Impacts of Pit Latrine Additives on Volatile Solids and E. coli in Faecal Sludge

Indiscriminate disposal of faecal matter is a health risk. Although sanitation facilities provide the first barrier to the spread of diseases, full pits may pose more risks. Therefore, it is a necessity to treat faecal sludge (FS) to reap the benefits of sanitation. This paper describes a laboratory and field pilot study of the effects of 10 additives on the volatile solids (VS) and E. coli concentrations in black water and FS, respectively, over a period of two weeks. The additives were dosed at 1.7% with one run for FS dosed at 3.4%. Generally, the additives showed no significant difference with the controls, except two of chemical origin (Ikati and Soda) which had VS reduction >38% and E. coli below detection limit at low total solids (TS) concentrations. However, performance of these additives reduced at higher TS concentrations. Further research on the optimal dosages of these two additives that yield sanitised and stabilised sludge is warranted.