Study of acidic air pollutant (SO2 and NO2) tolerance of microalgae with sodium bicarbonate as growth stimulant

Abstract

The major environmental toxicity of acidic pollutant in the fossil fuel gas substances has long been well known. Macro and microalgae are biological sources with a large range of biotechnological uses, for e.g., bioremediation, bio-fuel, air pollutant absorber, and many more. This study addresses the use of Chlamydomonas sp., an effective biomaterial in their tolerance against 2 and 5% of the SO2 & NO2. Growth kinetics were improved by the addition of sodium bicarbonate to the culture conical media. SO2 and NO2 were provided to culture media by the use of sodium meta-bisulfite and nitrous acid. The control combination of SO2 and NO2 provides: 2% SO2, 5% SO2, 2% NO2, 5% NO2, (2% SO2 + 2% NO2), (5% SO2 + 5% NO2) at the seventh day of incubation. The optimum pH ranged between 7.1 and 8.6 when exposed to gas. Results suggested that the growth kinetics of Chlamydomonas sp. is greater in SO2 and low in the 5% exposure of NO2. The maximum absorbing concentrations of SO2 and NO2 were 921.625 μg/ml and 906.25 μg/ml respectively for Chlamydomonas sp. This work highlights the potential of algae in tolerance to NO2 & SO2 from the polluted air. HIGHLIGHTS The study addresses the use of Chlamydomonas sp., an effective biomaterial in their tolerance against various combinations of 2 and 5% of SO2 & NO2.; Their growth kinetics were improved by addition of sodium bicarbonate to the culture conical media.; Results highlighted that the growth kinetics of Chlamydomonas sp. is greater in SO2.; This work highlights the potential of algae in tolerance to NO2 & SO2 from the polluted air.;

Keywords

• absorbance
• air pollution
• microalgae
• nitrogen dioxide
• photosynthesis
• sulfur dioxide