Separation of succinic acid from fermentation broth: Dielectric exclusion, Donnan effect and diffusion as the most influential mass transfer mechanisms

Nanofiltration can be used to separate succinic acid (SA) from other organic acids in a fermentation broth. However, commercial nanofiltration membranes insufficiently selective since some produced have similar molecular weights. SA production biomass entails separation of the concomitantly such as acetic acid, formic pyruvic etc. In this study, five were tested for rejection and selectivity under dead-end crossflow modes recovery selected synthetic solutions real rejections up 94.1 ± 1.5% 95.5 3.5% observed broth broth, respectively. The fractions obtained retentate nearly 70% 60% highest fraction values achieved with DK NF270 membranes, which also showed permeate flux. Model evaluation using Donnan-steric pore model dielectric exclusion (DSPM-DE) that 99% occurs at membrane interface not inside membrane. Based on modelling, most important mechanism affecting was both sides surfaces. Moreover, identified sensitive parameters, i.e. constant (εpore), charge density (Xd) radius (rp), estimated through fitting found highly correlated significant variations. Finally, first time, calibrated successfully predict (with 12% 3% prediction error succinate by DK, respectively). Such only measuring concentrations three parameters. Furthermore, potential contribution different transport mechanisms quantified time.