Absorption Capability of Carbon Dioxide (CO2) by Algae Phylum Chlorophytain Reducing Carbon Emissions in Urban Area

Research related to the mitigation of global warming, particularly in the absorption of carbon dioxide (CO2), has become the main focus among the scientists in the world. Carbon dioxide is naturally absorbed by green plants, sea, limestone carbonation, and algae. Green pigment in algae or chlorophyll absorbs carbon dioxide in the photosynthesis process. Alga is suitable as carbon sink because alga grows rapidly. This research aims to determine average uptake of carbon dioxide by algae in urban areas and determine the effect of aeration and variation of nutrient source on algae growth. The research was conducted in a laboratory scale unit, using reactors with a batch process. Alga used in this research was obtained from algae cultivation taken from urban drainage. This research used two experimental variables, i.e. aeration and nutrient source. The amount of carbon dioxide absorbed by algae was obtained by using stoichiometric ratio in the reaction of photosynthesis. Based on the stoichiometric ratio of photosynthesis, 1 gram of algae is equivalent to 1.92 grams of absorbed CO2.Based on the research, by adding urea fertilizer, algae absorbs 4.87 mg CO2/day in non-aerated condition or 3.84 mg CO2/day in aerated condition. While by adding NPK fertilizer, algae absorbs 3.61 mg CO2/day in non-aerated condition or 3.01 mg CO2/day in aerated condition.