Fermentation is an alternative for the large-scale production of succinic acid, obtained nowadays from petroleum. However, the fermentation process still needs improvement. Nanofiltration has been studied as a post-fermentation step to enhance the purification and to intensify the production process. In this work, the transport of succinic acid through nanofiltration membranes was investigated. The effects of the operating pressure, pH, concentration of succinic acid and the presence of glucose (as a neutral solute) and salts (NaCl and MgSO4) on acid retention and permeate flux were evaluated. It was found that acid retention increases with both pH and gauge pressure. Permeate flux increases with pressure and decreases with pH. From pH around the membrane isoelectric point (IEP), succinic acid retentions increase when either NaCl or MgSO4 are present.

中文翻译：

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进料条件和添加溶质对琥珀酸溶液膜纳滤性能的影响

发酵是目前从石油中获得的琥珀酸的大规模生产的替代方法。但是，发酵过程仍然需要改进。纳滤已被研究作为发酵后步骤，以增强纯化和强化生产过程。在这项工作中，研究了琥珀酸通过纳滤膜的传输。评估了操作压力、pH、琥珀酸浓度以及葡萄糖（作为中性溶质）和盐（NaCl 和 MgSO4）的存在对酸保留和渗透通量的影响。发现酸保留随着pH值和表压而增加。渗透通量随压力增加而随pH值降低。从膜等电点 (IEP) 附近的 pH 值，