Novel Utilization Technics Of Lysine Ion Exchange Wastewater

Resource utilization of lysine ion exchange wastewater has a great significance to achieve cleaner production of lysine. Electrodialysis (ED), with the advantages such as easy operation, high efficiency and low waste emission, can provide a alternative method for the regeneration and recovery of some resources.Based on the characteristics of lysine wastewater, the electrodialysis for utilization of lysine ion exchange wastewater was investigated in this thesis. The research progresses obtained are shown as follows:The effect of pretreatment of lysine ion exchange wastewater on electrodialysis desalination was investigated. It was indicated that the complexity of lysine ion exchange wastewater leads to the deterioration of process performance of ED, and fouling of ion exchange membrane and enhancing the energy consumption of electrodialysis desalination. The pretreatment of lysine ion exchange wastewater with decolouration with active carbon and ultrafiltration with hollow fiber membrane of 6kD could make electrodialysis process run smoothly for a long time.On the basis of the decreasing energy consumption and improving concentration of production, applied three-stage countercurrent to process of ED. It was showed that the energy consumption of desalination decreased significantly with three-stage countercurrent ED was adopted in the ammonium sulfate recovery. Compared with that of only single stage ED process, the energy consumption of desalination with three-stage countercurrent ED could be declined by 30%.It was studied that the pretreatment method and effect factor of lysine ion exchange wasrewater after ED desalination to be regenerated the acid and base with three-compartment BMED. The results demonstrated that the energy consumption of three-compartment BMED could be interfered significantly by the residual protein in lysine ion exchange wastewater after ED desalination. The membrane fouling of BMED process was mitigated effectively after pretreated by 5kD roll-up type membrane and its energy consumption was maintained to 2.3-2.5kWh kg-1. Furthermore, it was proved that the pH value in base cell had a significant effect on the regeneration of H2SO4 and NH3 from ammonium sulfate by BMED process. High pH may accelerate the deterioration of BMED performance. So very high pH in base cell was not suggested in industrial production.Researched on the reason of the proton leakage and water osmosis of acid cell in the process of regeneration of acid and base by three-compartment BMED, which found that the current density and bipolar membrane quality could influence the proton leakage of acid cell. The result showed that the current density and bipolar membrane quality can affect the water transport number of acid cell during the process of BMED, while the extent of proton leakage decreased with increase of water tansport number of acid cell. Furthermore, there were obvious proton leakage of experimental membrane of JAM-15 and GAM anion ion exchang membrane, comparatively, the performance of JAM-15 anion ion exchange membrane was superior to that of GAM anion ion exchang membrane.