| Abstract |
| Effects of molar ratio (x) and pH on calcium- or magnesium-aluminum layered double hydroxides (LDHs) syntheses and Cl- removal by ion-exchange with NO3- in synthesized LDHs were investigated. The LDHs were synthesized under two systems such as Ca/Al-NO3 (CAN) and Mg/Al-NO3 (MAN). The weights of LDHs synthesized were calculated from the change of the mole of NO3- removed during synthesis and compared to obtain the optimum condition. For synthesis of LDHs intercalated with NO3-, the optimum molar ratios for the CAN and MAN systems were 0.25 and 0.20, respectively. The optimum pH for CAN and MAN syntheses were 11 and 10, respectively. Ion-exchange reactions of Cl- with NO3- in both LDHs were finished within 10 minutes at Cl-/LDHs ratio of 0.1 (mol/mol). Increasing LDH dose led to increase linearly NO3- release. However, as the dose of LDHs increased over 0.5 g/L, the NO3- release was getting dominated by the dissolution of LDHs instead of ion-exchange according to mass balance analysis. |
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| Key Words |
| Layered double hydroxides, Ion exchange, Cl-, NO3-, Ca-Al-NO3 (CAN), Mg-Al-NO3 (MAN) |
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