CO2 Mitigation From The Flue Gas Of The Iron-Steel Making Industry By Microalgal Cultures
Integration of CO2 mitigation with nutrient removal from different wastewater sources can be realized by microalgae growth. In spite of being an option with significant environmental benefits, this technology still suffers from achieving high performances since atmospheric concentration of CO2 limits microalgae growth; i.e. biomass accumulation. This is why the use of flue gas with CO2 concentrations of 20-25% (by volume) should be considered as an inorganic C source for the microalgae culture reactors. This study has focused on the measurement of CO2 uptake and nutrient removal by microalgae as well as biomass accumulation in the photo-bioreactors containing domestic wastewater inoculated by freshwater microalgae cultures. The real flue gas (11% CO2) collected from an iron-steel industry was used to supply CO2. The total CO2 uptake was 0.75 g/L with a rate of 0.15 g/L.day in the reactors operated with autoclaved wastewater as the growth medium. The use of raw wastewater yielded 0.13 g/L total CO2 uptake with a rate of 0.06 g/L.day. The results indicated that microalgae culture was capable of tolerating high levels of CO2 and removal of nutrients from wastewater.
Keywords: Flue Gas, Iron-Steel Industry, Microalgae, Nutrient Removal, Wastewater