Sundberg C, Jönsson H
Department of Biometry and Engineering, Swedish University of Agricultural Sciences, PO Box 7032, SE-750 07 Uppsala, Sweden.
Waste Manag. 2008;28(3):518-26. doi: 10.1016/j.wasman.2007.01.011. Epub 2007 Apr 11.
Composting of source separated municipal biowaste has at several plants in Scandinavia been hampered by low pH. In this study the hypothesis that increased aeration would improve the process was tested in full-scale experiments at two large composting plants. The O2 concentrations were high (>15%) even at the low aeration rates, so the prevailing low pH was not due to an anaerobic process environment. In spite of this, increased aeration rates at the start of the process resulted in higher microbial activity, increased pH and a more stable compost product. At one plant the decomposition rate varied in proportion to the aeration rate, to the extent that the temperatures and O2 concentrations were similar during the early processes even though aeration rates varied between 10 and 50 m3/(h, m3 compost). However, increased aeration caused severe drying of the compost, but at one plant the addition of water was adequate to prevent drying. In conclusion, by increasing the aeration rates and adding water to compensate for drying, it was possible to shorten the time needed to produce a stable compost product and thus to increase the efficiency of the composting plants.
在斯堪的纳维亚半岛的几家工厂中，源头分类的城市生物垃圾的堆肥过程受到低pH值的阻碍。在本研究中，在两家大型堆肥厂进行了全规模实验，以检验增加曝气会改善该过程这一假设。即使在低曝气率下，氧气浓度也很高（>15%），因此当时普遍存在的低pH值并非由于厌氧过程环境所致。尽管如此，在过程开始时提高曝气率会导致更高的微生物活性、pH值升高以及更稳定的堆肥产品。在一家工厂，分解速率与曝气率成比例变化，以至于在早期过程中温度和氧气浓度相似，尽管曝气率在10至50立方米/（小时·立方米堆肥）之间变化。然而，曝气增加导致堆肥严重干燥，但在一家工厂，加水足以防止干燥。总之，通过提高曝气率并加水以补偿干燥，可以缩短生产稳定堆肥产品所需的时间，从而提高堆肥厂的效率。
