Engineering Research Center of Biofilm Water Purification and Utilization Technology of Ministry of Education, Anhui University of Technology, Ma'anshan, 243032, China.
School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
J Hazard Mater. 2022 Oct 5;439:129606. doi: 10.1016/j.jhazmat.2022.129606. Epub 2022 Jul 14.
Algal blooms caused by eutrophication are global phenomena that seriously threaten the sustainable use of freshwater resources. Traditional water treatment chemicals often typically lead to high levels of residue and cause damage to the morphology of algal cells. This study investigated an eco-friendly fungal bio-flocculant, Aspergillus oryzae, to remove the representative microalgae (Microcystis aeruginosa). Furthermore, it explored crucial flocculation parameters, adsorption kinetics, and thermodynamics of microalgae using A. oryzae. Accordingly, a flocculation efficiency of >95% was achieved when the fungus was cultured for six days, flocculant dosage was 11 g/L, rotation speed was 100 rpm, temperature was 25 °C, flocculation time was 5 h, and pH ranged between 4.0 and 9.0. KEGG analysis based on the genomic data, and chemical composition analysis revealed that proteins and polysaccharides were the major components of metabolites. Zeta potential analysis, scanning electron microscopy, three-dimensional fluorescence, X-ray spectroscopy, and infrared spectroscopy, electrostatic attraction revealed that electrostatic attraction promoted the destabilization and aggregation of microalgae. Additionally, hyphal surface adsorption and chemisorption from extracellular proteins and exopolysaccharides aided in the removal of microalgae. Therefore, fungi-based bio-flocculants have the potential to remove microalgae in a simple, effective, and eco-friendly manner without the complex extraction of extracellular metabolites.
富营养化引起的藻类水华是全球性现象，严重威胁着淡水资源的可持续利用。传统的水处理化学品通常会导致高残留水平，并对藻类细胞的形态造成损害。本研究利用真菌米曲霉（Aspergillus oryzae）开发了一种环保型真菌生物絮凝剂，用于去除代表性的微藻（铜绿微囊藻）。此外，还探讨了使用 A. oryzae 去除微藻的关键絮凝参数、吸附动力学和热力学。结果表明，当真菌培养 6 天时，絮凝效率>95%，絮凝剂用量为 11 g/L，转速为 100 rpm，温度为 25°C，絮凝时间为 5 h，pH 值在 4.0 到 9.0 之间。基于基因组数据的 KEGG 分析和化学成分分析表明，蛋白质和多糖是代谢物的主要成分。Zeta 电位分析、扫描电子显微镜、三维荧光、X 射线光谱和红外光谱分析表明，静电引力促进了微藻的失稳和聚集。此外，菌丝体表面吸附和胞外蛋白及胞外多糖的化学吸附有助于去除微藻。因此，真菌生物絮凝剂具有以简单、有效和环保的方式去除微藻的潜力，而无需对胞外代谢物进行复杂的提取。
