Effects of Different pH Control Strategies on Microalgae Cultivation and Nutrient Removal from Anaerobic Digestion Effluent

This study investigated nutrient removal from anaerobic digestion effluent by cultivating mixed-culture microalgae enriched from anaerobic sludge under different pH conditions: R (uncontrolled), R (maintained at 7-8), and R (maintained below 8). Significant amounts of NH -N were lost by volatilization in R cultures due to increased pH values (≤8.6) during the early period of cultivation. The pH control strategies significantly affected the biological NH -N removal (highest in R ), microalgal growth (highest in R ), biomass settleability (highest in R ), and microalgal growth relative to bacteria (highest in R ) in the cultures. completely dominated the microalgal communities in the inoculum and all of the cultures, and grew well at highly acidic pH (