Enhanced flocculation/sedimentation process by a jet mixed separator

This paper deals with the performance of a jet mixed separator (JMS) which has a series of porous plates inserted in the channel perpendicular to a flow. The water passes through holes in the plates, thus creating jets which gently mix the water on itself. Simultaneous flocculation of suspended particles and sedimentation of grown-flocs occur in the JMS, because large-scale eddies in the vertical plane are almost absent in it. The JMS incorporated with inclined tube settlers was applied to the rapid sand filtration system instead of the combination of mechanical flocculator and sedimentation basin. The turbidity of JMS effluent was constantly below I TU at the hydraulic retention time of about 1 hour. The JMS without inclined tube settlers was used as physico-chemical pretreatment process for the rotating biological contactors. The BOD and suspended solids concentration of JMS effluent were around 50 and 40 mg/L, respectively at the hydraulic retention time of 45 min.