Effects of Wastewater Characteristics on Activated Sludge
The treatment of wastewater using activated sludge systems is one of the most common secondary treatment
processes across the world.  Fully understanding the biological and chemical characteristics and composition of
the influent wastewater is critical to ensuring optimal operation and efficiency of the microbial biomass within the
treatment process.  The project examines the treatability and biodegradability of a wide range of wastewaters and
determines if there are specific treatability thresholds for carbonaceous removal, nitrification and denitrification.  
The variation of wastewater treatability is examined on a daily, weekly and monthly basis to identify the factors
that cause variation and to determine their effect on the treatment processes.  The effect on treatability of a
number of common wastewater treatment chemicals (e.g. flocculants and antifoams) is also examined.  The value
of using respirometry as an effective tool in determining and managing the treatability and biodegradability of
wastewaters for the activated sludge treatment process is assessed.

Fryer, M., O’Flaherty, E. and Gray, N.F. (2011) Evaluating the Measurement of Activated Sludge Foam Potential. Water ,3(1), 424-444.
Eoghan O'Flaherty
Centre for the Environment, TCD

contact:  oflahee@tcd.ie

Funded: Trinity College Dublin; Water Technology Research
 Water Technology Research Group
 Trinity College Dublin
   1980-2010 thirty years of research, training and consultancy
Eoghan is in his second
year of his PhD project