Maintaining proper aerobic conditions is a crucial factor in composting. Positive aeration (PA, blowing) has been widely applied but diffuses the odorous exhaust gas to the atmosphere. Negative aeration (NA, suction) enables to minimize the gas diffusion, but NA has scarcely been applied mainly because there has been no clear answer about the advantage in the organic matter degradation rate in this system. The air in the PA flows from the higher temperature zone (inside the pile) to the lower temperature zone (the top of the pile), while the air in the NA flows in the opposite direction. We hypothesized that the water vapor and NH₃ gas produced in the high-temperature zone of PA was more likely to be transported and absorbed/adsorbed in the lower temperature zone than that of NA, which could influence microbial activity during composting. This study quantitatively evaluated the effect of two aeration methods on organic matter degradation during composting. We examined the effect of absorption/adsorption of NH₃ on the compost by preventing the compost from drying. We found that PA indeed tended to accumulate more NH₃ than NA but did not show large differences, consequently having little influence on the organic matter degradation.

中文翻译：

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曝气方式对实验室规模反应器中有机物降解和堆肥氨排放的影响

保持适当的有氧条件是堆肥的关键因素。正充气（PA，吹气）已得到广泛应用，但将有气味的废气扩散到了大气中。负曝气（NA，吸气）可最大程度地减少气体扩散，但是几乎没有应用NA的主要原因是，对于该系统中有机物降解率的优势尚无明确答案。PA中的空气从较高温度区域（堆内部）流向较低温度区域（堆顶部），而NA中的空气沿相反方向流动。我们假设水蒸气和NH ₃与NA相比，PA高温区产生的气体更有可能在较低温度区进行运输和吸收/吸附，这可能会影响堆肥过程中的微生物活性。这项研究定量评估了两种曝气方法对堆肥过程中有机物降解的影响。我们通过防止堆肥干燥来检查NH ₃对堆肥的吸收/吸附作用。我们发现，PA的确比N积累了更多的NH ₃，但差异不大，因此对有机物降解的影响很小。