Impact and recovery of pH in marine sediments subject to a temporary carbon dioxide leak

Peter Taylor, Anna Lichtschlag, Matthew Toberman, Martin D. J. Sayer, Andy Reynolds, Toru Sato, Henrik Stahl

Research output: Contribution to journalArticle

32 Citations (Scopus)
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Abstract

A possible effect of a carbon dioxide leak from an industrial sub-sea floor storage facility, utilised for Carbon Capture and Storage, is that escaping carbon dioxide gas will dissolve in sediment pore waters and reduce their pH. To quantify the scale and duration of such an impact, a novel, field scale experiment was conducted, whereby carbon dioxide gas was injected into unconsolidated sub-sea floor sediments for a sustained period of 37 days. During this time pore water pH in shallow sediment (5mm depth) above the leak dropped >0.8unit, relative to a reference zone that was unaffected by the carbon dioxide. After the gas release was stopped, the pore water pH returned to normal background values within a three-week recovery period. Further, the total mass of carbon dioxide dissolved within the sediment pore fluids above the release zone was modelled by the difference in DIC between the reference and release zones. Results showed that between 14 and 63% of the carbon dioxide released during the experiment could remain in the dissolved phase within the sediment pore water.
Original languageEnglish
Pages (from-to)93-101
Number of pages8
JournalINTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
Volume38
DOIs
Publication statusPublished - Jul 2015

Keywords

  • Carbon capture and storage
  • Sediment pore water
  • pH
  • CO2

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