ABSTRACT

The use of Moringa oleifera and Inga eduli on treatment of domestic water supply sources in Ishiagu area was assessed. The water sources were Ivo river, well, spring, borehole and the abandoned mining pits of heavy metal and quarry. Physicochemical and microbiological analyses were carried out. Coagulant dosages of 0.5 g, 1.0 g and 1.5 g were used in 100ml of the water samples for 1 hour, 3 hours and 6 hours time intervals. From the physicochemical parameters before the treatment, the water samples showed that values of TSS ranged from 19.0 in spring water to 79.7 mg/l in Ivo river, TDS (19.8-435 mg/l), conductivity (425-750 µS/cm), turbidity (2.50-4.30 NTU) and total hardness ranged from 202 to 590 mg/l. Other parameters were NO₃ (0.31-1.68 mg/l), SO₄ (11.3-21.4 mg/l) and PO₄ (0.12-3.45 mg/l). The DO values were 3.7-5.2 mg/l and BOD (2.6-6.3 mg/l). Values obtained from the mining pit water were similar and higher while those from borehole, spring and well were low and similar (P0.05). The values of the metallic ions were low in the spring, borehole and well water but high in the abandoned mining pit water of heavy metal and quarry. Treatment with Moringa oleifera, Inga edulis, and alum at 1, 3, and 6 hours indicated significant (P0.05) reduction in all the physicochemical parameters and microbial groups analysed, except for pH and temperature which remained fairly constant. Reductions in the values of the physicochemical parameters were dependent on treatment time and coagulant dosage (P0.05). The values of Al increased non significantly when 1.5 g dose of alum was used. Pb and Zn were only reduced to the upper limits of acceptable standards in the mining pits water samples. The microbial groups examined were total heterotrophic bacterial count (THBC), total coliform count (TCC) and total fecal coliform count (TFCC). Ivo river had a reduction in THBC from 3.1x10⁶ before treatment to 1.0x10⁶ after treatment with Moringa oleifera, 2.2x10⁶ after treatment with I. edulis and 1.0x10⁶ after treatment with  alum. The highest microbial group in each water sample was the THBC, followed by TCC and then TFCC; and they had the highest counts in the river, followed by the abandoned pits, well, borehole and spring. Alum and M. oleifera removed TFCC from spring, borehole, well and Ivo river water samples at 1.0g and 1.5g doses for 3 and 6 hours respectively, although alum was more effective. The treatment with I. edulis was effective at 1.0 g and 1.5 g at 6 hrs. The efficiency of the coagulants on the microbial population were both time and dose dependent. The phytochemical analysis of the plants showed that both plants had similar compositions though in varying concentrations. Efficiency of the coagulants was in the order of Alum > Moringa oleifera > Inga edulis. Due to the adverse health effect that can result when alum is used for domestic water purification, Moringa oleifera should be considered first before Inga edulis as a domestic water coagulating or purifying agent.