Nitrogen transformation during co-composting of spent pig manure, sawdust litter and sludge under forced-aerated system

摘要

Forced-aerated piles were built to investigate the transformation of nitrogen during co-composting of spent pig litter and sludge at 2:1 wet volume ratio. The total N concentration of spent litter-sludge increased during the early stage of composting due to the concentration effect as a consequence of strong degradation of carbon compounds in the spent litter- sludge piles. After day 21, the total N concentration decreased but there was no significant loss in nitrogen. The total mass of N was maintained at around 30 kg during the composting process.