The Coupled Trickling Filter-Activated Sludge Process:Design and Performance.

摘要

A case history report was prepared on the upgrading of the Livermore,California,Water Reclamation Plant from a conventional trickling filter plant with tertiary oxidation ponds to a coupled trickling filter-activated sludge plant producing a nitrified effluent low in BOD5,suspended solids,and coliform organisms. The report covers planning,design,construction,startup,and operation and performance of the upgraded Livermore plant. Capital costs and operation and maintenance expenses are also given. Data and information from Livermore were used in conjunction with data from other coupled trickling filter-activated sludge plants to develop general design considerations for carrying out similar upgradings elsewhere. Over 7yr of records from Livermore show that the coupled trickling filter-activated sludge process is extremely stable and reliable. Effluent BOD5and suspended solids concentrations of 10to 20mg/l can be obtained,along with ammonia nitrogen concentrations less than 1mg/l. Monthly median total coliform concentrations of 2.1 MPN/100ml were consistently achieved at Livermore using high chlorine dosages and a chlorine contact tank with good hydraulic characteristics. The coupled trickling filter-activated sludge process is particularly adaptable to existing conventional trickling filter plants where stringent,new discharge requirements have been imposed and where existing structures and equipment are in good condition and can be used in an upgraded facility.