摘要

       城市污泥（以下称为厌氧消化污泥，ADS）经过厌氧消化后仍残留消化残渣，需要进一步处理以实现更高的可持续性。在这项研究中，评估了 ADS 的可堆肥性，重点是有机物的稳定性和典型抗生素抗性基因 (ARG) 的命运。结果表明，由于 NH4+ 和可溶性总有机碳的浓度非常高，ADS 不适合作为肥料（表现为 16.9% 的低发芽指数）。堆肥后处理稳定了 ADS；堆肥37 d内挥发性总固体的降解率达到18.5%。处理过的 ADS 的理化性质表明获得了成熟的堆肥产品。典型 ARG 的实时定量聚合酶链反应分析表明，由于典型 ARG 的减少和宿主微生物中的低水平基因转移，在 ADS 堆肥过程中 ARG 丰度降低了四倍。细菌群落的分析表明，放线菌门、变形菌门、厚壁菌门、拟杆菌门和绿屈曲菌门的成员对于 ADS 堆肥过程中的材料转化和 ARG 减少至关重要。这些结果表明，好氧堆肥进一步稳定了有机质并降低了 ARG 丰度；因此，它被发现是一种有效的 ADS 后处理方法。

       Digested residue remains after anaerobic digestion of municipal sludge (hereafter called anaerobic digested sludge, ADS) and needs further treatment to attain more sustainability. In this study, the compostability of ADS was assessed, focusing on the stability of organic matter and the fate of typical antibiotic resistance genes (ARGs). The results showed that ADS was not suitable as a fertilizer (reflected by a low germination index of 16.9%) due to very high concentrations of NH4+ and soluble total organic carbon. Composting post-treatment stabilized the ADS; the degradation efficiency of volatile total solids reached 18.5% within 37 d of composting. The physicochemical properties of the treated ADS indicated that a mature compost product was obtained. Real-time quantitative polymerase chain reaction analysis of typical ARGs revealed that ARG abundance was reduced four-fold during ADS composting due to a reduction in the typical ARGs and low horizontal gene transfer in host microbes. The analysis of bacterial communities revealed that members of the phyla Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Chloroflexi are crucial for material transformation and ARG reduction during the ADS composting process. These results demonstrated that aerobic composting further stabilized the organic matter and reduced ARG abundance; therefore, it was found to be an effective method for ADS post-treatment.

https://www.sciencedirect.com/science/article/abs/pii/S0959652621000184