Water Pollution

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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 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
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.
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 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 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 Levels of Heavy Metals in Water, Sediments and Fish in Sosiani River
(Science and Education Publishing, 2019-11-01) Shieunda, Ogara; Neyole, Edward; Oluchiri, Stanley; Orata, Francis; Analysis
The objective of the study was to examine spatial and temporal levels of heavy metals in water, sediments and fish in Sosiani River. This study was an experimental design approach in which a scientific analysis was done involving sample collection, preparation and laboratory work to determine Pb, Cd and Cr concentrations in fish water and sediments. The main Sosiani river flows from the Keiyo escarpment at the far South East through Uasin Gishu plateau to Turbo which is in the North West. The units of analysis used in the study included two species of fish, water and sediment; whereby water and sediment were sampled from eleven sampling locations (SR0 – SR10) and fish from ten sampling points (SR1 – SR10) along river Sosiani catchment. Sample analysis was done using Atomic Absorption Spectrometry. Data analysis was done using the statistical program for social sciences (SPSS) version 23. Inferential (ANOVA), regression and descriptive statistics were used to analyse data. Spatial and temporal levels of heavy metals in water, sediments and fish were the outcomes. In the upper Sosiani, SR3 (Chepkorio) registered the highest lead levels in the wet season of 0.127 mg/l. In both dry and wet seasons, and in all the sites, lead values in water were above the NEMA and WHO thresholds of 0.01 mg/l. In the analysis of cadmium concentrations, it was observed that in wet season water had all 50% of the sites above the NEMA and WHO thresholds while all the sites were had values below the limits during the dry season. Cr in water was high for 90% of the sites. Sediment had the highest lead values of 1.744mg/l. Barbus (Barbusbarbus) fish had high lead, cadmium and Cr values in both wet and dry seasons. In both seasons, catfish (Clariusgariapinus) had low values of lead and cadmium below the NEMA and WHO limits for most of the sites but high levels of Chromium. Spatial and temporal variations in heavy metal concentration were observed between the water, sediment and the two species of fish within the catchment. This study recommended mandatory measures (enforcement) to control the increased heavy metal concentration downstream the basin.Keywords: spatial, temporal, heavy metals, river sosiani catchment
Analysis of Spatial and Temporal Levels of Heavy Metals in Water, Sediments and Fish in Sosiani River
(Science and Education publishing (SciEP), 2019-10-09) Shieunda, Ogara Rose; Neyole, Edward; Omuterema, Stanley; Orata, Francis
The objective of the study was to examine spatial and temporal levels of heavy metals in water, sediments and fish in Sosiani River. This study was an experimental design approach in which a scientific analysis was done involving sample collection, preparation and laboratory work to determine Pb, Cd and Cr concentrations in fish water and sediments. The main Sosiani river flows from the Keiyo escarpment at the far South East through Uasin Gishu plateau to Turbo which is in the North West. The units of analysis used in the study included two species of fish, water and sediment; whereby water and sediment were sampled from eleven sampling locations (SR0 – SR10) and fish from ten sampling points (SR1 – SR10) along river Sosiani catchment. Sample analysis was done using Atomic Absorption Spectrometry. Data analysis was done using the statistical program for social sciences (SPSS) version 23. Inferential (ANOVA), regression and descriptive statistics were used to analyse data. Spatial and temporal levels of heavy metals in water, sediments and fish were the outcomes. In the upper Sosiani, SR3 (Chepkorio) registered the highest lead levels in the wet season of 0.127 mg/l. In both dry and wet seasons, and in all the sites, lead values in water were above the NEMA and WHO thresholds of 0.01 mg/l. In the analysis of cadmium concentrations, it was observed that in wet season water had all 50% of the sites above the NEMA and WHO thresholds while all the sites were had values below the limits during the dry season. Cr in water was high for 90% of the sites. Sediment had the highest lead values of 1.744mg/l. Barbus (Barbusbarbus) fish had high lead, cadmium and Cr values in both wet and dry seasons. In both seasons, catfish (Clariusgariapinus) had low values of lead and cadmium below the NEMA and WHO limits for most of the sites but high levels of Chromium. Spatial and temporal variations in heavy metal concentration were observed between the water, sediment and the two species of fish within the catchment. This study recommended mandatory measures (enforcement) to control the increased heavy metal concentration downstream the basin.
