R4: Mineral sciences of the Earth surface

[R4-12] Ammonium capturing behavior by saponite

*Hiroto Tokumon¹, Keisuke Fukushi², Yasuhito Sekine³ (1. Kanazawa Univ. Sci, 2. Institute of Nature and Environmental Technology, Kanazawa Univ, 3. Tokyo Institute of Technology)

Keywords:Saponite, exchange coefficient, Ceres

Ammonium saponite found on the surface of the Ceres is highly likely records the ammonium concentration of the ocean that existed on Ceres in the past. Understanding the ammonium uptake behavior of saponites is inevitable for understanding the water quality, but there are few examples of that. In this study, we quantitatively measure the sodium-ammonium selectivity coefficient and compare it among synthetic saponite, natural saponite, and montmorillonite attempt to recover the concentration of ammonium in solution in the early ocean on Ceres.