Browsing by Author "Alex, Saturday"
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Item Open Access Analysis of Bacteriological Quality of Domestic Water Sources in Kabale Municipality, Western Uganda(Scientific Research Publishing Inc., 2019) Alex, Saturday; Johnson, RunyonyoziIn the present study, we assessed the bacteriological quality of water of drinking water sources in Kabale Municipality. A total of 28 water samples were collected from 14 water springs during the dry and wet season and analyzed for determination of Escherichia coli (E. coli), and Total Heterotrophic Bacteria (THB) using the membrane filtration method. Most water springs located in less than 20 meters away from residential areas were associated with bacterial contamination. The mean concentrations of E. coli, total coliforms, and THB were 24.07 CFU/100 ml, 85.71 CFU/100 ml, and 197.07 CFU/100 ml, respectively in the wet season. While in the dry season, the mean concentrations were 2 CFU/100 ml, 10 CFU/100 ml, and 91 CFU/100 ml for E. coli , total coliforms, and THB, respectively. There were significant differences between CFU of total coliforms, HTB, between wet and dry seasons (p = 0.026). Samples collected and analyzed during the wet season for total coliforms did not conform to WHO drinking water quality guideline value of no detection per 100 ml. The study concludes that the majority of spring water sources are located in less than 20 meters away from residential areas with significant paved areas, the presence of septic tanks and pit latrines. Wet season significantly affects the quality of domestic water sources than the dry season. The study recommends that spring water should be treated before drinking due to high bacteria concentrations which makes it unsafe for consumption.Item Open Access Household Water Treatment Technologies for Microbial Removal in Kabale District, Southwestern Uganda(OMMEGA Publishers, 2016) Alex, Saturday; George Lukoye Makokha; Anthony MachariaHealth problems associated with the consumption of untreated drinking water is one of the greatest concerns in Kabale District in spite of government’s efforts to provide safe drinking water to the people. The objective of the study was to examine household water treatment technologies (HWTS) and evaluate their ability to improve the microbial quality of drinking water. We analyzed 20 paired samples (source and treated) of drinking water from four sources of drinking water in close proximity to homesteads. Samples were analyzed for total coliforms and Escherichia coli, the indicators of faecal contamination, to measure effectiveness of HWTS. The parameters were determined using membrane filtration method. Laboratory data was statistically analyzed using one way ANOVA from SPSS software version 17.0. All HWTS improved the microbial quality of drinking water under laboratory conditions. Mean log10 total coliforms reductions were 2 log10 (99.5%) for boiling, 0.9 log10 (84.8%) for biosand filtration, 1.9 log10 (99.5%) for application of Water Guard tablets and 2 log10 (98.1%) for application of aqua safe tablets. The mean log10 Escherichia coli reductions were 1.2 log10 (100%) for boiling, bio sand filtration, application of Water Guard tablets and application of aqua safe tablets. The microbial removal effectiveness of HWTS was significantly high and the differences in the mean total coliforms reductions by different HWTS were statistically significant (P < 0.05). Water Guard, bio sand filtration, boiling and aqua safe tablets significantly remove total coliforms and Escherichia coli and should therefore is promoted at local level.Item Open Access Mercury and its Associated Impacts on Environment and Human Health: A Review(Omega Publishers, 2018) Alex, SaturdayMercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or its compounds resulting in various toxic effects depending on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg) is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. Mercury has profound neurological, endocrine, reproductive, and fetotoxicity effects. Although most countries recognize the need to combat mercury pollution, controls are either nonexistence or inadequate. Based on articles reviewed, we recommend community education on need for a reduction in use of products that contain mercury. Dentists should reduce or eliminate the use of mercury amalgam and use pre-encapsulated amalgam instead of mixing their own if they are to continue using amalgam. Environment management agencies should expand existing national research on environmental and health effects of mercury.Item Open Access Modelling nitrogen transformation in the Lake Bunyonyi ecosystem, South‑Western Uganda(Applied Water Science, 2022) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Pamba, SiajaliLake Bunyonyi is one of the major resources of social-economic potential in the districts of Rubanda and Kabale, South- Western Uganda. The lake’s sub-catchment faces environmental problems because of intensive agriculture, settlement, business and tourism activities, which consequently