“…Actually, some studies have reported the potential use of LDHs as adsorbents or reservoirs of nitrate. [9,10,[13][14][15][16][17][18] However, the selectivity of LDHs for nitrate is generally considered not to be high, and a large number of studies have reported that anions with a higher charge density tend to be more preferentially intercalated into LDHs. [6][7][8]19,20] According to a report by Miyata, [19] the order of exchange selectivity for monovalent anions in the case of Mg-Al LDHs (Mg/ Al = 2.3) is OH -> F -> Cl -> Br -> NO 3 -> I -, and according to a report by Costa et al, [20] the order of exchange selectivity based on a computational simulation with Zn-Al LDHs (Zn/Al = 2) is CO 3 2-> OH -> F -> Cl -> Br -> NO 3 -.…”