CEER, Nanjing Hydraulics Research Institute, Guangzhoulu 223, Nanjing 210029, China.
NIGLAS, Chinese Academy of Sciences, Beijingdonglu 73, Nanjing 210008, China.
Bioresour Technol. 2017 Jun;233:127-133. doi: 10.1016/j.biortech.2017.02.084. Epub 2017 Feb 20.
Microalgae are often used as feedstock for renewable biofuel production and as pollutant up-takers for wastewater treatment; however, biomass harvesting still remains a challenge in field applications. In this study, electro-flocculation using aluminium electrolysis was tested as a method to collect Chlorella vulgaris. The electrolysis products were positively charged over a wide pH range below 9.5, which gave them a flocculation potential for negatively charged microalgae. As flocculants were in-situ generated and gradually released, microalgae flocs formed in a snowballing mode, resulting in the compaction of large flocs. When higher current density was applied, microalgae could be harvested more rapidly, although there was a trade-off between a higher energy use and more residual aluminium in the culture medium. Benefits of this flocculation method are twofold: the phosphate decrease in post-harvesting could improve nutrient removal in microalgae based wastewater treatment, while the ammonium increase may favor microalgae recovery for medium recycling.
微藻通常被用作可再生生物燃料生产的原料，也被用作废水处理中的污染物吸收剂；然而，生物量的收获在现场应用中仍然是一个挑战。在本研究中，使用铝电解进行电絮凝被测试为一种收集普通小球藻的方法。在 pH 值低于 9.5 的广泛范围内，电解产物带正电荷，这使它们对带负电荷的微藻具有絮凝潜力。由于絮凝剂是原位生成并逐渐释放的，微藻絮体以滚雪球的方式形成，导致大絮体的压实。当施加更高的电流密度时，微藻可以更快地收获，尽管在更高的能量使用和培养基中更多的残留铝之间存在权衡。这种絮凝方法有两个好处：收获后磷酸盐的减少可以提高微藻基废水处理中的养分去除，而铵的增加可能有利于微藻的回收以进行介质再循环。
