Management of Sorbent Selectivity Based On Modified Tin (IV) Phosphate
The ion-exchange properties of tin (IV) phosphate during sorption of alkali metal cations are studied. It was shown that the selectivity series has the form Cs +>Rb +> K +> Na + and, with an increase in the tin (IV) content during synthesis, the distribution coefficients slightly increase, which is associated with an increase in the amorphous state of the ion exchanger. When using citric and sulfosalicylic acids as modifiers, the selectivity series for transition elements is as follows: Fe3 +> Co2 +> Zn2 + ? Cu2 +> Ni2 +. For acetic, boric and formic acids: Cu2 +> Fe3 +> Zn2 +> Co2 +> Ni2 +.
A feature of inorganic ion exchangers is their selectivity. These include sorbents based on salts of tetravalent metals (zirconium, titanium, germanium, lead, hafnium, tin), a large number of works are devoted to the synthesis of which. Recently, attention has been paid to their modification [1-7]. The least studied inorganic ion exchanger is tin (IV) phosphate, whose properties can be changed by introducing various modifiers.