CAREER: Elucidating organic and inorganic nitrogen processes in algal resource recovery: integrating wastewater process design with harmful algal bloom dynamics

Excess nutrient such as nitrogen and phosphorus can cause toxic harmful algal blooms. These harmful algal blooms cause significant economic loss and public health risks across the nation. New methods to reduce nutrient pollution include using algae in wastewater treatment plants to reduce nitrogen and phosphorus before it is released to the environment. The goal of this research is to understand the types of nutrients that make algae more toxic in the environment. This goal will be achieved through experiments that grow algae on wastewater and examine different wastewater nutrient sources that cause environmental pollution. This work will be performed in collaboration with wastewater utilities as well as community groups that monitor and report harmful algal blooms. This research can be used to improve our wastewater treatment and reduce nitrogen and phosphorus pollution. These results can further inform public policy on the types of nutrients that are most important in causing toxic algal blooms. Eutrophication and nutrient management for point and non-point source pollution remain a critical challenge. While efforts to reduce eutrophication most often focus on limiting phosphorus discharges to the environment, nitrogen is an important driver in algal bloom growth and toxicity. The overall goal of this research is to improve the total nutrient recovery from algal wastewater treatment processes and to understand the role of organic and inorganic nitrogen in harmful algal bloom growth and toxicity. Specific research objectives are to (i) identify environmental and operational factors that improve total nitrogen and phosphorus removal from wastewater treatment using algae, (ii) characterize organic nitrogen effluents from both algal and traditional wastewater processes and to evaluate their potential for algal growth and toxicity, and (iii) determine the effects of organic nitrogen composition and nitrogen to phosphorus ratios on harmful algal bloom formation and dynamics. These objectives will be achieved by integrating process design with controlled lab-scale experimentation and advanced molecular and analytical chemistry methods to understand the mechanisms for nutrient conversion and recovery. This work will help advance nutrient recovery from algal wastewater systems and provide fundamental insights into the role of nitrogen in driving algal bloom dynamics and toxicity. Research will be performed in collaboration with local wastewater utilities and community groups to disseminate knowledge and inform stakeholders while broadly increasing public scientific literacy. Specific educational tasks and activities are designed to engage and excite students to improve the Nation’s STEM workforce. These include (i) the development of educational materials for community groups, (ii) an education module and workshop for high school students, and (iii) the creation of a resource-positive curriculum centered around sustainability and the environment. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.