电絮凝法收集湛江等鞭金藻

Harvesting of microalgae Isochrysis zhangjiangensis by electro-flocculation

建立了海洋微藻湛江等鞭金藻(Isochrysis zhangjiangensis)的电场絮凝收集方法。考察不同电极对絮凝率的影响,通过正交试验进行条件优化,分析了收集藻体的油脂含量及脂肪酸组成。结果表明:Al电极具有较高的絮凝率,但Fe电极具有较好的经济性。电流密度对絮凝率影响最大,其次是通电时间,最小是极板间距。最优电絮凝条件为电流密度12 m A/cm2、通电30 min以及极板间距2.0 cm,在此条件下,湛江等鞭金藻的絮凝率为92.7%,电絮凝过程能耗为2.0 k W·h/kg(以电收获微藻的干质量计)。电场絮凝和直接离心收集的藻体在油脂含量和主要脂肪酸组成及含量上均无明显差异。

An electroflocculation method to harvest marine microalgae Isochrysis zhangjiangensis was established. Effects of different electrodes on electro-flocculation rate were tested. The conditions for electroflocculation were optimized by orthogonal test. Fat content and fatty acid composition of Isochrysis zhangjiangensis harvested by electro-flocculation were analyzed. Aluminum electrode had a higher flocculation rate than that of iron electrode,but iron electrode had a lower cost. Current density had the most effect on flocculation rate,followed by power-on time and distance between the plates. Optimal conditions for the electro-flocculation process were： 12 m A / cm2 current density,30 min power-on time and2 cm plate spacing. Under the optimal conditions,the electro-flocculation process for Isochrysis zhangjiangensis reached a flocculation rate of 92. 7% and an energy consumption of 2. 0 k W·h / kg algae（ dry weight）. The fat content and fatty acid composition of Isochrysis zhangjiangensis harvested by centrifugation was similar to that by electro-flocculation.