One of the bottlenecks to commercialize microalgae-based biofuel production is harvesting of microalgae biomass from high dilute culture broth. Meanwhile, flocculation is identified as a low cost and promising technique to address this challenge. In this study, the flocculating potential of agricultural waste derived bio-based alkali from plantain peel ash was evaluated. The plantain peel ash and the produced bio-based alkali were characterized using inductively couple plasma mass spectrometry (ICP-MS) and scanning electron microscope-energy-dispersive X-ray spectroscopy (SEM-EDS). Results showed that more than 90% harvesting efficiency of microalgae biomass were obtained for both Nannochloropsis oculata and Dunaliella salina at 1, 2 and 3% v/v flocculant (bio-based alkali) dose, while the maximum biomass concentration factors were 20 and 14 at 1% v/v flocculant dose for N. oculata and D. salina respectively. The positive effect of calcium ion concentration on alkaline flocculation of freshwater microalgae species Neochloris conjuncta was demonstrated. Also, the characterization of the produced bio-based alkali indicates that the concentration of K⁺ (61,630 ppm) is highest, followed by Ca²⁺ (1,569 ppm) and Na⁺ (582 ppm), which clearly support the alkaline nature of the flocculant. The chromatogram obtained from SEM-EDS of the ash also corroborates the highest proportion of potassium in the ash sample. This study shows that the plantain peel-derived alkali can be used to effectively and efficiently harvest microalgae biomass from very dilute microalgae culture media.

商业化基于微藻的生物燃料生产的瓶颈之一是从高稀释培养液中收获微藻生物质。同时，絮凝被认为是解决这一挑战的低成本和有前途的技术。在这项研究中，评估了来自车前草皮灰的农业废料生物基碱的絮凝潜力。使用感应耦合等离子体质谱（ICP-MS）和扫描电子显微镜-能量色散X射线光谱（SEM-EDS）对车前草皮灰和产生的生物基碱进行了表征。结果表明，对于拟南芥和杜氏盐藻，微藻生物量的收获效率均超过90％。在1，2和3％V / V絮凝剂（基于生物的碱）的剂量，而最大生物量浓度的因素分别为20和14在1个％V / V对絮凝剂剂量微拟球藻和杜氏盐藻分别。证明了钙离子浓度对淡水微藻结球藻碱絮凝的积极作用。另外，对所产生的生物基碱的表征表明，K ⁺（61,630 ppm）的浓度最高，其次是Ca ²⁺（1,569 ppm）和Na ^+的浓度。（582 ppm），明显支持了絮凝剂的碱性。从灰分的SEM-EDS获得的色谱图也证实了灰分样品中钾的最高比例。这项研究表明，车前草皮中的碱可用于从非常稀的微藻培养基中有效有效地收获微藻生物质。