Browsing by Author "Kitalika, Aldo"

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Assessment of water quality variation in rivers through comparative index technique and its reliability for decision making
(Tanzania Journal of Science, 2018) Kitalika, Aldo; Machunda, Revocatus; Komakech, Hans; Njau, Karoli
The National Sanitation Foundation (NSF) and Weighed Arithmetic Index (WAI) methods for water quality index (WQI) have been studied to evaluate their reliability in water quality assessment in rivers. Water samples were collected in various GPS predetermined points in Temi, Nduruma, Tengeru and Maji ya Chai rivers-Tanzania during wet and dry seasons and were analyzed for several water quality parameters using standard methods as per APHA. Medium to excellent water qualities were observed for pristine environment in three rivers except Maji ya Chai under NSF and WIA methods, respectively. Excellent water quality was observed in the pristine environment of Temi and Tengeru rivers during wet season. Maji ya Chai water was identified unsuitable for drinking throughout the year. Fecal Coliforms (FC), Nutrients content, BOD and Fluorides (F- ) were the major contributors to the poor water quality in Maji ya Chai whereas FC and Nutrients were a serious problem in flood-plain for other rivers. The two methods showed different overall Water Quality Indices using the same data thus, making them unreliable tools for water quality assessment when used simultaneously for the same purpose. Therefore selection of the method for water quality assessment and decision making may depend on the water use.
Fluoride Variations in Rivers on the Slopes of Mount Meru in Tanzania
(Hindawi, 2018-01-23) Kitalika, Aldo; Machunda, Revocatus; Komakech, Hans; Njau, Karoli
This study reports the variations of fluoride ions in rivers on the slopes of Mount Meru in the northern part of Tanzania. More than 318 water samples were collected from Temi, Nduruma, Tengeru, andMaji ya Chai Rivers in both wet (mid-March and April) and dry (August) seasons. The samples were analyzed for fluoride levels using Ion Selective Electrode (ISE). The minimum and maximum average fluoride levels in the wet season were 0.24 ± 0.03 mg/l and 65.20 ± 0.03mg/l, respectively, whereas the average lowest and highest levels in the dry season were 1.02 ± 0.02 mg/l and 69.01 ± 0.03mg/l, respectively. Tengeru River had the lowest fluoride levels in both seasons, whereasMaji ya Chai recorded the highest fluoride levels in both seasons.Theheadwater of all rivers with the exception of Maji ya Chai met theWorld Health Organization’s (WHO) maximum acceptable fluoride levels of 1.50mg/l and the downstream environment qualified for Tanzania Bureau of Standards (TBS) maximum permissible fluoride concentration in drinking water of 4.00mg/l. Also, the laboratory experiments showed that fluoride containing rocks exposed to pH above 7.6 display high leaching of F− in solution which gradually increased with the increase in pH, indicating that dissolution of fluoride in water is a function of pH.
Fluoride Variations in Rivers on the Slopes of Mount Meru in Tanzania
(Hindawi, 2018-01-23) Kitalika, Aldo; Machunda, Revocatus; Komakech, Hans; Njau, Karoli
This study reports the variations of fluoride ions in rivers on the slopes of Mount Meru in the northern part of Tanzania. More than 318 water samples were collected from Temi, Nduruma, Tengeru, and Maji ya Chai Rivers in both wet (mid-March and April) and dry (August) seasons. The samples were analyzed for fluoride levels using Ion Selective Electrode (ISE). The minimum and maximum average fluoride levels in the wet season were mg/l and mg/l, respectively, whereas the average lowest and highest levels in the dry season were mg/l and mg/l, respectively. Tengeru River had the lowest fluoride levels in both seasons, whereas Maji ya Chai recorded the highest fluoride levels in both seasons. The headwater of all rivers with the exception of Maji ya Chai met the World Health Organization’s (WHO) maximum acceptable fluoride levels of 1.50 mg/l and the downstream environment qualified for Tanzania Bureau of Standards (TBS) maximum permissible fluoride concentration in drinking water of 4.00 mg/l. Also, the laboratory experiments showed that fluoride containing rocks exposed to pH above 7.6 display high leaching of F− in solution which gradually increased with the increase in pH, indicating that dissolution of fluoride in water is a function of pH.
Land use change and temporal water quality dynamics on the slopes of mount Meru
(NM-AIST, 2020-09) Kitalika, Aldo
This work reports on the results obtained following the study on the land use change and temporal water quality change in rivers of the slopes of Mount Meru in Northern Tanzania between 2015 and 2016. Satellite images collected from United States Geological Survey (USGS) were used to model the land use change using ArcGIS and IDRISI software. Also, 419 water samples and two (2) rocks samples were collected from various geo-referenced points and assessed for sixteen (16) water quality changes using standard methods for water and wastewater from American Public and Health Association (APHA). The stable isotope studies were done at the University of Waterloo stable isotopes laboratory using the Los Gatos Research Laser processes analyzer with Integrated Cavity Output Spectroscopy (LGRICOS™). The study showed significant land use changes in the area in every ten (10) years over a period of thirty (30) years such that, there is an increase in human settlement from 74.2 km 2 (1986) to 261.2 km 2 (2016), decrease in agricultural land from 545.8 km 2 to 531.5 km 2 (2016). Also, in similar years the bush-land decreased from 372.3 km 2 (1986) to 158.4 km 2 (2016) in favour of increase of settlement. Moreover, the mixed forest were improved from 139.7 km 2 (1986) to 116.0 km 2 (2016) whereas the water bodies decreased significantly from 14.0 km 2 (1986) to 4.2 km 2 (2016). In addition, the water quality in rivers deteriorated due to increased human activities, poor performing Wastewater Treatment Systems (WTS) which discharge its effluents in rivers, and bad agricultural practices. Few sampling points in rivers had Biochemical Oxygen Demand (BOD), NO 3  and Total Soluble Phosphate (TSP) levels higher than the World Health Organization (WHO) standards of 10 mg/L, 50 mg/L and 0.1 mg/L, respectively. Fluoride contamination in Themi, Nduruma and Tengeru Rivers were within the WHO and Tanzania Bureau of Standards (TBS) maximum acceptable limits of 1.5 mg/L and 4.0 mg/L, respectively. Maji ya Chai River showed the highest levels of fluorides and dissolved organic matter of up to 69.01 ± 0.03 mg/L and 10 ± 0.2 mg/L, respectively, which are higher than the WHO standards. The study confirmed the main source of fluorides in water is rocks containing fluoride in which its leaching is favoured in alkaline environment. Also the stable isotopes studies revealed the origin of Dissolved Organic Matter (DOM) were plant materials and soil composites whereas NO 3  originated from wastewater, urea fertilizers, and animal manures. The major sources for coloured dissolved organic matter and fluoride contents in Maji ya Chai River were discovered at Kirurumu hill (M1) and Jamera (M2), respectively.
