Microalgae bio-treatment of synthetic fertilizer wastewater is particularly attractive due to their photosynthetic capabilities. Microalgae tend to convert solar energy into useful biomass, incorporating with the nutrients that present in wastewater, such as nitrogen and phosphorus. However, harvesting of microalgae remains a challenge because of the small size (3–30 μm) of microalgae cells and the repulsion between the negatively charged microalgae cells maintains a stable cell suspension. Magnetic-aided-embedding-flocculation strategy, which is one-step method by mixing microalgae, magnetic particles and flocculant together, is proposed for microalgae harvesting in order to meet cost and time effectiveness. In this study, the optimum cell separation efficiency of Chlorella vulgaris microalgae above 96% at 5 mg/L of chitosan dosage is achieved. With the aid of iron oxide particles, either micro- or nano-size, the sedimentation rate of cell flocs up to 250 cm/h is obtained when 10 mg/L of iron oxide is embedded into the cell flocs. The sedimentation rate with the embedding of iron oxide shows about 2 times faster than that of without magnetic particles. This strategy had proven effective for the polishing of the pretreated synthetic fertilizer wastewater by removing up to 53%, 74% and 70% of ortho-phosphate, nitrate and ammoniacal nitrogen, respectively. In addition, the presence of iron oxide particles and chitosan in microalgae harvesting that showed no adverse effect toward the quantity and quality of extracted lipid. This strategy is proven feasible for fertilizer wastewater treatment and biodiesel production.

微藻生物处理合成肥料废水特别有吸引力，因为它们具有光合作用能力。微藻倾向于将太阳能转化为有用的生物质，并结合废水中存在的营养物，例如氮和磷。然而，由于微藻细胞的体积小（3–30μm），带负电荷的微藻细胞之间的排斥作用保持稳定的细胞悬浮液，因此微藻的收获仍然是一个挑战。为了满足成本和时间效益，提出了一种将微藻，磁性颗粒和絮凝剂混合在一起的一步法磁辅助包埋絮凝策略。在这项研究中，小球藻的最佳细胞分离效率在5 mg / L的壳聚糖剂量下，可实现96％以上的微藻。借助于微米或纳米尺寸的氧化铁颗粒，当将10 mg / L的氧化铁嵌入到细胞絮凝物中时，可获得高达250 cm / h的细胞絮凝沉淀速率。嵌入氧化铁的沉积速率比没有磁性颗粒的沉积速率快​​约2倍。事实证明，该策略可通过分别去除高达53％，74％和70％的正磷酸盐，硝酸盐和氨氮来抛光预处理的合成肥料废水。此外，微藻收获中氧化铁颗粒和壳聚糖的存在对提取脂质的数量和质量没有不利影响。实践证明，该策略可用于化肥废水处理和生物柴油生产。