蚯蚓堆肥处理剩余污泥混合有机垃圾的效率研究

Efficiency of Vermicomposting on Organic-Waste-Mixed Municipal Sludge

为了研究基质堆料高度和高密度接种条件对蚯蚓堆肥处理有机垃圾混合剩余污泥时蚯蚓生物量及其堆肥效率的影响,共设6个处理进行试验,按接种密度-堆料高度表示,分别为:1/10-10cm组、1/10-15cm组、1/15-10cm组、1/15-15cm组、1/20-10cm组、1/20-15cm组。试验结果表明,在堆料高度相同时,蚯蚓生物量与其接种密度呈显著的负相关关系,但接种密度对蚯蚓堆肥效率的影响有限,只有在1/10组同1/15组或1/20组比较时表现出显著差异,而后两个组别之间差异不显著;在接种密度相同时,堆料高度对蚯蚓堆肥效率的影响不显著,而对蚯蚓生物量的影响可能存在一个密度临界点(1/15),在此密度附近,堆料高度对蚯蚓生物量的影响较显著,呈显著正相关关系,而在此密度以上或以下,堆料高度的影响不显著。从产业应用的角度,综合考虑蚯蚓维持种群繁衍的再生产能力以及混合污泥的堆肥效率这两个因素,赤子爱胜蚓(Eisenia foetida)处理有机垃圾混合剩余污泥的最佳接种密度为1/15,堆料高度为15cm。

The effects of medium stack height and high inoculum density on earthworm＇s biomass and efficiency of vermicomposting were investigated in Eiseniafoetida vermieomposting on organic-waste-mixed municipal sludge. Combining medium stack height and earthworm inoculum density（mass ratio, worm wet mass/sludge dry mass）, six treatments, i.e., 1/10-10 cm, 1/10-15 cm, 1/15-10 cm, 1/15-15cm, 1/20- 10 cm and 1/20-15 cm, respectively, were set in the experiment. Results showed that, under the same medium stack height, the biomass of earthworms was negatively correlated with their inoculum density significantly. However, the effect of inoculum density on the efficiency of vermieomposting was limited. Specifically, there was significant difference in the efficiency of vermicomposting between high-density group （1/10） and low-density ones （1/15 and 1/20）, while insignificant between the latter two groups, 1/15 and 1/20. Under the same inoculum density, the effect of medium stack height on the efficiency of vermieomposting was insignificant, whereas on the earthworm＇s biomass, there was a critical point of inoculum density（ 1/15 ） where the earthworm＇s biomass was positively correlated with medium stack height signifi- cantly, while a lot above or below this density point, medium stack height had no significant effect. In the view of industrial application, there is a trade-off between the reproductive ability for the earthworm population and the efficiency of vermieomposting, and thereby the inoculum density of 1/20 and the medium stack height of 15 cm are possibly the optimum parameters for the vermieomposting of Eiseniafoetida on the organic-waste-mixed municipal sludge.