cause pollution of water in the lake’s system. This study, therefore, intended to determine the processes that govern nitrogen dynamism using a numerical model that takes into account various processes in the system using STELLA® 8.1.1 software. From the model simulation, it was found that mineralization, microbial uptake and nitrification were the major processes governing nitrogen transformation in the water phase, accounting for 47.8% (0.49 g/d m−2), 44.2% (0.45 g/d m−2), and 7.8% (0.05 g/d m−2), respectively. The developed model predicted reasonably well the behaviour of the lake evidenced by the validation results of observed and simulated data that showedgood linear regression coefficients (R2) of organic nitrogen (0.48), ammonia–nitrogen (0.68), and nitrate–nitrogen (0.61). The model has proven suitable for application on lakes with characteristics similar to that of Lake Bunyonyi. The study recommended that a compressive investigation that puts into consideration all the possible sources of nutrient and water inflow into the lake system be done on Lake Bunyonyi.Item Open Access Modelling nitrogen transformation in the Lake Bunyonyi ecosystem, South‑Western Uganda(Springer, 2022) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Siajali, PambaLake Bunyonyi is one of the major resources of social-economic potential in the districts of Rubanda and Kabale, South- Western Uganda. The lake’s sub-catchment faces environmental problems because of intensive agriculture, settlement, business and tourism activities, which consequently cause pollution of water in the lake’s system. This study, therefore, intended to determine the processes that govern nitrogen dynamism using a numerical model that takes into account various processes in the system using STELLA® 8.1.1 software. From the model simulation, it was found that mineralization, microbial uptake and nitrification were the major processes governing nitrogen transformation in the water phase, accounting for 47.8% (0.49 g/d m−2), 44.2% (0.45 g/d m−2), and 7.8% (0.05 g/d m−2), respectively. The developed model predicted reasonably well the behaviour of the lake evidenced by the validation results of observed and simulated data that showed good linear regression coefficients (R2) of organic nitrogen (0.48), ammonia–nitrogen (0.68), and nitrate–nitrogen (0.61). The model has proven suitable for application on lakes with characteristics similar to that of Lake Bunyonyi. The study recommended that a compressive investigation that puts into consideration all the possible sources of nutrient and water inflow into the lake system be done on Lake Bunyonyi.Item Open Access Performance of Household Water Treatment Methods for Microbial Removal under Household Conditions in Kabale District, Uganda(Omega Publishers, 2016) Alex, Saturday; George Lukoye Makokha; Anthony MachariaDespite the Ugandan government efforts to improve access to safe water sources, the rate at which diseases spread as a result of unsafe drinking water is absolutely high. The purpose the study was to assess the performance of household water treatment methods (HWT) and evaluate their ability to improve the microbial quality of drinking water under household conditions in Kabale District. We randomly selected 205 households, where we collected treated and untreated water samples. We analyzed 46 paired samples (untreated and treated) of drinking water from 46 households that reported treated water available. Samples were analyzed for total coliforms and Escherichia coli, the major indicators of biological contamination of drinking water, to measure effectiveness of treatment under household conditions. All reported HWT did not significantly improve the microbial quality of drinking water. Mean log10 total coliforms removal were 0.7 log10 (40.1%) for boiling method, 0.2 log10 (23.7%) for biosand filtration method, -0.01log10 (-18.1%) for let it stand and settle method and 0.1 log10 (16%) for application of aqua safe tablets. In addition, mean log10 Escherichia coli removal were 0.7 log10 (-22.6) for boiling method, 0.3log10 (37.5%) for biosand filtration method, -0.4 log10 (-200%) for let it stand and settle method and 0.6 log10 (50%) for application of aqua safe. The microbiological quality of stored treated drinking water was significantly low. The government should sensitize the local people on safe storage of drinking water.Item Open Access Restoration of Degraded Agricultural Land(Ommega Publishers, 2018-09-26) Alex, SaturdayRestoration of agricultural land is important for sustainability of agriculture and environment. Land is under immense pressure due to ever increasing population thereby ensuing growing demand for food, fiber and shelter. Agricultural land is being deteriorated due to different anthropogenic and natural factors. The basic factors causing soil erosion- induced degradation are wind and water erosion. Acidification, compaction and salinization are some other causes of agricultural land degradation. The main causes of erosion on agricultural land are intensive cultivation, overgrazing, poor