INVESTIGATING THE SYNERGISTIC EFFECTS OF MORINGA OLEIFERA SEED CAKE EXTRACT AND OPUNTIA STRICTA (CACTUS) MUCILAGE IN SURFACE WATER TREATMENT

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Department of Engineering

ABSTRACT
This research investigated the synergistic effects of Moringa oleifera seed cake extract and Opuntia stricta(cactus) mucilage in surface water purification. The synergistic effects of the two coagulants on turbidity, conductivity, total dissolved solid(TDS), pH, chemical oxygen demand (COD),biological oxygen demand (BOD) and bacteria (E.coli)were successively determined. The chemical composition analysis of Moringa oleifera and Opuntia stricta(cactus) was carried out. Moringa oleifera contains 0.70% of K, 0.02% of Na, 0.114% of Ca and 0.074% of Mg while Opuntia stricta(cactus) contains 0.35% of K, 0.18% of Na, 1.522% of Ca and 0.083% of Mg. For raw surface water with turbidity of 44 NTU, the optimum doses of Moringa oleifera and Opuntia stricta(cactus)were found to be, 3 mL and 2 mL respectively. Using Moringa oleifera and Opuntia stricta(cactus) 88.6%, and 42.7% reduction in turbidity was achieved, respectively after coagulation. Also, 86.1% turbidity reduction was recorded for the blend of cactus mucilage and Moringa oleifera at blending ratio of 40:60.The conductivity and TDS of Moringa oleifera water treatment increased from 80.6 to 154.3 μS/cm and from 42.6 to 92.8 mg/L respectively. The conductivity and TDS of cactus mucilage water treatment increased from 115.2 to 171.1 μS/cm and from 69.4 to 113 mg/L respectively. The blend of Moringa oleifera and cactus mucilage treatment increased the conductivity and TDS of the water from 109.8 to 112.8 μS/cm and from 66.1 to 68.1 mg/L respectively. Moringa oleifera increased the pH of the surface water from 6.69 to 7.1 while Opuntia stricta (cactus) reduced the pH from 6.69 to 5.9. The pH for the blend of Moringa oleifera and cactus mucilage was from 6.57 to 6.65. The highest percentage synergistic effects for the blend of Moringa oleifera and Opuntia stricta(cactus) on COD and BOD was recorded to be 77.1% and 64.9% respectively. Bacterial count was reduced from 82 cells per 100 ml to 7 cells per 100 ml for Moringa, to4 cells per 100 ml for cactus and to 2 cells per 100 ml for the blend. On the other hand, the elongation of the coagulated treated surface water with Moringa oleifera, Opuntia stricta(cactus) and the blend Moringa oleifera and Opuntia stricta(cactus) were 3 days, 3 days and 5 days, respectively