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A Comparative Study of the Physiochemical and Bacteriological Parameters of Potable Water from Different Sources in Kitui County, Kenya
(Journal of Environment and Earth Science, 2022-11-30) T, Wambua; W, Hunja Carol; Josphert, Kimatu; M, Muluvi Geoffrey; U, Kitheka Johnson; Festus, Mutiso; L, Githenya; K, Ndufa James; Kennedy, Mutati
Developing nations are experiencing an ever-increasing demand for safe water due to climate change and the ever-increasing human population. Various strategies including construction of shallow wells, boreholes and sand dams along the river are done to make water available to various households. However, availability of water sources near are faced with challenges of pollution from a variety of sources. The aim of this study was to determine the levels of selected bacteriological and physico-chemical parameters in three potable water sources namely Kiembeni borehole, Mwitasyano River and Kalundu Dam in Kitui County. The quality of this water was compared to the standards for potable water prescribed by Kenya Bureau of Standards (KEBS). Representative sampling was conducted during the wet season (October 2019) and the dry season (August 2020) in the three sampling sites. The samples were analyzed for physico-chemical parameters: pH, color, turbidity, alkalinity, conductivity, iron, calcium, magnesium, hardness, chloride, fluoride, sulphates, ammonia, total dissolved solids and bacteriological parameters: total and fecal coliform. The analysis was performed at the Kenya Water Institute (KEWI) laboratory using standard procedures. The values obtained for the different water sources in the wet season and dry season were pooled and mean values calculated to determine the overall quality of drinking water. The results indicated that all the water sources had fecal coliform levels unsuitable for drinking water. Most of the values obtained for pH, color, alkalinity, conductivity, calcium, fluoride and sulphates in all sources of water were within the recommended potable water standards by KEBS. However, turbidity, iron and total coliform obtained values for borehole water samples were not within the recommended KEBS standards. The river and dam water samples were within the recommended standards for magnesium, hardness, chloride, ammonia and total dissolved solids. Although results indicate that some of the physico-chemical parameters were in conformance with the recommended standards, the overall bacteriological parameters render the water unsuitable for drinking. Thus, public health intervention programmes should be focused on addressing various sources of water pollution including regular disinfection of water.
A Regional Assessment of Seasonal-to-decadal Changes in estuarine Socio-ecological Systems in the Western Indian Ocean. Published in Western Indian Ocean Journal of Marine Science
(WIO Journal of Marine Science, 2021) Jorge Santos; Johan C. Groeneveld; Fiona MacKay; Cosmas N. Munga
Abstract Estuarine socio-ecological systems (SES) in the Western Indian Ocean (WIO) region face mounting pressures from overexploitation, habitat degradation, impacts of climate change and governance inadequacies. A regional assessment of seasonal-to-decadal change in SES of three estuaries (Bons Sinais in Mozambique, Ruvu in Tanzania and Tana in Kenya) was undertaken along 2000 km of tropical coastline (3°-18°S), using a systems-oriented approach and information collected during the Estuarize-WIO project (2016-2019). All three estuaries were open and tidal, but differed along gradients of geomorphology, annual precipitation, exposure to tropical storms, drought, sea level rise, and rural to urban development. Despite physical differences, similar marine species, mangrove assemblages, seasonality in fish-based farming systems and cultivated crops, and fishing methods were apparent across the region. Key differences were related to the scale of anthropogenic disturbance, discerned from land use / land cover (LULC) change analysis, which showed decadal increases in developed-, cultivated- and grasslands, at the expense of wetlands and forests, and seasonal transformation of wetlands to agriculture and grasslands. The three estuaries represented a gradient along urban-production-conservation dimensions, brought about by rural to urban transformation, and by freshwater and sediment diversion for economic development in upstream catchment areas. Household surveys indicated strongly seasonal livelihood strategies, with highest diversity in peri-urban settings, and reliance on different combinations of ecosystem goods and services in coastal and upstream rural settings. Estuarine fisheries ranged from unselective, low trophic-level fisheries using fine-mesh nets at the urbanized and most-disturbed Bons Sinais Estuary, to a more complex organized fishery at the least-disturbed Tana. At Ruvu, fisheries and agriculture production exit the system to distant markets. The systems-oriented approach demonstrated that human-induced processes affected WIO estuaries and dependent livelihoods more deeply than inherent physical differences. A key conclusion is that research, management and governance will benefit from regional cooperation, given the similarities of the systems and the different levels of disturbance.
