Talebi Sahar, Garthe Michael, Roghmans Florian, Chen George Q, Kentish Sandra E
The ARC Dairy Innovation Hub, Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia.
Chemical Process Engineering, RWTH University, Forckenbeckstraße 51, 52074 Aachen, Germany.
Membranes (Basel). 2021 Feb 3;11(2):107. doi: 10.3390/membranes11020107.
Acid whey is a by-product of cheese and yoghurt manufacture. The protein and lactose within acid whey can be recovered using nanofiltration and electrodialysis, but this leaves a waste stream that is a mixture of salts and lactic acid. To further add value to the acid whey treatment process, the possibility of recovering this lactic acid was investigated using either low energy reverse osmosis membranes or an electrodialysis process. Partial separation between lactic acid and potassium chloride was achieved at low applied pressures and feed pH in the reverse osmosis process, as a greater permeation of potassium chloride was observed under these conditions. Furthermore, lactic acid retention was enhanced by operating at lower temperature. Partial separation between lactic acid and potassium chloride was also achieved in the electrodialysis process. However, the observed losses in lactic acid increased with the addition of sodium chloride to the feed solution. This indicates that the separation becomes more challenging as the complexity of the feed solution increases. Neither process was able to achieve sufficient separation to avoid the use of further purification processes.
酸性乳清是奶酪和酸奶生产的副产品。酸性乳清中的蛋白质和乳糖可以通过纳滤和电渗析回收，但这会产生一种由盐和乳酸组成的混合废物流。为了进一步提高酸性乳清处理过程的附加值，研究了使用低能耗反渗透膜或电渗析工艺回收这种乳酸的可能性。在反渗透过程中，在低施加压力和进料pH值条件下实现了乳酸和氯化钾之间的部分分离，因为在这些条件下观察到氯化钾有更大的渗透率。此外，在较低温度下操作可提高乳酸保留率。在电渗析过程中也实现了乳酸和氯化钾之间的部分分离。然而，随着进料溶液中添加氯化钠，观察到的乳酸损失增加。这表明随着进料溶液复杂性的增加，分离变得更具挑战性。两种工艺都无法实现足够的分离以避免使用进一步的纯化工艺。
