Quantitative Sustainable Design (QSD) for the Prioritization of Research, Development, and Deployment of Technologies: A Tutorial and Review

Abstract

The pursuit of sustainability has catalyzed broad investment in the research, development, and deployment (RD&D) of innovative water, sanitation, and resource recovery technologies, yet the lack of transparent and agile methodologies to navigate the expansive landscape of technology development pathways remains a critical challenge. This challenge is further complicated by the higher levels of uncertainty that are intrinsic to early-stage technologies. In this work, we review and synthesize published literature on the sustainability analyses of water and related technologies to present Quantitative Sustainable Design (QSD) – a methodology to expedite and support technology RD&D. With a shared lexicon and a structured approach, QSD facilitates interdisciplinary communication and research consistency. In introducing QSD, we review existing studies to highlight best practices and discuss them in the context of the specific steps of QSD, which include defining the problem space, establishing simulation algorithms, and characterizing system sustainability across economic, environmental, human health, and social dimensions. Next, we summarize tools for QSD execution and provide recommendations to account for uncertainty in this process. We further discuss applications of QSD in the fields of water/wastewater and beyond (e.g., renewable fuels, circular economy) in combination with uncertainty, sensitivity, and scenario analyses to generate the desired types of insight. Finally, we identify future research needs for sustainability analyses to advance technology RD&D. Ultimately, QSD can be used to elucidate the complex and intertwined connections among design decisions, technology characteristics, contextual factors, and sustainability indicators, thereby supporting transparent, consistent, and agile RD&D.

Electrochemical wastewater refining: a vision for circular chemical manufacturing

“…Tools like life-cycle assessment (LCA) and quantitative sustainable design (QSD) can concretize ROE and ROS as refining service indicators. 49,50 This relatively mature example of nitrogen and phosphorus fertilizers from municipal wastewater demonstrates the value of use-informed research. Adding the top-down approach beginning with the refining values informs which research questions to pursue and how more fundamental findings are translated to practice.…”

“…51 The QSD framework supports the informed deployment of sustainability research using a shared lexicon across disciplines that delineates broad qualitative goals (e.g., SDG 6 Clean Water and Sanitation), quantitative indicators that assess progress towards goals (e.g., percentage of population with regular access to improved sanitation), and target values of indicators with endpoints and time tables (e.g., halve the number of people without access to improved sanitation by 2030). 49 Refining services will be provided by specific technologies; refining context parameters highlight the system performance metrics that govern deployment feasibility in specific scenarios. Use-informed research must pursue practical knowledge gaps in these refining context parameters for a specific wastewater-pollutant-product triad to cross the "valley of death" in both directions between fundamental and applied electrochemistry research.…”

Advancing the economic and environmental sustainability of the NEWgeneratorTM non-sewered sanitation system

“…22 QSDsan enables an integrated workflow of design, simulation, techno-economic analysis (TEA), and life cycle assessment (LCA) under uncertainty. 23 The baseline NEWgenerator TM was designed to treat bodily waste from 100 users over a 25-year system lifetime. Since the NEWgenerator is a backend system only, the frontend, pretreatment, foundation, and sludge pasteurization units were also included to evaluate the complete NSS system's costs and environmental impacts.…”

QSDsan: an integrated platform for quantitative sustainable design of sanitation and resource recovery systems

“…With the increasing pace of technology development [1][2][3] and growing complexity of sustainability challenges, [4][5][6][7] there is a need for robust and agile tools to quickly identify critical barriers, prioritize research opportunities, and navigate multi-dimensional sustainability tradeoffs in the research, development, and deployment (RD&D) of technologies. [8][9][10] This need is particularly pressing for the field of sanitation as it concerns one of the most basic human rights. Ensuring the right to sanitation also directly addresses the sixth sustainable development goal (SDG) proposed by the United Nations (universal sanitation by 2030), and is connected to many other SDGs (e.g., resource circularity, carbon neutrality).…”

“…Herein, we present QSDsan – an open-source tool that leverages the quantitative sustainable design (QSD) methodology for integrated design, simulation, and sustainability evaluation of sanitation and resource recovery systems. 10 Built under the object-oriented programming (OOP) paradigm using Python (3.8+), QSDsan aims to address the lack of supporting tools for the RD&D of early-stage sanitation technologies. QSDsan is a community-led platform that provides flexible, transparent, and freely accessible modules for modeling and evaluation.…”