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.
A review of the impacts of invasive aquatic weeds on the bio- diversity of some tropical water bodies with special reference to Lake Victoria (Kenya)
(Biodiversity, 0020-12-30) Aloo, Peninah; Ojwang, William; Omondi, Reuben; Njiru, James Murithi; Oyugi, Dalmas
Aquatic weeds may be defined as troublesome or unsightly plants growing in abundance inaquatic situations where they are not wanted. These plants are either adapted to continuoussupplies of water or are at least tolerant to waterlogged soil conditions for substantial periodsof time. The wide range of adaptation to varying amounts of water, and the impossibility ofsharply distinguishing between aquatic and terrestrial environments, makes it difficult toprecisely define an aquatic plant. The menace of water weeds is reaching alarming proportions in many parts of the world, especially in tropical water bodies where they have led toserious ecological and economic losses. Lake Victoria, Kenya, which is the largest freshwaterbody in the tropics, has undergone serious ecological changes including over-exploitationof its fishery resources, degradation of the catchment area, introduction of exotic fish speciesand invasion by the water hyacinth, Eichhornia crassipes (Mart.) Solms (Pontederiaceae),among others. The presence of the weed in the lake has led to many problems includingblockage of water pumps, reduced fishing activities and increase in water borne diseasessuch as schistosomiasis. Positively, aquatic weeds constitute a free crop of great potentialvalue; they are a highly productive crop that requires no tillage, fertilizer, seed, or cultivation.Moreover, these plants have the potential for exploitation as animal feed, human food, sourceof food to some aquatic organisms, soil additives, fuel production, wastewater treatment,source of raw materials and habitat to many organisms. This paper reviews the effects ofaquatic weeds in aquatic systems with examples from some selected waterbodies and specialreference to Lake Victoria.
A review of the impacts of invasive aquatic weeds on the bio- diversity of some tropical water bodies with special reference to Lake Victoria (Kenya)
(Biodiversity Journal, 2013-12-30) Aloo, Peninah; Ojwang, William; Omondi, Reuben; Njiru, James Murithi; Oyugi, Dalmas
Aquatic weeds may be defined as troublesome or unsightly plants growing in abundance inaquatic situations where they are not wanted. These plants are either adapted to continuoussupplies of water or are at least tolerant to waterlogged soil conditions for substantial periodsof time. The wide range of adaptation to varying amounts of water, and the impossibility ofsharply distinguishing between aquatic and terrestrial environments, makes it difficult toprecisely define an aquatic plant. The menace of water weeds is reaching alarming proportions in many parts of the world, especially in tropical water bodies where they have led toserious ecological and economic losses. Lake Victoria, Kenya, which is the largest freshwaterbody in the tropics, has undergone serious ecological changes including over-exploitationof its fishery resources, degradation of the catchment area, introduction of exotic fish speciesand invasion by the water hyacinth, Eichhornia crassipes (Mart.) Solms (Pontederiaceae),among others. The presence of the weed in the lake has led to many problems includingblockage of water pumps, reduced fishing activities and increase in water borne diseasessuch as schistosomiasis. Positively, aquatic weeds constitute a free crop of great potentialvalue; they are a highly productive crop that requires no tillage, fertilizer, seed, or cultivation.Moreover, these plants have the potential for exploitation as animal feed, human food, sourceof food to some aquatic organisms, soil additives, fuel production, wastewater treatment,source of raw materials and habitat to many organisms. This paper reviews the effects ofaquatic weeds in aquatic systems with examples from some selected waterbodies and specialreference to Lake Victoria
A Test of the Applicability of the Lake Habitat Survey for Hydromorphological Monitoring of a Tropical Alkaline Lake (Simbi) with a Fisheries Potential
(International Journal of Fisheries and Aquatic Studies, 2019-09) Opiyo, Stephen; Getabu, Albert Mochache; Sitoki, Lewis Morara; Shitandi, Anakalo
The Lake Habitat Survey (LHS) is an ecological integrity monitoring tool developed for temperate lakes by an independent team of researchers to support the implementation of the EU Water Framework Directive (WFD). It has been widely applied but more testing is needed in different settings, therefore this study investigated the applicability of the LHS protocol in assessing the habitat quality of a tropical alkaline lake in the face of increasing impacts of anthropogenic pressure and climate change. The LHS metrics of Lake Habitat Quality Assessment (LHQA) and Lake Habitat Modification Score (LHMS) estimated for Lake Simbi collectively suggested that the physical habitat quality of the lake is moderate since its hydromorphology is moderately modified. In conclusion, LHS is effective for monitoring ecological condition of water bodies to inform decision making for conservation and management hence it is suitable for adoption in Kenya and the tropics as one of the standard tools for lake environmental assessments.
