A Study on Sorption of 226Ra on Different Clay Matrices

Abstract

The sorption of radium 226 ((226)Ra) on different clay materials (bentonite, illite and a mixture of bentonite-illite) was studied. Clay materials are used in the construction of disposal pits for technically enhanced naturally occurring radioactive materials (TENORM) wastes (i.e., contaminated soil and sludge) generated by the oil and gas industry operations. Experimental conditions (pH, clay materials quantity, and activity concentrations of (226)Ra) were changed in order to determine the optimal state for adsorption of (226)Ra. The results showed that the concentration of adsorbed (226)Ra on clay materials increased with time to reach an equilibrium state after approximately 5 h. More than 95 % of the radium was adsorbed. The mixture of bentonite-illite (1/9) exhibited the greatest adsorption of radium under all experimental conditions.

Inventory of Occupational Risk from Natural Occurring Radioactive Materials (NORMs) in Soil Samples of the Coastal Region of Nigeria After Six Decades of Oil and Gas Exploration

“…Accidental discharges, equipment failures and pipelines vandalization may cause oil spilled, sludge, produced water, effluents, leachates and scales to pollutethe coastal environment 1 . These pollutants are transported into the soil compartment of the coastal ecosystem gravitationally due to seepage, which can also increase the specific activities of the soil in the environment 18 . The Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) in the soil in the oil and gas industry has the potential to cause both internal and external exposures during production due to the accumulation of gamma emitted radiation exposure hazard to both workers and members of the public through the inhalation and ingestion of radionuclides 9,19,20 .…”

Association of Radionuclide Isotopes with Aquifer Solids in the Midwestern Cambrian–Ordovician Aquifer System

“…Geochemical interactions between Ra and aquifer solids in groundwater systems affect Ra partitioning to the aqueous system . In the laboratory, Ra sorption to solid phases such as clay and transition-metal oxides (e.g., Fe, Mn) has been verified. − At the laboratory scale, contaminant–solid interactions can be examined via sequential extraction of rock core obtained from aquifer systems to determine contaminant distribution between various solid phases. Due to the low concentrations of concern, counting methods used to analyze Ra in solution often require large sample volumes (>500 mL) and/or generate relatively high analytical detection limits, which limits applicability in situations where sample volume is limited. − Analytical techniques such as multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) can measure isotopes of contaminants at ultratrace levels in the small sample volumes produced by laboratory experiments. − …”

Biological Effects and Baseline Measures of Naturally Occurring Radioactive Materials in Freshwater Fish of the Athabasca Oil Sands Region

“…In addition to being used as tracers in geological processes and for dating rocks and minerals, 238 U and 232 Th decay series shed light on the behaviour of radionuclides in the environment and their ecotoxicological impact ( Angileri et al, 2020;Rollog et al, 2020;Vengosh et al, 2022). Radionuclides of interest for this study will be those that are produced by the 232 Th and 238 U decay series as well as primordial nuclide 40 K. One daughter isotope of the 238 U decay series, 226 Ra is of interest as it has been one of the most studied naturally occurring radionuclides with respect to the oil and gas industry (Alhajji et al, 2016;Bandong et al, 2005;Hamlat et al, 2001;Hilal et al, 2014;Omar et al, 2004). 226 Ra is also more soluble in water compared to some other nuclides in the 238 U decay series and can interact with sediments in water bodies leading to radium becoming more bioavailable.…”