Fighting Against Nitrate Pollution Of The Dam-Retained Waters Through Biological Treatment

Pollution of the water by nitrates was favored by setting husbandry intensive methods of production, which was implemented by an increased use of chemical manures. Most of this pollution is due to the difference in the proportion of nitrates in manures and what is actually uptaken by the plants. In response to this issue, we carried out a research intended for reducing the concentration of nitrates in the water streams supplying the Dam of Beni Haroun, Algeria, in order to avoid the eutrophication fatal effects. This was achieved thanks to a biological treatment, which is one of the cheapest and most efficient for reducing nitrates. In our paper, we used a mixed culture of microorganisms picked up in the El Menia Filtering Station, Constantine, Algeria.The use of methanol as a carbon source involved a rise in pH. In order to prevent the consequences on the degradation performance of the microorganisms, a buffer mixture of acetic acid and sodium acetate was used as a source of carbon. We noticed a growth in bacteria coupled with elimination proportionate to nitrates. During this elimination, the medium pH varies slightly, it moves from 7.00 to 7.88. This has improved denitrification, reducing the treatment time and increasing the denitrification rate. On the other hand, this work allowed to state that the best denitrification rate was obtained for the ratio value C/N that equals 2.5.