Table 2.

Abbreviations and the values of constants used in Eqs. (1) and (2)

[i]	Concentration of species i (mol l−1)
(i)	Activity of i (mol l−1)
ai	Effective diameter of ion i		Ref. [33]
A	Parameter A for Debye-Hükel limiting law	0.51144
B	Parameter B for Debye-Hükel limiting law	107.517
fi	Activity coefficient for species i
J	P/(HPO42−)
m	Total ionic strength of the solution
P	Total phosphate concentration (mol l−1)
S	Concentration of ion pairs (H2PO4)22−
T	Total concentration of ion pairs CaHPO4o and CaH2PO4+
U	Total concentration of ionpairs MgHPO4o and MgH2PO4+
Zi	Valence of ion I
	First dissociation constant of phosphoric acid	10−2.127	Ref. [34]
	Second dissociation constant of phosphoric acid	10−7.20	Ref. [35]
	Third dissociation constant of phosphoric acid	10−12.325	Ref. [36]
	Ionic product for water	10−13.99	Ref. [37]
	Dissociation constants of CaHPO40 ion-pair	10−2.3874	Ref. [36]
	Dissociation constants of CaH2PO4+ ion-pair	10−0.9138	Ref. [36]
	Dissociation constants of MgHPO40 ion-pair	10−2.852	Ref. [38]
	Dissociation constants of MgH2PO4+ ion-pair	10−1.276	Ref. [38]