Browsing by Author "Onchieku, J."

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  • Publication
    Publication
    An Assessment of Some Physical, Chemical and Biological Characteristics of Nyanchwa - Riana River Flowing through Kisii Town in South West Kenya Ogendi G. M. A. M., Getabu
    (International Journal of Applied Science and Technology, 2015-04) Onchieku, J.; Ogendi, G. M.
    A study was conducted to assess the water quality of Nyanchwa-Riana River flowing through Kisii town during the period May 2013 to June 2014. Sampling stations were selected on a transect covering the upper and middle reaches of Nyanchwa stream. A further two sampling stations were added after the confluence on the Riana River downstream. The water quality parameters assessed were dissolved oxygen concentration, pH, conductivity, turbidity, chlorophyll-a, total and soluble phosphate and nitrate concentrations and coliform counts. Nutrient concentrations generally increased from the source of the Nyanchwa -Riana River towards the lower reaches of the river. Soluble nutrient concentrations exhibited the same trend. The total phosphorous to total nitrogen ratio of 1:3 varied from the Redfield ratio of 1:16 commonly found in natural habitats. Total coliform counts exceeded those recommended in the international water quality standards of less than 10 coliform cells/100ml of water and those of NEMA of nil100ml -1 . Observations on the physical and chemical parameters showed levels stressful to aquatic life, with dissolved oxygen concentrations less than 5 mgL -1 in some sampling points. These findings are useful in the management of the water quality in the two streams and on the River Riana flowing through Kisii town.
  • Publication
    Publication
    Assessment of organochlorine pesticides (OCPs) contamination in relation to physico-chemical parameters in the Upper River Kuja Catchment, Kenya (East Africa)
    (International Journal of Fisheries and Aquatic Studies, 2018-12) Nyaundi, J. K.; Getabu, A. M.; Kengara, F.; Onchieku, J.; Njiru, M.; Kinaro, Z. O.; Babu, J. M.; Sitoki, L. M.; Nyamweya, C.; Osoro, E. M.
    Concentrations of 17 organochlorine pesticides residues (alpha-HCH, beta-HCH, gamma-HCH, deltaHCH, Heptachlor, Aldrin, Endrin, Endosulfan I, Dieldrin, p,p’-DDT, Endosulfan II, p,p’-DDD, Endrin aldehyde, p,p’-DDE, Endosulfan sulfate, Heptachlor epoxide and Methoxychlor) were analysed in water and sediment from Upper River Kuja catchment, Kenya, between January-October 2015, using GasChromatography (GC) with (GC-ECD) equipment. Nutrient levels and water quality parameters: pH (7.57±0.354), secchi disk (0.05±0.019), dissolved oxygen (DO) (6.96±0.897), temperature (25.39±2.201), conductivity (62.03±23.123) and hardness (26.39±6.063) contributed to significant variations in organochlorine pesticide residue levels observed. Statistical significance differences (p<0.05) between water quality parameters in the sampling stations occurred. Pesticide concentrations ranged within BDL – 0.263µgl-1 , for Heptachlor, BDL – 0.506 µgl-1 Heptachlor epoxide, BDL – 0.506 Aldrin, BDL – 0.014 Dieldrin, p,p’-DDT, BDL – 0.644 p,p’-DDE, BDL – 0.176 p,p’-DDD, and BDL – 2.220 methoxychlor. Sediment pesticide residues were higher during rainy period. Results indicate persistent organic pollutants (POPs) exist in our environment, and recent use in sampled area. Increased aquatic monitoring is recommended to detect persistency and changes in target environment.
  • Publication
    Publication
    Assessment of the microbial load of Nyanchwa-Riana and Nyakomisaro-Riana Rivers, Kisii, Kenya
    (International Journal of Fisheries and Aquatic Studies, 2015-06-26) OgendiG, M.; Getabu, A.; Onchieku, J.; Babu, J. M.