Land-Use and Land Cover Changes on the Slopes of Mount Meru-Tanzania
(Current World Environment, 2018-12) Kitalika, Aldo; Machunda, Revocatus; Komakech, Hans; Njau, Karoli
Environmental transitions analysis was done in part of the land on the slopes of the foothills of Mount Meru in thirty (30) years’ time from 1986 to 2016 using satellite-derived land use/cover maps and a Cellular Automata (CA) spatial filter under IDRISI software environment and assessed the important land use changes. Also, the future land use for 2026 which is the next ten (10) years was simulated based on Cellular-Automata Markov model. The results showed significant land use transitions whereby there is a huge land use change of bush land (BL) and agriculture land (AG) into human settlement (ST) which resulted into conversion of Arusha town into a City. In addition, the changes have caused slight changes in water bodies into mixed forest. Moreover, the future land use/land cover (LULC) simulations indicated that there will be unsustainable LULC changes in the next ten years since most of bush land and part of agriculture land will be used for building different structures thus interfering with fresh water sources and food availability in the City. These changes call upon the relevant planning authorities to put in place the best strategies for good urban development.
Physicochemical and Microbiological Variations in Rivers on the Foothills of Mount Meru, Tanzania.
(International Journal of Scientific & Engineering Research, 2017-09-09) Kitalika, Aldo; Machunda, Revocatus; Komakech, Hans; Njau, Karoli
Little is known on the physicochemical and microbiological changes in Nduruma, Tengeru and Maji ya Chai Rivers. Such important variations were studied during wet and dry seasons in 2015. Water samples from various predetermined points of the rivers were analyzed for major physicochemical and microbial contents using APHA standard methods. Pollution levels in Tengeru River were lower than those of Nduruma and Maji ya Chai Rivers. The fecal coliforms were found in all water samples whereas other parameters were found to be within the WHO maximum permissible limits in most samples. Few samples had BOD, nitrates and total soluble phosphates levels higher than the WHO of 10 mg/l, 50 mg/l and 0.1 mg/l, respectively. Most areas in wet season recorded COD levels higher than the WHO recommended values of 10 mg/l. Few areas in the dry season had EC of up to 1722 µS/cm which is above the WHO maximum recommended level of 500-1500 µS/cm. The stable isotopes studies in water samples revealed sources of DOC in Nduruma River was from plant materials and soil composite with its nitrates being mainly from urea fertilizers applied by farmers. Ground water was the main source of DOC in headwater of Tengeru while manure was its main source in the floodplain with its nitrates originating from animal manure.DOC in Maji ya Chai River originated from plant materials whereas the nitrates was from wild animal manure. The observed severe degradations of the riparian environment of the rivers call upon immediate rehabilitation measures
Sources of Nitrate in Ground Water Aquifers of the Semiarid Region of Tanzania
(Hindawi, 2021) Alex, Rita; Kitalika, Aldo; Mogusu, Emmanuel; Njau, Karoli
Nitrate isotopic values are often used as a tool to identify sources of nitrate in order to effectively manage ground water quality. In this study, the concentrations of NO3−, NO2−, and NH4+ from 50 boreholes and shallow wells in the Singida and Manyoni Districts were analyzed during the dry and wet seasons, followed by identification of nitrate sources using the hydrochemical method (NO3−/Cl−) and stable isotope (δ15N and δ18O) techniques. Results showed that NO2− and NH4+ concentrations were very low in both seasons due to the nitrification process. The concentrations of NO3− ranged from 2.4 ppm to 929.6 ppm with mean values of , during the dry season and from 2.4 ppm to 1620.0 ppm with mean values of , during the wet season. The higher NO3− contamination observed in the wet season could be due to rainfall which accelerated the surface runoff that collects different materials from various settings into the ground water sources. Nitrate source identification through hydrochemical technique revealed that most nitrates originated from sewage effluents and/or organic wastes such as manure. Likewise, the mean values of δ15N-NO3− ( and ) and the mean values of δ18O-NO3−( and ) suggest that 80% of boreholes and 52% of shallow wells were dominated with nitrate from sewage effluents and/or manure as most ground water sources were situated in densely populated areas with congested and poorly constructed onsite sanitation facilities such as pit latrines and manure. Therefore, to reduce nitrate pollution in the study area, a central sewer must be constructed to treat the discharged wastes. Also, groundwater harvesting should consider the proper principles for groundwater harvesting recommended by the respective authority to minimize chances of contamination and hence prevention of health risk