management of arable soils and deforestation. Restoration of eroded agricultural land is achieved through several agronomic and biological techniques. Crop rotations, agro-forestry, reduced tillage, cover crops, vegetative filter strips, residue, and no-till are important among these. Biological measures such as buffers, conditioner application in direct contact with the soil surface, crop residues using manure protect the soil from erosion. Restoration of saline agricultural land can be achieved through recharge stabilization and reconstruction of saline land through fencing, retain remnant vegetation, revegetation, runoff interception earthworks, and water table lowering.Item Open Access Spatial and temporal variations of faecal indicator bacteria in Lake Bunyonyi, South‑Western Uganda(SN Applied Sciences, 2021) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Siajali, PambaBackground Microbial water quality serves to indicate health risks associated with the consumption of contaminated water. Nevertheless, little is known about the microbiological characteristics of water in Lake Bunyonyi. This study was therefore undertaken to examine the spatial and temporal variations of faecal indicator bacteria (FIB) in relation to physicochemical parameters in Lake Bunyonyi. Result The FIB concentration was consistently measured during sampling months and correlated with each other showing the presumed human faecal pollution in the lake. The highest concentration values for E. coli (64.7 ± 47.3 CFU/100 mL) and enterococci (24.6 ± 32.4 CFU/100 mL were obtained in the station close to the Mugyera trading centre. On a temporal basis, the maximum values were recorded during the rainy season in October 2019 (70.7 ± 56.5 CFU/100 mL for E. coli and 38.44 ± 31.8 CFU/100 mL for enterococci. FIB did not differ significantly among the study stations (p > 0.05) but showed significant temporal variations among the months (p < 0.05) with concentrations being significantly high in wet season than dry season (U = 794, p < 0.0001 for E. coli; U = 993.5, p = 0.008 for enterococci). Spearman’s rank correlation revealed that FIB concentrations were significantly positively correlated with turbidity and DO concentration levels (p < 0.05). Approximately 97.2% of the water samples had E. coli and enterococci concentrations levels below USEPA threshold for recreational waters. Likewise, 98.1 and 90.7% of samples recorded E. coli and enterococci counts exceeding the UNBS, APHA, WHO and EU threshold values for drinking water. Conclusion The FIB counts show that the Lake Bunyonyi water is bacteriologically unsuitable for drinking unless it is treated since the FIB pose health risks to consumers. Besides, the water can be used for recreational purposes.Item Open Access Spatial and temporal variations of phytoplankton composition and biomass in Lake Bunyonyi, South‑Western Uganda(Springer, 2022) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Siajali, PambaThe purpose of this study was to examine the spatial and temporal variations of phytoplankton species composition and biomass in Lake Bunyonyi, South-Western Uganda. Samples were collected monthly from nine fixed stations in the lake from October 2019 to September 2020. Based on the morphological characterization, 52 different species of phytoplankton were recorded. These were dominated by cyanobacteria (21 species) and chlorophytes (15 species) followed by diatoms (10 species), euglenophytes (4 species), dinoflagellates (2 species), and cryptophytes (1 species). The biomass (Chl-a concentration) ranged from 0.019 ± 0.009 mg/L at Heissesero station to 0.045 ± 0.013 mg/L obtained at Nyombe station. On a temporal basis, the highest mean Chl-a concentration of 0.044 ± 0.03 mg/L was recorded in March 2020 while the least concentration of 0.015 ± 0.011 mg/L was obtained in September 2020. Significant differences existed in the Chl-a concentration values between stations and across sampling months. Chl-a concentration was significantly positively correlated with dissolved oxygen (DO), turbidity but negatively correlated with temperature. The Shannon–Wiener index and evenness put it clear that the distribution of phytoplankton species in the lake is inequitable. Besides, 94.2% of the phytoplankton species revealed had never been reported by the previous studies in the study area. The dominance of species cyanobacteria (such as Microcystis spp., Cylindrospermopsis raciborskii, Anabaenopsis sp., and Anabaena sp.) presents potential future challenges to water quality management. Therefore, the establishment of a strong and committed committee dubbed “Lake Bunyonyi Water Management Committee” to oversee the activities and avert potential water quality challenges is strongly recommended. The existence of some toxic phytoplankton species calls for regular monitoring and careful use of the lake and its food products.Item Open Access Spatial and temporal variations of trophic state conditions of Lake Bunyonyi, south‑western Uganda(Springer, 2022) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Siajali, PambaThe