Abstract:
Fecal Sludge Management (FSM) is a critical aspect of sanitation in developing countries like
Pakistan, where on-site sanitation systems are prevalent due to limited sewer networks. This
study investigated the effectiveness of a Densified Effluent Treatment System (DEWATS) for
treating fecal sludge. The DEWATS unit comprised an Anaerobic Baffled Reactor (ABR)
followed by Anaerobic Filters (AF). The DEWATS unit was constructed with six chambers, with
the first two functioning as ABR and the remaining four as AF. Synthetic fecal sludge was
prepared to mimic real fecal sludge characteristics. Real fecal sludge samples were also collected
from various sources. The study found that the DEWATS process was successful in removing
organic matter and solids from both synthetic and real fecal sludge. Treatment efficiencies were
high for COD (73%), BOD (74%), TSS (71%), and VSS (65.5%). However, lower to moderate
removal efficiencies were observed for TKN and TP. The composition of fecal sludge also
influenced treatment performance, with a mixed sample (household and commercial) achieving
the highest removal efficiency. In conclusion, DEWATS appears as a promising technology for
fecal sludge treatment in Pakistan. Further research is needed to optimize nitrogen and
phosphorus removal and account for variations in real-world fecal sludge characteristics.
