Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea.
J Microbiol Biotechnol. 2013 Jan;23(1):92-8. doi: 10.4014/jmb.1210.10033.
Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% CO(2) gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.
利用废水培养微藻现在被认为是生物柴油生产的必要条件，因为可以同时实现两个目标；即，养分去除效率和生物质生产。因此，本研究考察了碳源、N:P 比和水力停留时间（HRT）的影响，以确定养分去除效率和生物质生产的最佳条件。使用二级塘的出水来培养微藻。虽然藻类的物种多样性和脂质含量随着 HRT 的延长而增加，但藻类生物量的生产力却下降了。不同的碳源也会影响藻类的物种组成。当供应碳酸氢盐时，藻类的 pH 值升高，硅藻占主导地位。然而，2%的 CO(2)气体会导致较低的 pH 值和丝状绿藻占主导地位，生物量生产力低得多。在实验中，当添加的磷高达 0.5 毫克/升时，叶绿素-a 浓度和脂质生产力最高，因为磷的供应与氮相比是不足的。基于添加的磷酸盐，通过平衡 N:P 比，氮和磷的去除效率也更高。因此，优化优势藻类的 N:P 比对于获得更高的藻类生长、脂质生产力和养分去除效率可能是关键。