Application of phytoplankton community structure for ranking the major riverine catchments influencing the pollution status of a lake basin
(Wiley, 2020-02-18) Aura, Christopher Mulanda; Odoli, Cyprian; Nyamweya, Chrisphine S.; Njiru, James M.; Musa, Safina; Miruka, Jared Babu; Owili, Monica Ochieng; Omondi, Reuben; Raburu, Phillip; Manyala, Julius; Mwamburi, Job; Ogari, Zachary; Mbaru, Emmanuel K.
The present study demonstrates the application of a multi‑metric Phytoplankton Index of Biotic Integrity (PIBI) approach for ranking of major river catchments in the Kenyan part of Lake Victoria on the basis of their pollution status. The index utilizes water quality and zooplankton data, phytoplankton diversity, abundance and attributes, as well as literature information. The rivers were sampled from 2016 to 2018 during the wet season (March) and dry season (July). The separation power of the Mann–Whitney U test (p < .05) qualified eight discriminant metrics for phytoplankton samples into a scoring system of 1, 3 and 5, based on high, fair and slight deviation from the best site, respectively, in development of the final PIBI. The Kuja and Sondu‑Miriu rivers had the highest PIBI, signifying least pollution influence on the lake. In contrast, the Yala and Nzoia rivers exhibited the lowest PIBI, representing the catchments with a higher pollution influence on the lake. The fair to poor integrity classes for the major river catchments in the region signified a deteriorating lakescape. The present study presents the preliminary results of using phytoplankton metrics for development of the Index of Biotic Integrity (IBI) approach in the region as a decision‑making support tool for the effective management and sustainable use of water resources in the lake basin.
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.
Assessing the Impact of land-use types on the groundwater quality: a case study of Mid River Njoro Catchment, Kenya
(acque sotterranee, 2020-12-22) Rendilicha, Halake; Home, Patrick; Raude, James; M'Erimba, Charles; Muthoka, Stellamaris
The study assessed the impact of land-use types on the groundwater quality of the mid River Njoro catchment, Kenya. Groundwater samples were collected from eight boreholes between the period of October 2017 to February 2018 and analyzed for pH, temperature, electrical conductivity, dissolved oxygen, nitrate, ammonium, and total phosphorus. These parameters were used to calculate the Groundwater Quality Index (GQI) value of the study area. The concentration maps (“primary maps I”) were constructed using Kriging interpolation of ArcGIS software from the seven groundwater quality parameters. The “primary maps I” were standardized with the KEBS and WHO standards to the “primary maps II” for ease of integration into a GIS environment. The “primary maps II” were then rated and weighted using a polynomial function to generate “rank maps” before calculating the GQI using spatial analyst tools of ArcGIS software. The land use map was prepared from a high-resolution Google earth satellite imagery of 2015. The mean GQI values for the different land use polygons were calculated and compared using GIS techniques. The GQI ranged from 68.38 to 70.92, indicating a high groundwater quality of mid River Njoro catchment. The major land-use types identified include settlement area, forest cover, agricultural land and mixed area. The agricultural land dominated the study area, followed by settlement area, forest cover and finally mixed area. The mean GQI value in each land use type varied minimally and this could be because of the diffuse nature of the land use types of the study area. Settlement area had low GQI, followed by agricultural land, mixed area and the forest cover had the highest mean GQI value, which corresponds to good quality of groundwater. Even though the variation is insignificant in this particular study, it somehow indicates the adverse effects of different land use on the quality of groundwater.
Assessment of Available Phosphates and Nitrates Levels in Water and Sediments of River Isiukhu, Kenya
(Science and Education Publishing, 2020-06-22) Oremo, Jane; Orata, Francis; Owino, Joseph; Shivoga, William
Surface water contamination has become one of the main environmental issues of concern and achallenge to the world population, especially in the developing world, that face potable or usable water security. Inthis study concentrations of available nutrients (PO43- and NO3-) in sediments and water along River Isiukhu, withinLake Victoria catchment area in Kenya are presented. Sediments and water samples were collected from 11sampling sites along River Isiukhu. Available phosphorus was determined by a Spectrophotometric method in whichthe ammonium phosphomolybdate complex, was reduced by ascorbic acid in the presence of antimony to give adistinct blue color complex. Available nitrate was measured spectrophotometrically at 420nm using UVI609PCUV/VIS Spectrophotometer. Physicochemical parameters such as temperature, pH, dissolved oxygen, turbidity,salinity, conductivity, were measured on-site using mobile Hydrolab Quanta. Phosphates concentrations rangedfrom 1.18 ± 0.09 to 3.28 ± 0.5 in water (mg/l) and 2.30 ± 0.03 to 4.51 ± 0.31 in sediment (mg/kg) andnitrates concentrations ranged from 0.15 ± 0.04 to 0.75 ± 0.03 in water (mg/l) and 0.75 ± 0.02 to 1.93 ± 0.05 insediment (mg/kg). The coefficient of variation (CV) depicted that all the physical-chemical parameters measuredvaried widely except pH and temperature. Pearson's correlation matrix was used to show the relationship betweennutrients concentrations in sediments and water and also for the physical-chemical parameters at significantdifferences accepted at P ≤ 0.05 . There was variation in Pearson correlation coefficient analysis for all theparameters tested.
