Browsing by Author "Okereke, C. B. N."

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    Efficiency of water-purifying devices used in homes and industries
    (U. P., 2013-12-28) Okereke, J. N.; Nnoli, M. C.; Okereke, C. B. N.; Ahumibe, N. C.
    The use of water-purifying devices are gaining popularity, as many homes and industries are using them to treat water for dinking. However, most of the users do not know much about the performance/efficiency of these devices, hence this investigation. Efficiency of water-purifying devices were evaluated to determine their efficiencies in treating water consumed by people. Raw water samples from groundwater source, borehole (a major source of drinking water) in Owerri, Nigeria were treated using commonly used water treatment devices: resin ion-exchanger, sand-bed filter, activated carbon filter, micron filter, reverse osmosis membrane filter, ozonator, and UV-sterilizer. The resulting purified water samples were labeled, and each were subjected to physical, chemical and bacteriological analyses using APHA (2006) water analysis method. Raw water (control) sample had pH value of 6.7 while the pH values of treated water samples fell within 6.9 – 7.1. Turbidity value of control sample was 6.0 NTU with other samples recording 4.0 NTU and below. Total heterotophic bacteria count and total coliforms counts of the raw water sample were 4.0 x 102 CFU/ml and 2.2 x 102 CFU/100ml respectively, but were below 2.5 x 102 CFU/ml and 1.9 x 102 CFU/100ml respectively in some of the treated samples, and nil in others. The overall efficiency of the treatment devices were of the order: Reverse osmosis membrane filter (76.25%) > UV-sterilizer (72.24%) > micron filter (65.85%) > Ozonator (62.97%) > Activated carbon filter (51.86%) > Resin ion-exchanger (46.67%) > Sand-bed filter (43.55%). This implies that not all water treatment devices used in homes and indutries are efficient enough to yield qualitative drinking water for unsuspecting users.
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    Physico-chemical and bacteriological assessement of Oyibo River in Ehime Mbano, Imo State
    (U. P., 2015) Okereke, J. N.; Okanume, J. N.; Okereke, C. B. N.
    The physico-chemical and bacteriological assessement of Oyibo river, Ehime Mbano, was carried out between 2011 and 2012. Considering the communities that make use of this river for different purposes, water samples were collected from four different sampling points along the river and subjected to physico-chemical and bacteriological analyses. Pour plate method was adopted to determine total heterotrophic bacteria, and membrane filtration technique, for total coliforms and E. coli counts. Standard procedures for water analysis by APHA were adopted for the determination of physical and chemical parameters. Atomic Absorption Spectrophptometer (AAS) was used to analyze for heavy metals. The average values of total heterotrophic bacteria were 5.8 x 103 cfu/ml and 1.51 x 103 cfu/ml for rainy and dry seasons respectively. Average values for total coliforms and E. coli counts were 33.75 cfu/100ml and 6 cfu/100ml for rainy season, and 17.38 cfu/100ml and 4 cfu/100ml for dry season. Bacterial isolates included E. coli, Salmonella spp, Lactobacilli spp, Klebsiella spp, Staphylococcus spp, Proteus spp, and Pseudomonas spp. In all the water samples, the pH values ranged from 6.04– 6.52. Average values of total hardness for rainy and dry seasons were 5.90mg/l and 5. 43mg/l respectively. The concentrations of nitrate, phosphate, chloride, and sulphate ranged from 0.00 16.40mg/l; 0.01– 1.24mg/l; 0.13– 0.35mg/l; 0.00– 15.95mg/l respectively. Average COD, BOD and DO values were 5.63mg/l, 2.07mg/l, and 3.17mg/l in dry season, and 9.24mg/l, 1.77mg/l, and 4.26mg/l in rainy season. The values of heavy metals during the rains were within the range of 0.0008ppm– 1.5605ppm, but 0.0001ppm– 0.0339ppm, in dry season. There were no significant differences in some bacteriological and chemical properties with season, but the physical parameters such as depth, flow rate, pH, and turbidity were, at p ˂ 0.05. The study revealed that Oyibo River is not safe for drinking (inasmuch as it serves as source of drinking water for some communities), unless subjected to appropriate treatment.