Patent ID: 6409914
Filing Date: 2002-06-25
Classification: C02F,Y02W,Y10S

Abstract:
Wastewater pretreatment tank assembly to be interposed between a wastewater source and a sewer system that leads to a downstream sewage treatment facility, the tank assembly comprisinga shell having a bottom, a top, sides and first and second end walls, said shell having first and second weirs interposed between said first and second end walls, said shell having a divider wall interposed between said top and bottom, said first end wall, said first weir and said divider wall defining a first chamber between said shell sides, means coupled to said wastewater source for introducing wastewater into said first chamber so that solids in said wastewater settle to the bottom in said first chamber and undergo digestion, said divider wall and a baffle plate defining a second activated sludge chamber, and including means for further removing suspended solids from the wastewater that has spilled from said first chamber over said divider wall into said second chamber, said baffle plate, said second weir and a second divider wall defining a settling chamber where said wastewater from said second chamber enters so that solids in said wastewater settle to the bottom, said settling chamber including means for recycling said solids into said second chamber to enhance activated sludge processing, said second divider wall and said second end wall defining a fourth biological filtration chamber and including means for biologically removing ammonia and BOD from said wastewater that has spilled into said fourth chamber from said third chamber, a drain overflow for directing treated wastewater into said sewer system and a port open to said fourth chamber through which the treated wastewater is passed into said sewer system, and a sludge evacuation conduit having an inlet end in communication with the bottom of said first chamber, an outlet end connectable to said sewer system, and a valve interposed in said sludge evacuation conduit and connectable for normally retaining in said first chamber wastewater and sludge up to the level of said first weir, said valve being selectively operable for permitting discharge of the digested sludge from said first chamber into the sewer system.