EFFECTIVENESS OF CHARCOAL FILTERS INTEGRATED WITH Moringa oleifera SEED EXTRACTS IN PURIFYING WATER FROM UNPROTECTED SOURCES OF KAPSERET DIVISION, UASIN GISHU COUNTY, KENYA

Abstract

Moringa oleifera Lam (MO) is a pan tropical, multipurpose tree whose seeds contains high quality edible oil (up to 40% by weight) and water soluble proteins that act as effective coagulants for water and wastewater treatment. Chemical coagulation may leave certain residuals such as aluminum that raises health concerns. Besides, most rural residents are not able to read instruction manuals on the dosage rates of the chemical coagulants. It is in this light that this study was carried out with the objective of determining the effectiveness of Moringa oleifera integrated charcoal filter in improving surface water quality based on the physicochemical and biological parameters. Laboratory jar test procedures was used for coagulation studies on experimental runs using actual stream water from the five sampling streams in Kapseret. Water extracts of Moringa oleifera seeds and Aluminium sulphate were applied to stream water treatment sequence comprising coagulation–flocculation–sedimentation. Samples of water treated with Moringa oleifera were later filtered over charcoal before analysis was done.. A raw water sample from each of the sampling points acted as a control. The study was laboratory based using actual stream water from various unprotected sources. Statistical analysis was done using One-way Analysis of variance (ANOVA) to assess whether significant (p < 0.05) variations existed among the treatments. Tukey’s test was carried out to verify the significance of differences among the means. In this study, the most significant finding of using Moringa oleifera seed extract as coagulant is the reduction from initial reading of turbidity at 40 mg L–1 with 85.55% of removal efficiency where the lowest turbidity was achieved even with smaller doses used compared to aluminum sulphate at 50 mg L–1 with 78.72.%. The pH and conductivity of the stream water were not affected by the Moringa oleifera seed extract. Nitrate and sulphate were not influenced by the Moringa oleifera seed extract except phosphate which recorded a slight increase. Turbidity of raw water samples was significantly reduced by 97.52% in a combined treatment involving Moringa oleifera seed powder and charcoal filter with a p-value of 0.005. The pH of the purified water was within the WHO (2005) recommended range of 6.0-8.5. The effect of the combined treatment of M. oleifera and charcoal filter on sulphate, phosphate and nitrate was significant with p-values of 0.001, 0.001 and 0.025 respectively.Total coliforms was significantly reduced by 8.39% (p=0.014) while fecal coliforms was significantly reduced by 99.23% with a p-value of 0.003 in a combined treatment of Moringa oleifera and charcoal filter. The integrated treatment also reduced the conductivity and BOD of river water by28.68% and 21.25%, respectively. These studies have shown that M. oleifera integrated charcoal filter system can be very effective in treatment of surface water from streams.