Poster (EARTH)

[PE1-039] DESALINATION PROPERTY OF SEAWATER VARIOUS CALCINED LAYERED DOUBLE HYDROXIDES

○Daiki Tsutsui¹ (1. Chiba University)

Keywords:Seawater, Desalination agent, Calcined LDHs

Now, approximately 20% of farmland in the world becomes salt damage soil with unsuitable properties for agriculture. In general, salt was removed from soil by flushing out with rain water due to the improvement of soil permeability using gypsum, etc.. However, there are arid and semi arid areas which an insufficient supply amount of rain water to remove salts from soil. In this study, a novel method to capture salt in soil using various calcined Layered double hydroxides (LDHs) as a desalination agent was attempted. 4 kinds of LDH are prepared with the different M ^{2 +} / M ^{3 +} ratios using 2 kinds of Mg ²⁺, Ca ^{2 +} as M ^{2 +} and 2 kinds of Al ^{3 +} and Fe ^{3 +} as M ^{3 +}. The desalination ability of these calcined LDHs were investigated using seawater collected from an Imari bay in Saga prefecture, Japan. AS a result, the decrease of salinity was confirmed using all samples. Among these samples, the calcined MgAl LDH with Mg/Al = 3.45 and CaFe LDH with Ca/Fe=2.35 indicated the highest desalination property, due to the decrease of Cl^- and SO₄^2- from seawater. The structure of calcined LDH returned to that of LDH by reconstruction reaction after seawater desalination.