同©大学 2ation Tongji University SLOW SAND FILTER EFFLUENT FLOW RAW WATER HEAD SPACE CONTROL STRUCTURE VENT SUPERNATANT WATER SUPERNATANT ADJUSTABLE WATER DRAIN WEIR SCHMUTZDECKE SAND MEDIA DRAIN TILE TO FILTER DRAIN CLEARWELL & SUPPORT FIOW CONTROL BACKFILLING GRAVEL METER VALVE Fig.2 Slow sand filter and effluent control Slow sand filter removal of microorganisms,inorganic particles; Schmutzdecke:removal of dissolved organic matter;Tongji University (2) Slow filtration Fig. 2 Slow sand filter and effluent control Slow sand filter : removal of microorganisms, inorganic particles; Schmutzdecke: removal of dissolved organic matter;