不同干污泥返料量对污泥堆肥氮素损失的影响

Effect of Different Recycle Ratios of Dried Sludge on Nitrogen Loss During Sludge Composting

采用条垛式堆肥法,对污泥堆肥温度及氮素各项指标进行了测定。结果表明,堆体中添加不同量成品腐熟干污泥能够使堆体快速升温并在高温期维持较长时间,所有添加干污泥的处理均能达到《粪便无害化卫生标准(GB7959—1987)》要求。添加30%～40%干污泥的处理能够很好地控制氮素以铵态氮形式累积和损失,并且硝态氮损失也较少,堆肥结束后全氮损失量分别为12.26%和9.86%。经过50d的污泥堆肥化处理,物料由原来的深黑色变为灰黑色腐殖质状,疏松,臭味消失,基本达到腐熟。

Nitrogen loss is a common problem during composting of sewage sludge that affects its application. The study investigated the effect of dried sludge addition on nitrogen losses during the composting using municipal and mature dried sludge from Beijing. Five treatments, S （Sewage sludge ）, S＋20%DS （Dried sludge ）, S＋30%DS, S＋40%DS and S＋50%DS were designed in the experiment. Changes of pile temperature, content of ammonia volatilization, NH4^＋ -N, NO3-N and total nitrogen were monitored during composting. The results indicated that when 30%-40% dried sludge was added in the compost, the accumulation and loss of nitrogen in form of NH4^＋ -N decreased, and less NO3-N was lost. The losses of total nitrogen were 12.26% and 9.86% in the treatments adding 30% and 40% dried sludge respectively after the composting ending. The deep black compost materials turned to gray black, loose and odorless humus, and nearly reached mature after 50 days＇ composting.