Mejias Laura, Komilis Dimitrios, Gea Teresa, Sánchez Antoni
Composting Research Group (GICOM), Dept. of Chemical Biological and Environmental Engineering, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain.
Composting Research Group (GICOM), Dept. of Chemical Biological and Environmental Engineering, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain; Department of Environmental Engineering, Democritus University of Thrace, Xanthi, Greece.
Waste Manag. 2017 Jul;65:22-28. doi: 10.1016/j.wasman.2017.04.008. Epub 2017 Apr 7.
The aim of this study was to assess the effect of the airflow and of the aeration mode on the composting process of non-urban organic wastes that are found in large quantities worldwide, namely: (i) a fresh, non-digested, sewage sludge (FSS), (ii) an anaerobically digested sewage sludge (ADSS), (iii) cow manure (CM) and (iv) pig sludge (PS). This assessment was done using respirometric indices. Two aeration modes were tested, namely: (a) a constant air flowrate set at three different initial fixed airflow rates, and (b) an oxygen uptake rate (OUR)-controlled airflow rate. The four wastes displayed the same behaviour namely a limited biological activity at low aeration, while, beyond a threshold value, the increase of the airflow did not significantly increase the dynamic respiration indices (DRI, DRI and AT). The threshold airflow rate varied among wastes and ranged from 42NL air kgDMh for CM and from 67 to 77NL air kgDMh for FSS, ADSS and PS. Comparing the two aeration modes tested (constant air flow, OUR controlled air flow), no statistically significant differences were calculated between the respiration activity indices obtained at those two aeration modes. The results can be considered representative for urban and non-urban organic wastes and establish a general procedure to measure the respiration activity without limitations by airflow. This will permit other researchers to provide consistent results during the measurement of the respiration activity. Results indicate that high airflows are not required to establish the maximum respiration activity. This can result in energy savings and the prevention of off-gas treatment problems due to the excessive aeration rate in full scale composting plants.
本研究的目的是评估气流和曝气模式对全球大量存在的非城市有机废物堆肥过程的影响，这些废物包括：（i）新鲜的、未消化的污水污泥（FSS），（ii）厌氧消化的污水污泥（ADSS），（iii）牛粪（CM）和（iv）猪污泥（PS）。该评估使用呼吸测量指标进行。测试了两种曝气模式，即：（a）在三种不同的初始固定气流速率下设置恒定气流速率，以及（b）氧气吸收速率（OUR）控制的气流速率。这四种废物表现出相同的行为，即在低曝气时生物活性有限，而超过阈值后，气流增加并未显著提高动态呼吸指数（DRI、DRI和AT）。阈值气流速率因废物而异，CM为42NL空气·kgDM⁻¹·h⁻¹，FSS、ADSS和PS为67至77NL空气·kgDM⁻¹·h⁻¹。比较所测试的两种曝气模式（恒定气流、OUR控制气流），在这两种曝气模式下获得的呼吸活性指数之间未计算出统计学上的显著差异。这些结果可被视为城市和非城市有机废物的代表性结果，并建立了一种不受气流限制测量呼吸活性的通用程序。这将使其他研究人员在测量呼吸活性时能够提供一致的结果。结果表明，建立最大呼吸活性不需要高气流。这可以节省能源，并防止由于大规模堆肥厂曝气速率过高而导致的废气处理问题。
