Usually, the binary interaction parameter kij in Eq. (8) is adjusted
to properties of mixtures. Like in previous works, [25,27] the kij is
neglected for ion/water or ion/urea interactions and thus is considered
for urea/water interactions only. This directly allows for
predicting mixture properties of ternary water/urea/salt systems
using the pure-component parameters and the urea/water interaction
parameter only. The PC-SAFT parameters for ions which are
used in this work are given in Table 2. Also, urea and water parameters
as well as binary interaction parameters are represented in
Table 3