Research on the pollution characteristics, utilization, disposal and environmental management of coal-based solid waste in the mainstream region of the middle Yellow River Basin

The middle Yellow River Basin is a major energy and industrial agglomeration area in China, generating substantial quantities of coal-based solid waste. The ecological vulnerability of the region underscores the need for effective pollution prevention and control. This paper focuses on the mainstream cities in the middle Yellow River Basin, employing survey statistics and leaching experiments to systematically investigate the spatiotemporal distribution characteristics, pollution characteristics, and current utilization and disposal status of coal-based solid waste from 2017 to 2022. It also identifies and analyzes the key bottlenecks in policy implementation, as well as the prominent issues in environmental management. The results indicate that the spatiotemporal distribution of coal-based solid waste generation in the mainstream cities of Shanxi, Shaanxi and Henan provinces in the middle Yellow River Basin generally exhibits a pattern of “increasing year by year and regional concentration”. Coal gangue and fly ash show differentiated pollution characteristics, with coal gangue characterized by “acidic pH with heavy metals （Mn, Ni, etc.）” and fly ash characterized by “alkaline pH with heavy metals （Mo, As, etc.）”. The overall utilization and disposal of coal gangue in the study area is characterized by “total volume growth, efficiency improvement, and regional differentiation”, among which Henan Province demonstrating a relatively high utilization level and Shanxi Province having the largest utilization scale but low efficiency. The utilization and disposal of fly ash are characterized by “overall high utilization level, relatively limited disposal volume, and significant regional disparities”, with Shanxi still facing disposal pressures despite high output. This paper proposes targeted measures to address pollution from coal-based solid waste in the study area. Strategic planning should be strengthened to reduce waste generation at the source and improve resource utilization. Waste storage and disposal sites should be thoroughly investigated and assessed, followed by risk-based classification and targeted remediation. Policy coordination and technical standards should also be improved to facilitate the comprehensive utilization of coal-based solid waste.