Environmental and Ecosystem Effects, Risk Assessment, and Mitigation Strategies for Advanced Composting

Composting is widely applied in agriculture and waste management as a bioprocess that converts biodegradable materials into nutrient-rich soil amendments. While its benefits for soil fertility and ecosystem functioning are well recognized, composting can also introduce environmental and ecological risks through gaseous emissions, pollutant release, and material heterogeneity. Existing reviews often address these aspects separately, focusing either on emissions, life cycle assessment, or specific contaminants. This review synthesizes current knowledge on the environmental impacts and ecological risks of composting across air, soil, water, and biological systems, with particular emphasis on integrating ecological risk assessment with life cycle perspectives. By linking pollutant pathways, assessment frameworks, and mitigation strategies, this review provides a systems-level understanding of composting performance. In addition, the review discusses advanced composting approaches and proposes a conceptual taxonomy for characterizing compost and classifying processes to address variability in feedstocks and operating conditions. These perspectives aim to support more consistent assessment, management, and future development of composting practices.