不同填料对城市污泥堆肥过程中氮素转化的影响

以稻草、木屑、树叶为填料，采用人工翻堆好氧堆肥工艺，通过测定堆肥过程中的温度、pH、TN、NH4^＋N和NO3^--N的变化，研究了填料对堆肥过程中氮的转化及损失的影响．结果表明：以稻草、木屑＋稻草作填料，堆体的温度升高快，高温期持续的时间长，有利于污泥堆肥的快速腐熟和灭菌；堆肥初期，堆体NH4^＋-N含量逐渐升高，14d时达最大值，然后迅速下降，在堆肥结束时达到一个较低的水平，NO3^--N含量在14d后逐渐升高，仅以木屑或树叶作填料的堆体，其水溶性NH4^＋N，NO3^-—N含量均较以稻草、木屑＋稻草作填料的堆体低；堆肥后堆体的全氮含量降低，仅以稻草为填料的堆体，其氮损失率最高，木屑能降低氮素的损失；氮素的损失80％发生在堆肥的前期28d，此阶段应采取措施降低氮素的损失．

Effects of Different Bulking Agents on Nitrogen Transformation During Sewage Sludge Composting

Bulking agents,including rice straw,sawdust and tree leaves,were used to investigate the changes of temperature,TN,NH+4-N and NO-3-N during the sewage sludge composting by artificial turnover protocol.The results showed that using rice straw or rice straw plus sawdust as the bulking agents was beneficial for killing the pathogens and accelerating the speed of composting due to faster temperature increase and a longer duration of the high temperature period.Water-soluble NH+4-N was the highest on the 14th day of composting,which was followed by a rapid decline,while NO-3-N increased on the 14th day of composting.The contents of soluble NH+4-N and NO-3-N in the pile with sawdust or tree leaves were lower than the piles with rice straw or rice straw plus sawdust.The content of TN of the pile decreased during the process of composting due to NH 3 loss through volatilization,which occurred during the first 28 days of composting.Compost pile with rice straw resulted in a higher N loss,while sawdust decreased N loss.