Browsing by Author "Nkedi-Kizza, Peter"

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    Characterization and Hydrocarbon Identification of Liquid Fuel from Mixed Waste Plastics at Different Heating Time Intervals
    (International Journal of Scientific & Engineering Research, 2016) Kigozi, Moses; Wasswa, John; Ntale, Muhammad; Nkedi-Kizza, Peter
    Mixed waste plastics which included High Density Polyethylene ((HDPE), Low Density Polyethyline (LDPE),Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET) were investigated for production, characterization and hydrocarbon identification of fuel obtained from the plastics by catalytic pyrolysis. Silica-alumina was used as the catalyst. The mixed waste plastics were heatedfor one hour and two hours of contact time. The operation temperatures ranged between 250oC to 370oC giving a yellowish liquid after condensing the vapors with a chiller at 5oC. The reactor was connected to a fractionating column of one meter long and then to the condenser. The production ranged between 58 to 73% liquid, 18 to 34% cake and the rest was estimated as gas. The samples were investigated with different parameters based on diesel standards due to the wide range of hydrocarbon content. The parameters showed acceptable average ranges; cloud point 4oC, flash point 79.4 oC, kinematic viscosity 2.18 mm2/s, sulfated ash 4.7x10-5%, copper strip corrosion 1a, cetane number 63, acid number 72.9 μg and densities of 0.785 g/cm3. The identification of the hydrocarbons showed that the fuel falls into four classes of fuel which include diesel, aviation, naphtha and oil due to the range of hydrocarbons from C8 to C28 when analyzed with GC/MS and named from GC library
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    Organochlorine pesticide residues in sediments from the Uganda side of Lake Victoria
    (Chemosphere, 2011) Wasswa, John; Kiremire, Bernard T.; Nkedi-Kizza, Peter; Mbabazi, Jolocam; Ssebugere, Patrick
    Organochlorine (OC) residues were analysed in 117 sediment samples collected from four bays of the Uganda side of Lake Victoria. The sediments were collected with a corer at a depth of 0–20 cm, and extracted for OC residues using a solid dispersion method. The extracts were cleaned using gel permeation chromatography and analysed for pesticide residues using a gas chromatograph (GC) equipped with an electron capture detector. The results were confirmed using a GC equipped with a mass spectrometer (MS). A total of 16 OC residues, most of them persistent organic pollutants (POPs) were identified and quantified. The OC residue levels were expressed on an oven dry weight (d.w.) basis. Endosulphan sulphate, in the range of 0.82–5.62 lg kg 1 d.w., was the most frequently detected residue. Aldrin and dieldrin were in the ranges of 0.22–15.96 and 0.94–7.18 lg kg 1 d.w., respectively. DDT and its metabolites lay between 0.11–3.59 for p,p0-DDE, 0.38–4.02 for p,p0-DDD, 0.04–1.46 for p,p0-DDT, 0.07–2.72 for o,p0-DDE and 0.01–1.63 lg kg 1 d.w. for o,p0-DDT. The levels of c-HCH varied from 0.05 to 5.48 lg kg 1 d.w. Heptachlor was detected only once at a level of 0.81 lg kg 1 d.w., while its photo-oxidation product, heptachlor epoxide, ranged between non-detectable (ND) to 3.19 lg kg 1 d.w. Chlordane ranged from ND to 0.76 lg kg 1 d.w. Based on the threshold effect concentration (TEC) for fresh water ecosystems, aldrin and dieldrin were the only OCs that seemed to be a threat to the lake environment.