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.