Isolation of a New Highly CO_2 Tolerant Fresh Water Microalgae and Determination of Influence of Environmental Factors in the Flue Gases on Its Growth

摘要

Compared with a few latest methods for the isolation of highly CO_2-tolerant microalgae for fixing CO_2 from fuel gases, a systemic study was performed in this paper, consisting of isolating microalgae strains and determining influence of environmental factors in the flue gases on the strains isolated. The results were showed as following. A fresh water microalgae named the ZY-1 strain, which has high CO_2 tolerance, was isolated. The ZY-1 strain was identified as genus Chlorella. It showed maximum growth at 10% (v/v) CO_2 enriched air flowing condition, and showed a good growth rate in a broad range of physically controllable conditions, including CO_2 concentration up to 70% (v/v), CO_2 enriched air flow rate of 0.25～0.75 L/min, 25～30C and pH4～6. Again, the growth of ZY-1 did not been influenced by SO_2 gas itself, however, when the SO_2 concentration was higher than 50 x 10~(-6)(v/v), ZY-1 growth rates were all lowed in that the pH of the medium decreased , so the measures must be taken to desulfurize or control pH of medium temporality. The presence of NO with concentrations of lower than 300 x 10~(-6) (v/v) did not influence the growth of ZY-1, whereas, NO absorbed in the medium was utilized as a nitrogen source. All above results indicated the feasibility of the ZY-1 strain for fixing CO_2 from flue gases.