| With the improvement of people's living standard, the speeding up of urbanization, the increasing number of catering enterprises, lots of food waste has been produced. The ratio of food waste to municipal solid waste (MS W) has also been increased. If the food waste was not properly treated, it would seriously pollute the environment. As the mainly component of MSW, the component of food waste include amylum, fiber, animal fat, and other organic material. The characteristics of food waste were that it has high moisture, high fat, high salt, and perishable stunk,easily biodegradable. The organic materials of food waste could be reasonably transformed into biogas by anaerobic digestion.The first step of this study was that through batch test and single phase continuous anaerobic digestion test, some influence factors were studied, the results of the study were as follows:(1)The paper research the charge ratio as parameter for food waste of anaerobic digestion organic loading rate, the purpose of the study was to research the effect of different charge ratio for methane potential of food waste on mesotherm anaerobic digestion in batch test, and to ensure the suitable level of charge ratio for food waste on mesotherm anaerobic digestion. The maximum methane content was 52.88 %,when the charge ratio was 20 %. Identically, when charge ratio was 20 %, the removal rate of TS and VS was maximum, 32.11 % and 38.24 %, respectively. At the end of test, the concentration of VFAs did not accumulate when the charge ratio was 20 %. Therefore,20 % charge ratio was considered to be suitable charge ratio for batch and continuous test.(2)The paper research the saltness as parameter for food waste of anaerobic digestion organic loading rate. The results showed that the maximum accumulation biogas production (3550 mL) was obtained when the saltness was 1 g/L, and the methane content was high. When the saltness was 1g/L, the removal rate of TS and VS was maximum, 18.98 % and 36.42 %, respectively. The suitable of saltness was benefit to the removal of TS and VS, achieving the reduction of food waste.(3)The paper research the oil content as parameter for food waste of anaerobic digestion organic loading rate.The results showed that the maximum accumulation biogas production (8914 mL) was obtained when the oil content was 15 g/L, and the methane content was high. At the end of digestion, VFAs accumulate slightly appeared when the oil content was 15 g/L. The removal rate of TS and VS was high when the oil content was 15 g/L, 28.77 % and 53.77 %, respectively. Meantime, with the increasing of oil content in reactors, although the higher biogas production was obtained, the cycle of digestion was aslo longer, and easily lead the reactor acidized.(4) The purpose of this study is researching the biogas production of food waste for the mesophilic single phase with difference organic loading rate and its recover in completely stirred tank reactor (CSTR). The study conducted from four phases:starting phase, the phase of OLR was 1-5 gVS/(L-d), after acidification no loading phase and recovering phase. The suitable OLR (3.0 gVS/(L-d)) for this CSTR was obtained, and the maximum biogas production rate was about 1.95 L/(L·d). The methane content was about 54.43 %-77.24 %, the methane content didn't changed with the different OLRs. The pH decreasing seriously made the process irreversible unless adding inoculated sludge. In recovering phase, the OLR increased to 3.0 gVS/(L·d) again, the biogas production rate was 2.09 L/(L-d), which was similar with the first OLR (3.0 gVS/(L·d)). In the process of the whole study,only the VFAs stay at low level (about 200 mg/L) and pH was above to 7.0, could the reactor operate stable. |
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