Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea; Department of Civil and Environmental Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Graduate School of Energy Science and Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
Bioresour Technol. 2017 Sep;239:190-196. doi: 10.1016/j.biortech.2017.05.021. Epub 2017 May 5.
Chemical flocculation is considered to be an overall low-cost and up-scalable process for harvesting of microalgae. In this study a new flocculation approach utilizing metal coagulant (Fe(SO)) and sulfuric acid (HSO) was introduced for harvesting of Chlorella sp. KR-1, which overcome two main issues of contamination and reuse of coagulant. Reduction of pH successfully released precipitates attached to the microalgae, and the remaining acidic solution containing recovered ferric ions could be reused for harvesting up to three times with high, better-than 98% efficiencies. Moreover, the acid-treated microalgal biomass could be directly used for lipid extraction without additional catalyst. High extraction yields of around 32% were achieved with FAME conversion efficiencies of around 90%. The integrated approach devised in the present study is expected to make the best use of the age-old yet effective harvesting means of flocculation, which can be a practical and economical option in microalgal biorefinery.
化学絮凝被认为是一种总体上低成本和可扩展的微藻收获方法。在这项研究中，引入了一种新的絮凝方法，利用金属混凝剂（Fe(SO))和硫酸（HSO）来收获小球藻 KR-1，克服了混凝剂污染和再利用的两个主要问题。降低 pH 值成功地释放了附着在微藻上的沉淀物，并且含有回收的铁离子的剩余酸性溶液可以重复使用多达三次，效率高达 98%以上。此外，酸处理后的微藻生物质可以直接用于脂质提取，无需额外的催化剂。通过 FAME 转化率约为 90%，可实现约 32%的高提取收率。本研究设计的综合方法有望充分利用古老而有效的絮凝收获方法，这在微藻生物炼制中是一种实用且经济的选择。
