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Nitrate groundwater contamination is of major interest all over the world. This problem arises in agricultural regions across Morocco. An excess amount of nitrate causes a serious problem in urban water networks and human health. Because of these health risks, considerable attention has been paid to find effective treatment processes to reduce nitrate concentrations to safe levels. The World Health Organization has set an acceptable level for nitrate in drinking water at 50 mg/L. The aim of this study is to reduce the nitrate concentration from groundwater using two membrane processes: Electrodialysis (ED) and Nanofiltration (NF). Efficiencies of these two technologies are compared in respect to nitrate ions removal, cost process and final quality of water. The results of technologies show that, for electrodialysis standards level can be achieved for a demineralization rate of 15% and the physico-chemical quality of the produced water is satisfactory. For nanofiltration we obtain a nitrate removal of 90% but the produced water is very de-mineralized and must be remineralized.

The Sewage Treatment Plant (STEP) based on Skhirat City receive on average an important volume of wastewater (about 66473 m3 with a flow of 2173.56 m3/day). The aim of this research is to evaluate the pollutant load of wastewater and the performances of the sewage treatment plant of Skhirat city in treating domestic wastewater. Sampling was carried out on the level of the entry of sewage treatment plant with a monthly rate. The analyses were carried at the laboratory with the cubic measure of wastewater received by the sewage treatment plant. The results show that the CODe/BOD5e ratio of 2.08, which makes it possible to confirm the normal state of the station in biological treatment since the ratio is lower than three. The results showed that the rate of the Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5) and the Suspended Matter (SM) respectively it’s of the order 87,4%, 90,68% and 79,50%. Globally, the results of the investigation revealed by the unilateral test Student, that this difference between the entry and the exit of the station which significant by p-value calculated is lower than the level of significance alpha= 0,05.