通风速率对厨余垃圾堆肥NH3和H2S排放及腐熟度影响

为了减少厨余垃圾堆肥过程中NH3和H2S产生,该研究以通风速率0.16m3/h的纯厨余堆肥作为对照,以添加15%玉米秸秆(湿基)的厨余垃圾堆肥作为处理,并设置3个不同的通风速率(0.08、0.16和 0.24m3/h),研究通风速率对NH3和H2S排放及堆肥腐熟度的影响.结果表明:纯厨余垃圾堆肥总氮含量有所下降,添加秸秆后总氮量都有不同程度的提高,通风速率为0.16m3/h的处理效果最好,总氮含量可提高39.05%.与纯厨余堆肥相比,添加秸秆可减排14%~53% 的NH3 和67%~80%的H2S.随着通风速率的增加,NH3累计排放量呈对数增长趋势;H2S排放无明显规律,但过低和过高的通风速率,都会导致较高的H2S排放.堆肥结束后, 4个处理均可达到无害化标准和腐熟要求.综合NH3和H2S控制效果,厨余垃圾堆肥合适通风速率为0.16m3/h.

Effect of aeration rate on the NH3 and H2S emissions and maturity of kitchen waste composting

In order to decrease the NH3and H2S emissions during kitchen waste composting, this study investigated the effect of aeration rate on NH3 and H2S emissions and maturity. A control treatment was studied using pure kitchen waste with an aeration rate (AR) of 0.16m3/h, and three different ARs (0.08, 0.16 and 0.24m3/h) were set to compost using a mixture of 85% kitchen waste and 15% cornstalks (wet weight). The results showed that adding cornstalks could increase the total nitrogen compared with kitchen waste composted alone, the TN content of the treatment (AR = 0.16m3/h) was the highest among all treatments, its TN content increased 39.05%. Kitchen waste mixed with cornstalks reduced the NH3emissions by 14%~53% and H2S emission by 67%~80% than did pure kitchen waste. The NH3emissions increased with the AR increasing, and the NH3cumulative emissions showed a logarithmic growth trend. The H2S emissions has no obvious regularity, but low and high AR would lead to higher H2S emission. Moreover, all treatments met the sanitation requirements and reached the required maturity standard. Given the comprehensive effect, the recommended aeration rate for kitchen waste composting is 0.16m3/h.