Feasibility of CO2 mitigation and carbohydrate production by microalga Scenedesmus obliquus CNW-N used for bioethanol fermentation under outdoor conditions: effects of seasonal changes

Table 3 Comparison of biomass productivity, carbohydrate productivity, and CO₂ fixation rate of S. obliquus CNW-N grown in different seasons in outdoor surroundings

Seasonal condition	Avg. light intensity (μmol m⁻²s⁻¹)	Avg. water temperature (^oC)	Biomass productivity (mg L⁻¹d⁻¹)	Carbohydrate (glucose) productivity (mg L⁻¹d⁻¹)	CO₂ fixation rate (mg L⁻¹d⁻¹)^a
Spring (Mar–May)	148.3 ± 44.5	27.1 ± 2.8	190.4 ± 26.8	79.7 ± 19.1 (61.1 ± 16.0)	333.1 ± 46.8
Summer (Jun–Aug)	198.7 ± 43.4	31.3 ± 1.9	205.1 ± 23.1	83.9 ± 9.9 (65.6 ± 7.3)	358.8 ± 40.4
Autumn (Sep–Nov)	171.6 ± 91.7	27.3 ± 4.4	178.9 ± 60.2	75.9 ± 32.1 (60.4 ± 27.0)	313.2 ± 105.4
Winter (Oct–Feb)	93.0 ± 50.2	20.5 ± 1.0	119.2 ± 18.7	47.3 ± 6.0 (35.5 ± 5.2)	208.7 ± 32.7

Values are the mean ± standard deviation of three-month experiments. (CO₂ feeding concentration = 2.5%; working volume = 60 L.)
^aCalculated from the following equation: CO₂ fixation rate = Biomass productivity (mg L⁻¹d⁻¹) × C(%) × 44/12

ISSN: 2731-3654