农林废弃物对厨余垃圾堆肥腐殖化的影响与微生物驱动机制

    Effects of agricultural and forestry wastes on humification and its microbially driven mechanisms in kitchen waste composting

    • 摘要: 高碳源农林辅料复配是实现厨余垃圾好氧堆肥促腐提质的关键技术,但不同辅料对厨余垃圾堆肥过程腐殖化的影响及其相应的微生物驱动机制仍不清楚,从而限制了对辅料的有效筛选与利用。为此,该研究选用园林废弃物、玉米秸秆和西瓜秧3种典型高碳源农林废弃物为辅料,探究其对厨余垃圾堆肥过程有机质腐殖化的调控效果与机制。研究结果表明:相较于园林废弃物和西瓜秧,添加15%玉米秸秆(湿质量)作为辅料,能够有效调节堆体物料结构,富集功能微生物,促进厨余垃圾堆肥产物腐熟度提升,种子发芽指数可达139%。具体而言,西瓜秧蛋白质含量较高,作为辅料能够在堆肥初期促进堆体快速升温,但不利于高温期延续,且产物腐殖化程度较低。相比之下,园林废弃物和玉米秸秆添加可以在高温期和降温腐熟期富集更多UreibacillusBacillus OceanobacillusFlavobacterium等具有木聚糖降解和纤维素降解功能的细菌,促进有机质转化为多酚、氨基酸等腐殖质前驱物,进而推动稳定的腐殖酸生成。特别是玉米秸秆作为辅料时有效增加了具有木质纤维素降解功能的细菌,从而能够加速有机质的降解,促进腐殖化提升75%,研究结果为选取适宜的辅料强化厨余垃圾堆肥产品品质提供参考。

       

      Abstract: Carbon-rich agroforestry auxiliary materials can be regulated to improve the humification and quality in aerobic composting of food wastes. However, it is still unclear on the effects of different auxiliary materials on the humification in food waste composting and their corresponding microbially driven mechanisms, thus limiting the effective selection and utilization of auxiliary materials. Herein, three typical carbon-rich agroforestry auxiliary materials were selected fromdifferent sources, including garden waste, corn straw, and watermelon vine. A systematic investigation was then implemented on their effects and mechanisms on the organic humification in food waste composting. Some parameters were then measured, such as the organic matter fraction, humic substances, and their precursors. Moreover, the high-throughput sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX) database were also used to analyze the succession and function of the microbial community during composting. Results showed that the addition of 15% corn straw (wet weight) effectively adjusted the matrix structure to enrich the functional bacteria and thus enhance the compost maturity. Specifically, the watermelon vine with the high protein content was promoted the rapid temperature increase at the beginning of composting, but unfavorable to maintain the thermophilic stage for better product humification. In contrast, the garden waste and corn straw addition were enriching more bacteria (such as Ureibacillus, Bacillus, Oceanobacillus, and Flavobacterium) for the xylan and cellulose degradation at the thermophilic, cooling, and mature stages. Such enrichment in turn promoted the conversion of organic matter into humus precursors (i.e., polyphenols and amino acids) for stable humic acid production. Especially, the corn straw as an auxiliary material promoted the humification by 75%, indicating the accelerated degradation of organic matter. Anyway, the corn straw can be expected to effectively increase the bacteria with the lignocellulosic degradation function.

       

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