Industrial solid waste (ISW) is a critical issue for sustainable development. Strengthening ISW management is essential for promoting the clean production process and transforming industrial structures towards eco-friendly models. The present study developed an advanced management system to identify the influencing factors of ISW generation and conduct projections, supported by machine learning methods. The results show that the stacking model StackNet2 is the optimal model for China's ISW generation projection, with a mean absolute percentage error value of 6.65%. Scenario analyses reveal that China's ISW generation continues to rise overall in the baseline scenario and stabilizes at 7.1 (±0.36) billion tons in 2050, while the positive circular economy and technology-driven scenarios decrease it to approximately 3 billion tons with a 42% reduction. The study further uncovers dynamic variations in waste management efficiency, where utilization efficiency is not only influenced by technological and managerial strategies but also significantly depends on the scale of waste generation. Based on these predictions, the constructed ISW management system is expected to help policymakers optimize solid waste management decision-making.

Phosphogypsum (PG) is a byproduct generated in large quantities by the phosphate industry, and it serves as a significant source of total phosphorus (TP) pollution along the Yangtze River. Environmentally sound management of PG has, therefore, become a critical challenge. This review outlines the generation processes and environmental risks associated with PG in China. It further examines the technical characteristics of various PG utilization methods and explores the relevant technical standards and policy frameworks. Enhanced utilization of PG in building materials, road construction, soil remediation, and other high-value products is essential. Additionally, the urgent need to promote ecological restoration of PG tailings ponds is emphasized. This study provides a valuable reference for developing effective technological systems for managing PG and preventing TP pollution in China.

As the main consumer group for online shopping and ordering fast food, young people—particularly university students—have contributed to a substantial amount of packaging waste. In the present study, the material flow method was employed to quantify the generation and end-of-life flows of packaging waste from both the express delivery and food delivery sectors at universities in China. Moreover, this study takes reusable packaging materials for food delivery services as a case study to evaluate their environmental benefits through a simplified life cycle assessment approach. The results show that approximately 1.7 (±0.3) million metric tons and 123 (±1.0) kilo metric tons of packaging waste were generated from express delivery and food delivery services, respectively, for university students in 2021. Although reusable food packaging is more complex and costly than regular disposable food packaging is, our modeling results show that reusable food packaging has significant emission reduction benefits under the current practice of 63 cycles per year of actual operation at a specific university. The reusable packaging mode in universities is feasible from an environmental perspective; however, it faces significant challenges due to a few concerns among stakeholders, such as high costs and inadequate recycling supply systems.