Biomass Production Potential of Chlorella vulgaris Under Different CO_2 Concentrations and Light Intensities

초록

The increasing demand of the crops(soybean and corn) for biofuel production has increased the focus of the animal nutritionists to look for alternative feeds, which are economic and environmental friendly. To identify microalgae as suitable candidate as an alternative feed, growth response of Chlorella vulgaris was studied under varying concentrations of carbon dioxide (0.07, 1.4, 3.0 and 5.0%) and photon densities(39.19, 72.97, 105.41, 116.22, 135.14, 175.68µmol/m^2/s) by employing a photo-bioreactor. Swine wastewater was also investigated as nutritional source to economize the biomass production. Results showed that the higher biomass production was found to be at 3.0% CO_2 compared to other CO_2 concentrations. However, no difference in biomass production was found at 105.41μmol/m^2/s and above photon densities with 12 h of photoperiodicity. It was observed that C. vulgaris could easily grow in 200 times diluted swine wastewater and growth was found to be similar with that of artificial medium. Provided the conducive conditions for optimal growth, it has also the potentiality of depleting ammonia nitrogen(NH_4-N) and orthophosphate(PO_4^3－-P) completely from the wastewater after 3~4 days of cultivation. Thus, growing C. vulgaris would not only solve the problem of animal feed, but also help in biological CO_2 mitigation and wastewater treatment.

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