碳捕集及资源化利用对缓解全球变暖、冰川融化等环境问题具有重要意义，是实现碳中和的有效途径之一。传统的化学吸收法捕集CO2能耗高，而微藻生物固定CO2时，由于CO2在培养基中溶解度低，导致CO2逃逸，造成固碳效率低及CO2二次排放。化学吸收与微藻固碳耦合系统具有潜在的降低再生能耗及提升一体化CO2资源化利用优势。采用氨水作为化学吸收剂，充分吸收CO2后生成的NH4HCO3部分替代传统微藻培养过程中的氮源NaNO3，为降低高浓度NH+4-N对螺旋藻的毒性，进一步降低耦合系统的氮源成本，采用分批补加NH4HCO3的形式优化氮源组成。结果表明，分批补加NH4HCO3可在不影响螺旋藻生长的情况下，降低NaNO3总需求量，促进脂质合成。每6 d补加50 mg/L NH4HCO3螺旋藻的固氮率和固碳能力最高，分别为32.33%和149.24 mg/(L·d)，并在第12天获得最大生物量1.30 g/L。此外，不同分批补料方式影响了耦合系统中螺旋藻后期产物的形成，每6 d补加50 mg/L NH4HCO3有利于螺旋藻蛋白质生产，质量浓度达889.17 mg/L；每6 d补加75 mg/LNH4HCO3有利于螺旋藻碳水化合物的累积，质量浓度达1 632.86 mg/L。本研究通过分批补料为化学吸收-微藻转化耦合体系推广提供指导，具有一定应用前景。

Carbon capture and resource utilization are of great significance to alleviate environmental problems such as global warming and glacier melting, and it is one of the effective ways to achieve carbon neutrality. The conventional CO2 capture way by chemical absorption has the problem of high energy consumption. Due to the low solubility of CO2 in the medium, CO2 escape is often caused when fixed by microalgae, then resulting in low carbon fixation efficiency and secondary CO2 emissions. Chemical absorption and microalgae conversion hybrid system has the potential advantages of reducing renewable energy consumption and improving CO2 resource utilization.Ammonia was used as a chemical absorber, and NH4HCO3 generated after fully absorbing CO2 partially replaced NaNO3 in the process of traditional microalgae culture. In order to reduce the toxicity of high concentration NH+4-N to Spirulina and further reduce the nitrogen source cost of the coupling system, the nitrogen source composition was optimized by batch addition of NH4HCO3. Results shows that batch addition of NH4HCO3 can reduce the required total nitrogen content and promote the synthesis of lipid without affecting the growth of Spirulina. When 50 mg/L NH4HCO3 is added every 6 days, the nitrogen fixation rate and carbon fixation capacity are the highest, which are 32.33% and 149.24 mg/(L·d), respectively, and the maximum biomass is 1.30 g/L on the 12th day. In addition,the components of Spirulina in the coupling system are affected by different feding-batch modes. Supplementation of 50 mg/L NH4HCO3 every 6 days is beneficial to the production of protein, which reaches 889.17 mg/L. Adding 75 mg/L NH4HCO3 every 6 days is conducive to the accumulation of carbohydrates in Spirulina, reaching 1 632.86 mg/L. This study provides guidance for the further application of the chemical absorption and microalgae conversion hybrid system by batch feeding mode, and has the potential and application prospects.

0 引言

1 试验

   1.1 藻种和材料

   1.2 培养条件

   1.3 分析方法

2 结果与讨论

   2.1 分批补料对微藻生长的影响

   2.2 耦合系统中的氮分布

   2.3 分批补料对微藻固碳能力的影响

   2.4 分批补料对螺旋藻后期产物的影响

3 结论