Effects of Deamination Pre-Treatment on Mixed Anaerobic Fermentation of Chicken Manure and Straw

In view of the problem of ammonia nitrogen inhibition caused by high protein content during the anaerobic fermentation of chicken manure, a process for deamination nitrogen pretreatment of chicken manure using nitrifying bacteria was proposed. Under the condition of 40 degrees C, the anaerobic fermentation effect and degradation of the materials after de-ammonia nitrogen pretreatment were studied for the fermentation concentrations of TS12%, TS16% and TS20%, respectively. The results showed that the using of nitrifying bacteria on the denitrification nitrogen of chicken manure can achieve better fermentation results. Under the same anaerobic fermentation conditions, compared with the non-pretreated group, the pretreated material had a faster start-up speed and higher average rate of gas production. In the pretreatment groups, the average rates of gas production for the first 15 days were 593.1 ml/d for TS12%, 550.9 ml/d for TS16%, and 433.4 ml/d for TS20%, respectively. In the non-deaminized nitrogen treatment groups, the average gas production rate in the first 15 days was TS12%: 420.8 ml/d, TS16%: 379.2 ml/d, and TS20%: 433.4 ml/d, respectively. Pretreated test groups produce more stable gas; had higher removal of total solids (TS) and volatile solids (VS), the removal rates of TS of pretreated groups can reach: 30.5% in TS12% test group, 36.4% in TS16% test group, and 34.6% in TS20% test group. The removal rate of TS in non-pretreatment groups were 28.6% in TS12% test group, 28.5% in TS16% test group, and 17.2% in TS20% test group. The removal rates of VS in the pretreated group were 44.95%, 42.60%, 50.06%, respectively. The removal rates of VS in the untreated groups were 42.73%, 39.33%, and 21.70%. And after pretreatment, the ammonia nitrogen content is always kept in a low and reasonable range. In the test group with the highest fermentation concentration of TS20%, the final concentration of ammonia-nitrogen reached to 2,695.32 mmol/L, and no ammonia inhibition occurred. This experiment has a certain guiding significance for the actual project.