餐厨垃圾厌氧消化运行试验研究

EXPERIMENTAL STUDY ON OPERATING PERFORMANCE OF ANAEROBIC DIGESTION BY FOOD WASTE

采用猪粪厌氧消化的消化污泥为接种物,在中温(37℃)条件下,以连续进料的方式对餐厨垃圾的湿式厌氧消化进行了启动以及运行试验,监测整个实验过程中产气量、pH、VFA、碱度等能够反映厌氧消化的系统指标。结果表明:本实验中系统最佳有机负荷为2.8 kg/(m^3·d)(以VS计),超过此负荷后,依靠系统自身恢复和人工调节,pH很难恢复正常运行状态。正常运行过程中,pH稳定在7.5~8.0,VFA稳定在2 000 mg/L左右,碱度在6 000~9 000 mg/L,氨氮在1 500~2 000 mg/L,底物含水率为96%~98%。系统超负荷运行后,产气量和pH下降,VFA浓度上升,碱度、氨氮、含水率基本保持稳定。

The starting and running of wet continuous kitchen garbage anaerobic digestion system was conducted under the temperature of 37 ℃ , with digested sludge of swine manure as the inoculum. Some key parameters, such as the methane production, pH, VFA, alkalinity, were monitored throughout the experiment process. The result showed that the best organic load of the system was 2. 8 kg/（m3·d） （by weight of VS）. It was difficult to restore the normal running state once overloading, either by system self-recovery, or manual adjustment of pH. Under normal operation, pH, VFA, alkalinity and ammonia nitrogen concentration was stable at 7.5 -8.0, 2 000 mg/L, 6 000 -9 000 mg/L, 1 500 -2 000 mg/L, respectively, and the substrate moisture content was between 96% -98%. After the system overloading, methane production and pH decreased, and VFA content increased, while ammonia nitrogen concentration, alkalinity and moisture content kept stable.