School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China; Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou 730070, China.
School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
Waste Manag. 2022 Apr 15;143:116-124. doi: 10.1016/j.wasman.2022.02.026. Epub 2022 Feb 28.
Vermicomposting is characterized by transforming organic waste into nutrient-rich organic fertilizer through the action of different earthworms and microorganisms. Although vermicomposting can recycle the excess sludge in an eco-friendly manner, the longer stabilization period has limited its industrial application. The present study sought to investigate a novel operation process of vermicomposting combined with room drying (VD) to improve the stabilization efficiency of dewatered sludge. Subsequently, the performance and efficiency of vermicomposting without room drying, room dry without vermicomposting, and VD for sludge stabilization were compared simultaneously. In the VD process, the sludge water content reduced from 60.8% to 1.64%, showing the highest electrical conductivity and lowest organic matter content, making the humus substances abundant in the final product. Moreover, the vermicomposting achieved the highest ammonia and nitrate content in final product. Additionally, the bacterial and eukaryotic abundances in the VD product were significantly higher (P < 0.01, i.e., 15.6% and 180.7%) than the vermicomposting product. The specific bacterial genus of Glutamicibacter, Chitinibacter, and Acidobacteria was dominated in the VD product. The Partial least squares-Path modeling (PLS-PM) results revealed that the maturity degree in the VD product was significantly associated with microbial component, and the organic form was strongly driven by the change in the physicochemical properties, which was contradictory to vermicomposting model. The study suggests that the VD process could shorten the vermicomposting period by rapidly accelerating the physical, chemical, and biological stabilization of sludge.
蚯蚓堆肥的特点是通过不同蚯蚓和微生物的作用，将有机废物转化为营养丰富的有机肥料。虽然蚯蚓堆肥可以以环保的方式回收多余的污泥，但较长的稳定化周期限制了其工业应用。本研究旨在探索一种新的蚯蚓堆肥与风干（VD）联合操作工艺，以提高脱水污泥的稳定化效率。随后，同时比较了不进行风干的蚯蚓堆肥、不进行风干的风干和 VD 对污泥稳定化的性能和效率。在 VD 过程中，污泥的含水量从 60.8%降低到 1.64%，电导率最高，有机物含量最低，最终产品中腐殖质丰富。此外，蚯蚓堆肥使最终产物中的氨和硝酸盐含量最高。此外，VD 产物中的细菌和真核生物丰度明显更高（P < 0.01，即 15.6%和 180.7%）。VD 产物中的细菌属主要为谷氨酸杆菌属、Chitinibacter 和酸杆菌属。偏最小二乘路径模型（PLS-PM）结果表明，VD 产物的成熟度与微生物组成显著相关，有机形态强烈受物理化学性质变化的驱动，这与蚯蚓堆肥模型相反。研究表明，VD 工艺可以通过快速加速污泥的物理、化学和生物稳定化来缩短蚯蚓堆肥周期。
