产油嗜碱绿球藻MC-1的烟气适应性

Adaptability of oleaginous microalgae Chlorococcum alkaliphilus MC-1 cultivated with flue gas

摘要:

为了降低微藻产油成本和减少温室气体的排放，利用煤炭烟气培养一株具有pH快速漂移和高碱适应特性的产油微藻Chlorococcum alkaliphilus MC-1。首先于15 L光生物反应器中分三组 (空白组、CO2组和烟气组) 进行小体积培养实验，然后在24 m2开放式跑道池中进行放大培养，研究了微藻MC-1对烟气培养的适应性。结果表明，在光生物反应器培养实验中，烟气组的最高生物量浓度、生长速率、藻体总脂含量和CO2固定速率分别为：(1.02±0.07) g/L、(0.12±0.02) g/(L·d)、(37.84±0.58)％和(0.20±0.02) g/(L·d)，比CO2组分别提高了36％、33.33％、15.34％和33.33％。在开放式跑道池培养实验中，烟气与纯CO2的培养效果相似，烟气培养下的最高生物量浓度、生长速率、藻体总脂含量和CO2固定速率分别为：147.40 g/m2、14.73 g/(m2·d)、35.72％和24.01 g/(m2·d)；烟气培养产出的藻粉中有毒重金属Pb、As、Cd和Cr的含量均低于国家限量标准。实验同时测定了烟气培养下藻液对烟气中CO2、NO和SO2的吸收效果，结果显示，在光生物反应器和开放式跑道池培养中此三种气体的平均吸收率均高于以往研究结果。上述结果说明，该藻能适应烟气培养条件，耦合微藻MC-1产油与烟气减排的室外放大培养是可行的。

Abstract:

In order to lower the cost of lipid production of microalgae and reduce greenhouse gas emissions, microalgae Chlorococcum alkaliphilus MC-1 with the characteristics of rapid pH drift and high pH adaptability, was cultivated with bubbling of flue gas. The experiment was first performed in the photobioreactor (15 L) in three groups (control group, CO2 group and flue gas group), then, in the open raceway pond (24 m2). The adaptability of microalgae MC-1 to the cultivation with flue gas was studied. The results showed that the maximum biomass concentration, growth rate, total lipid content and CO2 fixation rate were (1.02±0.07) g/L, (0.12±0.02) g/(L·d), (37.84±0.58)% and (0.20±0.02) g/(L·d) in the photobioreactor treated with flue gas, 36%, 33.33%, 15.34% and 33.33% higher than those of the CO2 group, respectively. In the open raceway pond with aeration of flue gas, the maximum biomass concentration, growth rate, total lipid content and CO2 fixation rate were 147.40 g/m2, 14.73 g/(m2·d), 35.72% and 24.01 g/(m2·d), respectively, which were similar to the cultivation with pure CO2. The toxic heavy metal contents (Pb, As, Cd and Cr) in the biomass of MC-1 treated with flue gas were all below the legal limits. Additionally, the absorptive effect of CO2, NO and SO2 were determined. In the photobioreactor and open raceway pond, the average absorption ratios of these gases were all higher than previous studies. Therefore, our study showed that MC-1 can adapt to the cultivation with flue gas, and it is feasible to enlarge the outdoor cultivation of MC-1 for lipid production coupling with emissions reduction of flue gas.