation engineers as well as supervising and funding administrators in chemical water and waste water treatment, have come together to exchange ideas, experiences and personal views on issues of water and waste water management. While the main thrust of past symposia was in the description of the technological know-how of existing chemical unit-operations in water technology this ninth symposium focuses in addition on aspects of overall energy and mass flux analyses, the strive for more and more sustainable solutions (not only in technological turns) and public private partnership in all areas of water management. As the symposium in its effort to address also different geographical areas and therefore different water problems moved to Istanbul in Turkey a special effort was made in developing a platform for industrial water management.