Browsing by Author "Chinu, K"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Characterisation of groundwater dissolved organic matter using LC-OCD: implications for water treatment
    (Elsevier, 2021-01-01) Rutlidge, H; McDonough, LK; Oudone, PP; Andersen, MS; Meredith, KT; Chinu, K; Peterson, MA; Baker, AA
    The polarity and molecular weight of dissolved organic matter (DOM) is an important factor determining the treatability of water for domestic supply. DOM in surface water and groundwater is comprised of a mixture of carbon with varying molecular weight ranges, with its composition driven by DOM sources and processing. Here, we present the largest dataset of chromatographic DOM in surface and groundwater samples (n = 246) using liquid chromatography organic carbon detection (LCsingle bondOCD). Our data represents four categories (surface water, hyporheic zone water, local groundwater, and regional groundwater) from five different sites across Australia. In all environments, high molecular weight hydrophilic DOM such as biopolymers (BP) and humic substances (HS) are present in surface waters and are processed out of groundwater as it moves from surface water and hyporheic zones into shallow local groundwater and deeper regional groundwaters. This results in a higher percentage of low molecular weight neutrals (LMWN) and hydrophobic organic carbon (HOC) in deeper regional groundwaters. Our findings indicate that the presence of sedimentary organic matter strongly influence the character of surface and groundwater DOM, resulting in groundwater with higher HS aromaticity and molecular weight, and reduced percentage of LMWNs. We also observe highly variable hydrophilic / HOC ratios in groundwater at all sites, with 9.60% and 25.64% of samples at sites containing sedimentary peat layers and non-sedimentary peat sites respectively containing only hydrophilic dissolved organic carbon (DOC). We identify average hydrophilic / HOC ratios of 4.35 ± 3.76 and 7.53 ± 5.32 at sites containing sedimentary peat layers and non-sedimentary peat sites respectively where both hydrophilic DOC and HOC are present. Overall our results suggest that fractured rock and alluvial aquifers in sedimentary organic carbon poor environments may contain DOC which is better suited to ozonation, biologically activated carbon filtration powdered activated carbon, suspended ion exchange treatment or magnetic ion exchange resin since DOC is more hydrophilic and of lower molecular weight and lower aromaticity. Aquifers located near sedimentary organic matter layers may benefit from pre-treatment by coagulation/flocculation, sedimentation and sand filtration which have high removal efficiency for high molecular weight and polar compounds. © 2021 Elsevier Ltd.
  • Thumbnail Image
    Item
    The new Chronos 14carbon-Cycle Facility, University of New South Wales, Sydney, Australia.
    (Australian Nuclear Science and Technology Organisation, 2021-11-17) Turney, CSM; Thomas, Z; Becerra-Valdivia, L; Palmer, JG; Haines, HA; Cadd, H; Wacker, L; Baker, AA; Andersen, MS; Jacobsen, GE; Meredith, KT; Chinu, K; Hiscock, W; Vohra, J; Marjo, CE
    The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the Chronos facility, the pretreatment methods currently employed (bones, carbonates, peat, pollen, charcoal, and wood) and results of radiocarbon and stable isotope measurements undertaken on a wide range of sample types. Our measurements on international standards, known-age and blank samples demonstrate that the facility is capable of measuring 14C samples from the Anthropocene back to nearly 50,000 years ago. Future work will focus on improving our understanding of the Earth system and managing resources in a future warmer world.
  • Thumbnail Image
    Item
    Radiocarbon protocols and first intercomparison results from the Chronos 14Carbon-Cycle Facility, University of New South Wales, Sydney, Australia
    (Cambridge University Press, 2021-05-11) Turney, CSM; Becerra-Valdivia, L; Sookdeo, A; Thomas, ZA; Palmer, JG; Haines, HA; Cadd, H; Wacker, L; Baker, AA; Andersen, MS; Jacobsen, GE; Meredith, KT; Chinu, K; Bollhalder, S; Marjo, CE
    The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the Chronos facility, the pretreatment methods currently employed (bones, carbonates, peat, pollen, charcoal, and wood) and results of radiocarbon and stable isotope measurements undertaken on a wide range of sample types. Measurements on international standards, known-age and blank samples demonstrate the facility is capable of measuring 14C samples from the Anthropocene back to nearly 50,000 years ago. Future work will focus on improving our understanding of the Earth system and managing resources in a future warmer world. © The Author(s) 2021. Published by Cambridge University Press for the Arizona Board of Regents on behalf of the University of Arizona.