Department of Physics

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Browsing Department of Physics by Subject "Baseline"

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    ASSESSMENT OF HEAVY METAL CONCENTRATION IN WATER AROUND THE PROPOSED MKUJU RIVER URANIUM PROJECT IN
    (College of Natural and Applied Sciences, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    Effective verification for compliance with water quality standards in uranium mining in Tanzania requires data sensitive to monitor heavy metal concentration in water around the Mkuju River Uranium Project before mining commences. The area susceptible for pollution by the project was estimated using AERMOD dispersion model and found to cover about 1300 km2. Thirty one surface and groundwater samples were collected and analysed for heavy metals and physicochemical properties using ICP-MS and standards techniques, respectively. The physicochemical properties for water samples analysed ranges from 5.7 to 7.8 for pH, 2.8 to 80.2 mg/L for TDS and 15 to 534.5 mS/cm for EC. These values show that the water in the vicinity of the Mkuju River Uranium Project is normal. The ranges of concentration of heavy metals (μgL-1) determined in water ranges were: Al(2 to 9049), Cr(0.2 to 19.96), Mn (0.1 to 1452),Fe(2 to 53890),Co(0.02 to 27.63), Ni(0.2 to 9.7), Cu(2 to 17), Zn(2 to 62.94), As(0.4 to 19.17), Cd(0.02 to 0.14), Pb (0.02 to 78.68), Th (0.002 to 1.73),U(0.002 to 29.76). These values are below the tolerance levels of concentrations set by different International organisations. Therefore heavy metal toxicity in the study area is marginal. The parameters that could serve as baseline data because of their enhanced sensitivity to pollution were (i) concentration of chromium, cobalt, nickel, copper, zinc, arsenic, cadmium and lead in water (ii) pH, TDS and EC for water, (iii) TDS ratio for surface to ground water values and (iv) correlation coefficients between the heavy metals. However, since TDS values are season dependent, this indicator can serve as baseline data when measured during the dry season as was the case in the study.
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    Assessment of Heavy Metal Concentration in Water around the Proposed Mkuju River Uranium Project in Tanzania
    (2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    Effective verification for compliance with water quality standards in uranium mining in Tanzania requires data sensitive to monitor heavy metal concentration in water around the Mkuju River Uranium Project before mining commences. The area susceptible for pollution by the project was estimated using AERMOD dispersion model and found to cover about 1300 km2 . Thirty one surface and groundwater samples were collected and analysed for heavy metals and physicochemical properties using ICP-MS and standards techniques, respectively. The physicochemical properties for water samples analysed ranges from 5.7 to 7.8 for pH, 2.8 to 80.2 mg/L for TDS and 15 to 534.5 mS/cm for EC. These values show that the water in the vicinity of the Mkuju River Uranium Project is normal. The ranges of concentration of heavy metals (µgL-1 ) determined in water ranges were: Al(2 to 9049), Cr(0.2 to 19.96), Mn (0.1 to 1452),Fe(2 to 53890),Co(0.02 to 27.63), Ni(0.2 to 9.7), Cu(2 to 17), Zn(2 to 62.94), As(0.4 to 19.17), Cd(0.02 to 0.14), Pb (0.02 to 78.68), Th (0.002 to 1.73),U(0.002 to 29.76). These values are below the tolerance levels of concentrations set by different International organisations. Therefore heavy metal toxicity in the study area is marginal. The parameters that could serve as baseline data because of their enhanced sensitivity to pollution were (i) concentration of chromium, cobalt, nickel, copper, zinc, arsenic, cadmium and lead in water (ii) pH, TDS and EC for water, (iii) TDS ratio for surface to ground water values and (iv) correlation coefficients between the heavy metals. However, since TDS values are season dependent, this indicator can serve as baseline data when measured during the dry season as was the case in the study.
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    Assessment of Natural Radioactivity in Soil and its Contribution to Population Exposure in the Vicinity of Mkuju River Uranium Project in Tanzania
    (Science Technol, 2016) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    The level of 226Ra, 232Th and 40K was established in soil collected in an area about 1,300 km2 in the vicinity of Mkuju uranium project in Tanzania and selected points in the concession using HPGe spectrometer and associated exposure risks to population were estimated. The radioactivity concentration in the vicinity range (Bqkg-1) for 226Ra (24.94 to 53.50), 232Th (20.86 to 47.14), and 40K (344.50 to 697.54). Whereas, radioactivity in the concession range for 226Ra (2430.00 to 4200.00), 232Th (130.00 to 220.00), and 40K (1293.30 to 1466.10). On average the radioactivity in the concession were about 89, 5 and 3 times high than those in the vicinity. Based on the measurements, the hazards attributable to use of soil from the vicinity for different purposes is marginal. However, the hazards indices indicate that soils from the concession have relatively a significantly risk by range of factors about 27 to 29 and 40 to 42 times high than in the vicinity for the external and internal hazards, respectively. Also the radium equivalent radioactivity, dose rate and effective dose tend to be significantly high in the concession than in the vicinity by range of factors from 27 to 29, 23 to 25 and 23 to 25, respectively. These findings reveals that soils in the vicinity of the project could pose less radiological risk to human health when compared to soil in the concession.
