Fate of radium on the discharge of oil and gas produced water to the marine environment

Understanding the speciation and fate of radium during operational discharge from the offshore oil and gas industry into the marine environment is important in assessing its long term environmental impact. In the current work, Ra-226 concentrations in marine sediments contaminated by produced water discharge from a site in the UK were analysed using gamma spectroscopy. Radium was present in field samples (0.1-0.3 Bq g(-1)) within International Atomic Energy Agency activity thresholds and was found to be primarily associated with micron sized radiobarite particles (<= 2 mu m). Experimental studies of synthetic/field produced water and seawater mixing under laboratory conditions showed that a significant proportion of radium (up to 97%) co-precipitated with barite confirming the radiobarite fate pathway. The results showed that produced water discharge into the marine environment results in the formation of radiobarite particles which incorporate a significant portion of radium and can be deposited in marine sediments. (C) 2021 The Authors. Published by Elsevier Ltd.

Automated summary

This study analyzed the Ra-226 concentrations in marine sediments contaminated by produced water discharge from a site in the UK and found that radium was primarily associated with micron-sized radiobarite particles. Experimental studies showed that a significant proportion of radium co-precipitated with barite, confirming the radiobarite fate pathway. The results indicate that produced water discharge into the marine environment leads to the formation of radiobarite particles incorporating a significant portion of radium that can be deposited in marine sediments.