After the well's pressure starts to decrease, it will be unable to produce oil independently; the water is injected into the oil wells to raise the pressure of the well to sustain oil production from the well. This water requires special specifications not to affect the oil well and close the pores of the well, so the water turbidity and TSS must be less than 3, and the particle size must be less than 10 microns. So this research studies raw water treatment to produce treatment water within the required specifications for injection water. The main objective of this research is to improve the coagulation and flocculation process in the treatment of raw water taken from the river by determining the optimum dose of the coagulant and flocculant with the specific concentration of the microsand and optimal PH level to obtain the lowest value of turbidity, TSS and filterability. Also, to understand the mechanisms of coagulation and flocculation process in the water treatment. The water treatment process in the plant is done through a compact Actiflo unit that uses a turbo mixer to mix the coagulated water with the polymer and microsand to form high-density and fast-settled ballasted flocs that improves the settling process. The jar test simulated the coagulation and flocculation process in the plant, where the mixing speed of the coagulation process was 200 rpm for one minute. The mixing speed of the flocculation process was 140 rpm for 3.5 minutes. The settling time was 6 minutes, as can be seen, the short time of the settling step compared to conventional treatment plants due to the compact use of the microsand and polymer with turbo mixer that produced the fast-settled ballasted flocs in addition to the presence of the lamella plate that enhanced the settling process.
