Browsing by Author "Shimels, Kebede (PhD)"

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    Investigation on Recycling of Waste Beer Label Paper
    (Addis Ababa University, 2020-02) Eden, Amdebirhan; Shimels, Kebede (PhD)
    The solid wastes generated from beer industries during beer packaging in which each bottle has to be labeled with a paper then turned to wastes after usage. In this study repulping of waste beer label paper was carried out by repulping Heniken‘s waste beer label and blended it with used A4 sized paper found in AAiT. The study was conducted under different conditions with the influence of mixing ratio (0, 25 and 50 %), drying temperature (100,110 and 120 0 C) and drying time (60, 90 and 120 min) on repulp yield properties. Results indicated that mixing ratio and drying time had a significant influence on repulp yield. Likewise the optimum result with respect to yield was obtained by 50% mixing ratio, 120 0 C drying temperature and 120 min drying time. At the optimum operating conditions the physical tests of hand sheets made from repulping of mixed beer label paper was carried out at Ethiopian Pulp and Paper Factory resulting 66.3 Nm/g, 6.26 mNm 2 /g and 5.421 kN/g tensile index , tear index and burst index respectively.. In general, results based on morphological and repuling analysis indicated that wasted beer label fibers are promising fibrous raw material for the paper production and have tremendous results for environmental challenges in the brewing industries.
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    Removal of Methylene Blue Dye Using Titanium Dioxide Photocatalyst
    (Addis Ababa University, 2018-06) Tigabu, Halefom; Shimels, Kebede (PhD)
    The application of dyes in different process industries will cause environmental impact. Thus, the need for removal of dyes using an Advanced oxidation process is a vital issue to decrease the effect of dyes. An Advanced oxidation process works based on the generation of hydroxyl radicals as an intermediate to takes place the photocatalytic process under UV irradiation. Titanium dioxide was used in the photocatalytic decolorization study of a dye i.e., methylene blue (MB). During Usage of this semiconductor as a photocatalyst for removal of dye, physiochemical characteristics of the photocatalyst, the effect of the various process parameters like initial dye concentration, catalyst loading, and UV irradiation time on the photodegradation of MB were investigated using surface Response methodology. We obtain that the photocatalyst material has anatase composition of 100%, the specific surface area 55.64 m 2 /g and crystallite size of 39.93 nm respectively. In addition to this, analysis on degradation of methylene blue (MB) as an organic dye pollutant upon photocatalytic oxidation of TiO 2 nanoparticles under UV-light (393 nm) irradiation was optimized. According to analysis of variance numerical optimization 94.89 % removal efficiency were predicted through adjusting the selected parameters under specified or bounded conditions. Furthermore, the rate of dye degradation (reaction) kinetics were also studied. The result indicates from first order Languier-Hinshewood kinetics model, is good fitting with regression coefficient of 97.93 %.