Recovery of ammonium sulfate from fermentation waste by electrodialysis

Electrodialysis experiments of the lysine fermentation waste were performed to generate demineralized feed and ammonium sulfate, which can be utilized as a fertilizer and an animal feed, respectively. The electrodialysis performances were compared for different ion exchange membranes in terms of ammonium sulfate removal rate, resistance and conductivity change. Analysis of fouling phenomena revealed that organics fouled ion exchange membranes reversibly in electrodialysis of the fermentation waste. In this study, mitigation of membrane fouling with the pulsed electric field was examined for the electrodialysis of the fermentation waste containing strong foulants. The half-wave power reduced membrane fouling significantly. For a quantitative measure of the membrane fouling tendency, a membrane fouling index for electrodialysis was used. This study showed the potential use of pulsed power as an effective fouling mitigation method for the electrodialysis of fermentation waste.