fsm_book

Chapter 9
Co-treatment of Faecal Sludge
in Municipal Wastewater
Treatment Plants
Technology
Carlos M. Lopez-Vazquez, Bipin Dangol, Christine M. Hooijmans and
Damir Brdjanovic
Learning Objectives
• Understand the biodegradability and fractionation of organic matter and nitrogen compounds
in faecal sludge.
• Understand the principles, key considerations and potential impacts of co-treatment of faecal
sludge in sewer-based wastewater treatment systems.
• Determine volumes of faecal sludge that can be effectively co-treated in wastewater treatment
plants.
• Understand the potential negative ramifications of co-treating faecal sludge in sewer-based
wastewater treatment systems.
9.1 Introduction
The use of onsite sanitation technologies can be a sustainable solution to meet sanitation goals in a
faecal sludge management (FSM) service chain, as long as the faecal sludge (FS) from these systems is
collected, transported, treated, and then used for resource recovery or safely disposed of. One possibility
for FS treatment is co-treatment with sewer-based wastewater treatment technologies. However, it
is common knowledge that the majority of wastewater treatment plants (WWTPs) in low-income
countries have failed, and improper co-treatment with FS has even been the cause of some failures.
Hence, the objective of this chapter is to illustrate through modelling of WWTPs how these failures
occurred, and the extreme difficulties with co-treatment that must be addressed to avoid failures. First,
the chapter addresses activated sludge processes, and then anaerobic technologies including upflow
anaerobic sludge blanket (UASB) reactors, digesters, and ponds. Co-treatment in ponds is also discussed
in Chapter 5.
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