Correlation Engine 2.0
Clear Search sequence regions

  • ammonium (1)
  • cold (1)
  • Fe3 (1)
  • iron (22)
  • nitrate (11)
  • nitrogen oxides (2)
  • redox (1)
  • water pollutants (2)
  • Sizes of these terms reflect their relevance to your search.

    The effect of low temperatures on abiotic and biotic nitrate (NO3-) reduction by zero-valent iron (ZVI) were examined at temperatures below 25 °C. The extent and rate of nitrate removal in batch ZVI reactors were determined in the presence and absence of microorganisms at 3.5, 10, 17, and 25 °C. Under anoxic conditions, NO3- reduction rates in both ZVI-only and ZVI-cell reactors declined as temperature decreased. In ZVI-only reactor, 62% and 17% of initial nitrate concentration were reduced in 6 days at 25 and 3.5 °C, respectively. The reduced nitrate was completely recovered as ammonium ions (NH4+) at both temperatures. The temperature-dependent abiotic reduction rates enabled us to calculate the activation energy (Ea) using the Arrhenius relationship, which was 50 kJ/mol. Nitrate in ZVI-cell reactors was completely removed within 1-2 days at 25 and 10 °C, and 67% of reduction was achieved at 3.5 °C. Only 18-25% of the reduced nitrate was recovered as NH4+ in the ZVI-cell reactors. Soluble iron concentrations (Fe2+ and Fe3+) in the ZVI reactors were also measured as the indicators of anaerobic corrosion. In the ZVI-cell reactors, soluble iron concentrations were 1.7 times higher than that in ZVI-only reactors at 25 °C, suggesting that the enhanced nitrate reduction in the ZVI-cell reactors may be partly due to increased redox activity (i.e., corrosion) on iron surfaces. Anaerobic corrosion of ZVI was also temperature-dependent as substantially lower concentrations of corrosion product were detected at lower incubation temperatures; however, microbially induced corrosion (MIC) of ZVI was much less impacted at lower temperatures than abiotic ZVI corrosion. This study demonstrated that ZVI-supported microbial denitrification is not only more sustainable at lower temperatures, but it becomes more dominant reaction for nitrate removal in microbial-ZVI systems at low temperatures. Copyright © 2020 Elsevier B.V. All rights reserved.


    Inyoung Kim, Daniel K Cha. Effect of low temperature on abiotic and biotic nitrate reduction by zero-valent Iron. The Science of the total environment. 2021 Feb 01;754:142410

    Expand section icon Mesh Tags

    Expand section icon Substances

    PMID: 33254888

    View Full Text