Microalgae hold great promise as environmentally sustainable sources of food, animal feed, and fuel. However, large amounts of water are used during microalgae cultivation and this negatively impacts economic viability and environmental sustainability. Reusing cultivation water can reduce the direct impacts of water usage and also reduce nutrient requirements and algal wastewater treatment. However, studies have shown that algae growth in reused water can be compromised, unaffected, or sometimes enhanced compared to controls. This review examines recent studies on water reuse to qualitatively understand these varied effects. Growth inhibitors and stimulators in reused water and their underlying mechanisms are discussed, as well as recent pre-treatment technologies and factors affecting the quality of reused water, such as microalgae taxa, culture conditions, and harvesting methods, are considered. A scheme is proposed for water reuse and harvesting methods based on the desired algal end products. Taking these findings together, here we provide recommendations for further research directions as well as new insights into designing and integrating a cultivation strategy with a harvesting platform to reuse water for more efficient microalgae cultivation.

微藻作为食物，动物饲料和燃料的环境可持续来源具有广阔的前景。但是，在微藻培养过程中会使用大量的水，这会对经济可行性和环境可持续性产生负面影响。再利用栽培水可以减少用水量的直接影响，还可以减少营养需求和藻类废水处理。但是，研究表明，与对照相比，回用水中的藻类生长可能受到损害，不受影响或有时得到增强。这篇综述审查了有关水回用的最新研究，以定性地了解这些不同的影响。讨论了再生水中的生长抑制剂和刺激剂及其潜在机理，以及最近的预处理技术和影响再生水质量的因素，例如微藻类群，考虑培养条件和收获方法。提出了一种基于所需藻类最终产品的水回用和收集方法的方案。综合这些发现，我们在此为进一步的研究方向提供建议，并为设计和将栽培策略与收割平台整合以重新利用水以进行更有效的微藻栽培提供新见解。