The bio-flocculation ability of UTEX 2341 was studied for the purpose of improving microalgae harvesting efficiency to cut the high cost of biofuel production. The algae cells of UTEX 2341 cultured under heterotrophic and municipal wastewater conditions were found to have better self-flocculation ability, with flocculation rates of 92% and 85% at 2 h, respectively. Moreover, the flocculation rates of 16 freeze-dried microalgae powder samples cultured under different stress conditions were 0~72% with an algae powder dosage of 35 mg L⁻¹. The flocculation efficiency of DIM, DCd1, DT28, and L6S was stable under different pH of 3~9 and temperatures of 15~50 °C. For samples of IM, LCd0.6, LMn2, and LZn2, the flocculation efficiency decreased or increased respectively with increased pH or temperatures. Though the flocculation properties of the eight samples showed wide differences, their flocculant compositions were almost the same with unknown components occupying large proportions. More studies needed to be further carried out to reveal the flocculation mechanisms and analyze the flocculation abilities in practical application, which would be conducive to future large-scale application of the bio-flocculation method and also cost reduction.

中文翻译：

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含油微藻原生态小球藻UTEX 2341的生物絮凝特性分析

研究了UTEX 2341的生物絮凝能力，目的是提高微藻的收获效率，从而降低高昂的生物燃料生产成本。发现在异养和城市废水条件下培养的UTEX 2341藻类细胞具有更好的自絮凝能力，在2 h时的絮凝率分别为92％和85％。另外，在不同胁迫条件下培养的16种冻干微藻粉样品的絮凝率为0〜72％，藻粉用量为35 mg L ^-1。。DIM，DCd1，DT28和L6S的絮凝效率在3〜9的不同pH和15〜50°C的温度下稳定。对于IM，LCd0.6，LMn2和LZn2样品，絮凝效率分别随pH或温度的升高而降低或升高。尽管八个样品的絮凝性能差异很大，但它们的絮凝剂组成几乎相同，未知组分占很大比例。需要进一步开展研究，以揭示絮凝机理，并在实际应用中分析其絮凝能力，这将有利于生物絮凝方法的未来大规模应用和降低成本。