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

Abstract

The study aimed to reduce the storage time of urine treatment and assess the quality of treated urine after Solar DISinfection (SODIS) method. Microbiological analyses were performed on urine samples taken before each sunlight exposition, 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 is suitable to predict the inactivation of Salmonella in urine by SODIS the best way. General results showed that after 3 days of exposure to sunlight, urine collected via eco-toilet becomes bacteriological sanitized and therefore can be used in agriculture.

Resource recovery technologies as microbial risk barriers: towards safe use of excreta in agriculture based on hazard analysis and critical control point

“…Moreover, solar heating gives the added advantage of ultraviolet radiation when a transparent container is used; the container temperature can be increased to 65 °C in a tropical climate, which promotes pathogen inactivation. 40 At thermophilic temperature, bacterial inactivation occurs via damages on metabolic functions, cell membranes, and enzyme activities; while viral inactivation occurs due to the loss in ability to bind with its host cell, which probably caused by structural change in proteins. 41,42 Increasing temperature can indirectly facilitate helminth eggs inactivation by increasing the membrane permeability of the lipid layer on the egg shell.…”

The Potential of BIM in Disseminating Knowledge about Decentralized Wastewater Treatment Systems: Learning through the Design Process

“…Regarding the search for universal basic sanitation services, the decentralization strategy has proven to be increasingly complementary to the centralization of wastewater treatment, since the substantial capital investment made in the implementation of centralized systems can be reduced, thus increasing the accessibility of wastewater management systems. However, the lack of research activities in developing countries has led to the selection of inappropriate technologies in terms of local climatic and physical conditions, financial and human resources, and social and cultural acceptance [5], thereby harming the environment and failing to take advantage of some other benefits, such as reuse in agriculture [7] and construction [8]. The first challenge in implementing this type of system is choosing the most appropriate wastewater treatment technologies for each situation-a complex task, which involves evaluating many variables simultaneously.…”

Sanitation By-Products Used for Lettuce (<i>Lactuca sativa</i> L.) Production: Quantitative Microbial Risk Assessment

“…Indeed, for production and raw consumption of crops, urine has to be stored for at least six months (T > 20˚C) before application to ensure a high level of pathogen inactivation, as outlined by WHO (2016) guidelines. On the other hand, Sangare et al (2021) showed also that after 3 days of exposure to sunlight (SODIS method) urine collected via toilet becomes bacteriologically (Salmonella, E. coli) sanitized, and can therefore be used in agriculture. In current scenario, lower annual risk infection is observed in lettuce consumption compared the both others routes exposure (soil ingestion and urine ingestion).…”