While major improvements in wastewater treatment have reduced nutrient loading to watersheds from point
sources over the last two decades, further reductions are necessary tomeetwater quality goals and reduce coastal
eutrophication. Many of the water resource recovery facilities (WRRFs) are already at their limit of technology
with respect to nutrient removal and so new, cost-efficient and easily adaptable approaches to wastewater treatment
must be designed to reduce total nitrogen (N) and phosphorous (P) further. Here we report on a novel
phycoremediation strategy that employs algae to remove N (and P) from treated effluents prior to discharge.
To make phycoremediation viable within municipal WRRFs that operate at high flow rates and have short inplant
hydraulic residence times, “wash out” of algal biomass must be prevented, algae must be easily separated
and removed from the treated effluent before discharge, and sufficient algal biomass must be retained within or
returned to the reactor to ensure stable algal populations