Optimization of simultaneous soybean processing wastewater treatment and flue gas CO2 fixation via chlorella sp. L166 cultivation

Abstract

Abstract Microalgae has the potential to purify wastewater and flue gas. In this work, soybean product wastewater and CO2 in flue gas are used to co-culture microalgae. The effects of CO2 concentration and flow rate, and nitrogen-phosphorus ratio of nutrients in wastewater on the growth rate of Chlorella sp. L166, CO2 fixation and nutrients removal capacity of wastewater were investigated. Experimental results showed that Chlorella sp. L166 could be cultured in the hybrid culture system of soybean wastewater and simulated flue gas. When the ratio of nitrogen to phosphorus was 5:1 in 20 % soybean wastewater and 5% CO2 was introduced at a rate of 0.1 vvm, the concentration of chlorophyll a achieved 48.08 mg/L. In addition, the maximum removal efficiency of TN, TP, COD and CO2 fixation was 96.07 %, 95.55 %, 78.20 % and 28.60 %, respectively were achieved by Chlorella sp. L166. It indicated that Chlorella sp. L166 has certain potential to simultaneously fix CO2 in flue gas and treat soybean processing wastewater.