Access and utilization of Information resources and services by Water specialists in Kenya: The case of the Ministry of Water and Irrigation
(Moi University, 2019) Kariuki, Alice Wanjiru
Enabling technologies have led to the transformation of libraries and informationcenters‘ collection & services from the traditional prints to e-collections such as e-books, e-journals and other virtual reference services. This has been necessitated bythe environment of increasing economic pressure, rapid shifts in the behaviors andexpectations of the patrons and evolving patterns of scholarly publishing. Thechanges have exerted pressure on libraries and more on the parent institutions in theprovision of the necessary infrastructure and the actual access to e-resources. Thepressure on libraries is in the sourcing, acquisition, repackaging and the provision ofnecessary guidance to end users. Underutilization of these resources may lead to userapathy and affect funding. The aim of the study was to investigate the access and useof e-journals by students and academic staff at USIU and propose strategies forimprovement. The objectives of the study were to: identify the types of e-journaldatabases available in the library; determine the frequency of access and use of e-journals by users; establish the policies in place for governing access to and use of e-journals; examine the level of information and computer literacy skills among userson their access and use of e-journals; establish the degree of awareness of theavailability of e-journals; identify major inhibitors to access and use of e-journals,and suggest measures to enhance access to and use of e-journals. The study wasguided by the Unified Theory of Acceptance and Use of Technology Model byVenkatesh, et al (2003). The study adopted mixed method approach. Stratifiedrandom sampling, simple random sampling and purposive sampling techniques wereused to collect data from students and academic staff. Questionnaires and semi-structured interviews were used to collect data from 202 respondents constituting 186students, 16 academic staff and 4 informants from the library. Collected data wasintegrated, presented and analyzed using qualitative and quantitative techniques ofnarratives and numerical. The major findings of the study were: USIU library has avariety of online research databases hosting online journals that are not adequate andcurrent in meeting the ever-changing information needs of users; the frequency ofaccessing e-journals is relatively low with most users accessing them occasionally;the level of awareness of e-journals and their use is low among the library clientele asmost of them do not go through training prior to access and use e-journals; libraryusers are challenged in their access and use of e-journals by restrictions via InternetProtocol (IP) addresses and slow internet speeds. The study recommends that:librarians develops and offer orientation and training programmes regularly; offercurrent awareness on e-resources; acquire and make available peer reviewed e-journals in support of education and research to meet their needs and institutionalbandwidth bundle as well as providing computer literacy program to cater for lowskill users. The librarians to develop promotional strategies that is blended, integratesand coordinates all communications channels.
Access to Water in Kenya’s Coast Region: A Challenge to Community Development and Poverty Alleviation in Lamu County
(Kenya Aquatica Journal, 2018-11-30) Ignatius, David O.; Hassan, Farida A.; Morara, George N.; Osore, Melckzedeck K.; Mutua, Benedict; Kitaka, Nzula K.
Water is considered a basic commodity and essential for life - living on planet earth is dependent on it. However, access to water has been and will continue to be a dilemma for a majority of the residents at the coast of Kenya. A close look at the window on “Coastal Resources and People” reveals that water is a key resource but despite its immense importance, many people especially in the rural areas and the Vulnerable and Marginalized Groups (VMG’s) do not have adequate access to potable, reliable and convenient sources of water. Lamu, currently considered among water scarce counties in Kenya as per the Lamu County Integrated Development Plan (http://lamu.go.ke/wp-content/uploads/2016/03/LAMU_CIDP-Revised.June_2014-1.pdf), faces serious challengeof provision of potable water to its residents. With the influx of people from other parts of the country as a result of the implementation of the Kenya Vision 2030 flagship project - Lamu Port Southern Sudan Ethiopia Transport Corridor (LAPSSET), the current water stresses is only expected to worsen. The Lamu County Government plans to address the ever-increasing demand for access to water but resources to actualise these plans are yet to be consolidated. To complement this situation, Kenya Coastal Development Project (KCDP), a World Bank funded project is working with local communities in Lamu in thedevelopment and implementation of community-led water projects targeting to increasing access to water at household level.This paper will focus on community-based approaches to understand the water-web in Lamu East Sub-County to provide an assessment of opportunities, challenges and sustainability implications. Primary data is used on surveys, Social Assessment (SA) Vulnerable and Marginalised Group Plan (VMGP), observations and recommendations from the Lamu CIDP. It further proposes that of direct usage of saline water, seawater or brackish water, for sanitation purposes could alleviate the freshwater shortage.
