Radioactivity concentration in liquid and solid phases of scale and sludge generated in the petroleum industry

• Published in: Journal of environmental radioactivity 2005, Vol.81 (1), p.47-54
• Main Authors: Paranhos Gazineu, Maria Helena, de Araújo, Andressa Arruda, Brandão, Yana Batista, Hazin, Clovis Abrahão, de O. Godoy, José Marcos
• Format: Article
• Language: English
• Subjects: Applied sciences; Background Radiation; Brazil; Chemical Precipitation; Exact sciences and technology; Extraction and Processing Industry; Humans; Industrial Waste - analysis; Occupational Exposure - prevention & control; Other industrial wastes. Sewage sludge; Petroleum; Phase Transition; Pollution; Radiation Monitoring - methods; Radioactivity; Radium - analysis; Sanitary Engineering; Scale; Sludge; Spectrometry, Gamma; Wastes; Water Pollutants, Radioactive - analysis; Water Pollution, Radioactive - prevention & control
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2004.11.003

Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90 ± 5°C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material.