2.5 Mio. m3 decontaminated waste water - successful operation of the treatment plant for waste water from uranium ore mines

During the period from 1950 to 1989, approx. 70 million t of uranium ore from the former WISMUT company was processed under Soviet management in the Crossen treatment plant in the former GDR. While the mined uranium was mainly used in nuclear technology in the Soviet Union, the storage of the solid residues contaminated with residual uranium, radium and arsenic at the WISMUT site led to considerable environmental damage over this long period. One of the main aims of WISMUT GmbH, which was newly founded in 1991, is therefore to remediate and recultivate the adsettling plants. Due to the extent of this problem, the processes used must not only prove themselves by showing a high degree of innovation with regard to process engineering, but also by being highly economic. The waste water treatment plant in Helmsdorf, which was planned and erected by Preussag Noell Wassertechnik GmbH, made a major contribution to achieving this objective. Apart from the central plant for degrading the surplus water, which is to be treated to meet the required limits before being discharged into the Zwickauer Mulde, the treatment plant also includes the construction of a plant to immobilize the associated residues. This guarantees that they are deposited in an environmentally acceptable manner. Since starting operation in May 1995, more than 2.5 mio. m3 of waste water had been treated up to the end of 1996. Using the experience gained from more than one year of operation, the throughput, which was planned to be 250 m3/h max., has now been raised by about 10% to 280 m3/h. (orig.)