Laboratory of Environmental Bioprocesses, Sfax Centre of Biotechnology, University of Sfax, P.O. Box 1177, 3018 Sfax, Tunisia; Chemical Engineering Department, University of Almería, 04120 Almería, Spain.
Chemical Engineering Department, University of Almería, 04120 Almería, Spain.
J Environ Manage. 2018 Apr 1;211:112-124. doi: 10.1016/j.jenvman.2018.01.043. Epub 2018 Feb 4.
This work investigates the production of the native microalgae strain Scenedesmus sp. in semi-continuous mode at lab scale in open raceway-simulating reactors and using centrate as the culture medium. The biomass productivity and nutrient removal capacity of Scenedesmus sp. at different dilution rates were investigated indoors as well as its tolerance to centrate as the culture medium at different concentrations. A biomass productivity of 7.80 g/m day was obtained at 200 μE/m s, 5 cm culture depth, 0.30 1/day of dilution rate and 60% centrate while nitrogen and phosphorus removal rates were 1.50 g/m day and 0.15 g/m day, respectively. The produced biomass characterization under these conditions showed a lipid content of 12.60% d wt. along with a favorable fatty acids profile with 57.70% of total fatty acids composed of saturated and monounsaturated fatty acids. Subsequently, the effect of light intensity and culture depth on biomass productivity and nutrient uptake as well as the biochemical composition and fatty acids profile was studied using two irradiance levels (200 and 1000 μE/m s) and four culture depths (5 cm, 10 cm, 15 cm and 20 cm). Under optimal conditions of 1000 μE/m s, 60% centrate, 0.30 1/day dilution rate and 15 cm culture depth, a maximum biomass productivity of 22.20 g/m day was obtained. Nitrogen and phosphorus removal rates of 2.00 gN/m day and 0.40 gP/m day, respectively, were recorded. An amount of 11.70% d wt. of lipids was determined along with a suitable fatty acids profile for biofuel production.
本研究以浓缩废水为培养液，在开放型跑道式模拟光生物反应器中采用本地微藻小球藻（Scenedesmus sp.）进行半连续培养，考察不同稀释率下小球藻的生物量生产力和营养物质去除能力，以及不同浓缩废水浓度下小球藻对培养液的耐受能力。结果表明，在 200 μE/m²·s、5 cm 培养液深度、0.30 1/d 的稀释率和 60%浓缩废水条件下，小球藻的生物量生产力达到 7.80 g/m²·d，氮磷去除率分别为 1.50 g/m²·d 和 0.15 g/m²·d。在这些条件下，所产生物量的特征分析表明，其干重脂肪含量为 12.60%，脂肪酸组成中饱和脂肪酸和单不饱和脂肪酸的比例高达 57.70%。随后，研究了光照强度和培养液深度对生物量生产力和营养物质吸收以及生物化学组成和脂肪酸组成的影响，采用 200 和 1000 μE/m²·s 两种光照强度和 5、10、15 和 20 cm 四种培养液深度。在 1000 μE/m²·s、60%浓缩废水、0.30 1/d 稀释率和 15 cm 培养液深度的最佳条件下，小球藻的生物量生产力达到 22.20 g/m²·d，氮磷去除率分别为 2.00 gN/m²·d 和 0.40 gP/m²·d。干重脂肪含量为 11.70%，脂肪酸组成适合生物燃料生产。
