RECENT DEVELOPMENTS IN THE TREATMENT OF CHEMICAL WASTE-WATER IN EUROPE

Up to the beginning of the 60s, chemical waste water in Europe was purified only mechanically and chemically. This was mainly done in sedimentation basins situated next to the factories and sometimes equipped with neutralizing and flocculating plant. As production rose and crowded areas developed, these processes were no longer adequate. The quality of water in rivers increasingly deteriorated, and fish regularly died in many areas in the summer months. In the then Federal Republic of Germany, the chemical industry started to develop biological processes for waste water treatment in their factories and in conjunction with consultant engineers who had experience in the purification of municipal waste water. Since the large works of the chemical industry are usually in densely populated areas, the processes which already existed in the USA at that time could not simply be adopted. Installations were required which achieved the maximum purification effect for the minimum possible space requirement. Because of high energy costs, it was at the same time necessary to aim for the lowest possible energy consumption.