The quality of water provided by the Budapest Waterworks should comply
with the standards prescribed by the European Community. According to
these provisions, on one of the major water-producing regions (Csepel
Island), rows of wells of 60,000 m3/day yield have been closed recent
ly, and in the immediate future further plants would have been closed
because of the high iron and manganese content of the water. The raw w
ater obtained from 100 different wells will be purified by a water tre
atment plant of 150,000 m3/day capacity. Considering the high iron con
tent (0.05-0.15 mg/L) and manganese content (0.05-0.2 mg/L), the raw w
ater fails to comply with the requirements of the potable water standa
rd. Since 1990, over a period of three years, we conducted water purif
ication experiments in several stages. In these, three methods of oxid
izing as well as single and double layer open rapid filters were appli
ed to oxidize the manganese (and, to a lesser extent, the water) prese
nt in dissolved form, resp., to destroy various living organisms. In t
he course of the experiments, it became clear that the chlorine and ch
lorine + air methods are efficient in case of a small quantity of iron
to be oxidized and only 20-25% of the dissolved manganese content cou
ld be oxidized. Neither of the two methods could ensure firm managemen
t of microbiological and bacteriological characteristics. The best res
ults were obtained by ozone oxidation, in which case the chemical oxid
izing process was almost fully completed and even the chlorine-resista
nt living organisms could be destroyed. On the basis of the experiment
s carried out, the investment program of the water treatment plant was
worked out and the conditions of an international tender were compile
d whose winner will be commissioned to build up the water works in the
time period 1993-1996. One of the main steps of the proposed technolo
gy is the ozone treatment.