Botany Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt.
Environ Sci Pollut Res Int. 2023 Mar;30(12):35492-35504. doi: 10.1007/s11356-023-25628-y. Epub 2023 Feb 3.
This study demonstrates the combination of wastewater treatment and green microalgae cultivation for the low-cost production of lipids as a feedstock for biodiesel production. Three green microalgal species were used: Chlamydomonas reinhardtii, Monoraphidium braunii, and Scenedesmus obliquus. Nutrient, heavy metals and minerals removal, biomass productivity, carbohydrate, protein, proline, lipid, and fatty acids methyl ester (FAMEs) contents besides biodiesel properties were evaluated. The results showed that all algal species were highly efficient and had the potential to reduce nitrate, ammonia, phosphate, sulfate, heavy metals (Zn, Cu, Mn, and Fe), calcium, magnesium, sodium, and potassium after 10 days of algal treatment compared to initial concentrations. The removal efficiency of these parameters ranged from 12 to 100%. The growth rates of M. braunii and S. obliquus cultivated in wastewater were significantly decreased compared to the control (synthetic medium). In contrast, C. reinhardtii showed the highest growth rate when cultivated in sewage water. Wastewater could decrease the soluble carbohydrates and protein content in all tested algae and increase the proline content in M. braunii and S. obliquus. In wastewater culture, M. braunii had the highest lipid productivity of 5.26 mg L day. The fatty acid profiles of two studied species (C. reinhardtii and M. braunii) revealed their suitability as a feedstock for biodiesel production due to their high content of saturated fatty acids, representing 80.91% and 68.62% of the total fatty acid content, respectively, when cultivated in wastewater. This study indicated that wastewater could be used to modify biomass productivity, lipid productivity, and the quantity of individual fatty acids in some algae that affect biodiesel quality to achieve international biodiesel standards.
本研究展示了废水处理与绿色微藻培养相结合，以低成本生产生物柴油原料脂质。使用了三种绿色微藻物种：莱茵衣藻、单歧藻和斜生栅藻。评估了营养物、重金属和矿物质去除、生物量生产力、碳水化合物、蛋白质、脯氨酸、脂质和脂肪酸甲酯（FAMEs）含量以及生物柴油特性。结果表明，与初始浓度相比，所有藻类在 10 天的藻类处理后都能高效去除硝酸盐、氨、磷酸盐、硫酸盐、重金属（锌、铜、锰和铁）、钙、镁、钠和钾。这些参数的去除效率在 12%至 100%之间。与对照（合成培养基）相比，在废水中培养的 M. braunii 和 S. obliquus 的生长速度显著降低。相比之下，C. reinhardtii 在污水中培养时表现出最高的生长速度。废水可以降低所有测试藻类中的可溶性碳水化合物和蛋白质含量，并增加 M. braunii 和 S. obliquus 中的脯氨酸含量。在废水培养中，M. braunii 的脂质生产力最高，为 5.26mg L -1 天。两种研究物种（C. reinhardtii 和 M. braunii）的脂肪酸谱表明，由于其饱和脂肪酸含量高，分别代表总脂肪酸含量的 80.91%和 68.62%，因此适合用作生物柴油生产的原料。本研究表明，废水可以用于改变一些藻类的生物量生产力、脂质生产力和个体脂肪酸的数量，从而影响生物柴油的质量，以达到国际生物柴油标准。
