污泥高温好氧发酵有机质降解动力学研究

Study on Dynamics of Organic Matter Degradation in Sludge Thermophilic Aerobic Fermentation

采用30 L发酵反应装置模拟高温好氧环境,研究高温好氧发酵过程中污泥自身有机组分的降解动力学特征。结果表明,在高温发酵的前10 d,污泥中挥发性有机质含量、水溶性有机碳含量、氮素含量、二氧化碳产生速率、耗氧速率和氨气挥发速率的下降率分别达到25.5%、32%、33.3%、67.5%、64.3%、76%,但是在相同运行条件下高温发酵10～20 d过程中上述各指标的下降率却仅分别为3.6%、13.6%、3.1%、17.5%、17.9%、11.3%。试验证明污泥有机组分的生物降解速率存在显著差异,尽管其中大部分快速降解组分在高温条件下可在10 d左右得到生物转化,但慢速降解组分经过高温发酵20 d仍不能完成生物稳定化过程。

Thermophilic aerobic environment was simulated in a 30 L fermentation reactor, and the dynamics of organic matter degradation in sludge thermophilic aerobic fermentation were studied. The results show that the decline rates of the volatile organic compound content, soluble organic carbon and total nitrogen in the sludge as well as CO： production rate, oxygen uptake rate and NH3 volatilization rate in the system are 25.5%, 32%, 33.3%, 67.5%, 64.3% and 76% respectively during the first 10 d of thermophilic fermentation. However, these parameters are reduced only by 3.6% , 13.6% , 3. 1% , 17.5% , 17.9% and 11.3% respectively during the next 10 d in the same operating conditions. It shows that there is a huge difference of the biodegradation rate among the organic matters in the sludge. Most readily biodegradable substances in the sludge can be biodegraded during the first 10 d, but even after 20 d of thermophilic fermentation, not readily biodegradable substances can not achieve the biological stabilization.