Aerobic digestion of waste activated sludge from biological nutrient removal activated sludge systems

Waste activated sludge (WAS) is a biological sludge that contains biodegradable and non-biodegradable volatile suspended solids (VSS) and non-volatile inorgainic suspended solids (ISS). Stabilization for safe disposal of the WAS is a process of paramount importance at wastewater treatment plants (WWTPs). Hence, aerobic digestion of the WAS from biological nutrient removal (BNR) activated sludge (AS) systems was carried out under batch conditions to (1) measure changes in nitrogen and phosphorus concentrations in solid and liquid phases during aerobic batch digestion tests (2) simulate the parent system with Activated Sludge Model No. 2 (ASM-2) in AQUASIM computer program to obtain the initial conditions for batch test simulation (3) simulate the batch aerobic digestion process with ASM-2 and compare with experimental data (4) develop VSS-based and total suspended solids (TSS) (with the addition of ISS to the VSS-based) batch reactor and steady state models for aerobic digestion of nitrification denitrification biological excess phosphorus removel (NDBEPR) WAS based on the individual biomass die-off rates of phosphorus accumulating organisms (PAOs) and ordinary heterotrophic organisms (OHOs), and (5) evaluate the ASM-2 simulation results with steady state aerobic batch digestion model.

Grantor dc:publisher.institution

Department of Civil Engineering

Year dc:date.issued

2007

Author dc:creator

• Mebrahtu, Michael Kidane

Advisors dc:contributor.advisor

• Ekama, George A
• Wentzel, Mark C

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/5025

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/5025