Acoustical properties of compressed earth blocks: Effect of compaction pressure, water hyacinth ash and lime
(Elsevier, 2023-07-01) Ouma, Justus; Ongwen, Nicholas; Ogam, Erick; Auma, Mercy; Fellah, Z. E. A.; Mageto, Maxwell; Ben Mansour, Mohamed; Oduor, Andrew
This study assessed the potential use of a mixture of lime and water hyacinth ash (WHA) as binders in fabrication of cylindrical compressed earth blocks (CEBs) with good acoustic absorption properties for building and construction. Different concentrations of the binders and compaction pressures were employed so as to vary the acoustical properties of the fabricated blocks. The geometric and transport parameters of their porous microstructure were recovered through probing using acoustic waves. A low-frequency acoustic wave guide was built for this purpose. It was found out that the transmission coefficient decreased with the compaction pressure, and with addition of lime, while WHA increased the transmission coefficient. The non-acoustical parameters recovered using the equivalent fluid model (JCAL) showed that the variation of the geometry of the microstructure of the blocks is what influences the acoustic transmission coefficient. Thus, the properties of the CEBs can be steered using binder concentration and compaction pressure in a controlled manner.
Adaptation to climate change impacts on crop water requirements in Kikafu Catchment Tanzania
(Journal of Water and Climate Change, 2017) Rotich, Stella; Mulungu, Deogratias
Agricultural activities are the main livelihood for about 70% of Tanzania’s population, with women being the main players. Crops need water (crop water requirements, CWRs) for their growth and production, which can either be rain-fed or irrigation sourced. However, climate change has affected the hydrological cycle, particularly water available for agricultural crops. Since impacts and consequently adaptation are site-specific, an assessment of the effects of climate change on maize water requirements in Kikafu sub-catchment was conducted using a crop simulation model, CROPWAT. Accordingly, climate scenarios were obtained from A2 emission scenario using three general circulation models (GCMs). These scenarios were downscaled at two site locations using the Long Ashton Research Station Weather Generator (LARS-WG) model. The baseline period for the change analysis was 1971–2000. The CWRs are projected to increase by 3.8% in the 2020s and 7.1% in the 2050s at the Moshi Airport and 19.9 and 22.4% at Lyamungu station, respectively. More impact is projected to be during 70–80 days of the development stage and the entire mid-season (81–140 days) whereby the temperature will be high but with low precipitation. With the increasing CWRs, better adaptation measures are increase crop diversification, restore soil organic matter and change cropping systems as established through the multi-criteria analysis.
Adsorption of Caffeine and Ciprofloxacin onto Pyrolitically Derived Water Hyacinth Biochar: Isothermal, Kinetic and Thermodynamic Studies
(David Publishing, 2016-09-07) Ngeno, Emily; Orata, Francis; Baraza, Danstone; Shikuku, Victor; Kimosop, Selly
Adsorption of Caffeine and Ciprofloxacin onto Pyrolitically Derived Water Hyacinth Biochar: Isothermal, Kinetic and Thermodynamic StudiesFull-Text PDFDownload XML 10 ViewsDOI:10.17265/1934-7375/2016.04.006Author(s)Emily Chelangat Ngeno, Francis Orata1, Lilechi Danstone Baraza, Victor Odhiambo Shikuku and Selly Jemutai KimosopAffiliation(s)ABSTRACTIn this work, the adsorptive features of water hyacinth (Eichhornia crassipes) derived biochar for sequestration of ciprofloxacin and caffeine from aqueous solution is reported. The isothermal behaviour, adsorption kinetics, mechanisms and thermodynamic parameters were investigated in batch mode. Langmuir and Freundlich models described the equilibrium adsorption data with regression values > 0.9. The kineticsdata obeyed the pseudo-second-order kinetic law while intraparticle pore diffusion was not the only rate controlling step. The computed thermodynamic parameters, namely change in Gibbs free energy (ΔG), change in enthalpy (ΔH) and change in entropy (ΔS) indicated that the adsorption processes were spontaneous and exothermic with less randomness. pH dependence studies depicted multi-mechanistic adsorption for both compounds and is hypothesized to involve hydrophobic interactions besides other non-coulombic interactions. The findings demonstrate that water hyacinth biochar presents an excellent low cost and environmentally benign adsorbent for mitigation of pharmaceuticals from water with a removal efficiency of above 60 % for caffeine and ciprofloxacin.KEYWORDSAdsorption, ciprofloxacin, caffeine, biochar, water hyacinth.
