Combination of brewery wastewater purification and CO2 fixation with potential value-added ingredients production via different microalgae strains cultivation

Microalgae have the advantages of eco-friendly and cost-effective for wastewater and flue gas purification. In this work, four different microalgae strains (Chlorella sp. L166, Chlorella sp. UTEX1602, Scenedesmus sp. 336 and Spirulina sp. FACHB-439) were investigated for the hybrid brewery wastewater purification and CO2 fixation. Experimental results indicated that Chlorella sp. UTEX1602 could tolerate 15% CO2, and Scenedesmus sp. 336 presented good brewery wastewater purification performance for standalone CO2 fixation and wastewater purification tests. Chlorella sp. UTEX1602 and Scenedesmus sp. 336 were further used in the hybrid brewery wastewater and CO2 fixation process. It was found that Scenedesmus sp. 336 could well adapt to the hybrid system of brewery wastewater integrated with 15% CO2. After 10 days of cultivation, the dry weight of algae biomass could achieve 1.02 g L−1, and the NH3–N, TN, TP, and COD removal rates of brewery wastewater achieved 89.99%, 75.96%, 95.71%, and 73.66%. The contents of chlorophyll, carotenoids, carbohydrates, lipid productivity and percentage in algal biomass were 20.40 mg L−1, 7.54 mg L−1, 63.61 mg L−1, 38 mg L−1·d−1, and 37.16%. It indicated that microalgae have the potential to simultaneously realize brewery wastewater purification and CO2 fixation with value-added ingredients co-production.