污泥堆肥过程中氮素损失和氨气释放的动态与调控

Changes of Nitrogen Loss and Ammonia Emission during Composting of Municipal Sludge and Their Control

通过不同鼓风强度、分层堆肥和添加吸湿剂的自动控制堆肥中试,研究了城市污泥堆肥过程中温度、挥发性固体含量、氮素含量和氨气释放浓度的变化。结果表明,在堆肥升温较快的处理中,挥发性固体的降解速度较快,污泥中的氮素容易向氨氮转化,使释放的氨气浓度升高;增大鼓风强度,有利于促进堆肥的升温和腐熟,加速无害化过程,但释放的氨气浓度较高;在保持整个堆体中污泥比例不变的前提下,分层堆肥可以显著提高堆肥的升温效果并减少氨气的释放。

Changes of temperature, volatile solids content, nitrogen content and ammonia emission concentration during composting of municipal sludge were studied in autocontrol composting pilot experiment with different aeration intensity, layered composting and adding hygroscopic agent. The results show that in the composting treatment with rapid temperature rise, the volatile solids decompose more quickly, and the nitrogen is easy to be transformed into ammonia nitrogen, resulting in the high concentration of ammonia released. When augmenting the aeration, it has a good effect on the compost temperature rise and maturation and the innocnity of municipal sludge. Nevertheless, the ammonia emission of the pile is increased. Layered composting can significantly improve the compost temperature rise effect and decrease the ammonia emission.