Agronomic effectiveness of water hyacinth-based composts
(African Journal of Agricultural Research, 2018-09-27) Beesigamukama, Dennis; Katusabe, Alice; Tumuhairwe, John; Muoma, John; Maingi, John; Ombori, Omwoyo; Nakanwagi, Josephine; Mukaminega, Dative
Because water hyacinth-based compost contains substantial amounts of nitrogen (N), phosphorus (P) and potassium (K) its application can boost crop production. We evaluated the agronomic performance of water hyacinth-based composts using field experiments and five treatments which were; water hyacinth compost made using cattle manure (WH+CM), poultry manure (WH+PM), molasses (WH+MO), water hyacinth alone (WH alone) and the control. The composts were applied at two rates of 3 and 6 t ha-1 using maize (LONGE 4) as a test crop. Grain yields of 6.8 t ha-1 harvested in WH+CM applied at 6 t ha-1 and 6.5 t ha-1 harvested in WH+PM applied at 3 t ha-1 were statistically similar, and were the highest in the experiment. The highest harvest index and agronomic nitrogen efficiency were obtained at 3 t ha-1 from WH+PM (4.57) and WH+MO (42.6 kg kg-1) respectively. Compost formulation WH+PM applied at 3 t ha-1 was the most effective as measured in terms of grain yield and is recommended for application by farmers for good yields of maize crop.
An Assessment of Ground Water Quality in Yatta Plateau in Kitui County, Kenya
(2017-03-21) Mwamati, Fredrick T.
The study is primarily an assessment of groundwater quality in the Yatta Plateau of Kitui County. The study focused on the spatial temporal distribution of key chemical parameters namely pH, TDS, Colour, Total hardness, Turbidity, Conductivity, Total alkalinity, Fluoride and Iron. Yatta Plateau is a volcanic formation which is characteristically flat at the top thus limiting overland flow and depression storage necessary for other methods of water supply to the community resident on the Plateau. Surface water sources are therefore not readily available as most of the rain water percolates easily owing to the flat nature of the plateau. The development of groundwater sources has therefore taken preference to other sources of water supply in the study area. Reliable and good quality water supply on the Yatta Plateau corridor may be affected by the type of chemicals found in the ground water, concentration of the dissolved minerals or even ground water quality changes over time. The purpose of this study was therefore to determine the variability or changes on ground water quality in Yatta Plateau in relation to rainfall, land use, geology among others and determine how the same influences water utilization. Groundwater samples were collected in boreholes distributed on the plateau and the key physicochemical parameters were measured using standard methods . These were then analyzed in order to determine the variability of groundwater quality on the Yatta plateau, the extent of influences of the groundwater chemical parameters on water utilization and, finally come u p with recommendations on the appropriate ways of addressing groundwater quality degradation. The study is also important in that the findings provide a better understanding of possible changes in groundwater quality over time and this will prompt planning for appropriate treatment that is required to address the quality changes. The samples were collected in the period between March 2015 and March 2016 covering two dry seasons and two wet seasons experienced in the study area. Samples were collected four t imes from each of the six target boreholes. In total, twenty four (24) water samples were collected for analysis. The samples were analyzed at the Water Resources Management Authority (WARMA) Water Quality Testing Laboratory in Nairobi. The data obtained f rom the laboratory tests was analyzed using Surfer for spatial - temporal analysis, and were also subjected to Statistical analysis using SPSS (Statistical Package for Social Science). A questionnaire was also administered on the users of water derived from the sampled boreholes. The questionnaires were analyzed using various statistical methods including the analysis of variance (ANOVA), correlation analysis, and regression analysis, test of hypothesis, frequency distribution tables, means, percentages and b ar charts. The results of the study show that there is no direct relationship between rainfall and variations of groundwater quality in the Yatta plateau. It was however found that there was spatial - temporal variability in different groundwater quality parameters that were analysed. The spatial - temporal variability was attributed to differences in the geologic formations forming the aquifers of individual boreholes that were sampled within the study area. Although the groundwater is generally of good quality, electrical conductivity, TDS and fluoride were found to be increasing drastically and may surpass the WHO and KEBS drinking water standards in future. The increase in the parameters was attributed to the nature of the geological formations common on the plateau. The results of the analysis of the questionnaires showed that groundwater chemical parameters do not influence water utilization in the Yatta Plateau. The major water quality concern was taste and this was attributed to salinity. The study provide s recommendations to governmental and non - governmental institutions that are mandated with the responsibility of ground water development planning and quality monitoring.
