Sellami MH , Benhabireche F and Frouhat H
Wastewaters arising from oil and gas industries are a source of soil, water and air pollution and lead to a mortal danger to our environment. Elimination of hydrocarbons from oily-water is carried out by chemical methods such as the process of coagulation - flocculation. Our purpose in this work is to contribute to the collective efforts to treat the huge amount of wastewater purges storage bins and reuse them to prevent any ecosystem damage; this was achieved by studying the wastewaters separation effectiveness by coagulation- flocculation using two types of sequestering; citric and ascorbic acid. Chemical treatment investigated in the laboratory of the petroleum field of BERKAOUI /southern Algeria, showed that the best result is obtained by using 2% of ascorbic acid within wastewater solution containing 12 ml of 4% concentration of activated silicates; consequently : - Suspended matter decreased to reach 41 mg/l; with 87.54% of elimination. - Turbidity of treated water reached 22 FTU; with 91.88% of clarification. - Hydrocarbons amount was 3 ppm; with 97.32% of reduction. - COD and BOD5 reductions were 85.81% and 92.77% respectively. Finally, after irrigation tests throughout local dune sand, we suggest using it as biological filter before any chemical treatment for further wastes elimination.