In this study, we examined a Chlorella vulgaris-based system as a potential solution to change liquid waste, such as blackwater, into valuable products for agriculture while protecting waters from pollution without technical demanding pre-treatment. To evaluate the possibility of nutrient removal and biomass production from raw blackwater, four blackwater dilutions were tested at lab-scale: 50%, 30%, 20%, and 10%. The results showed that even the less diluted raw blackwater was a suitable growth medium for microalgae C. vulgaris. As expected, the optimum conditions were observed in 10% blackwater with the highest growth rate (0.265 d−1) and a nutrient removal efficiency of 99.6% for ammonium and 33.7% for phosphate. However, the highest biomass productivity (5.581 mg chlorophyll-a L−1 d−1) and total biomass (332.82 mg dry weight L−1) were achieved in 50% blackwater together with the highest chemical oxygen demand removal (81%) as a result of the highest nutrient content and thus prolonged growth phase. The results suggested that the dilution factor of 0.5 followed by microalgae cultivation with a hydraulic retention time of 14 days could offer the highest biomass production for the potential use in agriculture and, in parallel, a way to treat raw blackwater from source-separation sanitation systems.

中文翻译：

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基于普通小球藻的系统处理和再利用原黑水

在这项研究中，我们研究了基于普通小球藻的系统作为将液体废物（如黑水）转化为有价值的农业产品的潜在解决方案，同时无需技术要求的预处理即可保护水免受污染。为了评估从原黑水中去除养分和生产生物量的可能性，在实验室规模下测试了四种黑水稀释液：50%、30%、20% 和 10%。结果表明，即使是稀释程度较低的原黑水也是微藻 C. vulgaris 的合适生长培养基。正如预期的那样，在 10% 的黑水中观察到最佳条件，其生长速率最高（0.265 d-1），铵盐和磷酸盐的养分去除效率分别为 99.6% 和 33.7%。然而，最高的生物量生产力（5.581 mg 叶绿素-a L-1 d-1）和总生物量（332. 由于最高的养分含量和延长的生长期，在 50% 的黑水中获得了 82 mg 干重 L-1) 以及最高的化学需氧量去除 (81%)。结果表明，稀释系数为 0.5 后进行微藻培养，水力停留时间为 14 天，可为农业潜在用途提供最高的生物质产量，同时也是一种处理来自源头分离卫生系统的原黑水的方法.