2.4.3. Activated carbon treatment
0.6 g activated carbon powder was mixed with 100 mL ADE and the mixture was conducted at 150 rpm, 30.0 ± 1 °C for 30 min. Then the mixture was centrifuged (4000×g, 20 min) and the supernatant was used for citric ha peptide fermentation or electrodialysis treatment.
2.4.4. Electrodialysis treatment
Fig. 2 has shown the schematic of the electrodialysis system in this work which was designed by Shanghai Daming, China. The range of voltage applied was 0–25 V by using a transformer and the range of flow rate was 0–60 mL/min. Heterophase polyethylene ion-exchange membrane was used in this system for selective separation of ions and its characteristics were shown in Table 1. The membrane system consisted of 24 pairs and each membrane had an effective area of 15 × 20 cm2.
Fig. 2. Schematic of the electrodialysis system used in this work.Figure optionsDownload full-size imageDownload as PowerPoint slide