Practice and challenges for beneficial use of municipal solid waste incineration bottom ash in China

Municipal solid waste incineration bottom ash (MSWIBA) is a major by-product of incineration and has been classified as non-hazardous waste in most countries. Owing to its mineral composition being similar to that of natural aggregates, MSWIBA has attracted increasing attention for use in construction materials such as road subbase and cement-based products. However, concerns remain about its environmental risks due to the potential release of heavy metals and soluble salts during long-term field applications. This review critically examines the current status of MSWIBA management in China, including generation, physicochemical characteristics, and national regulatory frameworks. Comparative insights are provided based on international practices, highlighting differences in pretreatment technologies, utilization pathways, and environmental standards. The review identifies several key challenges in China, such as decentralized management, lack of long-term risk assessment, and absence of enforceable standards. Drawing on global experience, the paper proposes policy and technical recommendations to support safe and efficient reuse of MSWIBA, contributing to the development of a circular economy and China’s “Zero-Waste City” initiative.