Influence Of Ventilation On The Dead Chickens Decomposition In Compost

The methods of dead animal treatment are lack. There will be secondary pollution in current treatment methods of dead animal. The test used force aeration static composting bin system to deal with the dead hens. Search for the harmless and utilizable method of dead animal treatment. In summer, we have studied the feasibility of composting dead hens, and on the basis of the results we have studied the influence of ventilation on the dead hens decomposition and gas emission of composting dead hens in winter. The main conclusions are as follows:We set two ventilation treatment for dead hens composting in summer test, the two treatments were 3.6m³/h and 4.8m³/h. The temperature of the 4 bins rose to above 60℃within two days after the beginning of the summer test. The temperature above 60℃maintain about 70 days of the high ventilation treatment and then the low ventilation treatment maintain about 40 days. No E.coli were detected in composting materials when the test end. Dead hens were almost completely decomposed of two treatments. The decomposition rates of the dead hens in 4 bins were higher than 95%.We set three ventilation treatment for dead hens composting in winter test, the three treatment were 2.1m³/h,1.5m³/h,0.9m³/h. Treatment 1 of large ventilation had a big decomposition rate of dead hens which was 90.69%, then treatment 2 was 89.67%, minimum 85.15% for treatment 3. Analysis (p<0.05) showed that the decomposition rate of the treatment 1 and treatment 2 was significantly higher than the treatment 3, treatment 1 and treatment 2 were not significantly different. Ventilation rate have a important influence to the decomposition of the dead hens in composting process.Ventilation rate have a significantly influence to ammonia and greenhouse gas emissions in composting process. The unit weight stack cumulative emissions flux of NH3, CO₂, CH₄ and N2O had a increasing with the increase of ventilation rate during the test. The unit weight stack cumulative emissions flux of NH3 of treatment 1, treatment 2 and treatment 3 were 1373.67mg/kg DM, 946.52mg/kg DM and 487.77mg/kg DM. The emissions flux decreased with the reduced of ventilation rate. Analysis (p<0.05) showed that significant differences among the treatments.The unit weight stack cumulative emissions flux of CO₂ of treatment 1, treatment 2 and treatment 3 were 140401.85mg/kg DM, 109055.79mg/kg DM and 77431.03mg/kg DM. The emissions flux decreased with the reduced of ventilation rate. Analysis (p<0.05) showed that significant differences among the treatments.The unit weight stack cumulative emissions flux of CH₄ of treatment 1, treatment 2 and treatment 3 were 109.80mg/kg DM, 95.93mg/kg DM and 104.40mg/kg DM. The emissions flux decreased with the reduced of ventilation rate. Analysis (p<0.05) showed that there were not significant difference among the three treatments.The unit weight stack cumulative emissions flux of N2O of treatment 1, treatment 2 and treatment 3 were 17.86 mg/kg DM, 14.71mg/kg DM and 10.67 mg/kg DM. The emissions flux decreased with the reduced of ventilation rate. Analysis (p<0.05) showed that the cumulative emissions flux of the treatment 1 was significantly higher than the treatment 3, treatment 1 and treatment 2 were not significantly different, treatment 2 was significantly higher than treatment 3.