Emerging themes, opportunities, and future directions for modeling decentralized wastewater resource recovery and treatment systems

ABSTRACT This review examines the emerging themes, opportunities, and future directions for the modeling of decentralized wastewater treatment and resource recovery systems. Models are grouped by application, including system design, operation, and assessment of broader-scale impacts. Process design models (e.g., mechanistic models, mass and energy balances), comparison frameworks (e.g., life cycle and techno-economic analyses), and uncertainty analyses are discussed, along with new tools for synergistic integration of these models. A discussion of operational models for fault detection and predictive maintenance, the growing availability of supportive sensors, and automation is also presented. Last, systems-scale models, including decision support, geospatial, and various multi-optimization models, are considered to identify broader impacts of decentralization through integration with existing infrastructure, the localization of resources, and resiliencies of water, energy, and food systems. The improvement of models for decentralized technologies will ultimately streamline design, operation, and impact quantification of these increasingly important and widespread systems, resulting in better implementation and decision-making.