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.
An Assessment of the Spatial and Temporal variations of Groundwater quality in Yatta Plateau in Kitui County, Kenya
(IISTE, 2017) Mwamati, Fredrick T.; Kitheka, Johnson U.; Njuru, Peter G.
The study is primarily focused on the assessment of groundwater quality in the Yatta Plateau of Kitui County. The study focused on the spatial temporal distribution of key chemical parameters namely pH, TDS, Colour, Total hardness, Turbidity, Conductivity, Total alkalinity, Fluoride and Iron. Groundwater samples were collected four times from the six target boreholes found on the plateau in the period between March 2015 and March 2016. The sampling programme covered two dry seasons and two wet seasons. Key physicochemical parameters were analysed using standard laboratory methods. The water samples were analyzed at the Water Resources Management Authority (WARMA) Water Quality Testing Laboratory in Nairobi. The results of the study show that there is no direct relationship between rainfall and variations of groundwater quality in the Yatta plateau. The influence of water abstraction on water quality was also limited. The dominant influence on groundwater quality in the Yatta Plateau was found to be the geological characteristics of the area. It was however found that there was spatial-temporal variability in different groundwater quality parameters that were analysed. The study recommends integrated groundwater resources management including continuous water quality monitoring in the Yatta Plateau in Eastern Kenya.
An Overview of Heavy Metal Pollution in the Western Indian Ocean (WIO) region of Kenya: A Review
(Blueprint Academic, 2024-06-20) Nyamora Moraa Jane, Njiru James, Nyakeya Kobingi, Getabu Albert and Muthumbi Agnes
This study is a review on heavy metal pollution in the Western Indian Ocean (WIO) region of Kenya. The review examines heavy metal pollution of copper, lead, cadmium, iron and zinc that are toxic to marine life and human health; and identifies gaps for future monitoring and assessment. Each pollutant was addressed in order to determine their status in the environment, sources and their effect on biological systems, marine organisms, and human health. Although the concentration levels of these metals are still low and within the recommended standards of global regulating bodies, there is little information in relation to their effects along the food web, human health and how they affect the population dynamics of fish species. Apart from regular monitoring and assessment further research on their effects in the food web and an assessment of human health is recommended.
An Overview of Heavy Metal Pollution in the Western Indian Ocean (WIO) region of Kenya: A Review
(Journal of Aquatic Terrestrial Ecosystems, 2023-06-20) Nyamora, Jane Moraa; Njiru, James; Nyakeya, Kobingi; Getabu, Albert; Muthumbi, Agnes
This study is a review on heavy metal pollution in the Western Indian Ocean (WIO) region of Kenya. The review examines heavy metal pollution of copper, lead, cadmium, iron and zinc that are toxic to marine life and human health; and identifies gaps for future monitoring and assessment. Each pollutant was addressed in order to determine their status in the environment, sources and their effect on biological systems, marine organisms, and human health. Although the concentration levels of these metals are still low and within the recommended standards of global regulating bodies, there is little information in relation to their effects along the food web, human health and how they affect the population dynamics of fish species. Apart from regular monitoring and assessment further research on their effects in the food web and an assessment of human health is recommended.
