Influence of C/N Ratio on Nitrogen Changing during Composting

Poultry litter, municipal solid waste and corn straw were conducted in static vessel to testify the practicability of aerobic co-composting with C/N ratio at 15, 20 and 25. Various kinds of nitrogen transformation were determined at different composting stages. C/N ratios of three treatments all tended to decrease and it was remarkable at the treatment of PMC25 during composting. The total nitrogen reduced gradually with the composting time. The lower the C/N ratio was, the higher the final total nitrogen concentration has. Main way of nitrogen loss was volatilization in the form of ammonia originated from ammonium. The main period of nitrogen loss was during the thermophilic composting time, at the same time, the NH₄⁺-N decreased. The NO₃^--N increased after thermophilic composting time. The concentration of usable nitrogen was increased after composting. The experimental results demonstrated composting in low C/N ratios is practicability.