Browsing by Author "Kayiwa, Ronald"

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    Active Pharmaceutical Ingredients Sequestrated fromWater Using Novel Mesoporous Activated Carbon Optimally Prepared from Cassava Peels
    (Water, 2022) Kayiwa, Ronald; Kasedde, Hillary; Lubwama, Michael; Kirabira, John Baptist
    The increasing occurrence of active pharmaceutical ingredients (APIs) in water systems coupled with their recalcitrance to conventional water treatment methods calls for research into more eco-friendly and cost-effective curbing media. Mesoporous cassava peel activated carbon (CPAC) was prepared under conditions derived from optimizing the surface area and yield with the temperature and holding time as the model inputs using the response surface methodology. The sequestration potential and mechanisms of the resultant activated carbon (AC) for active pharmaceutical ingredients from wastewater were studied using batch experiments. The CPAC adsorption kinetics and isothermal mechanisms for the three pharmaceuticals (carbamazepine (CBZ), clarithromycin (CLN), and trimethoprim (TRM)) were studied in both wastewater and Milli-Q water. The API concentrations were measured using liquid chromatography coupled to a mass spectrometer (LC-MS) system. The maximum removal efficiencies were 86.00, 58.00, and 68.50% for CBZ, CLN, and TRM for wastewater, which were less than those from the Milli-Q water at 94.25, 73.50, and 84.5%, respectively. The sorption process for the CLN was better explained by the Freundlich model, whereas the CBZ and TRM adsorption processes could suitably be explained by both the Langmuir and Freundlich models. At an initial concentration of 20 mgL􀀀1 for all APIs and a CPAC dosage of 2.0 gL􀀀1, the maximum adsorption capacities were 25.907, 84.034, and 1.487 mgg􀀀1 for CBZ, TRM, and CLN, respectively. These results demonstrated the potential of CPAC to remove APIs from water, with its sequestration potential being more exhibited after the removal of the organic matter owing to the lower competition for active sites by the APIs. Additionally, positive adsorbates were better removed than negatively charged adsorbates due to the dominance of anions in the cassava peel lattice.
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    Effect of Different Organic Substrates on Reproductive Biology, Growth and Offtake of the African Night Crawler Earthworm (Eudrilus eugeniae)
    (Saly Portudal, Senegal, 2018) Kabi, Fred; Kayima, Denis; Kigozi, Abasi; Mpingirika, Eric Zadok; Kayiwa, Ronald; Okello, Dorothy
    Rapid growth and high fecundity of Eudrilus eugeniae makes it a commercial vermicomposting agent. The worm is also a rich protein source (50-70%CP) in livestock diets. The major question, however, is how do we promote earthworm production as a strategy for ecological livestock intensification and integration with crops through earthworm domestication as a source of protein and vermicompost. Reproduction characteristics, growth and offtake of E. eugeniae were studied using four organic substrates including abattoir waste (AW), cattle manure (CM), soya bean crop residue (SBCR) and a mixture of cattle manure and soya bean crop residue (CM+SBCR) aged 15 days. Irrespective of the substrate, length and biomass of earthworms increased at a decreasing rate between the 1st and 8th weeks. Clitellum appearance was initiated at 31.5±2.4, 32.8±3.2, 33.7±3.3 and 35.5±2.4 days for AW, CM,CM+SBCR and BCR, respectively, while cocoon initiation was at 69.0±1.4 (AW), 54.9±2.3 (CM), 51.7±1.7 (CM+SBCR) and 60.0±2.4 (SBCR) days. Organic substrate used affected reproductive biology,