Academician Ning DUAN has innovatively proposed the theories of product metabolism and waste metabolism based on China's national conditions, enriching the discipline of industrial ecology. These theories have been widely adopted in the planning of national eco-industrial parks, resulting in notable social, economic, and environmental benefits. Currently serving as the Director of the Cleaner Production Engineering Technology Center for Typical Metal Wet Electrolysis Processes at the Chinese Research Academy of Environmental Sciences (CRAES), Academician Duan has held various esteemed positions, including former Deputy Director of CRAES, Vice Chairman of the Industrial Ecology Economy and Technology Professional Committee of the China Society of Ecological Economics, and Vice President of the China Association of Industrial Energy Conservation and Cleaner Production.

 His primary research interests lie in the technologies, fundamental data acquisition methodologies, and engineering practices of cleaner production. Academician Duan introduced China's first large-scale cleaner production project that aligns with international standards, establishing the country's first dedicated research unit focused solely on cleaner production. Through his efforts, he has influenced and advanced China's cleaner production agenda in terms of cognition, technology, and methodology. He also initiated China's first quantitative research project on pollution generation and discharge coefficients, establishing a relatively systematic and comprehensive approach to collecting fundamental industrial pollution data.

 Moreover, Academician Duan's research on cleaner production technologies and technology-driven cleaner production models for electrolytic manganese has significantly promoted pollution reduction and technological advancements across the entire electrolytic manganese industry in China.