Browsing by Author "Kirabira, J. B."

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    Characterisation And Evaluation Of Pulp And Paper From Selected Ugandan Grasses For Paper Industry
    (Cellulose Chemistry and Technology, 2016) Kamoga, Omar L. M.; Kirabira, J. B.; Byaruhanga, J. K.; Godiyal, R. D.; Anupam, Kumar
    Non-wood fibrous materials and recycled fibres offer an opportunity to decrease or replace the use of wood fibres in the production of pulp and paper in countries with insufficient forest resources. The aim of this study was to characterise and evaluate the pulp and paper derived from four Ugandan grasses, namely Cymbopogon nardus, Paspalum notatum, Saccharum officinarum, and Digitaria scalarum, obtained using Soda-AQ and Kraft pulping methods for their potential use in the paper industry. The fibre morphology, as well as the physical properties, of both pulp and handmade paper sheets was analysed. The pulp and paper were identified with reasonable yield, medium viscosity, high bleachability, short and narrow fibres, and moderate paper strength. Saccharum officinarum pulp was characterised with high weighted average fibre length (1.143 mm), moderately high fibre width (18 μm), slenderness ratio (68), brightness (71.27%) and low kappa number (11.9); and the paper sheets with a tear index of 7.05 mNm2/g, while Cymbopogon nardus pulp was characterised with higher yield (44.20%), viscosity (915 cm3/g), low kinked fibre (20%) and curl (6%). The pulps from the two grasses superseded the others. Nevertheless, all the four grasses were recommended for pulp and paper production.
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    Mesoporous activated carbon yielded from pre‑leached cassava peels
    (Bioresources and Bioprocessing, 2021) Kayiwa, R.; Kasedde, H.; Lubwama, M.; Kirabira, J. B.
    The search for alternatives to fossil-based commercial activated carbon (AC) continues to reveal new eco-friendly potential precursors, among which is agricultural waste. The key research aspect in all these endeavors is empirical ascertainment of the core properties of the resultant AC to suit a particular purpose. These properties include: yield, surface area, pore volume, and the active surface groups. It is therefore pertinent to have process conditions controlled and tailored towards these properties for the required resultant AC. Pre-leaching cassava peels with NaOH followed by KOH activation and carbonization at holding temperatures (780 °C) above the melting point of K (760 °C) yielded mesoporous activated carbon with the highest surface area ever reported for cassava peel-based AC. The carbonization temperatures were between 480 and 780 °C in an activation–carbonization stepwise process using KOH as the activator at a KOH:peel ratio of 5:2 (mass basis). A 42% maximum yield of AC was realized along with a total pore volume of 0.756 cm3g− 1 and BET surface area of 1684 m2g− 1. The AC was dominantly microporous for carbonization temperatures below 780 °C, but a remarkable increase in mesopore volume (0.471 cm3g− 1) relative to the micropore volume (0.281 cm3g− 1) was observed at 780 °C. The Fourier transform infrared (FTIR) spectroscopy for the pre-treated cassava peels showed distortion in the C–H bonding depicting possible elaboration of more lignin from cellulose disruption by NaOH. A carboxylate stretch was also observed owing to the reaction of Na+ ions with the carboxyl group in the raw peels. FTIR showed possible absorption bands for the AC between 1425 and 1712 cm− 1 wave numbers. Besides the botanical qualities of the cassava peel genotype used, pre-leaching the peels and also increasing holding activation temperature above the boiling point of potassium enabled the modified process of producing highly porous AC from cassava peel. The scanning electron microscope (SEM) and transmission electron microscope (TEM) imaging showed well-developed hexagonal pores in the resultant AC and intercalated K profile in the carbon matrices, respectively.
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    Occurrence and toxicological assessment of selected active pharmaceutical ingredients in effluents of pharmaceutical manufacturing plants and wastewater treatment plants in Kampala, Uganda
    (Water Practice & Technology, 2022) Kayiwa, R.; Kasedde, H.; Lubwama, M.; Kirabira, J. B.; Kayondo, Timothy
    There is an increasing eco-toxicological risk associated with pharmaceuticals globally. The prevalence of six active pharmaceutical ingredients (APIs) was studied in effluents of three pharmaceutical manufacturing plants (PMPs) and two wastewater treatment plants (WWTPs) in Kampala, Uganda to ascertain the removal potentials for APIs. The APIs include atenolol, losartan, carbamazepine, sulfamethoxazole, clarithromycin, and diclofenac. The APIs were extracted using solid-phase extraction cartridges and concentrations were analyzed using a liquid chromatography-mass spectrometer system. The concentration ranges of the APIs were
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    The Potential of Cymbopogon nardus in the Production of Pulp for Paper Industry
    (Singapore, 2015) Kamoga, Omar L. M.; Kirabira, J. B.; Byaruhanga, J. K.
    Cymbopogon nardus believed to contain cellulosic fibres has been proposed to be a potential source of pulp for paper industry with less environmental degradation threat. This study involved characterisation of Cymbopogon nardus as a new potential raw material, identifying the appropriate pulping techniques and conditions as well as characterisation and evaluation of the pulp and paper made. Norman and Jenkins‘s methods as well as the standard TAPPI methods were used to determine the chemical composition. Soda and Kraft pulping techniques were studied at varied temperature and chemical charges. It contained high hollocellulose, α-Cellulose; and moderately low extractives, ash content and lignin Content. The pulp yield of 42.82% at a kappa number of 24.4 was achieved with soda pulping at soda charge of 25%, at160oC and in one hour. A yield of 45.79% at a kappa number of 31.2 was achieved with Kraft pulping at 30 % sulphidity, 20% active alkalis, at the same time and temperature. The isolated pulp contained moderate fibre length (0.771mm), fibre width (14.4μm), slenderness ratio (51.67), a brightness (69.65%); and paper sheets with a tear index (6.44m Nm2/g). Properties of Cymbopogon nardus as a raw material, pulp and paper were very closer to those of other non-wood materials. Cymbopogon nardus stands a potential source of pulp for paper industry.