The effect of aeration rate on forced-aeration composting of chicken manure and sawdust

The composting of chicken manure and sawdust has been investigated in forced-aeration composting systems at aeration rates of 0.3, 0.5, and 0.71 min(-1) kg(-1) organic matter (OM), corresponding to pile A, pile B, and pile C. The temperature exceeding 55 degrees C in pile A and pile B remained more than three consecutive days, but only 2 days were above 55 degrees C in pile C. The final electrical conductivity (EC) did not exceed the limit content of 3000 mu s cm(-1) in the three piles, and the cation exchange capacity (CEC) met the requirement maturity degree of over 60 cmol kg(-1). The OM loss contents in pile A, pile B, and pile C were 14%, 15.4%, and 12.8%, respectively, corresponding to the final C/N ratio of 17.1, 16.2, and 18.3. The final NH(4)(+)-N content in pile A did not meet the limit value of 400 mg kg(-1), respectively, and the NO(3)(-)-N was 1942, 2190, and 1638 mg kg(-1) in pile A, pile 13, and pile C. The final germination index (GI) for pile A, pile B, and pile C was 90.2%, 95.2%, and 79.4%. (C) 2009 Elsevier Ltd. All rights reserved.