Urine treatment by solar disinfection for agriculture reuse purpose in a poor rural context: case of Burkina Faso

The study aimed to reduce the storage time of urine treatment and assess the quality of treated urine following the Solar DISinfection (SODIS) method. Microbiological analyses were performed on urine samples taken before each sunlight exposure, between 10am and 4pm at a frequency of 1 h, during which temperature was measured in PET bottles (1.5 L). The initial concentrations of Escherichia coli (E. coli) and Salmonella in unstored urine were 106 and 103 CFU/100 mL respectively. The combined effect of temperature and UV radiation increased inactivation efficiency of E. coli at 5 log units. On the other hand, 98% of Salmonella were inactivated in less than 3 h of continuous exposure between 12am and 3pm with temperature varying between 50 and 65 °C in PET bottles. The k values showed that the inactivation rate of Salmonella tested was accelerated when the temperature was above 50 °C. Then, the results indicated that the first-order exponential decay model was the best method to predict the inactivation of Salmonella in urine by SODIS. General results showed that after 3 days of exposure to sunlight, urine collected via eco-toilet becomes bacteriologically sanitized and therefore can be used in agriculture.