Microalgae have been increasingly used for wastewater treatment due to their capacity assimilate nutrients. Samples of were taken from the Erbil channel near Dhahibha village in northern Iraq. The microalga Coelastrella sp. was three doses (0.2, 1, and 2g. l-1) this experiment 21 days, samples periodically (every 3 days) analyzed physicochemical parameters such as pH, EC, Phosphate, Nitrate, BO...