Permeable Biofilms Can Support Persistent Hyporheic Anoxic Microzones Academic Article uri icon

abstract

  • AbstractExperimental observations reveal the existence of anoxic microzones within oxygenrich aquatic sediments. The microzones are hotspots of enhanced removal of nitrate and production of greenhouse gas nitrous oxide. Here we established a new microscale flow, reactive transport and biofilm growth model and explore how anoxic microzones form and evolve within hyporheic zones under dynamic interactions among porescale flow, reactive transport and biofilm growth. The microzones can form and evolve by two patterns as streambeds are progressively clogged due to biofilm growth: (a) physical and biogeochemical conditionsdependent perennial microzones for permeable biofilms, and (b) physical and biogeochemical conditionsindependent ephemeral microzones for low permeability biofilms. During biofilm growth, persistent transportdominated systems sustain for the former, whereas the transformation of transportdominated to reactiondominated systems occurs for the latter. These findings are significantly different from previous single pattern of ephemeral microzones.

published proceedings

  • GEOPHYSICAL RESEARCH LETTERS

author list (cited authors)

  • Xian, Y., Jin, M., Zhan, H., & Liang, X.

citation count

  • 1

complete list of authors

  • Xian, Yang||Jin, Menggui||Zhan, Hongbin||Liang, Xing

publication date

  • July 2022