Quality of Human Urine Used as Fertilizer: Case of an Ecological Sanitation System in Ouagadougou Peri-Urban Areas-Burkina Faso

Abstract

The use in agriculture of excreta from urine-diversion toilets can be an alternative solution to the lack of sanitation and high costs of mineral fertilizers inherent to developing countries. The objective of this study was to evaluate the hygienic quality of urine used as fertilizer through an ecological sanitation system in Ouagadougou peri-urban areas. Chemical and microbiological analyses were performed in urine samples taken before and after thirty (30) days of storage in jerry cans exposed to sunlight. The concentrations of 7.0 g/l; 3.5 and 9.6 g/l of ammonia nitrogen for mean, minimum and maximum respectively, are obtained in unstored urine samples. These concentrations did not practically vary with the storage. On average, values of other chemical parameters analyzed in stored urine were as follows: pH, 8.8; phosphorus (P), 0.3 g/l; potassium (K), 1.9 g/l; total dissolved solids (TDS), 21.0 g/l; cadmium (Cd), 154.3 µg/l; copper (Cu), 5.2 µg/l; lead (Pb), 15.2 µg/l; chromium (Cr), 6.1 µg/l; nickel (Ni), 154.0 µg/l. Escherichia coli, staphylococci, enterococci, Salmonella and spores of Clostridium perfringens were detected in unstored urine samples, with 26% of fecal contamination rate. The time of storage (30 days) under sunlight was enough for almost all bacteria removal in urine samples. Although the fertilizing value of urine was confirmed, it would be important to take account of the best practices on applying in soils, because of the high TDS contents. Also, the risk linked to micropollutants in urine-based fertilizers could be negligible in view of low quantities. The results obtained in this study prove that after 30 days of exposure to sunlight urine collected via eco-toilet becomes bacteriologically sanitized, and can therefore be J. M. Makaya et al. 468 used to fertilize soils. However, it is necessary to demonstrate the inactivation of other groups of enteric microorganisms in human urine during storage.

Norovirus and Rotavirus Survival in Urine Collected from a Public Ecological Sanitation System in Ouagadougou, Burkina Faso

“…Because urine is a major source of nitrogen (e.g., urea), which can be used for agricultural purposes, urine diversion is considered a very promising technology for agriculture. Despite the fact that urine from healthy individuals is usually free of bacterial pathogens (Pradhan et al 2009), it can be polluted with feces during urine diversion (Hoglund et al 2002;Makaya et al 2014). Source-separated urine contamination by fecal materials has been shown for dry toilets (Höglund et al 2002;Jonsson and Vinneras 2007).…”

Pretreating Stored Human Urine for Solar Evaporation by Low-Technology Ammonia Stripping

“…The constant K L is the overall mass transfer coefficient for NH 3 for the liquid phase, and "a" is the specific gas/liquid interface. The equilibrium FAN concentration in the liquid phase the system strives for, is * L c .…”

Exploring the Potential for Concentration of Nutrients from Urine Using Solar Evaporation and Carbon Dioxide Trapping of Ammonia

“…The value of nutrients derived from urine, such as those collected from urine diversion dry toilet (UDDT), has been repeatedly demonstrated (Heinonen-Tanski and Van Wijk-Sijbesma, 2005;Tidåker et al, 2007;Karak and Bhattacharyya, 2011;Makaya et al, 2014). Such nutrients were found to be less costly alternatives to commercial fertilizers (Esrey et al, 2001).…”