Enhanced Removal of River‐Borne Nitrate in Bioturbated Hyporheic Zone

Autor: Qihao Jiang, Shivansh Shrivastava, Guangqiu Jin, Hongwu Tang, Junzeng Xu, Jing Xu, Changchun Huang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Geophysical Research Letters, Vol 51, Iss 13, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 1944-8007
0094-8276
DOI: 10.1029/2024GL108673
Popis: Abstract The influence of bioturbation induced by bottom‐dwelling macrozoobenthos on nitrogen dynamics in lotic stream sediments remains unclear. In this work, we advance the understanding of faunal bioturbation in lotic environments by developing a fully‐coupled flow and multicomponent reactive transport model and investigate the influence of sediment reworking and burrow ventilation processes on nitrogenous transformations. The model results indicate that sediment reworking and burrow ventilation significantly increase nitrate (NO3−) influx, penetration depth, and reaction rates in the streambed. Denitrification rates were observed up to three times higher in beds with U‐shaped burrows compared to flatbeds. The ratio of mound height to stream water depth ratio (h/H0) is a dominant control on determining the relative importance of the sediment reworking and burrow ventilation processes in modulating nitrogenous reactions. A power‐law scaling framework is ultimately proposed to predict NO3− removal efficiency based on the Damköhler number in bioturbated lotic streambeds.
Databáze: Directory of Open Access Journals
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