高密度培养小球藻去除CO_2的研究

Enhanced Algal CO_2 Sequestration through Optimum Cultivation by Chlorella vulgaris

抗逆性强、生长速率快且能高密度培养的微藻是生物法固碳的良好材料。沼液中含有小球藻生长所需的基本营养物质,但其比例及浓度并不能满足微藻高密度发酵以大量固碳的要求。文章以沼液中驯化出的抗逆性小球藻为实验藻株,以沼液为基础培养基,考察了该藻高密度培养的条件,并将其应用于CO2的去除。结果以50%沼液为基础培养基,补加氮80 mg,磷40 mg,柠檬酸铁12 mg,MgSO.47H2O 24 mg,MnSO.4H2O 1.6 mg,泵入含有1.5%CO2的混合空气,通气量100 mL/min的培养条件最利于小球藻的生长,对CO2的去除率也最高。该藻在0.5%~10.0%的CO2浓度下皆生长良好,对数生长初期固碳能力最强。优化条件下培养的小球藻干重可达12.032 g/L,为基础培养基的5.89倍;对CO2的去除率为27.69%,固碳量达到256.86 mg/（L.h）。

Microalgae with strong environmental resistance,high growth rate and high biomass yields are good materials for CO2 bio-fixation.Biomass slurry contains the basic nutrients needed for microalgal cells growth,but the proportion and concentration could not meet the requirement of CO2 fixation by microalgae cultured with high cell density.Using the microalgae strains domesticated in slurry medium as the experimental strain and 50% slurry as basic medium,Chlorella vugaris was cultivated to determine the optimum culture conditions and applied to removal of CO2.Under the conditions of 50% slurry medium supplemented with nitrogen 80 mg,phosphorus 40mg,ferric citrate 12 mg,MgSO4·7H2O 24 mg,MnSO4·H2O 1.6 mg,CO2 concentration 1.5% and aerating 100 mL/min,the cells exhibited high ability of both producing high biomass and reducing CO2.With the maximum capacity of CO2 fixation in the early logarithmic phase,grew well in a wide CO2 concentration from 0.5% to 10.0%.With the optimum culture conditions,the cells dry weight was increased by 5.89 fold to 12.032 g/L comparing to slurry medium.The peak efficiency of CO2 removal was 27.69% and rate of CO2 reduction was 256.86 mg/（L·h）.