Near-Stoichiometric Adsorption of Phosphate by Silica Gel Supported Nanosized Hematite

Table 3

Natural ferric phosphates [27] ordered according to Fe³⁺ : PO₄³⁻ : OH⁻ ratio.

Fe^3+ : PO4^3− : OH^− ratio	Chemical formula	Name
1 : 0.75 : 0.75	Fe4(PO4)3(OH)3⋅5H2O	Tinticite
1 : 0.66 : 1	Fe3(PO4)2(OH)3⋅5H2O	Ferristrunzite (or allanpringite)
1 : 0.66 : 1.33	NaFe3(PO4)2(OH)4⋅2H2O	Cyrilovite
1 : 0.5 : 1.5	Fe4(PO4)2(OH)6⋅4--6H2O	Delvauxite