Potentials of Moringa oleifera Seeds and Aluminium Sulphate as Coagulants for Treatment of Water Samples from Usuma River, Abuja

ABSTRACT

The potentials of Moringa oleifera seeds and Aluminium Sulphate as coagulants for the treatment of water samples from Usuma River Abuja was carried out. The physicochemical parameters investigated were the Turbidity (in NTU), Total Dissolved Solids (in mg/l), Conductivity (in μS), and Salinity (in ppm). For the water treatment with Alum, the standard municipal water treatment dosing of 360 mg/l was used. For the treatment with the natural coagulant, there was need to determine the optimum amount and conditions of application. The Box-Wilson Central Composite Rotatable Factorial Design was applied using Design Expert software for modeling the impacts of Moringa oleiferaseed concentration (X1 in mg/l), mixing time (X2 in minutes), and mixing speed (X3 in rpm) on the percentage reduction of each of the studied parameter. Data from the experimental run for each parameter were fitted sequentially with a linear model, two factor interaction model, quadratic model, and cubic model. For each model fit, the model equation was obtained and the Analysis of Variance (ANOVA) carried out to assess the statistical significance of the model and the experimental factors based on their p-values. Further statistical inferences were drawn from the determination coefficients of the model (R2), “lack of fit” of the model and the model graphs where applicable. Results obtained showed that the effect of Moringa oleiferaseeds on the % turbidity reduction was best represented by the quadratic model. The maximum % Turbidity reduction that could be achieved was 74.79% and would be achieved with a coagulant concentration of 10mg/l, mixing time of 43 minutes and mixing speed of 80 rpm. For the total dissolved solids, salinity and conductivity, none of the models tested gave adequate representation of the data and hence it was not possible to predict optimum conditions for the effects of Moringa oleiferaseeds on these parameters. However from the experimental results, average reductions of 54.96%, 49.36%, and 56.19% were achieved for the total dissolved solids, conductivity and salinity respectively. For aerated water treated with 360 mg/l of Alum, a percentage decrease of 16.17%, 2.13%, 2.08% and 3.85% was achieved for turbidity, total dissolved solids, conductivity and salinity respectively. These results indicate that the natural coagulant performed better than the artificial coagulant under the treatment conditions investigated in this study.

Key words: Moringa oleifera, Aluminium Sulphate, Turbidity, Total dissolved solids, Conductivity, Salinity.