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    Distribution of Heavy Metals in Soils in the Vicinity of the Proposed Mkuju Uranium Mine in Tanzania
    (Canadian Center of Science and Education, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    Tanzania is at advance stages in the preparation to start uranium mining at Mkuju River Deposit. In order to implement best practice in environmental management in uranium mining as required by national and international regulations and standards, a set of site specific baseline data have to be established prior the mining operation. In order to establish heavy metal baseline data for this purpose, a total of 84 soil samples were collected from clustered area of about 1,300 km2 at two depths: 0-15 cm and 15-30 cm. Analysis of the data using EDXRF showed a total metal concentration ranges of 3570-19400 for Al, 15200-58600 Fe, 400-1400 Mn, 15.2-54.9 Cr, 13.5-51.0 Zn, 2.2-45.3 Pb, 2.1-37.3 Cd, 0.2-23.0 Hg, 1.8-25.1Cu, 2.1-22.7 Ni and 0.8-9.1 mgkg-1for Co. Since the spatial distributions of heavy metals in the vicinity of the planned uranium mine are comparable to established global concentration ranges in soils, it is an indication that the distribution is natural. By virtue of their strong association with uranium and immobility in soil, spatial distributions of lead and copper concentrations would be more sensitive indicators for monitoring uranium related soil contaminants when the uranium mine become operational.
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    Distribution of Heavy Metals in Soils in the Vicinity of the Proposed Mkuju Uranium Mine in Tanzania
    (Canadian Center of Science and Education, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    Tanzania is at advance stages in the preparation to start uranium mining at Mkuju River Deposit. In order to implement best practice in environmental management in uranium mining as required by national and international regulations and standards, a set of site specific baseline data have to be established prior the mining operation. In order to establish heavy metal baseline data for this purpose, a total of 84 soil samples were collected from clustered area of about 1,300 km2 at two depths: 0-15 cm and 15-30 cm. Analysis of the data using EDXRF showed a total metal concentration ranges of 3570-19400 for Al, 15200-58600 Fe, 400-1400 Mn, 15.2-54.9 Cr, 13.5-51.0 Zn, 2.2-45.3 Pb, 2.1-37.3 Cd, 0.2-23.0 Hg, 1.8-25.1Cu, 2.1-22.7 Ni and 0.8-9.1 mgkg-1for Co. Since the spatial distributions of heavy metals in the vicinity of the planned uranium mine are comparable to established global concentration ranges in soils, it is an indication that the distribution is natural. By virtue of their strong association with uranium and immobility in soil, spatial distributions of lead and copper concentrations would be more sensitive indicators for monitoring uranium related soil contaminants when the uranium mine become operational.
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    Natural Radioactivity in Water and Its Potential Human Health Risk in the Vicinity of Mkuju River Uranium Projectin Tanzania
    (SciencePG, 2016) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
    Consistent with best practices in uranium mining, the collection and use of site characterisation data are indispensable to ensure compliance with regulations. To comply with this requirement, two samples from each of the 47 locations were collected in an area of about 1300 km2 in the vicinity and concession area of the Mkuju River Project. The samples were analysed for radioactivity using alpha spectrometry. The activity concentrations were used to estimate health risks attributable to the consumption of drinking water containing radionuclides. The range of activity concentrations (mBqL-1) were much higher in groundwater collected from the concession area for 238U (79.89 to 87.06), 234U (79.44 to 88.38), 226Ra (41.61 to 59.07), 232Th (5.32 to 9.41), and 228Ra (3.98 to 8.59) than in groundwater for 238U (20.61 to 47.21), 234U (21.70 to 49.10), 226Ra (16.80 to 43.45), 232Th (0.12 to 2.80), and 228Ra (0.10 to 2.43), and surface water for 238U (17.33 to 27.24), 234U (21.06 to 34.43), 226Ra (15.00 to 25.61), 232Th (0.16 to 2.10), and 228Ra (0.12 to 1.99) collected in the vicinity of the project. The calculated annual effective doses and carcinogenic risks resulting from the activity concentrations in drinking water were relatively marginal, since the activity concentrations were lower than the WHO permissible limits for drinking water. These findings suggest that the water resources at MRP are safe. Thus, since this study was conducted before mining activities, these data can be used as a baseline for monitoring potential future water pollution around the Mkuju River Project.