1996/05/01 by Hans Christian Bruun Hansen, Christian Koch, Hanne Nancke-Krogh +2 · 9 citations
Materials Science · Chemical Engineering · Environmental Science · #Layered Double Hydroxides Synthesis and Applications #Ammonia Synthesis and Nitrogen Reduction #Phosphorus and nutrient management
paper · doi:10.1021/es950844w
openalex publication_date 1996/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
Leaching of nitrate from soils and sediments can be reduced in anoxic environments due to denitrification to N 2 O/N 2 or reduction of nitrate to ammonium. While microbial dissimilatory reduction of nitrate to ammonia is well known, it is shown here that this conversion can also proceed at appreciable rates in abiotic systems in the presence of green rust compounds [Fe II 4 Fe III 2 (OH) 12 SO 4 · y H 2 O]. In the reaction nitrate is stoichiometrically reduced to ammonium, and magnetite (Fe 3 O 4 ) is the sole Fe-containing product. At a constant pH of approximately 8.25 and 25 °C, the rate expression is given as: d[NH 4 + ]/d t = k [Fe(II)] GR [NO 3 - ],where k = 4.93 × 10 - 5 ± 0.39 × 10 - 5 L mol - 1 s - 1 . In anoxic soils and sediments, this reaction may also lead to a nitrate to ammonium reduction, at rates of similar magnitude or even higher than microbial reduction rates. Hence green rust should be considered a possible important reductant for nitrate reduction to ammonium in subsoils, sediments, or aquifers where microbially mediated reduction rates are small.