厌氧发酵连续运行中有机负荷与工艺参数相互作用研究

Test of interaction between the organic load and the processing parameters on the continuous operation of anaerobic fermentation

以餐厨垃圾为研究对象,在高温(55±1)℃条件下,采用连续湿式厌氧发酵技术研究发酵过程中进料有机负荷、日产气量、p H值、挥发性有机酸(VFA)质量浓度等参数的变化情况及相互作用关系。结果表明:厌氧消化过程中出现了4个阶段,即适应阶段、提高阶段、稳定阶段和超负荷阶段;反应达到稳定阶段时,反应器运行有机负荷为3.9 kg/(m3·d),系统p H值稳定在7.8左右,平均产气速率达到5.26 L/d;负荷达到4.2 kg/(m3·d)时,对系统产生明显抑制作用。

This paper intends to present its study results on the effects of the organic load on the dispose of the organic solid wastes（ OSW） based on the so-far gained research results both at home and abroad. As is well known,the anaerobic digestion is a kind of approaches to transforming the organic matters into carbon dioxide and methane gas,which has a lot of advantages,such as less energy consumption,less surplus sludge and great energy-recovering gains. It is just for the above said advantages that it is generally considered to be one of the most promising ways to dispose OSW in the future. However,in this paper,what we would like to do is just to make a practical simulated engineering project by using the continuous dosing material and tracing the parameter changes under various organic loads in the reaction system so as to gradually improve the organic loading condition of the reactor.What is more,we have also managed to perform an experiment of the urban food waste and investigated the wet thermophilic anaerobic digestion in the laboratory condition at（ 55 ± 1） ℃. In the fermentation process,we have managed to raise the organic load,and analyzed the variations of pH value,VFA concentration and gas production. The experimental test results show that：（ 1） The anaerobic digestion process may experience four stages,that is,the adaptation stage,the improvement stage, the stabilization stage and the overload stage;（ 2） When the reaction comes to a stable stage,the average gas production rate should be 5. 7 L / d,with pH value keeping stabilized at about 7. 8 and coming to the maximum organic load at 3. 9 kg /（ m3·d）;（ 3） There should come a clear inhibitory effect on the system,on the condition that the organic loading is coming up to 4. 2 kg /（ m3·d）;（ 4） The interaction among the organic load and the process parameters doesn＇t tend to be identical. And,therefore,it is of a guiding significance to study the interaction of the organic load and the process parameters to promote the actual engineering application.On the other hand,the stabilization phase is also of great importance for the best production of gas,for the system has the strongest resistance to the impact of the load capacity so as to achieve the best state of the various process parameters and practical engineering status.