Regional Water and Environmental Sanitation Centre, Kumasi, Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Regional Water and Environmental Sanitation Centre, Kumasi, Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
J Environ Manage. 2021 Sep 1;293:112817. doi: 10.1016/j.jenvman.2021.112817. Epub 2021 Jun 4.
This study was carried out to assess the degradation and accumulation rates of fresh human excreta and how addition of anal cleansing materials affect performance during vermicomposting by Eisenia fetida and Eudrilus eugeniae. Vermicomposting setups consisting of two transparent containers (length 0.27 m, breadth 0.17 m and depth 0.12 m) stacked on top of each other were installed and operated under laboratory conditions. Earthworms, Eisenia fetida and Eudrilus eugeniae, were obtained from Green Cycle Technologies Limited in Accra, Ghana and the species verified and cultured before use. Fresh human excreta for feeding the experimental setups was collected from an Enviro-loo public toilet and 13 g applied to the setups daily. Similar setups were fed with 0.3 g of anal cleansing material in addition to the fresh excreta. A setup without any earthworms (NW) was set up as a control. Physicochemical characteristics of vermicompost accumulating in the setups were determined weekly for 28 days using standard laboratory procedures while the sludge accumulated in the various setups were weighed and recorded daily. One-way analysis of variance (ANOVA) and Post-hoc LSD tests were conducted to determine whether the differences in results between the two earthworm species and among setups with and without anal cleansing materials were statistically significant (p ≤ 0.05). The study showed 12.3% and 26.2% reduction in volatile solids in EE (Eudrilus eugeniae and excreta only) and EF (Eisenia fetida and excreta only) while ash content increased indicating good degradation. The percentage mass reductions recorded at the end of the fourth week were 67.5%, 58.8% and 40.5% in systems EE, EF and NW respectively, while reductions of 73.7% and 68.5% were realized in EEA (Eudrilus eugeniae with excreta and toilet paper) and EFA (Eisenia fetida with excreta and toilet paper) respectively. There was greater amount of sludge accumulated in systems without earthworms, 0.00020 m (59.5%) in NW, than in systems with earthworms where 0.00011 m (32.5%) and 0.00014 m (41.2%) were recorded for EE and EF respectively. The rate of accumulation in vermibeds EE and EF was relatively higher than in vermibeds with excreta and toilet paper (EEA and EFA). EEA and EFA recorded accumulation rates of 0.00009 m (26.3%) and 0.00011 m (31.5%) respectively. Complete removal of helminth eggs was not achieved in any of the treatment systems.
本研究旨在评估新鲜人类粪便的降解和积累速率，以及添加肛门清洁材料如何影响以赤子爱胜蚓（Eisenia fetida）和双齿多刺蚯蚓（Eudrilus eugeniae）进行堆肥时的性能。堆肥装置由两个透明容器（长 0.27 m，宽 0.17 m，深 0.12 m）堆叠而成，在实验室条件下安装和运行。从加纳阿克拉的 Green Cycle Technologies Limited 获得蚯蚓，赤子爱胜蚓（Eisenia fetida）和双齿多刺蚯蚓（Eudrilus eugeniae），并在使用前进行了验证和培养。用于喂养实验装置的新鲜人类粪便从 Enviro-loo 公共厕所收集，每天应用 13 g。类似的装置除了新鲜粪便外，还添加了 0.3 g 的肛门清洁材料。一个没有任何蚯蚓的装置（NW）作为对照。使用标准实验室程序每周确定 28 天内在装置中积累的堆肥的理化特性，同时每天记录各种装置中积累的污泥重量。使用单向方差分析（ANOVA）和事后 LSD 检验来确定两种蚯蚓种类之间以及有和没有肛门清洁材料的装置之间的结果差异是否具有统计学意义（p ≤ 0.05）。研究表明，EE（双齿多刺蚯蚓和粪便）和 EF（赤子爱胜蚓和粪便）中的挥发性固体分别减少了 12.3%和 26.2%，而灰分含量增加，表明降解良好。第四周结束时，系统 EE、EF 和 NW 中的质量减少率分别为 67.5%、58.8%和 40.5%，而在 EEA（双齿多刺蚯蚓和粪便以及卫生纸）和 EFA（赤子爱胜蚓和粪便以及卫生纸）中则分别实现了 73.7%和 68.5%的减少。在没有蚯蚓的系统中积累的污泥量更大，NW 为 0.00020 m（59.5%），而在有蚯蚓的系统中分别为 0.00011 m（32.5%）和 0.00014 m（41.2%）。EE 和 EF 蚯蚓床的积累速度相对高于有粪便和卫生纸的蚯蚓床（EEA 和 EFA）。EEA 和 EFA 的积累率分别为 0.00009 m（26.3%）和 0.00011 m（31.5%）。在任何处理系统中都未完全去除寄生虫卵。
