Field-Scale MCDM Ranking of Microalgae PBR Operations for NH3/CO2 Mitigation in Broiler House

This study presents a field evaluation of microalgae photobioreactor (PBR) systems for mitigating ammonia (NH ₃ ) and carbon dioxide (CO ₂ ) emissions from a commercial broiler house, and multi-criteria decision-making (MCDM) ranking to optimize system operation. Building upon previous findings from laboratory experiments, nine PBR experiments were conducted using Scenedesmus sp. , Ankistrodesmus sp. , and Synechococcaceae cultivated under three media conditions (BBM, BBM─N, and DI─water). The PBRs were operated for 30 days to assess biological (biomass productivity, growth rate), environmental (NH ₃ and CO ₂ mitigation efficiencies), and operational (cost, energy and nutrient demand) performances. With the obtained data, three MCDM techniques, including Integrated Determination of Objective CRIteria Weights (IDOCRIW), Logarithmic Percentage Change-driven Objective Weighting (LOPCOW), and Measurement Alternatives and Ranking according to COmpromise Solution (MARCOS), were applied to rank the PBR setups across three performance domains: biological, environmental, and overall efficiency. Among all alternatives, Ankistrodesmus sp. in BBM–N medium achieved the highest overall score, followed by Scenedesmus sp. in BBM–N, demonstrating superior pollutant mitigation with moderate operational costs. The MCDM analysis that integrates biological and environmental indicators enables a more holistic evaluation of PBR performance than single-parameter assessments. The findings provide a robust decision-support framework for scaling up microalgae-based air treatment systems in livestock production facilities, contributing to the development of sustainable emission mitigation strateges aligned with circular bioeconomy goals.