乳化液膜提取柠檬酸及其溶胀的研究

本文研究了采用Ｗ／Ｏ型乳化液膜提取水溶液中的柠檬酸，同时研究了柠檬酸提取过程中水的传质行为（乳液溶胀）。考察了表面活性剂、载体、反萃剂Ｎａ２ＣＯ３、柠檬酸浓度对柠檬酸传质和乳液溶胀的影响。实验结果表明：萃取率随载体和内相试剂浓度的增加而增加；当载体和初始柠檬酸浓度较高时，乳液更易于溶胀，由此得出了除渗透压造成的乳液溶胀外，溶质与载体形成的络合物也能促成乳液的溶胀。提出了分离浓缩柠檬酸的最佳乳液配方

STUDIES ON EXTRACTION OF CITRIC ACID BY LIQUID SURFACTANT MEMBRANE AND EMULSION SWELLING

Emulsion liquid membranes (ELMs) were applied to the seperation of citric acid from an aqueous feed solution, and the water transport (emulsion swelling) was studied during separation of citric acid. The effect of variables, such as the concentration of surfactant, carrier, Na2CO3,and initial citric acid concentration on citric acid transport and emulsion swelling was investigated. The experimental results showed that the transport rate of citric acid was increased with the increases in concentration of carrier and Na2CO3. When the concentration of carrier and initial citric acid increased, the emulsion was more easy to swell, which means that emulsion swelling can also be promoted by solute/carrier complexes although it is generally driven by the osmotic pressure difference between the external phase and internal phase. An optimal ELM formula was given for separation and concentration of citric acid. A new process for separation of organic acid from fermentation broth was proposed,