    Water is an elixir of life, a precious gift of nature to mankind and other animal and plant species living on the planet earth. Water quality was assessed in two parallel rivers flowing through Kisii town. Parameters assessed were; Electrical Conductivity, TDS, TSS, pH, temperature, total and fecal coliform counts monthly for 18 months along five sampling sites in the rivers’ transects. Mean TDS in Nyanchwa and Nyakomisaro rivers were 142.59±22.68 mgL-1 and 96.62±11.76 mgL-1 respectively. Nyanchwa had an overall EC of 110.35±2.09 μScm-1 while Nyakomisaro had 107.55±4.15 μScm-1. EC was also correlated with TDS, temperature, TSS, T-coli and F-Coli at all sites. TSS in Nyanchwa River and Nyakomisaro ranged from 2.00 – 396 mgL-1 with an overall mean of 53.86±5.67 mgL-1 and 56.38±6.45mgL-1 respectively. TSS had significant differences in sampling sites and was above the recommended NEMA levels of 30 mgL-1. F-Coli was strongly correlated with the T-Coli in the two rivers. Nyanchwa had an overall mean of fecal and total coliforms of 740± 94 cells100ml-1 and 627 ±112 cells100ml-1 respectively while Nyakomisaro had an overall mean of fecal coliform counts of 786±104 cells100ml-1 and mean total coliform counts were 842±105 cells100ml-1. Chlorophyll-a in both rivers was not significantly different across the sampling sites. Both rivers had chlorophyll-a concentrations beyond 10μgL-1. The results suggested that environmental loading of pollutants from car washing sites, leaked sewage, defecation in the bushes, organic wastes and dumping soils from construction sites adversely altered natural stream water quality dynamics, underlining the need for improved management practices, including controlling leachate from dumpsites into the rivers to minimize the large-scale escape of pollutants into the rivers.
  • Publication
    Publication
    Assessment of the microbial load of Nyanchwa-Riana and Nyakomisaro-Riana Rivers, Kisii, Kenya
    (Semantic Scholar, 2015-07-01) OgendiG, M.; Getabu, A.; Onchieku, J.; Babu, J. M.
    Water is an elixir of life, a precious gift of nature to mankind and other animal and plant species living on the planet earth. Water quality was assessed in two parallel rivers flowing through Kisii town. Parameters assessed were; Electrical Conductivity, TDS, TSS, pH, temperature, total and fecal coliform counts monthly for 18 months along five sampling sites in the rivers’ transects. Mean TDS in Nyanchwa and Nyakomisaro rivers were 142.59±22.68 mgL-1 and 96.62±11.76 mgL-1 respectively. Nyanchwa had an overall EC of 110.35±2.09 μScm-1 while Nyakomisaro had 107.55±4.15 μScm-1. EC was also correlated with TDS, temperature, TSS, T-coli and F-Coli at all sites. TSS in Nyanchwa River and Nyakomisaro ranged from 2.00 – 396 mgL-1 with an overall mean of 53.86±5.67 mgL-1 and 56.38±6.45mgL-1 respectively. TSS had significant differences in sampling sites and was above the recommended NEMA levels of 30 mgL-1. F-Coli was strongly correlated with the T-Coli in the two rivers. Nyanchwa had an overall mean of fecal and total coliforms of 740± 94 cells100ml-1 and 627 ±112 cells100ml-1 respectively while Nyakomisaro had an overall mean of fecal coliform counts of 786±104 cells100ml-1 and mean total coliform counts were 842±105 cells100ml-1. Chlorophyll-a in both rivers was not significantly different across the sampling sites. Both rivers had chlorophyll-a concentrations beyond 10μgL-1. The results suggested that environmental loading of pollutants from car washing sites, leaked sewage, defecation in the bushes, organic wastes and dumping soils from construction sites adversely altered natural stream water quality dynamics, underlining the need for improved management practices, including controlling leachate from dumpsites into the rivers to minimize the large-scale escape of pollutants into the rivers.