Abstract An issue of acid whey processing, well known in the dairy industry, is its high amount of lactic acid, a key feature that hampers acid whey industrial utilization. As a result, dried products of acid whey treatment possess a number of undesirable properties such as elevated acidity, hygroscopicity and caking. In the present study, electrodialysis with bipolar membranes (EDBM) was used to alkalinize acid whey at laboratory scale. Two alternative configurations of electrodialysis cells were designed, where the whey stream was directly connected to the bipolar membrane generating hydroxide ions. pH of acid whey was raised up to 6.5. The above said pH adjustment corresponded to 25% lactic acid removal rate and 24–34% demineralization rate. The operation of EDBM, although efficient, induced fouling on the anion-exchange side of bipolar membranes after acid whey alkalinization. A complex analysis of membranes after whey processing was conducted. The analysis of whey precipitate and membrane fouling revealed 13 and 7% protein content in respective dried samples. Membrane fouling displayed minor protein content; thus, mineral fraction was likely to be dominant in the fouling matter.

中文翻译：

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双极膜电渗析法碱化酸性乳清及诱导膜污染分析

摘要 乳制品行业众所周知的酸乳清加工问题是乳酸含量高，这是阻碍酸乳清工业利用的一个关键特征。结果，酸乳清处理的干燥产品具有许多不良特性，例如酸度升高、吸湿性和结块。在本研究中，双极膜电渗析 (EDBM) 用于在实验室规模碱化酸乳清。设计了两种不同的电渗析池配置，其中乳清流直接连接到双极膜，产生氢氧根离子。酸性乳清的 pH 值提高到 6.5。上述 pH 调节对应于 25% 的乳酸去除率和 24-34% 的脱矿率。EDBM 的运行虽然高效，酸乳清碱化后在双极膜的阴离子交换侧诱导结垢。对乳清加工后的膜进行了复杂的分析。对乳清沉淀和膜污染的分析表明，各自干燥样品中的蛋白质含量分别为 13% 和 7%。膜污染显示少量蛋白质含量；因此，矿物部分可能在污垢物质中占主导地位。