餐厨垃圾高温中试两相厌氧发酵的稳定性

A pilot-scale study on the stability of two-phase anaerobic digestion of food waste under thermophilic conditions

为了考察在高负荷条件下餐厨垃圾厌氧发酵的稳定性,采用餐厨垃圾为发酵原料,以某污水处理厂脱水污泥为接种污泥,在中试规模条件下,采用产酸相中温(35℃,0.33 m3)产甲烷相高温(55℃,1.6 m3)进行连续式发酵。结果表明,餐厨垃圾厌氧发酵的产酸相有机负荷可达29.27 kg VS·(m^3·d)^(-1),产甲烷相有机负荷为6.04 kg VS·(m3·d)-1,容积产气率平均为5.61 m3·(m^3·d)^(-1),原料产气率平均达0.913 m3·(kg VS·d)-1,甲烷浓度平均为73.07%,总菌数为2.41×109个·m L-1,产甲烷菌最高为7.08×108个·m L-1,产甲烷菌数占总菌数的29.4%。两相厌氧发酵工艺可实现餐厨垃圾高负荷条件下的稳定运行。

The operational stability of two-phase anaerobic digestion（ 0. 33 m^3 acidogenic reactor and 1. 60m^3 methanogenic reactor） at high temperature（ 55℃） was examined in continuous anaerobic fermentation,utilizing food waste as fermented raw material and dewatered sludge as inocculation sludge. It is demonstrated that the maxmium organic loading rates of the acidogenic and methanogenic reactors were 29. 27 kg VS·（ m^3·d）^（-1） and 6. 04 kg VS·（ m^3·d）^（-1）,respectively. At these conditions in the methanogenic reactor,biogas production was 0. 913 m^3·（ kg VS·d）^（-1）. The gas production rate of average volumetric was 5. 61 m^3·（ m^3· d）^（-1）,and average methane concentration was 73. 07%. Total cell density was 2. 41 × 109 cells · m L^（-1）,while methanogen density was 7. 08 × 108cells·m L-1（ 29. 4% of total cell density）. The results show that anaerobic fermentation of food waste via two-phase anaerobic digestion can be operated stably at a high organic loading rate.