城市污泥堆肥过程中H_2S的释放动态及其控制策略

Dynamics of H_2S emission from pile during composting of sewage sludge and its control measure

以城市污泥为对象,研究了不同堆肥原料配比对H2S释放的影响.结果表明,在堆肥过程中,尽管从释放H2S浓度的动态变化来看存在一定的波动,但总体趋势是:降温期>高温期>升温期.采用堆肥物料上、下分层的处理,堆肥所需时间较短,堆体腐熟时H2S的总释放量也最少;同时,采用大功率风机进行鼓风,堆体释放H2S浓度的最大值降低.因此,在城市污泥的堆肥中,采用堆肥物料上下分层与大功率风机相结合的措施,既可以减少H2S的释放量,又可以缩短堆肥时间,是一种有潜在应用价值的堆肥技术.

The process of H2S emission from the pile was studied in static forced-aeration composting. The results indicated that the emission of H2S from the pile fluctuated greatly during the composting. The trend of H2S Emissions was found to follow the order that： the cooling phase 〉 the thermophilic phase 〉 the mesophilic phase. Compared to the treatment of unifonn ratio of sewage sludge to bulking agent in the whole pile, the period of composting was shortened when the ratio of sewage sludge to bulking agent in the lower layer of the pile was increased to 1 ： 0.5 and the ratio of the sewage sludge to the bulking agent in the upper layer of the pile was decreased to 0.5 ： 1 or 0.75 ： 1. Therefore, the change in the ratio of sewage sludge to bulking agent in different layer had great effect on the process of the composting. The total quantity and the maximum concentration of H2 S emitted from the pile were higher when the air was forced into the pile with the highpower, 550 W, blower motor than the low-power, 250 W, blower motor. Therefore, the application of an appropriate blower motor and/or a suitable ratio of sewage sludge to bulking agent were suggested to be important techniques that could not only decrease the emission of H2S, but also accelerate the process of composting.