From manure to fertilizer in minutes: Radical induced humification and decontamination

Global livestock/poultry manure output (approximately 13 billion tons/year) poses a major sustainability challenge. Conventional recycling via composting and anaerobic digestion after solid-liquid separation is slow (20-60 d) and inefficient at removing pollutants (i.e. pathogens, antibiotics, and heavy metals). This study develops a minute-scale, one-step process using microwave and FeSO₄ to activate persulfate, generating radicals that rapidly convert chicken manure into a fertilizer rich in fulvic-like acids (41.7 wt% on a dry-product basis) and nutrients, including K (a primary nutrient) and Fe (a micronutrient). It simultaneously inactivates culturable bacteria, achieves approximately 99% removal of the parent antibiotics, reduces the combined acid-extractable and reducible fractions of Cd, Cu, and As by approximately 90%, and reduces odors (>97%). Carbon and nitrogen losses, calculated on an absolute-mass basis, were 15.6% and 12.6%, respectively. In a 21-day pot experiment, the fertilizer increased the fresh biomass of pak choi seedlings by 214.3% compared with the unamended soil control (Blank), while increasing soil total potassium and available nitrogen and potassium. This process shows cost (201 RMB/t wet CMPFM) advantage compared with composting, offering an efficient green alternative for manure recycling and circular agriculture.