Effects of potassium persulfate on nitrogen loss and microbial community during cow manure and corn straw composting

Strong oxidants can reduce the emission of NH₃ during composting. But as a commonly used oxidant, the influence of persulfate on nitrogen transformation during composting is unclear. In this study, the effects of 0.3 %-1.2 % potassium persulfate (PS) on nitrogen losses and microbial community during air-dried cow manure composting were investigated. The results showed that PS could reduce nitrogen losses compared to the control. This was because it decreased pH and the maximum NH₄⁺-N content of treatments, which was beneficial to nitrogen retention. In addition, Pseudoxanthomonas and Chelativorans were enriched compared to the control, which might be associated with NH₄⁺-N transformation and nitrogen fixation. Meanwhile, PS increased the abundance of thermophilic lignocellulose degrading bacteria, and 0.3 % and 0.6 % PS increased the maximum temperature and the duration of the thermophilic period. This study indicated that PS could reduce nitrogen losses in composting and greatly influence nitrogen transforming and lignocellulose degrading bacteria.