Water Pollution

Permanent URI for this collection

https://repository.nrf.go.ke/handle/123456789/19

Browse

Now showing 1 - 11 of 11

A review of the changes in phytoplankton community structure and ecology in lake naivasha, kenya
(Academic Journals, 1970-01-01) Argwings Owino Omondi, Steve Opiyo Balaka, George Ogendi Mokua, James Onchieku Mokua, Steve Oduor Omondi
Phytoplankton community structure plays a vital role in freshwater ecosystems. Besides the provision of dissolved oxygen through photosynthesis, they also form an important diet for several fish and zooplankton species. Plankton are also used as biological indicators of water quality. The objective of this paper is to provide a comprehensive review on the changes in phytoplankton community structure and their ecological functional roles. Phytoplankton are the primary producers in Lake Ecosystem. The diversity, distribution, and abundance of phytoplankton are influenced by both abiotic and biotic factors. Lake Naivasha has undergone drastic ecological changes due to the growth in human population, horticultural and floricultural developments and changes in its fisheries. Lake Naivasha is surrounded by horticultural farms that are greatly influencing its ecosystem health and the major fish species in the lake are of introduced species. These anthropogenic activities together with hydrological changes are expected to play a role in the changes in phytoplankton community structure. Previous investigations indicate that there are more than 143 species of phytoplankton and seasonal shift in phytoplankton dominance overtime between Chlorophyta, Bacillariophyta, and Cyanophyta. Due to various limnological, hydrological, and ecological changes being witnessed in the Lake, there is need for the monitoring of phytoplankton community structure. Such information would be useful in the Lakeâ€™s management and conservation.
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.
Application of the Carlson’s Trophic State Index for the Assessment of Trophic Status of Lake Simbi Ecosystem, a Deep Alkaline-Saline Lake in Kenya
(International Journal of Fisheries and Aquatic Studies, 2019-08) Opiyo, Stephen; Getabu, Albert Mochache; Sitoki, Lewis Morara; Shitandi, Anakalo; Ogendi, George Mokua
Eutrophication is increasingly becoming the greatest threat to the ecological health of global water resources hence constant screening of the trophic state of these ecosystems is important. This study was aimed at defining the trophic status of Lake Simbi through the Carlson’s Trophic State Index (CTSI) which is based on the interactions of three water quality variables viz., Secchi depth (SD), total phosphorus (TP) and the chlorophyll-a (Chl-a). The classification scale for Trophic State Index (TSI) runs from 0 to 100, and the results of this study showed that the mean TSI for SD was 67.60, for TP was 118.56, for Chl-a was 74.86 and finally the overall CTSI was 87.01. These show that Lake Simbi is hypereutrophic which reflects the high concentration of nutrients in the lake. The lake suffers from cultural eutrophication which symptomatically manifests in the prevalent proliferation of algal bloom in the lake. The study therefore recommends adoption of an efficient multi-sectoral plan for monitoring and controlling nutrients loading and other pollutants input into the lake.
Assessment of Heavy Metal Concentrations (Cu, Cd, Pb, and Zn) in Wastewater from Gusii Treatment Plant in Kisii County, Kenya
(Pan Africa Journal of Sciences, 2022) Rayori, Douglas; Albert, Getabu; Omondi, Reuben; Paul, Orina; Hellen, Nchore; Boniface, Gisacho; Obed, Nyabaro; Omondi, Argwings; Omweno, Job
The concentrations of heavy metals were determined from wastewater samples collected from the Gusii wastewater treatment plant, from May to July, 2021. Heavy metal analysis was done using a flame atomic absorption spectrophotometer, model AA 7000 Shimadzu, Japan. The results showed that the concentrations of Zinc and Cadmium were below the detection limit for all the sampling sites. The concentrations of Lead and Copper (Mean ± SE) ranged between 0.34 ± 0.06 mg/L and 0.86 ± 0.08 mg/L and 0.25 ± 0.05 and 0.34 ± 0.01 mg/L respectively. The month of July exhibited a higher mean Cu concentration of 0.35 ± 0.004 mg/L compared to the mean Cu concentration (0.2 ± 0.02 mg/L) of May. Likewise, the mean lead concentration of May (0.60 ± 0.04 mg/L) was higher than the mean (0.53 ± 0.05 mg/L.) of July. The independent sample t-test showed that mean Cu concentration difference was significant between the sampling months (t (34) = 21.58; p < 0.05) while for Pb it was not significant between the sampling months (t (30) = 1.241; p = 0.274). The percentage removals of Copper and Lead were generally low at 12.61 % and 6.27 %, respectively. The continued discharge of effluent into River Riana may lead to accumulation of heavy metals in the environment, which in turn poses health risks to the general public. Therefore, the study recommends that Gusii Water and Sanitation Company continue monitoring and assessing the levels of heavy metals in the treatment plant for its sustainability.
