ABSTRACT
The implementation of new technological processes, the intensive application of fertilisers and pesticides, as well as the scarcity and limitations of treatment facilities leads to a reduction in the quality of water resources, which is essential to the proper functioning of the economy. A significant proportion of the toxic organic chemical compounds and biological pollutants (industrial effluents and municipal waste) ends up, in a more or less uncontrolled fashion, in the natural water basins. Purification methods, used to date, do not always produce the desired effects. The new sewage treatment technologies are frequently multistage processes.
