Effectiveness of Moringa oleifera defatted cake versus seed in the treatment of unsafe drinking water : case study of surface and well waters in Burkina Faso.

anglais. peer reviewed

anglais. Safe drinking water access for rural populations in developing countries remains a challenge for a sustainable develop-ment, particularly in rural and periurban areas of Burkina Faso. The study aims to investigate the purifying capacity of Moringa oleifera defatted cake as compared to Moringa oleifera seed in the treatment of surface and well waters used for populations alimentation. A total of 90 water samples were collected in sterile glass bottles from 3 dams’ water reservoirs, a river, and a large diameter well, respectively. The water samples were treated in triplicate with Moringa oleifera seed and defatted cake coagulants. At different settling time and coagulant concentration, turbidity and pH were measured to determine the optimal conditions and factors influencing treatment with regard to sampling source. Nine physicochemical parameters (turbidity, pH, nitrates, nitrites, calcium, magnesium, total hardness, organic matter and sulfates), three bacterial fecal pollution indicators (Escherichia coli, fecal Coliforms and fecal Streptococcus) and parasite cysts were monitored based on laboratory standard methods. Data were analyzed using the Student’ t test and XLSTAT 7.5.2 statistical software. From the results obtained, for the same concentration of coagulant, settling times providing the lowest turbidity were significantly shorter (p<0.0001) with Moringa oleifera cake than seed. Optimum settling time with Moringa oleifera cake was between 15-60 min versus 60-120 min, with Moringa oleifera seed. Both treatments reduced significantly minerals concentration in water excepted sulfates for which the concentration reversely increased. However, only Moringa oleifera cake treatment reduced organic matter content in all the water samples, while it increased with Moringa oleifera seed one (p<0.0001). The reduction of microbial pollution indicators was 92-100% with M. oleifera cake treatment and 84-100% with M. oleifera seed one. Overall, for all water samples, Moringa oleifera cake treatment appeared more efficient in improving drinking water quality than the M. oleifera seed treatment.