Optimizing composting parameters for nitrogen conservation in composting

• Published in: Bioresource technology 2008-07, Vol.99 (11), p.5069-5077
• Main Authors: Bueno, P., Tapias, R., López, F., Díaz, M.J.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological treatment of sewage sludges and wastes; Bioreactors; Biotechnology; Carbon; Composting; Conservation of Natural Resources; Environment and pollution; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Leucaena; Nitrogen - metabolism; Nitrogen losses; Optimization; Organic Chemicals - metabolism; Particle Size; Soil; Temperature; Time Factors
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2007.08.087

A central composite experimental design was used to investigate the influence of environmental composting parameters (moisture, aeration, particle size and time) for legume trimming residues, used on soil restoration, on the properties of products obtained (organic matter, Kjeldahl-N, C/N ratio and nitrogen losses (N-losses)) in order to determine the best composting conditions. A second-order polynomial model consisting of four independent process variables was found to accurately describe (the differences between the experimental values and those estimated by using the equations never exceeded 10% of the former) the composting process. Results of the experiment showed that compost with acceptably chemical properties (OM, 85%; Kjeldahl-N, 3.2%), high degradation and minimum N-losses entails operating at high operation time (78 days), low particle size (1 cm), medium moisture content (40%) and medium to low aeration level (0.2–0.4 l air/min kg).