A new conceptual framework for the transformation of groundwater dissolved organic matter

Groundwater comprises 95% of the liquid fresh water on Earth and contains a diverse mix of dissolved organic matter (DOM) molecules which play a significant role in the global carbon cycle. Currently, the storage times and degradation pathways of groundwater DOM are unclear, preventing an accurate estimate of groundwater carbon sources and sinks for global carbon budgets. Here we reveal the transformations of DOM in aging groundwater using ultra-high resolution mass spectrometry combined with radiocarbon dating. Long-term anoxia and a lack of photodegradation leads to the removal of oxidised DOM and a build-up of both reduced photodegradable formulae and aerobically biolabile formulae with a strong microbial…

• NS
  National Science Foundation

  Awards: 1644779, DMR-1644779, DMR-1157490, 1157490
• AN
  Australian Nuclear Science and Technology Organisation
• NH
  National High Magnetic Field Laboratory

  Awards: DMR-1157490, DMR-1644779, 1157490, 1644779
• AC
  Analytical Center for the Government of the Russian Federation
• UO
  University of New South Wales
• AR
  Australian Research Council

  Award: DP160101379
• DO
  Division of Materials Research

  Awards: 1644779, DMR-1157490, DMR-1644779, 1157490
• DO
  Division of Chemistry

  Awards: DMR-1644779, DMR-1157490
• HM
  High Magnetic Field Laboratory, Chinese Academy of Sciences