2017 Volume 8 Issue 2 Pages 70-74
Soil salinization has being occurred not only in arid and semiarid region but in humid region under saline and shallow groundwater condition in the world. In Northeast Thailand, approximately 17% of land is salt- affected and it appears even in paddy fields in dry season. It is not easy to develop water resources in the region because of uneven rainfall patterns and geological formation such as unevenness of terrain. Rainfall in monsoon season charges soil water and groundwater, and it could be used as irrigation water resources. However, the water is salinized, and it needs treatment of desalinization process for the use of irrigation. In preliminary study, we developed artificially saturated mordenite with hydrogen ion for the first step of the development of the technology, and we found high rate of ion-exchange of the mordenite, sodium adsorption and hydrogen desorption, in test solution which was formed by one monovalent cation of sodium. However, soil and groundwater in salinized agricultural fields are not formed by one cation, containing various cations and pH is high, so that we need to reveal ion-exchange ability of the mordenite in such a complicate ion mixed conditions. Therefore, the objective of this study is to develop the saturated mordenites as ion-exchangeable materials for desalinization and to reveal ion-exchange ability of it by batch test. Batch test was conducted using the saturated mordenite and groundwater taken from the salt-affected field in Khon Kaen Province, Northeast Thailand. As a result, we found that sodium ion of the groundwater which contains various cations was adsorbed selectively by saturated mordenite. It is also revealed that alkalization is solved since pH decreased by desorption of hydrogen ion from saturated mordenite to groundwater. Hence, we concluded that the saturated mordenite can be utilized as ion-exchangeable material for desalinization of saline soil and groundwater in the experimental field.
