Abstract:

In order to clarify the characteristics of N2O accumulative emission and its influencing factors, and it will provide the techniques for reducing N2O accumulative emission in the composting of water hyacinth (Eichhornia crassipes). Composting is the common method in handling and using the harvested water hyacinth. However, few studies have been focused on greenhouse gas released from the composting. The objectives of this paper were to study the dynamics of nitrous oxide (N2O) emission and the effects of different influencing factors such as composting temperature, carbon and nitrogen ratio(C/N), nitrogen forms, ammonia-fixing synergist, and pile-turning frequency on N2O accumulative emission in the composting of hyacinth by using the static chamber-GC theory with manual method. The results showed that N2O daily mean emission reached a maximum during the fifth to tenth days, the N2O accumulative emission can be fitted into regression model; N2O daily mean emission were both significantly positive linear correlation to composting temperature and ammonium nitrogen (NH4+-N) content, lowering the pile temperature and increasing the C/N could decrease the N2O accumulative emission in the composting of hyacinth. Adding ammonia-fixing synergist could decrease the N2O emission during the first 8 days of composting, while the whole N2O accumulative emission treated with ammonia-fixing synergist was more than the control group. Reducing the pile-turning frequency can decrease the N2O emission.