Dynamic Transformation of Organic Matter During Thermophilic Composting of Litter

Thermophilic composting of litter was studied to evaluate the dynamic characteristics of organic matter transformation and provide parameters for product maturity with chemical analysis.The results indicated that organic matter,volatile solid,humus(HM),free humic acid and fulvic acid [w(FA)] decreased constantly,but humic acid increased during the composting.However The ratio of HM to organic matter decreased to minimum at 4th d,but increased thereafter and then the ratio stablized in 47.3%-47.6% at last.w(HA)/w(FA) was keeping quickly increase during the composting,it was from 0.43 at beginning to 1.02 at the end of composting,that indicated the progression of composting to humification and stability.On the contrary the E4/E6 increased in the initial stage but decreased thereafter.All results demonstrated that w(CHM)/w(TOC) was suitable to be used as the chemical index of litter compost maturity and stability,but the HM content,w(HA)/w(FA),and E4/E6 were unsuitable.