Increasing Phosphorus Uptake Efficiency by Phosphorus-Starved Microalgae for Municipal Wastewater Post-Treatment.

Four microalgal species, , , , and were studied for enhanced phosphorus removal from municipal wastewater after their exposure to phosphorus starvation. Microalgae were exposed to phosphorus starvation conditions for three and five days and then used in a batch experiment to purify an effluent from a small WWTP. After 3-day P-starvation, biomass growth rate increased by 50% and its PO removal rate reached > 99% within 7 days. maintained good biomass growth rate and nutrient removal regardless of the P-starvation. All species showed 2-5 times higher alkaline phosphatase activity increase for P-starved biomass than at the reference conditions, responding to the decline of PO concentration in wastewater and biomass poly-P content. The overall efficiency of biomass P-starvation on enhanced phosphorus uptake was found to be dependent on the species, N/P molar ratio in the wastewater, as well as the biomass P content.