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.
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.
Assessment of the Temporal and Spatial Variability in the Phytoplankton Dynamics of a Tropical Alkaline-saline Lake Simbi, Kenya
(International Research Journal of Environmental Sciences, 2020-10-22) Opiyo, Stephen
This study evaluated the phytoplankton dynamics of abundance, species composition and diversity across spatial and temporal scales in Lake Simbi for the period between December 2018 and May 2019. This was necessary, considering the significance of phytoplankton communities in this lake for conservation and ecological role. Sampling was done on a monthly basis for 6 months at six fixed stations systematically selected. A total of 84 phytoplankton species were identified comprising of Cyanophyceae (36 species), Chlorophyceae (25 species), Bacillariophyceae (11 species), Zygnematophyceae (4 species), Dinophyceae (3 species) and Euglenophyceae (3 species). Although, the Cyanophyceae family still dominated in Lake Simbi, a shift in the species composition was realized and this can be probably attributed to the changes in the water quality regime of the lake. The results showed a high phytoplankton density in the lake due to its eutrophic nature. However, reduced abundance of the cyanobacterial species, especially Spirulinaspecies on which flamingos feed and the subsequent dominance of the toxin producing Microcystis species might have contributed to the decline of the flamingo population. All the phytoplankton characteristics of density and diversity indices evaluated in Lake Simbi exhibited no significant spatial and temporal variations. Generally, activities that help to improve and maintain ecosystem integrity need to beadopted by all stakeholders to promote sustainability of all aquatic resources in Lake Simbi.
Determination of the Pollution Levels of Waste Water from Nakuru Tanners, Kenya | African Journal of Education,Science and Technology
(African Journal of Education,Science and Technology, 2018)
Wastewater from leather processing industries is very complex and leads to water pollution if discharged before treatment, especially due to its high organic loading and chromium content. Over the past years, Nakuru Tanners Ltd has been discharging raw effluents into the Ndarugo River causing pollution of surface waters, groundwater and soil. Since the water from this river is used for drinking, agricultural and industrial purposes, the assessment of the effluents is necessary. A study to determine the level of toxicants in Nakuru tannery wastewater discharged to the environment was undertaken. Water samples from four sampling points (S1 – Pre-tanning Stage, S2 – Tanning Stage, S3 – Post-tanning Stage and S4 – Drainage to the river) were collected and analyzed. A comprehensive experimental evaluation of tannery wastewater was performed as a basis for the determination of the levels of different pollutants , BOD, COD, pH, turbidity, TSS, NO3- and NO2- and the values obtained were compared to the standards set by NEMA and WHO. The levels of the metals chromium, iron and lead were determined using FAAS, Kjeldahl method was used for the quantization of NO3-, NO2- and P determined by Mehlich II extraction while UV-Vis was used in colour determination. The results show that sampling point S1 (wastewater from the pre-tanning stage) recorded the highest parameter levels for pH, TSS and SO42- of 11, 294.40 mg/L and 318.50 mg/L, respectively. Sampling point S2 had the highest levels of COD, BOD, Cr and Pb with corresponding values of 9,107 mg/L, 9,150 mg/L, 945 µg/L and 6.50 mg/L. Sampling point S3 recorded the highest parameters of temperature, DO, Fe, P and electrical conductivity of values 24.62 0C, 1.15 mg/L, 5.40 mg/L, 12.40 mg/L and 14720 µSCm-3 while S4 recorded the highest of NO3 - and NO2-pollutants with respective values of 85.20 mg/L and 146.70 mg/L. These levels were, however, above the recommended values set by WHO and NEMA for such parameters in tannery waste water. The company should therefore take immediate counteractive actions to lower these levels of the toxicants in order to avert the associated effects to human and environment. This study has made various recommendations which if undertaken will help make the tannery effluents safe before di sposal.
Level of Metal Pollutants in Water from Nyakomisaro Stream through Kisii Town
(University of Nairobi Research Archive, 2016-07) Janes, Omoko; Onyatta, John; Obed, Nyabaro; Kenada, and
