针对严寒地区冬季生活垃圾发酵过程中细菌群落演替设计实验,探究发酵过程中不同温度下(0,10,15,20,30,40 ℃)的有机物含量变化及细菌温度响应特性。研究表明:在0~40 ℃内发酵前3 d渗滤液中有机物含量变化均呈先下降再上升的变化趋势,温度越高,渗滤液中有机物在第3天的COD值也越高,且3~6 d下降幅度增大,而后6~10 d内的回升幅度也增大。通过微生物测序发现,最优势菌门为厚壁菌门(Firmicutes),其相对丰度为64.41%~99.74%,最优势菌属为乳杆菌属(Lactobacillus),其相对丰度为13.18%~96.95%。在0 ℃发酵温度下,乳杆菌属(Lactobacillus)相对丰度占比下降迅速,魏斯氏菌属(Weissella)成为最优势菌属;在其他温度下,乳杆菌属(Lactobacillus)相对丰度占比均超过68.92%。结果表明:垃圾样品中细菌种类及数量受发酵温度影响显著,在15 ℃以上的发酵温度下,乳杆菌属(Lactobacillus)的数量均出现上升趋势,30 ℃发酵温度下增长幅度最大。乳杆菌属数量的增加对有机物的降解作用也增强,并对其他菌属有明显的抑制作用。从利于垃圾入炉焚烧的角度考虑,结合垃圾解冻能耗问题,建议将垃圾储存池温度设置为15~20 ℃。
This study aimed at the designed experiment of bacterial community succession in the fermentation process of domestic waste in winter in severe cold areas, and explored the changes in organic matter content and temperature response characteristics of bacterial community succession law, under different temperatures (0, 10, 15, 20, 30, 40 ℃). The results showed that organic matter content in leachate decreased first and then increased at 0~40 ℃. The higher the temperature, the higher the initial COD value of the organic matter in leachate on the 3rd day; the decrease range increased from the 3rd to 6th day, and the recovery and increase range also increased from the 6th to 10th day. Through microbial sequencing, it was found that firmicutes was the dominant phyla, accounting for 64.41% to 99.74% of the total, and lactobacillus is the dominant specie, accounting for 13.18% to 96.95%. Under a fermentation temperature of 0 ℃, the relative abundance of Lactobacillus decreased rapidly, and Weissella became the dominant specie. But under other temperatures, the abundance of lactobacillus all exceeded 68.92%. The results showed that the type and quantity of bacteria in garbage samples were significantly affected by fermentation temperature. The quantity of Lactobacillus showed an upward trend at 15 ℃ and above, with the largest increase range at 30 ℃. At the same time, the increase of lactobacillus also enhanced the degradation of organic matter and significantly inhibited other bacteria, enhancing the degradation of organic compounds. For facilitating waste incineration into the incinerator, combined with the energy consumption of waste thawing, it was recommended to set the temperature of waste storage pool at 15 to 20 ℃.