Impact of Radioactivity and Heavy Metal Concentrations from subsurface formation cuttings on the Environment

Okoro, Emeka Emmanuel and Sanni, Samuel Eshorame and Okolie, Amarachi G and Abraham, V. D. and Omeje, Maxwell and Obomanu, Tamunotonjo (2020) Impact of Radioactivity and Heavy Metal Concentrations from subsurface formation cuttings on the Environment. BALTICA, 33 (2). ISSN 0067-3064

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Abstract

An assessment of Naturally occurring Radioactive Materials (NORM) and heavy metals (Al, Cr, As, Hg, Ni, Cd, Pb, Cu and Zn) from drill cuttings of six different layers in the subsurface of an oil well in the Niger-Delta was carried out. The assessment was carried out to estimate the radionuclides and heavy metals in the drill cuttings and as well determine, the radiological risks posed by the radionuclides and heavy metals to operators and nearby-inhabitants. The radionuclide activities and heavy metal concentrations of the samples were analyzed. The health hazard potential of human exposures to the metals, were estimated in terms of intensity and time using the USEPA recommended model. The average concentrations of the heavy metals present in the samples obtained from the formation zone, varied significantly and decreased in the order of Al > Zn > Ni > Pb > Cr > Cu > Cd > As > Hg. The mean activity concentration for the different radionuclides are 238U, 232TH and 40K were 3.9, 17.5 and 221.2 Bqkg-1 respectively. Comparing the results from this study with those of a previous study, shows that for sandstone formations, the uranium (238U) concentration was greater in the current study than what was obtained in the previous study while the 232TH and 40K concentrations were lesser in the former than the latter. A similar observation was made for a shale formation whereas, for a sandstone shale formation, the estimated 238U, 232TH and 40K concentrations are less than those of the previous study. The radionuclide activities decreased in the order of Layer 2 > Layer 1 > Layer 4 > Layer 5 > Layer 3 > Layer 6 whereas, for the heavy metal concentration obeyed this trend: Layer 5 > Layer 4 > Layer 3 > Layer 2 > Layer 1 > Layer 6. The risk assessment for the Annual Effective Dose Rate was greater than the allowable limit; while the exposure factor for heavy metal was within the allowable limit.

Item Type:	Article
Subjects:	T Technology > T Technology (General) T Technology > TP Chemical technology
Divisions:	Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User:	nwokealisi
Date Deposited:	26 Sep 2023 12:04
Last Modified:	26 Sep 2023 12:04
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/17323

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