SUMMARY
The region of El-Ghrous is located in the territories of wilaya of Biskra. It is characterized by a very important agricultural development particularly during the last decades. The objective of this study is to give an idea of presence of nitrates in the groundwater of this region and to observe the capacity of adsorption of a granular activated carbon (GAC) in the denitrification of contaminated waters in this region. The adsorption tests showed that nitrates desorption was observed beyond the equilibrium time. This equilibrium time varies according to the tested water from 2 hours and 30 minutes to 3 hours. The optimal yields are obtained at pH 4. The variation of adsorbent dose in the range 0,1 to 4 g/L, resulted in improved denitrification yields. The models of Langmuir and Freundlich are perfectly applicable for the results obtained.Nitrates in groundwater of El-Ghrous region (Biskra) and treatment possibilities