Multiobjective Optimal Siting of Algal Biofuel Production with Municipal Wastewater Treatment in Watersheds with Nutrient Trading Markets

Abstract

Using municipal wastewater effluent as a feedstock in algae cultivation is a promising approach for increasing the commercial viability of algal biofuel production. However, differences in site-specific characteristics at municipal wastewater treatment plants (WWTPs) could drive tradeoffs between maximizing the profitability of algae production and minimizing the cost of meeting water quality standards. A complicating factor is how water quality regulations are enforced, namely the potential presence of nutrient trading markets that would monetize removal of nutrients from wastewater effluent. This study develops an analytical framework for optimizing the siting of an algal biofuel production facility within a network of WWTPs. A combined life cycle assessment (LCA) and techno-economic analysis (TEA) model of an algal biofuel production facility is integrated with a simplified watershed model. An evolutionary algorithm is used to identify optimal sites for algal biofuel production and explore financial tradeoffs for algae biofuel producers and wastewater treatment plants. This analytical framework is then applied to a high-priority, impaired watershed in North Carolina, the Neuse River Basin.