Compost-enhanced humification of organic pollutants: Mechanisms, challenges, and opportunities

Organic pollutants remain a persistent threat to ecosystems and human health. In soils, humification gradually converts these compounds into stable humic substances and attenuates their toxicity, but the transformation can take decades—far too slow to match current pollution loads. In this Perspective, we argue that mature compost offers a pragmatic means to accelerate this process: it delivers partially humified intermediates that can “seed” soil humification and shorten its timescale from decades to seasons. Spectroscopic evidence shows that compost-derived humus is enriched in aromatic backbones and reactive functional groups (–COOH, –OH) that both catalyze further condensation of organic matter and immobilise pollutants through π–π stacking, hydrogen bonding and covalent coupling. By merging these catalytic and sorptive functions, compost amendments provide a scalable, low-cost route to the long-term stabilization of organic contaminants. We outline the key mechanistic questions that now need resolution—particularly the reactivity of specific intermediates in situ—to guide field trials and unlock the full potential of compost-driven accelerated humification as an environmental remediation platform.