study was conducted to assess the spatial and temporal variations of the trophic state condition of Lake Bunyonyi between October 2019 and September 2020. Secchi depth (SD), total phosphorus (TP) and chlorophyll-a (Chl-a) concentration were measured to aid the quantification of trophic state condition of the lake using Carlson trophic state index (CTSI). The trophic state index (TSI) values based on SD, TP and Chl-a values were 60.82 ± 5.35, 68.99 ± 11.04 and 61.74 ± 7.51, respectively. March 2020 recorded the highest mean CSTI value (70.14 ± 4.04), while in September 2020, the lowest mean value (58.03 ± 6.22) was obtained. Based on CTSI values, the lake was eutrophic in both dry and wet seasons albeit with differences in the values. The eutrophic state of the lake is possibly attributed to nutrients inflow into the lake via runoff and drainage from farmlands. The negative value of TSI-Chl-a–TSI-TP deviation pointed out that the lake is not phosphorus limited, while the positive TSI-Chl-a–TSI-SD mean deviation value revealed the effect of Chl-a and TP on the lake’s transparency. The study recommends the necessity to develop guidelines for the trophic status monitoring of Lake Bunyonyi since results suggest the deteriorating lake condition.Item Open Access Spatial and temporal variations of trophic state conditions of LakeBunyonyi, south‑western Uganda(Springer, 2022-11-15) Alex, Saturday; Thomas J., Lyimo; John, Machiwa; Siajali, PambaThe study was conducted to assess the spatial and temporal variations of the trophic state condition of Lake Bunyonyibetween October 2019 and September 2020. Secchi depth (SD), total phosphorus (TP) and chlorophyll-a (Chl-a) concentra-tion were measured to aid the quantification of trophic state condition of the lake using Carlson trophic state index (CTSI).The trophic state index (TSI) values based on SD, TP and Chl-a values were 60.82 ± 5.35, 68.99 ± 11.04 and 61.74 ± 7.51,respectively. March 2020 recorded the highest mean CSTI value (70.14 ± 4.04), while in September 2020, the lowest meanvalue (58.03 ± 6.22) was obtained. Based on CTSI values, the lake was eutrophic in both dry and wet seasons albeit withdifferences in the values. The eutrophic state of the lake is possibly attributed to nutrients inflow into the lake via runoffand drainage from farmlands. The negative value of TSI-Chl-a–TSI-TP deviation pointed out that the lake is not phospho-rus limited, while the positive TSI-Chl-a–TSI-SD mean deviation value revealed the effect of Chl-a and TP on the lake’stransparency. The study recommends the necessity to develop guidelines for the trophic status monitoring of Lake Bunyonyisince results suggest the deteriorating lake condition (11) (PDF) Spatial and temporal variations of trophic state conditions of Lake Bunyonyi, south-western Uganda. Available from: https://www.researchgate.net/publication/365402681_Spatial_and_temporal_variations_of_trophic_state_conditions_of_Lake_Bunyonyi_south-western_Uganda [accessed Dec 19, 2022].Item Open Access Spatio‑temporal variations in physicochemical water quality parameters of Lake Bunyonyi, Southwestern Uganda(SN Applied Sciences, 2021) Alex, Saturday; Thomas, J. Lyimo; John, Machiwa; Siajali, PambaThe current study was carried out to examine the spatial and temporal variations of physicochemical water quality parameters of Lake Bunyonyi. The observations were made on the surface water of Lake Bunyonyi for 1 year to determine the water quality. The basic 12 variables used to determine the quality of water were measured monthly at nine stations. Water temperature, dissolved oxygen (DO), turbidity, electric conductivity (EC), pH and Secchi depth (SD) were measured in the field, while parameters like total nitrogen (TN), total phosphorus (TP), nitrite-nitrogen ( NO2-N), nitratenitrogen ( NO3-N), soluble reactive phosphorus (SRP) were determined following APHA 2017 standard guidelines for physicochemical analysis. Taking into account standard guidelines for drinking water by the Uganda National Bureau of Standards (UNBS) and the World Health Organization (WHO), the water quality index (WQI) was used to determine the water quality. Temperature, DO, pH, turbidity and EC did not differ significantly among the study stations (p > 0.05) but showed significant temporal variations among the study months (p < 0.05). Likewise, TN, TP, NO2- N, NO3- N and SRP did not differ significantly among the study stations (p > 0.05) but showed significant temporal variations among the study months (p < 0.05). The WQI values ranged from 28.36 to 49 across and from 28.2 to 56.2 between study months with an overall mean value of 36.9. The measured water quality variables did not exceed the UNBS and WHO standards for drinking water in all months and at all stations. According to these values, the water quality of Lake Bunyonyi generally belongs to the ‘good’ class in terms of drinking water quality based on the WQI classification. The study findings are fundamentally important for policy makers in setting guidelines for effective lake management.