The purpose of this study is to evaluate the feasibility of reusing filter backwash water (FBWW) from the water treatment plant (WTP)as a substitute for the conventional coagulants (primary coagulant) in the coagulation-sedimentation process applied for synthetic effluent.The coagulation effect on the elimination of the turbidity and UV254 was investigated by treating synthetic effluent using FBWW as a substitute for conventional coagulants.