New Research Article by Barros et al. 2019
Investigation of electrodialysis conﬁgurations for vinasse desalting and potassium recovery
This study aimed to investigate three diﬀerent electrodialysis (ED) conﬁgurations using two distinct membranes, a monovalent ion selective membrane and a non-selective heterogeneous membrane. The conﬁgurations were evaluated in terms of eﬃciency of potassium recovery from vinasse and energy requirements. Moreover, the contribution of vinasse pretreatment by ultraﬁltration was assessed. The results showed that ultraﬁltration is important to prevent membrane fouling and save energy. Tests with only monovalent-selective membranes, only non-selective membranes and a mixed conﬁguration (one cationic selective membrane and the others non- selective) were performed. The mixed ED conﬁguration was able to recover 72% of potassium applying a current density of 60 A m−2, with the lowest energy consumption (9 kW h m−3) and the best current eﬃciency (54%). Therefore, the ED was proved to be an advantageous method for vinasse treatment, generating a concentrated solution that can be proﬁtably used as fertilizer and a diluted eﬄuent that could be used for biogas production or fertigation.