The present study is related to the possibility of using Up flow Anaerobic Filter reactor (UAF) applied to the treatment of dairy wastewater and studies the effect of hydraulic retention time(HRT) (8,12,16 and 24 h) and different loading rates on the performance of the reactors. The dairy wastewater is characterized by high biological oxygen demand and chemical oxygen demand requiring systematic treatment prior to disposal.

Keywords : Up flow anaerobic filter, Hydraulic Retention time, Chemical Oxygen Demand, Biochemical Oxygen Demand, Total Solids.