Browsing by Author "Philip, Joseph Yoeza Naimani"
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Item Corrosion Inhibition of Amino Pentadecylphenols (APPs) Derived from Cashew Nut Shell Liquid on Mild Steel in Acidic Medium(Materials Sciences and Applications, 2016-08-05) Philip, Joseph Yoeza Naimani; Buchweishaija, Joseph; Mwakalesi, AlinanusweIn this study, corrosion inhibiting properties of amino pentadecylphenols (APPs) derived from Cashew Nut Shell Liquid (CNSL) on mild steel in aerated 0.10 M HCl at 303 K were studied using Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization measurements. Both methods indicated the potential of a mixture of amino pentadecyphenols to serve as a corrosion inhibitor in mild steel in 0.10 M HCl. Corrosion inhibition efficiencies were observed to increase with increase in the inhibitor concentration, with maximum corrosion inhibition of about 98% at inhibitor concentration of 600 ppm. The adsorption of the inhibitor on mild steel surface was found to obey Temkin adsorption isotherm, signifying physical adsorption of the inhibitor molecules on mild steel surface.Item LEVELS OF HEAVY METALS IN DEPOSITED DUST AND SOIL FROM SELECTED PRIMARY SCHOOLS IN DAR ES SALAAM(Tanzania Journal of Science, 2018) Philip, Joseph Yoeza Naimani; Mkenga, Eliamini Ismail; Othman, Othman ChandeThe objective of this study was to examine the levels of heavy metals, lead, manganese, nickel, copper, chromium and cadmium in standard one and kindergarten classroom dusts and playing ground soils from selected primary schools along Morogoro road highway (Kimara, Mbezi, Kibamba and Kiluvya primary schools) and away from Morogoro road highway (Makabe, Msumi and Mbopo primary schools) as well as in the Dar es Salaam city center (Uhuru, Mzimuni, Dr. Omari Ali Juma, Manzese and Ubungo National House primary schools), Tanzania. The samples were acid digested and the supernatant analyzed using inductively coupled plasma optical emission spectrometer (ICP-OES). The mean concentrations (mg/kg) range of heavy metals in kindergarten and standard one classroom dust samples were bdl – 3.2 ± 0.2 (Cd), 14.7 ± 0.5 – 30.1 ± 2.2 (Cr), 6701 ± 1201– 277775 ± 32632 (Mn), 5.18 ± 0.59 – 122 ± 145 (Cu), 6.95 ± 1.57 – 30.3 ± 31.1 (Ni) and 17.67 ± 3.56 – 104.9 ± 94.7 (Pb). Similarly, the mean concentrations (mg/kg) range of heavy metals in kindergarten and standard one playing ground soil samples were bdl – 1.86 ± 0.06 (Cd), 5.8 ± 0.8 – 105 ± 124 (Cr), 7176 ± 226 – 191779 ± 82776 (Mn), 1.64 ± 0.01 – 11.51 ± 6.5 (Cu), 1.11 ± 0.2 – 37.5 ± 45.9 (Ni) and 8.9 ± 2.4 – 34.04 ± 1.9 (Pb). The present results, which indicate significantly high levels of heavy metals in school classroom dusts and playing ground soils, signify an important advancement towards shedding light on the alarming threat to school children’s health since classrooms and playing grounds are their immediate environments where they spend significant amount of their early life time.Item LEVELS OF HEAVY METALS IN SELECTED FACIAL COSMETICS MARKETED IN DAR ES SALAAM, TANZANIA(Tanzania Journal of Science, 2018) Philip, Joseph Yoeza Naimani; John, Silvia; Othman, Othman ChandeThe aim of this study was to determine the levels of heavy metals: lead, cadmium, copper, zinc, arsenic and mercury in facial cosmetics (lipstick, lip glossy, facial powder, foundation, eyeliner, eye shadow and mascara) which were purchased randomly in Dar es Salaam, Tanzania. The levels of lead, cadmium, copper and zinc were determined using Atomic Absorption Spectrometry (AAS). The levels of arsenic were determined using Hydride Generation Atomic Absorption Spectrometry (HGAAS), and levels of mercury were determined using Cold Vapour Atomic Absorption Spectrometry. Prior to determination of the concentration of heavy metals, the samples were acid digested. The average order of concentration of heavy metals in the sample was found to be zinc > lead > cadmium > copper >arsenic > mercury (foundation), zinc > cadmium > lead > arsenic > copper > mercury (powder), copper > lead > cadmium > zinc > arsenic > mercury > (eye shadows), zinc > copper > lead > cadmium > mercury > arsenic (eyeliners), zinc > cadmium > mercury > copper > lead >arsenic (mascaras), zinc > lead > cadmium > arsenic > copper > mercury (lipsticks), lead > cadmium > zinc > copper >arsenic > mercury (lip glossy). The observed higher percentage concentrations of heavy metals beyond limits of Canadian standards for cosmetics were as follows: lead 62.79%, cadmium 16.28%, arsenic 34.88% and mercury 6.98%.Item The Potential of Minjingu Phosphate Rock for Water Defluoridation(International Journal of Science, Technology and Society, 2016-01-25) Olambo, Francisco Lucas; Philip, Joseph Yoeza Naimani; Mdoe, James Epiphan GabrielIn some parts of Tanzania, fluoride ion concentrations in potable water are higher than recommended by WHO. Consequently, searches for economically and technically viable strategies are required to address this problem. This work aims to determine the potential of phosphate rock mined from Minjingu area in Northern Tanzania as water de-fluoridatant. The results obtained are reported herein. The rock particles were chemically activated and then characterised by XRF, XRD and nitrogen physisorption. Results showed that the main component of chemically activated rock particles was calcium hydroxyapatite with Ca/P ratio of 1.55 whereas the main component of non-activated particles was calcium fluoroapatite (Ca/P ratio of 1.66). The results also indicated that activated rock material was mesoporous with a BET surface area of 57.4 m2/g. Results for water defluoridation showed that the material had a fluoride ion percentage removal of about 90%, when the adsorbent dose was 8 g, contact time of 30 minutes, initial fluoride ion concentration 5 mg/L, pH values of 6.0 to 7.2 and batch volume of 50 mL. The material could be regenerated using 1% NaOH and reused in the water defluoridation process. Therefore, Minjingu Phosphate Rock (MPR) is potential water de-fluoridatant.