Published October 29, 2015
0 views Journal article Open Access Open Access

Lactic acid fermentation, urea and lime addition: Promising faecal sludge sanitizing methods for emergency sanitation

Creators

  • 1. WASTE advisers on urbane environment and development, Lange Houtstraat, 26, 2511 CW, The Hague, The Netherlands. catherine.anderson85@gmail.com.
  • 2. UNESCO-IHE Institute for Water Education
  • 3. Delft University of Technology
  • 4. WASTE advisers on urbane environment and development, Lange Houtstraat, 26, 2511 CW, The Hague, The Netherlands. jspit@waste.nl.
  • 5. University of Malawi

Description

In this research, three faecal sludge sanitizing methods—lactic acid fermentation, urea treatment and lime treatment—were studied for application in emergency situations. These methods were investigated by undertaking small scale field trials with pit latrine sludge in Blantyre, Malawi. Hydrated lime was able to reduce the E. coli count in the sludge to below the detectable limit within 1 h applying a pH > 11 (using a dosage from 7% to 17% w/w, depending faecal sludge alkalinity), urea treatment required about 4 days using 2.5% wet weight urea addition, and lactic acid fermentation needed approximately 1 week after being dosed with 10% wet weight molasses (2 g (glucose/fructose)/kg) and 10% wet weight pre-culture (99.8% pasteurised whole milk and 0.02% fermented milk drink containing Lactobacillus casei Shirota). Based on Malawian prices, the cost of sanitizing 1 m3 of faecal sludge was estimated to be €32 for lactic acid fermentation, €20 for urea treatment and €12 for hydrated lime treatment.
Enabled by The Lens

Open Access

Licence Attribution (CC BY)
Publisher Website Access full text