Analysis of Constituent Chemicals and their Effects on the Physico-Chemical Properties of Spring Water in Ngariama location Gichugu Division Kirinyaga County of Kenya
(Journal of Natural Sciences, 2013-08) Ngari, Mwaniki; Wanjau, Tabitha; Njeru, Sospeter
Keywords: Ground water, Gichugu division has numerous springs, which are a manifestation of potentially high volumes of groundwater. This water is characteristically different from river water in terms of physical parameters like fizzling, characteristic taste and clarity chemistry was studied to explain the above differences. The study established that groundwater in Gichugu area is slightly a (pH 6.49), moderately hard (123.99 mg/l CaCO Cl-). These salts and the pH explained the taste of the water. Also, NaCl and other ionic compounds accounted for the relatively higher conductivity (4.700 Ec µS/cm) while such ions as Ca The percolation of this water through the surface soils of recharge areas generally results in significant purification hence clarity. Fizzling was as a result of dissolved gases such as carbon dioxide and oxygen as they escaped. It was also established that a common groundwater aquifer underlies the area. Iron (0.426 mg/1) and manganese (0.322 mg/1) were found in excess of WHO recommended limits (0.3 mg/1 and 0.1 mg/1 respectively) for potable water quality while fluoride was in relatively low amounts (0.642 mg/1). However, their levels in this water do not make this water unsuitable for drinking since they are still within the acceptable tolerance levels.
Analysis of Microbial Quality of Drinking Water in Njoro Sub-county, Kenya
(Science and Education publishing (SciEP), 2019) Kirianki, Philip; JO, Othira; Silas, Kiruki
Drinking water should be free of microbial pathogens so as to be regarded as potable water and safe for drinking. However, water is prone to fecal contaminants which are the sources of gastrointestinal illnesses. In Njoro Sub-county, river Njoro and rain water are the primary sources of water which also reduces during dry seasons. Other water sources include boreholes, dams, springs and wells while in other cases, the residents store water in household storage containers for future uses. In this study, various water sources and water stored in different containers in Njoro Sub-County was analyzed for its microbial quality. Various microbial parameters such as total viable colony counts (TVCC), total coliforms (TC) and fecal coliforms (FC) were evaluated by use of the culture methods. Most of the water sources were contaminated. TVCC ranged from 0.47 to 1.76 CFU/1mL in water sources and 0.48 to 2.04 CFU/1mL in domestic storage containers. TC was in the range of between 0.30 to 1.89 CFU/100mL in water sources and 0.59 to 2.47 CFU/100mL in domestic storage containers. The mean FC in water sources ranged from 0.10 to 1.68 CFU/100mL and from 0.81 CFU/100mL domestic storage containers. Therefore frequent water testing should be performed by water authorities as recommended by WHO. At households, the people should employ various water treatment methods and practice safe water handling so as to avoid gastrointestinal infections.
Analysis of spatial and temporal drought variability in a tropical river basin using Palmer Drought Severity Index (PDSI)
(Acadamic Journals, 2017-08-31) Wambua, Raphael; Mutua, Benedict; Raude, James
Analysis of spatial and temporal drought variability in the upper Tana River basin using Palmer Drought Severity Index (PDSI) was conducted. The drought is critical for formulation of mitigation measures in the river basin. A monthly temporal and 90-m spatial resolution was applied. This was achieved within ArcGIS environment. Climatic data for 1970 to 2010 was used for computation of the PDSI while the missing data sets were filled using Artificial Neural Networks (ANNs). The results of PDSI for dry and wet seasons at meteorological stations indicate that the time series plots for the PDSI values for dry season are generally lower than those for the wet seasons. The PDSI values for meteorological stations located at the lower elevation of the basin are lower than those located at higher elevation. On the other hand, spatially distributed drought severity based on PDSI show that the ranges of maximum and minimum drought severity values in 1970 are -0.868 to -0.804 and -0.675 to -0.610 respectively. These values of drought severity occur respectively in the north-western and south-eastern areas of the basin. PDSI values increased from the range -0.675 to -0.610 in 1970 and from -1.087 to 0.957 in 2010 for the north-eastern areas of the upper basin. The south eastern areas of the basin are more prone to drought risks than north-western parts. Use of the PDSI reflects the spatial heterogeneity and temporal variability of drought across the basin. The drought assessment offer technical approach for comprehensive understanding of drought for effective drought-induced disaster mitigation and its management, with a view to reducing adverse effects on livelihoods.

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