Environmental effects on ammonium adsorption onto clay minerals: Experimental constraints and applications

Deep-marine brine seeps stimulate microbial nitrogen cycling: implications for the formation of sediment-hosted ore deposits

“…Joye et al ( 2005) attributed these high concentrations to three possible sources, including decomposition of sinking organic matter, desorption of ammonium from sinking inorganic particles, and desorption of ammonium from deeper sedimentary strata as the brine rises to the seafloor. Ammonium can adsorb to and become incorporated into clay minerals in substitution for potassium, as both ions have the same charge and similar radii (Abdulgawad et al, 2009;Yu et al, 2023). This substitution typically occurs during diagenesis, when ammonium is released from organic matter and appears in close contact with the sedimentary clay matrix (Müller, 1977;Schroeder and McLain, 1998).…”

“…This substitution typically occurs during diagenesis, when ammonium is released from organic matter and appears in close contact with the sedimentary clay matrix (Müller, 1977;Schroeder and McLain, 1998). However, this process is salinity-dependent (Rysgaard et al, 1999;Yu et al, 2023), and therefore the high ionic strength of the brine that rises up through the sedimentary package may desorb ammonium that was previously stored in clay particles, possibly deeper down in the sediment column. Meckler et al (2011) report bulk sedimentary δ 15 N values up to 4 ‰ at 3 m depth, and so it is conceivable that the isotopic offset that we observed between the dissolved ammonium and the bulk sediments in our Orca Basin brine pool samples (core MUC_6, Fig.…”

Deep‐Marine Brine Seeps Stimulate Microbial Nitrogen Cycling: Implications for the Formation of Sediment‐Hosted Ore Deposits

“…Joye et al (2005) attributed these high concentrations to three possible sources, including (a) decomposition of sinking organic matter, (b) desorption of ammonium from sinking inorganic particles, and (c) desorption of ammonium from deeper sedimentary strata as the brine rises to the seafloor. Ammonium can adsorb to and become incorporated into clay minerals in substitution for potassium (relevant to process b and c), as both ions have the same charge and similar radii (Abdulgawad et al, 2009;Yu et al, 2023). This substitution typically occurs during diagenesis, when ammonium is released from organic matter and appears in close contact with the sedimentary clay matrix (relevant to c) (Müller, 1977;Schroeder & McLain, 1998).…”

“…This substitution typically occurs during diagenesis, when ammonium is released from organic matter and appears in close contact with the sedimentary clay matrix (relevant to c) (Müller, 1977;Schroeder & McLain, 1998). This adsorbed ammonium can be displaced by other cations, meaning that adsorption decreases with increasing salinity (Rysgaard et al, 1999;Yu et al, 2023). Therefore, the high ionic strength of the brine that rises up through the sedimentary package may desorb ammonium that was previously stored in clay particles, possibly deeper down in the sediment column (see (Meckler et al, 2011).…”

Fodder oats as catch crop: potential to reduce nitrogen losses from soil

“…Here, we assess the impact of fodder oats through the soil profile. Also, this study focused on a soil with high clay content (34-44%), prevalent in South Africa (Sumner, 2015;Daniell and van Tonder, 2023), where ammonium (NH4 + ) is expected to be rapidly adsorbed onto clay minerals and slowly released over time (Yu et al, 2023).…”