Abstract
This scientific work presents the way that bacteria act in the process of self- purification, some experiments made in the heterotrophic denitrification, as well as the technology of treating for removing nitrates by using biofilters. Microorganisms like bacteria, worms, insect`s larva, can use hydrocarbons from water directly as food, transforming them in CO2, H2O, energy and biological substance.
Cuvinte cheie
self-purification
bacteria
residual waters
polluted waters.