Masters Degree Dissertations

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12504/470

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Browsing Masters Degree Dissertations by Subject "Environmental aspects"

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    Occurrence and ecological risk assessment of the selected residual active pharmaceutical ingredients in the Kinawataka channel – Uganda
    (Kyambogo University (Unpublished work), 2025-10) Ndyabahika, Aggrey
    Kinawataka channel, its streams and wetland is an important ecosystem that plays a vital role as a drainage system in the Eastern part of Kampala City, the capital of Uganda. The pollution and floods from the surrounding environment are taken through a series of natural treatment which improves the quality of water entering in Lake Victoria Basin. The presence of 7 residual Active Pharmaceutical Ingredients (APIs), comprising of 5 antibiotics, 1 non-steroidal antiinflammatory (NSAID) and 1 analgesic and antipyretic drugs, was analyzed in thirty-three (33) water specimens obtained from the Kinawataka channel, 2 streams, and a wetland to investigate the potential ecological risk posed by these residual APIs to aquatic life in this ecosystem. Random grab samples collected into the sampling bottles previously well cleaned and soaked in distilled water over night, were refrigerated in an ice box (preferably 2-8 ºC) and then transported to the Directorate of Government Analytical Laboratories (DGAL) for analysis. Solid phase extraction was used for sample extraction and residual APIs analysis was done with the help of high-performance liquid chromatographyconnected to a mass spectrometer and their Risk Quotients (RQ) calculated. Only six (6) residual APIs, Amoxicillin (0.82-607.86), Erythromycin (0.0-3431.87), Ciprofloxacin (0.0-79.17), Sulfamethoxazole (0.0-987.16), Oxytetracycline (0.0- 5.34) and Paracetamol (0.09-1070.20) were detected at quantifiable concentrations (ng/l). The highest concentrations of residual APIs were erythromycin (0.0-3431.87), Sulfamethoxazole (0.0-987.16) and paracetamol (0.09-1070.20). The most contaminated sampling compartments were Jamaica and Kawooya streams, the main recipients of Pharmaceutical Manufacturing Facility (PMF) waste water. This study also revealed that the detected residual APIs posed high, moderate and low ecological risks, where Erythromycin and Sulfamethoxazole (RQ=1.92, RQ=1.12 respectively) showed a high risk suggesting a huge threat to aquatic organisms in the Kinawataka channel, Amoxicillin (RQ=0.54) also posed a moderate risk whereas Ciprofloxacin, Oxytetracycline, and paracetamol (RQ=0.02, RQ=0.01, RQ=0.06 respectively) pose a low risk. Overall, residual APIs especially Erythromycin and Sulfamethoxazole were detected in high concentrations hence posing significant ecological risks in the Kinawataka channel. This being the first study to report the residual APIs pollution in the Kinawataka channel, policy makers should priotize implementing targeted measures that reduce pollutant levels especially in the streams by adhering to the polluter pays principle, enforcing regulations on industries, imposing fines on environmental pollution and promoting sustainable practices to prevent future contamination.
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    Potential of selected plant species for phytoremediation of heavy metals in soil, and wastewater sediment from Nakivubo wetland, Uganda
    (Kyambogo University (Unpublished work), 2025-06) Akatukunda, Roselyne
    Heavy metal pollution from industrial effluent has posed serious impacts on both humans and the environment. Several methods including chemical, biological, physical, and integrative approaches have been used to eliminate this kind of pollution. The study was conducted in Nakivubo wetland, Uganda, to assess the potential of phytoremediation as an eco-friendly and cost-effective method for removing heavy metals [Lead (Pb), Cadmium (Cd), Copper (Cu), and Arsenic (As)] from contaminated soil and wastewater sediments. Four plant species (Commelina benghalensis, Pennisetum purpureum, Sida acuta, and Cynodon dactylon) were analysed for their metal accumulation efficiency. Soil and wastewater sediment samples from four sites were analysed using Atomic Absorption Spectrophotometry (AAS). Results showed significant contamination, with Pb (4.66 - 83.49 mg/kg), Cd (0.65 - 1.49 mg/kg), Cu (5.64 - 52.09 mg/kg), and trace amounts of As (0.00 - 1.24 mg/kg) in soil, while wastewater sediments contained Pb (52.33 - 90.49 mg/kg), Cd (0.96 - 1.24 mg/kg), Cu (26.29 - 47.59 mg/kg), and As (0.08 - 0.28 mg/kg). All selected plant species effectively accumulated heavy metals. From soil, C. benghalensis was most efficient at accumulating Pb (39.82%) and Cd (171.3%), while C. dactylon was most effective for Cu (155.17%) and As (50.30%). In wastewater sediments, C. dactylon exhibited the highest Cu (137.51%) and As (116.83%) uptake, while C. benghalensis was most efficient for Pb (36.74%) and Cd (225.48%). High percentages of heavy metals in specific plants could have accumulated over time. Statistical analysis (p < 0.05) confirmed significant differences in metal accumulation. The Bio-concentration Factor, Translocation Factor, and Biological Absorption Coefficient values >1 indicated successful heavy metal uptake. C. benghalensis, P. purpureum, S. acuta, and C. dactylon are therefore effective phytoremediators and can be utilised for heavy metal cleanup in soil and wetlands.