RADIOLOGICAL AND ELEMENTAL CHARACTERIZATION OF SOIL AND MILL TAILING SAMPLES FROM ANGWAN MAIGERO GOLD MINING SITES, NIGER STATE, NIGERIA.
RADIOLOGICAL AND ELEMENTAL CHARACTERIZATION OF SOIL AND MILL TAILING SAMPLES FROM ANGWAN MAIGERO GOLD MINING SITES, NIGER STATE, NIGERIA.
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Date
2016-12
Authors
ESIOLE, Stephen Onyeka
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Abstract
Mining activities has been observed to be one of the major contributors of heavy metals in the environment. The effect of heavy metals on gold mining areas is of serious concern, as such threatens life in all forms. This present study involves the determination of heavy metal concentration and its pollution levels in Angwan Maigero Gold mining sites, Niger State Nigeria using Contamination Factor (CF), Pollution load Index (PLI), Degree of Contamination (DC) Index, Geo-accumulation Index (I-geo), Hazard Quotient (HQ) and Ecological Risk Factor (ERF). Soil and mill tailing samples were analyzed using Flame Atomic Absorption Spectroscopy (FAAS) to obtain their composition and concentration. The study area was observed to be contaminated with Pb, Fe, Mn, Cu, Zn, As, Cr, Co, Ni, and Cd. The mean concentrations (ppm) of the studied heavy metals in mine site was observed to be 319.765, 1707.631, 181.614, 90.945, 37.412, 17.992, 93.187, 47.940, 22.282 and 3.232 respectively, Also the mean concentrations (ppm) in the mill tailing site was observed to be 846.867, 1914.993, 177.703, 739.333, 100.405, 43.519, 163.284, 53.476, 45.591, 5.828, respectively. The Highest concentration corresponds to Fe and the lowest corresponds to Cd. The increasing trend was in the order: Cd <As <Ni <Zn <Co <Cu <Cr <Mn <Pb <Fe. The concentrations of all the elements in the mill tailing sites were observed to be higher than that obtained in the mine site with greater variation in relative abundance of most of the metals. These variations can be attributed to the variable dumping of mill tailing deposit. The extremely high contents of the heavy metals are terribly alarming in terms of environmental population, when compared with the world recommended value by WHO. Therefore, the inhabitants and the mine workers, who reside and work at the environment, are at serious risk of heavy metal toxicity and awareness needs to be created. Also, the radionuclide concentrations were determined using the sodium iodide [NaI
(TI)] detector with a low background configuration. The mean activity concentrations of 226Ra, 232Th and 40K were observed to be 43.94 ± 3.02, 38.61 ± 2.06 and 304.17 ± 23.03 Bq/kg at the mine site and 45.39 ± 5.07, 72.41 ± 7.18 and 472.16 ± 35.26 Bq/kg at the mill tailing site, respectively. Effects of different parameters of interest on measured values of gamma dose rates for the region under investigation was carried out. The mean absorbed gamma dose rate (D) was found to be 53.94 ± 2.84 and 84.39 ± 5.21 nGy/h in the mine and mill tailing sites, respectively; the mean annual effective dose equivalent (AEDE) in the mine and mill tailing sites, respectively was found to be 0.07 ± 0.003, in line with the world wide effective dose of 0.07mSv/y and 0.10±0.01mSv/y, higher than the world mean value. The mean values Raeq was found to be lower than the accepted safety limit value of 370Bq/kg. The ELCR was calculated and was found to be (0.23 ± 0.01) × 10-3 below the world mean value of (0.29 × 10-3) in the mine site while the mean value of the mill tailing was found to be (0.36 ± 0.02) × 10-3 above the world mean value.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT FOR THE AWARD OF MASTER DEGREE IN RADIATION BIOPHYSICS DEPARTMENT OF PHYSICS, FACULTY OF PHYSICAL SCIENCE, AHMADU BELLO UNIVERSITY, ZARIA NIGERIA
Keywords
RADIOLOGICAL,, ELEMENTAL,, CHARACTERIZATION,, SOIL,, MILL,, ANGWAN MAIGERO,, GOLD MINING,, NIGER STATE,, NIGERIA,