Environmental pollution is currently one of the major issues facing humanity. It has increased exponentially in the past few years and reached alarming levels in terms of its effects on living creatures (Renge et al., 2012). The presence of toxic metals in the environment and more specifically in the various water sources is of major concern because of their toxicity, non-biodegradable nature and threat to human, animal and plant life. According to Kadirvelu et al., (2001) electroplating, painting, metallurgical, mining, textile, municipal, incineration and chemical manufacturing industries all generate toxic metals at various levels. Toxic metal ions enter into water and soil from different waste-water sources. As a result they pollute the water streams and soil. A number of crops and aquatic plants take up these metals and bio-accumulate them. As trace elements, some of the heavy metals such as Copper and Zinc are essential to maintain the metabolism of the human body however at high concentrations and accumulated levels they could be poisonous. According to Ocharo and Bokea (2014), the concern over the pollution of Nyakomisaro stream has been raised by the regulatory authorities who have cited activities such as car wash centres and damping sites along Nyakomisaro stream as the cause, hence recommending cleanup. The aim of this study was to access the concentrations of cadmium, copper, lead and zinc metals in water sampled from Nyakomisaro stream.
Phytoplankton community structure and ecology in Lake Naivasha, Kenya
(International Journal of Fisheries and Aquatic Studies, 2020-04-21) Owino, Omondi A; Mokua, Ogendi G; James, Onchieku M; Omondi, Reuben; Ombiro, Omweno J
The phytoplankton community structure and ecology of L. Naivasha was studied for a period of six months on a monthly basis between February 2019 and July 2019. The main objective was to determine the phytoplankton species diversity, distribution, and abundance from the seven sampling points in L. Naivasha. A total of one hundred and twenty four (124) species belonging to six (6) taxonomic group were identified. Chlorophyceae was represented by 43 species consisting of 34.68% by species composition, Bacillariophyceae was represented by 38 species consisting of 30.65% by species composition. Cyanophyceae was represented by 24 species leading to 19.35% species composition. Other taxonomic groups included Zygnematophyceae, Euglenophyceae, and Dinophyceae represented by 9 (7.26%), 7 (5.65%) and 3 (2.42%) species respectively. Cyanophyceae recorded the highest abundance in cells/litre, followed by Chlorophyceae and Bacillariophyceae. The total number of algal species was highest in Hippo point with 72 (16.59%) species, followed closely by 68 (15.67%) species in Crescent Island, followed by 66 (15.21%) species in Oserian Bay. Mouth of R. Malewa recorded 59 (13.59%) species, Sher Bay had 58 (13.36%) species, this was followed by Mid Lake station with 56 (12.90%) species, and Sewage Discharge Point had 55 (12.67%) species. Shannon-wiener diversity (H) index ranged from 2.0455 (Mouth of R. Malewa) to 2.7077 (Oserian Bay). In conclusion, Lake Naivasha depicted a higher diversity of phytoplankton species. Results from this study showed the state of L. Naivasha trophic status based on phytoplankton ecology.
Spatial and temporal variation in water quality between the Lakes Naivasha and Oloiden in the Kenyan Rift Valley
(Journal of Technology & Socio-Economic Development, 2023-07-06) Carolyne, Guto Kerubo; Njiru Murithi James; Getabu Albert; Gichana Moraa Zipporah
Lakes Naivasha and Oloiden merged due to the rise in the water level in the former. A study was conducted for one year in an endeavor to investigate spatial temporal variation of select physical and chemical parameters between the Lakes Naivasha and Oloiden. The water quality was sampled monthly in each site in Lake Oloiden and Lake Naivasha by measuring some water quality variables insitu and collection of water samples for laboratory analysis. The water depth and the secchi depth were measured in each site while some physicalchemical parameters were measured insitu using a YSI Multiparameter probe. Nutrients (phosphates and nitrates), total suspended solids, chlorophyll-a analysis was done in the laboratory using the standard methods. The lakes depth and the secchi depth have increased in both lakes. The phosphates varied site-wise and chlorophyll-a concentration has decreased post water level rise. Lake Oloiden’s temperature, pH, conductivity and salinity were higher as compared to the Lake Naivasha’s. The principal component analysis showed 4 principal components (PCA-1 to PCA-4) which accounted for 94.7% of the variation. PCA-1 and PCA-2 biplots suggested: a link between chlorophyll-a to orthophosphates, nitrates, phosphates (Oloiden ST1 and ST2). Oseria and Korongo sites were closely associated with the secchi depth, lake depth, pH and salinity. 4 distinct clusters were noted: Crescent, Malewa, midsection (Midlake, Korongo, Oseria) and Lake Oloiden (Oloiden ST1 and ST2). The increase in the water level and the merging of saline and fresh water ecosystem led to the creation of a salinity gradient; an area where abiotic and biotic processes are non-linear. There was spatial temporal variation in water quality among the sites. Analysis of variance in water quality in the Lake Naivasha and Lake Oloiden provided an insight about water quality status: associations between water quality variables and sites may aid in effective management decisions.

Browse

Browsing Water Pollution by Subject "Kisii University"

Results Per Page

Sort Options