Assessment of Environmental Sources, Levels and Distribution of Polycyclic Aromatic Hydrocarbons within Nzoia Catchment Area in Kenya
(Scientific Research, 2019-06) Shitandayi, Agripina; Orata, Francis; Lisouza, Fred
Continuous concerns about Polycyclic Aromatic Hydrocarbons (PAHs) presence in the environment have raised concern because of their toxic effects to various organisms. Sugarcane farming and cane processing industries are major economic activities within River Nzoia catchment area in Kenya. For instance, the sugar industries produce wastes and by products which can cause PAHs emission and environmental contamination in addition to activities related to rapid urbanization that is being observed within the catchment. This study presents a report on sources and distribution of PAHs levels in sugarcane by products waste, sediments, water and soils within the River Nzoia catchment area. Soil and sediment samples were extracted by soxhlet extraction using dichloro-methane and with C-18 catridges. Analyte separation and identification was done by GC-MS. Fourteen PAHs were detected with concentration ranges of; 0.6 μg/L - 80 μg/L for water, 0.01 μg/kg - 1200 μg/kg for soils and 0.13 μg/kg - 19.6 μg/kg for sediments. Bagasse waste had PAHs concentrations in the range of 0.4 - 14 μg/kg, and filter cake in the range of 1.7 - 30 μg/kg. Boiler waters reported the presence of 8 PAHs. The ratio of concentrations of PAHs in boiler water, filter cake and bagasse waste to the soils and water samples within the vicinity to the sugar processing companies did not indicate a point source of contamination; rather it pointed to diffuse sources. The same results were observed for water and sediment samples obtained in the vicinity of waste dumpsite. Variation of PAHs concentrations from sugar manufacturing processes corresponded to the kind and conditions of the processes. Lower molecular weight PAHs dominated in water sample. The presense of benz: 1) pyrene, benz 2) flourancene and Indeno(123,cd)pyrene in both water and sludge soils are of concern since this water is abstracted for domestic use, while sludge soil is used as fertilizer in agricultural farms. Although the levels of PAHs obtained in this study were below the established environment and human health safefty limits, the results underscore the need for mornitoring levels and determining potential sources for PAHs in the environment.
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 heavy metals in benthic macroinvertebrates, water and sediments in River Isiukhu, Kenya
(Springer, 2019-10-16) Oremo, Jane; Orata, Francis; Owino, Joseph; Shivoga, William
A major ecological challenge facing freshwater resources such as rivers is the influx of chemical contaminants from anthropogenic sources. A report on the levels of heavy metals, namely Zn, Cu, Cr, Cd and Pb in benthic macroinvertebrates, sediments and water along River Isiukhu, within Lake Victoria catchment area in Kenya is presented. Families of benthic macroinvertebrates that were investigated included Gerridae, Baetidae and Unionidae. Samples were digested using the appropriate acid combination and analysed using Spectra AAS Varian 200. Physicochemical parameters were measured on-site using mobile Hydrolab Quanta. Pearson’s correlation matrix and post hoc Tukey’s test were used to show the relationship between metal concentrations in the various matrices at significant differences accepted at p ≤ 0.05. Positive correlations were obtained for heavy metal concentrations in sediments and benthic macroinvertebrates with significant correlations observed for Zn (r = 0.655, p = 0.029) and Cu (r = 0.641, p = 0.034). Sediments presented the highest range of heavy metal concentrations compared to water and benthic macroinvertebrates and presented the only matrix with quantifiable Pb levels. The range in heavy metal concentration in benthic macroinvertebrates samples were as follows: Zn, 30.73–46.64, 21.93–38.17, and 26.85–41.69 mg/kg, Cu, 1.17–6.54, 1.11–3.87 and 1.15–5.79 mg/kg, Cr, 0.47–1.61, 0.22–0.74 and 0.25–0.92 mg/kg, for families Unionidae, Baetidae and Gerridae respectively. Heavy metal concentration profile along the river indicated an influx of pollutants from anthropogenic sources due to rapid urbanization along the river.

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