不同填料对城市污泥堆肥堆体温度动态变化影响

EFFECT OF DIFFERENT BULKING AGENTS ON TRANSFORMATION OF NITROGEN DURING SEWAGE SLUDGE COMPOSTING

以稻草、木屑、树叶为填料,采用人工翻堆堆肥工艺,研究了4种填料组合下城市污泥堆肥过程中的温度变化及层次差异。结果表明,与填料的木质素含量有关,填料木质素含量低,堆体温度升高快,最高温度较高。堆肥过程中堆体各层次的温度均为中层高于上层和下层,堆肥初期,堆体上层温度低于下层,随后则高于下层,堆肥腐熟时3层温度趋于一致。以稻草等木质素含量低的物质作填料,堆体上层温度升高快,各层次最高温到达时间差异小,最高温相差大。

Rice straw, sawdust and tree leaves were used as bulking agents to investigate the changes in temperature, total N, NH4^＋ -N and NO3^- -N during sewage sludge composting by artificial turnover protocol. The results showed that using rice straw or rice straw plus sawdust as bulking agents was beneficial to killing the pathogens and accelerating composting due to faster temperature increase and a longer hightemperature period. Water soluble NH4^＋ -N increased to the maximum on the 14^th day of composting, followed by a rapid decline thereafter. The content of NO3^- -N started to rise gradually 14 days after the commencement of composting. Contents of NH4^＋ -N and NO3^- -N in the composting piles with sawdust or tree leaves were lower than those in the piles with rice straw or rice straw plus sawdust. Total N in the piles decreased during eomposting due to loss of NH3 through volatilization, mainly in the first 28 days of composting. Sawdust helped to decrease N loss.