The evolutions of the microstructure characteristics and the combustion reactivity of lignite during high temperature drying process at 600–800°C were addressed in the paper. The information about the oxygen functional groups, carbon skeleton, pore structure, and combustion reactivity of the lignite before and after the drying treatment was obtained by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller technique, Raman spectroscopy and thermogravimetric analyzer, respectively. The results show that a different evolutionary trend of the chemical structure of the lignite appears at the high drying temperature of 700°C at which the carbonyl, carboxyl, and carboxylate significantly decomposed and the treatment gave a slight elimination of structural imperfections and the formation of new cross-linking structures. Then, at the drying temperature of 800°C, a slight increase of the oxygen functional groups was found. The break of the aromatic ring or heterocycle contributed to the rapid increase of amorphous carbon to some extent. During the drying process, the surface area of the resulted lignite gradually increased until 700°C and then decreased. The evolution may be attributed to the decomposition of organic compounds, shrinkage forces, and thermal relaxation effect. The investigation indicates that the change in chemical nature of the coal had a greater impact on the combustion reactivity than the internal pore structure did. In addition, the combustion intensity and performance of the treated lignite was enhanced by the drying process.

As the urgency of addressing climate change grows, strategies such as developing zero-emission campuses to achieve carbon neutrality are becoming increasingly crucial. Yet, research in this field remains somewhat underdeveloped and fragmented. This study aims to bridge this gap, providing a scientometric analysis of the research conducted on zero-emission campuses from 1997 to 2023, using data from the Web of Science Core Collection. The study analyzed 1009 bibliographic records with the aid of CiteSpace software, focusing on identifying key co-authors, co-words, co-citations, and clusters. The findings indicate a rapid increase in research in the field of zero-emission campuses, with a significant surge in the number of publications in recent years, culminating in 174 in 2021 alone. The leading universities in terms of publication count were the University of California System, Egyptian Knowledge Bank, and the Chinese Academy of Sciences. Furthermore, the United States, China, and the United Kingdom were identified as the main contributing countries/regions to publishing in this field, indicating a broad, global collaboration. The scope of research has broadened from technical elements, such as energy, to encompass social factors that influence sustainability. Emerging research areas were identified, including education and sustainability, renewable energy and energy efficiency, campus planning and design, waste management and recycling, policy support, and pro-environmental behavior. This study provides a structured overview of the research landscape in the field of zero-emission campuses, offering valuable guidance for academics and encouraging further collaboration. The identified research clusters, notable authors, and influential institutions hold significant implications for policy decisions, industry practices, and the implementation of zero-emission strategies on campuses, aiding in the broader pursuit of sustainability.

As urbanization and extreme stormwater events increase, sustainable stormwater management becomes vital. Sponge city green infrastructure offers a solution to flooding and pollution, providing additional benefits like recreation and clean air. However, understanding public preferences for sponge city green infrastructure's ecosystem services and balancing its co-benefits poses challenges, especially regarding financial sustainability. This study used a discrete choice experiment with 1,154 residents from three Chinese sponge cities to assess the monetary value of five sponge city green infrastructure benefits: improving black and malodorous water bodies, flood prevention, mitigating urban heat island effects, rainwater reuse, and landscape recreation. Analyzing data via the mixed logit model, distinct preferences for sponge city green infrastructure benefits emerged. Residents across all cities were significantly willing to pay for rainwater reuse, indicating a gap in existing research. Preferences varied for other benefits, with positive responses for water body improvement and flood prevention but indifference towards heat island effect and mixed views on landscape recreation. This information is crucial for stormwater managers to optimize sponge city green infrastructure design and fee evaluation.