The Kyoto protocol was signed by 170 countries in 1997 to reduce greenhouse gases by 5.5% based on emission in 1995. Carbon dioxide, the prominent greenhouse gas, is the number one cause of global warming.The CO2 remediation can be accomplished in three methods; (1) chemical-based strategies including washing with alkaline solutions[1], multiwalled carbon nanotubes[2], and amine coating activated carbon[3]. The second method of CO2 remediation is direct injection to the ocean[4]. These two non-biologicalmethodsare relatively costly and energy intensive.We, therefore, consideredbiological CO2 mitigation as a good alternative method. Among different biological methods, microalgae have shown high capability for carbon dioxide bioremediation from the atmosphere and produce high amount of biomass. In this study we used Chlorella vulgaris to investigate carbon dioxide removal and biomass production that can be used as human nutrient and animal feed[5]. Approximately 6% CO2 with aeration rate of 1vvm under 4000lux light intensity at 27ºC was used to cultivate Chlorella vulgaris. By this study, 0.126gl-1d-1CO2 fixation rate, 1.1gl- 1biomass concentration, and 0.078gl-1d-1 biomass productivity were obtained. Additionally, monitoring the pH of the medium during the experiment showed an increase from 5.46 to 8. It was also observed that algal growth rate rose by increasing the pH. The results indicate that Chlorella vulgaris has a high capability for carbon dioxide bioremediation. References: 1. Diao, Y.-F., et al., Experimental study on capturing CO2 greenhouse gas by ammonia scrubbing. Energy Conversion and Management, 2004. 45(13–14): p. 2283-2296. 2. Su, F., et al., Capture of CO2 from flue gas via multiwalled carbon nanotubes. Science of The Total Environment, 2009. 407(8): p. 3017-3023. 3. Plaza, M.G., et al., CO2 capture by adsorption with nitrogen enriched carbons. Fuel, 2007. 86(14): p. 2204-2212. 4. Israelsson, P.H., A.C. Chow, and E.E. Adams, An updated assessment of the acute impacts of ocean carbon sequestration by direct injection. International Journal of Greenhouse Gas Control, 2010. 4(2): p. 262-271. 5. Natrah, F.M.I., et al., Effects of micro-algae commonly used in aquaculture on acyl-homoserine lactone quorum sensing. Aquaculture, 2011. 317(1–4): p. 53-57.

Keywords