Study On Inhibition Of Volatile Fatty Acids And Ammonia-nitrogen In Anaerobic Digestion For Urban Organic Wastes

At present, The Municipal Organic Refuse (MOR) is becoming an important environmental challenge. Along with the increasing content of the MOR in municipal solid waste (MSW), Anaerobic Digestion is a good approach for MSW treatment and accord with sustainable development strategic. Nevertheless, traditional anaerobic digestion presents many limitations such as organic acid restraint, ammonia-nitrogen restraint. How to solve these problems is a research hotspot at present. In order to resolve them, the Research Group (or research team) for the National Scientific and Technological Key Task program in the tenth five year plan of Chongqing University bring forward a project that is"the anaerobic-aerobic combination ferment techniques of the municipal organic refuse and nightsoil". Combining with the project, using the MSW in Chongqing as experimental material, the discourse has studied several problems.(1)single-phase anaerobic digestion experimentation. The project contains two processes. The first is choosing 0%, 30%, 50%, and 60%, four levels of inoculation quantity, to process the experiment. During the process, the temperature is 35℃and the total solid (TS) is 15%. Another process is adding fresh refuse into equipment periodical.(2)two-phase anaerobic digestion experimentation. The experiment contains the study of the startup of the two -phase anaerobic digestion, the restraint of the Volatile fatty acids(VFA) and the restraint of ammonia-nitrogen, the study of the two -phase anaerobic digestion of nightsoil and MOR。According to these studies, we gain the experimental result and draw the conclusions:(1)After the first process of single-phase anaerobic digestion, we found that along with the increasing of inoculation sludge level, the reactor increase its ability of resistance。At the anaphase of the reaction, when the consistence of organic acid achieve to 20000mg/L,According to ADM1 ,we can conclude to restrained function :I= I≈0.56<1, the system breaks out the phenomena of acid restraint. At the same time, the consistence of ammonia-nitrogen is less than 500mg/L and don't break out the ammonia-nitrogen restraint. It explains that inoculating sludge may not always avoid the problem of acid poisoning; at the second process of single-phase anaerobic digestion,...