0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Remediation Sign in to save

Humic acid accelerates polyurethane microplastic degradation via light-dark synergy, shortening degradation cycle over one-third

Journal of Hazardous Materials 2025
Zixin Zhang, Conghui Wang, Lihua You, Heping Chen, Jingjing Dong, Qi Chen, Zhanbo Wei, Zhanbo Wei, Lili Zhang, Min Zhang, Zhiguang Liu

Summary

Researchers found that applying humic acid alongside controlled-release fertilizer coated in polyurethane accelerated the degradation of polyurethane microplastics by 34.3-43.9% through a light-dark synergistic mechanism while simultaneously increasing crop yields by 12.3-22.4%, addressing both agricultural productivity and plastic pollution.

Polymers
Body Systems

In agricultural ecosystems, the accumulation of polyurethane microplastics (PuM) resulting from the long-term application of controlled-release fertilizer (CRF) constitutes an irreversible pollution-each kilogram of CRF introduces approximately 32,000 particles-and these particles are difficult to recover. This study proposes a synergistic approach: the combined use of CRF and humic acid (HA) not only increases crop yields by 12.3 %-22.4 % but also accelerates the degradation of polyurethane microplastics by 34.3 %-43.9 %, which is of great significance for addressing the dual challenges of ensuring food security and remediating soil microplastic contamination. This study also explores the interaction between HA and PuM: under dark conditions, HA facilitates radical formation through the cleavage and isomerization of C-H bonds in PuM macromolecules; under light conditions, the phenolic hydroxyl and carboxyl groups in HA moieties mediate the generation of reactive oxygen species via photoexcitation, thereby initiating the oxidative scission of PuM's carbon backbone. This research provides new ideas on how to solve the pollution of polyurethane microplastics in farmland and for the in-situ treatment of microplastics in farmland.

Share this paper