Faecal sludge stabilization by two chemical processes

The search for an alternative solution to biological faecal sludge stabilization methods that requires significant funds and a lot of time, led us to undertake work on chemical stabilization processes for FS that are less expensive and fast. Thus, the faecal sludge collected is stabilized by quicklime (CaO) on the one hand and sodium nitrite NaNO2) on the other. The results of the analyses showed that these stabilized faecal sludge are hygienic due to the total absence of pathogenic germs (Thermotolerant coliforms, Entamoeba Coli, Faecal streptococci, Anaerobic sulfito-reducers, Salmonella sp) and the very sensitive abatement of parasites (Entamoeba Coli cysts) and metal pollutants (Zn, Cu, Ni, Pb, Cd and Cr). The white bean germination test also appreciated the germinative and fertilising power of the treated faecal sludge. Then, the sludge volume index calculation yielded 25 ± 0.08 mL/g and 32 ± 0.12 mL/g respectively for CaO-stabilized sludge and NaNO2-stabilized faecal sludge. These values are less than 100 mL/g, indicating that these stabilized faecal sludge sediment easily and will optimize their drying time.