Cernas - Natural Resources, Environment and Society Research Centre, College of Agriculture, Polytechnic Institute of Coimbra, Bencanta, P-3040-316 Coimbra, Portugal.
J Environ Manage. 2013 Oct 15;128:75-82. doi: 10.1016/j.jenvman.2013.04.041. Epub 2013 May 27.
Free air space (FAS) is a physical parameter that can play an important role in composting processes to maintain favourable aerobic conditions. Aiming to predict the FAS of initial composting mixtures, specific materials proportions ranged from 0 to 1 were tested for a case study comprising industrial potato peel, which is characterized by low air void volume, thus requiring additional components for its composting. The characterization and prediction of FAS for initial mixtures involving potato peel, grass clippings and rice husks (set A) or sawdust (set B) was accomplished by means of an augmented simplex-centroid mixture design approach. The experimental data were fitted to second order Scheffé polynomials. Synergistic or antagonistic effects of mixture proportions in the FAS response were identified from the surface and response trace plots in the FAS response. Moreover, a good agreement was achieved between the model predictions and supplementary experimental data. Moreover, theoretical and empirical approaches for estimating FAS available in literature were compared with the predictions generated by the mixture design approach. This study demonstrated that the mixture design methodology can be a valuable tool to predict the initial FAS of composting mixtures, specifically in making adjustments to improve composting processes containing primarily potato peel.
自由空气空间（FAS）是一个物理参数，在堆肥过程中可以发挥重要作用，以维持有利的好氧条件。本研究旨在预测初始堆肥混合物的 FAS，测试了特定材料比例从 0 到 1 的范围，用于包含工业马铃薯皮的案例研究，其特点是空气空隙体积低，因此需要添加其他成分进行堆肥。通过增广单纯形质心混合设计方法，对包含马铃薯皮、草屑和稻壳（A 组）或木屑（B 组）的初始混合物的 FAS 进行了表征和预测。通过二阶谢菲多项式对实验数据进行拟合。通过 FAS 响应的表面和响应跟踪图，确定了混合物比例在 FAS 响应中的协同或拮抗作用。此外，模型预测与补充实验数据之间达到了良好的一致性。此外，还比较了文献中可用的 FAS 理论和经验方法与混合设计方法生成的预测。这项研究表明，混合设计方法可以成为预测堆肥混合物初始 FAS 的有用工具，特别是在主要包含马铃薯皮的堆肥过程中进行调整以改善堆肥过程。
