Alidadi H, Parvaresh A R, Shahmansouri M R, Pourmoghadas H, Najafpoor A A
Department of Environmental Health, Faculty of Health, Mashhad University of Medical Sciences, Iran.
Pak J Biol Sci. 2007 Nov 1;10(21):3944-7. doi: 10.3923/pjbs.2007.3944.3947.
Traditional thermophillic composting is commonly for treatment of sludge. A related technique as vermicomposting process, using earthworms to breakdown sludge, is also becoming popular. These two techniques have their inherent advantages and disadvantages. The combined approach suggested in this study to enhance the overall process and improve the products qualities. Two systems, vermicomposting and combined compost-vermicomposting processes, have been investigated in this study. The sludge used in this study was obtained from the drying beds of South Isfahan wastewater treatment plant. The sludge mixed with sawdust to provide C/N ratio of 25/1. Eisenia fetida was the species of earthworms used in the vermicomposting processes. The results obtained indicate reduction in the amount of volatile solids, total carbon and C/N ratio with the vermicompost age, which indicates the reduction in the biodegradable organic content and mineralization of sludge. Also increase in phosphorus concentration by the end process because of mineralization of organic matter. The results indicate that, a system that combines the two mentioned processes not only shortens stabilization time, but also improves the products quality. Combining the two systems resulted in a product that was more stable and homogenous; the product could meet the pathogen reduction requirements.
传统的嗜热堆肥通常用于处理污泥。一种相关技术即蚯蚓堆肥法，利用蚯蚓分解污泥，也越来越受欢迎。这两种技术都有其固有的优缺点。本研究提出了一种联合方法，以强化整个过程并提高产品质量。本研究对两种系统，即蚯蚓堆肥系统和堆肥 - 蚯蚓堆肥联合系统进行了研究。本研究中使用的污泥取自伊斯法罕南部污水处理厂的干燥床。污泥与锯末混合，使碳氮比达到25/1。赤子爱胜蚓是蚯蚓堆肥过程中使用的蚯蚓品种。所得结果表明，随着蚯蚓堆肥时间的推移，挥发性固体、总碳量和碳氮比均有所降低，这表明污泥中可生物降解有机物含量减少且发生了矿化。由于有机物的矿化作用，最终过程中磷浓度也有所增加。结果表明，将上述两种过程结合起来的系统不仅缩短了稳定时间，还提高了产品质量。将这两种系统结合得到的产品更稳定、更均匀；该产品能够满足减少病原体的要求。
