Table 2.
Transport numbers and ion fluxes. The inoculum solution was assumed to be mainly composed of 60 mM KCl and 20 mM sodium acetate. The solution in the end compartments was composed of phosphate buffer pH 7, sodium acetate, and addition or absence of 60 mM KCl. For each ion species (i), the transport number (ti) was calculated by equation (3) using the values of molar ionic conductivity (λ0i, 10-4 m2.S.mol-1) from Oliot et al.[52].
| K+ | Na+ | Total cations | Cl- | CH3COO- | HPO42- | H2PO4- | Total anions | |
|---|---|---|---|---|---|---|---|---|
| zi | 1 | 1 | 1 | 1 | 2 | 1 | ||
| λi0 (10-4 m2.S.mol-1) | 73.5 | 50.1 | 76.3 | 40.9 | 114 | 36 | ||
| Inoculum (central compartment) | ||||||||
| Ci (mol.m-3) | 60 | 20 | 60 | 20 | 0 | 0 | ||
| ti | 0.408 | 0.093 | 0.424 | 0.076 | 0 | 0 | ||
| Ni,100 | 40.8 | 9.3 | 50.1 | 42.4 | 7.6 | 0 | 0 | 49.9 |
| PBS with KCl (end compartment) | ||||||||
| Ci (mol.m-3) | 86 | 102 | 60 | 20 | 41 | 26 | ||
| ti | 0.282 | 0.228 | 0.204 | 0.036 | 0.208 | 0.042 | ||
| Ni,100 | 28.2 | 22.8 | 50.9 | 20.4 | 3.6 | 10.4 | 4.2 | 38.6 |
| PBS without KCl (end compartment) | ||||||||
| Ci (mol.m-3) | 26 | 102 | 0 | 20 | 41 | 26 | ||
| ti | 0.142 | 0.380 | 0 | 0.061 | 0.348 | 0.070 | ||
| Ni,100 | 14.2 | 38.0 | 52.2 | 0 | 6.1 | 17.4 | 7.0 | 30.4 |
Ion fluxes (Ni,100) were calculated as the number of ions that flowed through the solution when 100 electrons were flowing through the electric circuit, according to Equation (5). Multiplying these values by Jflied/100.F gives the molar flux densities Φi in mol.s-1.m-2.