Feasibility Assessment of Cultivating Native and Non-Native Algae Species at Different Stages of a Municipal Treatment Plant

Two monocultures (Chlorella sorokiniana and Botryoccocus braunii) and two native polycultures derived from the clarifiers (following a pure oxygen BOD reactor and a nitrification reactor) at a municipal wastewater treatment plant were cultivated in synthetic media and clarified effluent from two stages of the wastewater treatment plant. Water quality and algae biomass composition were measured at the beginning and end of 12 day batch tests to compare nutrient removal, assimilation, and growth potential. Soluble COD increased significantly (p<0.05) in with algae monocultures and one polyculture grown in clarified effluent. Total nitrogen decreased significantly (p<0.05) in all wastewater batches, and phosphate removal was also significant (p<0.05) in most cases. After cultivation in most growth media, the two monocultures and one polyculture appeared to accumulate phosphorous. The post-BOD clarified effluent supported the highest yield for all species studied, and the algae community native to the post-BOD clarifier achieved the highest yield of all species studied.