SECTION 8
SANITARY
WASTEWATER
TREATMENT
AND CONTROL
KEVIN D. WILLS, M.S.E., P.E.
Consulting Engineer
Stanley Consultants, Inc.Design of a Complete-Mix Activated Sludge Reactor
Design of a Circular Settling Tank
Thickening of a Waste- Activated Sludge Using a Gravity-Belt Thickener
Design of an Aerobic Digester
Design of an Aerated Grit Chamber
Design of Solid-Bowl Centrifuge for Sludge Dewatering
Sizing of a Traveling-Bridge Filter
Design of a Rapid-Mix Basin and Flocculation Basin
Sizing a Polymer Dilution/Feed System
Design of a Trickling Filter Using NRC Equations
Design of a Plastic Media Trickling Filter
Sizing a Rotary-Lobe Sludge Pump
Design of an Anaerobic Digester
Design of a Chlorination System for Wastewater Disinfection
Sanitary Sewer System Design
Selection of Sewage-Treatment Method
8.1
8.8
8.10
8.12
8.16
8.19
8.23
8.26
8.28
8.29
8.33
8.36
8.41
8.44
8.45
8.49DESIGN OFA COMPLETE-MIX ACTIVATED
SLUDGE REACTOR
Domestic wastewater with an average daily flow of 4.0 Mgd (15,140 m^3 /d) has a five day
Biochemical Oxygen Demand (BOD 5 ) of 240 mg/L after primary settling. The effluent is
to have a BOD 5 of 10 mg/L or less. Design a complete-mix activated sludge reactor to
treat the wastewater including reactor volume, hydraulic retention time, quantity of
sludge wasted, oxygen requirements, food to microorganism ratio, volumetric loading,
and WAS and RAS requirements.