Optimisation de l'efficacité des graines de moringa oleifera dans le traitement des eaux de consommation en afrique sub-saharienne: Cas des eaux du Burkina Faso

Abstract

Access to safe water remains a major concern in sub-Saharan Africa, particularly in rural areas where populations are faced with the optimal management of water distribution points, inadequate hygiene and sanitation and a lack of appropriate methods of disinfection at the family level. Thus the integration of biological processes for the treatment of drinking water is emerging as a viable alternative for improving the quality of drinking water, because of the availability and non toxicity of the substances. This study aimed to optimize the efficiency of Moringa oleifera seeds in producing clean water for consumption in rural Burkina Faso. Surface and well water samples consumed by populations were treated with different concentrations of M. oleifera seeds as a coagulant. Te measurement of physico-chemical and microbiological parameters, after different settling times, was used to determine the optimum conditions and assess treatment efficacy. Settling times between 90 min and 2 h appeared sufficient to remove almost all suspended solids and colloids. Te reduction of turbidity obtained for a settling time of 2 h was 24 to 96%, depending to the initial turbidity of the water samples. For the same settling time, the microbial reduction was related to the nature of the water samples and was in the range of 82-94% for fecal coliforms, 81-100% for Escherichia coli and 94-100% for faecal streptococci. By this treatment we also obtained the total elimination of cysts of Giardia intestinalis. In the treated water we also found lower levels of nitrates, calcium, magnesium and total hardness, but rising concentrations of sulfates and organic matter. These results indicate that treatment of raw water with M. oleifera seeds is a function of the initial quality of the water and may be sufficient to obtain clean water for human consumption.