Analytical and Circular Chemistry, Institute for Materials Research (imo-imomec), Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
Analytical and Circular Chemistry, Institute for Materials Research (imo-imomec), Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; Chemical Engineering Department, Escola Politécnica of the University of São Paulo, São Paulo, Brazil.
Bioresour Technol. 2024 Nov;411:131290. doi: 10.1016/j.biortech.2024.131290. Epub 2024 Aug 15.
Extracellular soluble algal organic matter (AOM) significantly interferes with microalgae flocculation. This study investigated the effects of various AOM fractions on Chlorella sp. flocculation using ferric chloride (FeCl), sodium hydroxide (NaOH), and chitosan. All flocculants achieved high separation efficiency (87-99 %), but higher dosages were required in the presence of AOM. High molecular weight (>50 kDa) AOM fraction was identified as the primary inhibitor of flocculation across different pH levels, whereas low/medium molecular weight (<3 and <50 kDa) AOM had minimal impact. Compositional analysis revealed that the inhibitory AOM fraction is a glycoprotein rich in carbohydrates, including neutral, amino, and acidic sugars. The significance of this study is in identifying carboxyl groups (-COOH) from acidic monomers in >50 kDa AOM that inhibit flocculation. Understanding AOM composition and the interaction dynamics between AOM, cells, and flocculants is crucial for enhancing the techno-economics and sustainability of flocculation-based microalgae harvesting.
细胞外可溶性藻类有机物质（AOM）会显著干扰微藻絮凝。本研究使用三氯化铁（FeCl）、氢氧化钠（NaOH）和壳聚糖研究了各种 AOM 级分对小球藻絮凝的影响。所有絮凝剂都实现了高分离效率（87-99%），但在存在 AOM 的情况下需要更高的剂量。高分子量（>50 kDa）AOM 级分被确定为不同 pH 值下絮凝的主要抑制剂，而低/中分子量（<3 和<50 kDa）AOM 的影响最小。组成分析表明，抑制絮凝的 AOM 级分是一种富含碳水化合物的糖蛋白，包括中性、氨基和酸性糖。本研究的意义在于确定>50 kDa AOM 中酸性单体中的羧基（-COOH）抑制絮凝。了解 AOM 的组成以及 AOM、细胞和絮凝剂之间的相互作用动态对于提高基于絮凝的微藻收获的技术经济性和可持续性至关重要。
