GEPEA, Université de Nantes, CNRS, Saint-Nazaire Cedex, France.
AZM Center for Biotechnology Research and Its Applications, Laboratory of Applied Biotechnology, Lebanese University, Tripoli, Lebanon.
Environ Technol. 2020 Apr;41(9):1167-1184. doi: 10.1080/09593330.2018.1523234. Epub 2018 Sep 27.
The red microalga is exploited industrially for its exopolysaccharides (EPS) and pigments production. EPS produced by are partially released and dissolved into the surrounding environment, they can be recovered from the culture medium after removing the cells. This paper presents a parametric study of the ultrafiltration of EPS solutions on organic membrane. The EPS solutions were produced in conditions representative of an industrial production. They were filtered at lab-scale on a flat, PES 50 kDa MWCO membrane in a complete recirculation mode of permeate and retentate. Permeate flux-transmembrane pressure (TMP) curves were established up to the limiting flux for the filtration of solutions with various values of concentration in EPS (0.10-1.06 kg GlcEq m), fluid tangential velocity (0.3-1.2 m s) and temperature (20°C and 40°C). The reversible and irreversible parts of fouling were evaluated for each experiment and the critical flux was determined for an intermediate EPS concentration (0.16 kg GlcEq m). The results showed that EPS solutions had a strong fouling capacity. When filtering the lowest concentrated solution (0.10 kg GlcEq m) with moderate fouling conditions, the overall fouling resistance was approximately half of the membrane and the share of irreversible/reversible fouling was 88% and 12%. However, the part of reversible fouling becomes predominant when approaching the limiting flux. Permeate fluxes which were obtained allow to estimate that a VRR of approximately 10 could be obtained when concentrating EPS solutions using PES membranes in flat or tubular modules but not in spiral-wound.
红色微藻被工业上用于其胞外多糖 (EPS) 和色素的生产。由 产生的 EPS 部分释放并溶解到周围环境中，在去除细胞后可以从培养基中回收。本文对 EPS 溶液在有机膜上的超滤进行了参数研究。在代表工业生产条件的条件下生产 EPS 溶液。它们在实验室规模上用平片 PES 50 kDa MWCO 膜在渗透物和截留物的完全再循环模式下进行过滤。建立了各种 EPS 浓度（0.10-1.06 kg GlcEq m）、流体切向速度（0.3-1.2 m s）和温度（20°C 和 40°C）下的跨膜压力（TMP）曲线，直至过滤溶液的极限通量。为每个实验评估了可逆和不可逆部分的污垢，并确定了中间 EPS 浓度（0.16 kg GlcEq m）的临界通量。结果表明，EPS 溶液具有很强的污垢能力。当过滤污染条件适中的最低浓度溶液（0.10 kg GlcEq m）时，总污垢阻力约为膜的一半，不可逆/可逆污垢的份额为 88%和 12%。然而，当接近极限通量时，可逆污垢的部分变得占主导地位。获得的渗透通量允许估计当在平板或管状模块中使用 PES 膜浓缩 EPS 溶液时，VRR 约为 10，但在螺旋缠绕中则不行。
