Reduction of Ammonia, Hydrogen Sulfide, and Short-Chain Fatty Acids Emission during the Sewage Sludge Composting

摘要

The effect of mature compost (MC) used as a bulking agent on ammonia, hydrogen sulfide, and short-chain fatty acids emission reduction during sewage sludge (SS) composting process was studied in this paper. Three types of mixtures, single SS, SS+wood chips (SS+WC), and SS + MC, were composted in a laboratory reactor. Among the different treatments, decrement rates of NH3 emission (based on initial TN) from SS to SS + MC and SS+WC to SS + MC were 63 and 59%, respectively. The H_2S concentration ranged from 0.759 to 1.140 mgm~(-3) for SS, from 0.075 to 0.455 mgm~(-3) for SS+WC, and from 0.075 to 0.425mgm~(-3) for SS + MC and the short-chain fatty acids (C_2-C_5) concentration ranged from 0.10 to 1.00 ppm for SS, from 0.10 to 1.50ppm for SS+WC, and from 0.10 to 0.80ppm for SS + MC. In addition, the temperature apparently, as well as the thermophilic stage, was also elevated by bulking agent addition, especially by the MC addition. The denaturing gradient gel electropho-resis analysis indicated that there was more diversity of the bacterial community during the SS + MC process. According to these results, MC was a suitable bulking agent for reduction ammonia, hydrogen sulfide, and short-chain fatty acids emission during the SS composting.