Department of Agricultural Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria.
J Environ Manage. 2011 Jan;92(1):85-91. doi: 10.1016/j.jenvman.2010.08.026.
A passive aeration composting study was undertaken to investigate the effects of aeration pipe orientation (PO) and perforation size (PS) on some physico-chemical properties of chicken litter (chicken manure + sawdust) during composting. The experimental set up was a two-factor completely randomised block design with two pipe orientations: horizontal (Ho) and vertical (Ve), and three perforation sizes: 15, 25 and 35 mm diameter. The properties monitored during composting were pile temperature, moisture content (MC), pH, electrical conductivity (EC), total carbon (C(T)), total nitrogen (N(T)) and total phosphorus (P(T)). Moisture level in the piles was periodically replenished to 60% for efficient microbial activities. The results of the study showed that optimum composting conditions (thermophilic temperatures and sanitation requirements) were attained in all the piles. During composting, both PO and PS significantly affected pile temperature, moisture level, pH, C(T) loss and P(T) gain. EC was only affected by PO while N(T) was affected by PS. Neither PO nor PS had a significant effect on the C:N ratio. A vertical pipe was effective for uniform air distribution, hence, uniform composting rate within the composting pile. The final values showed that PO of Ve and PS of 35 mm diameter resulted in the least loss in N(T). The PO of Ho was as effective as Ve in the conservation of C(T) and P(T). Similarly, the three PSs were equally effective in the conservation of C(T) and P(T). In conclusion, the combined effects of PO and PS showed that treatments Ve35 and Ve15 were the most effective in minimizing N(T) loss.
一项被动曝气堆肥研究旨在探讨曝气管方向（PO）和穿孔尺寸（PS）对鸡粪（鸡粪+木屑）堆肥过程中某些物理化学性质的影响。实验设计采用两因素完全随机区组设计，有两种管方向：水平（Ho）和垂直（Ve），以及三种穿孔尺寸：15、25 和 35 毫米直径。堆肥过程中监测的特性有堆温、含水量（MC）、pH 值、电导率（EC）、总碳（C(T)）、总氮（N(T)）和总磷（P(T)）。为了促进微生物的有效活动，定期向堆肥中补充水分至 60%。研究结果表明，所有堆肥中都达到了最佳的堆肥条件（高温和卫生要求）。在堆肥过程中，PO 和 PS 都显著影响堆温、水分水平、pH 值、C(T)损失和 P(T)增加。EC 仅受 PO 影响，而 N(T)受 PS 影响。PO 和 PS 都没有对 C:N 比产生显著影响。垂直管有利于空气的均匀分布，因此在堆肥过程中堆肥速率均匀。最终值表明，Ve 方向的 35 毫米直径的 PS 处理导致 N(T)损失最小。Ho 方向与 Ve 方向在 C(T)和 P(T)的保持方面同样有效。同样，三种 PS 在 C(T)和 P(T)的保持方面同样有效。总之，PO 和 PS 的综合影响表明，Ve35 和 Ve15 处理在最小化 N(T)损失方面最为有效。
