Using a second-order polynomial model to determine the optimum vinasse/Grape marc ratio for in-vessel composting

• Author(s): Bertoldi, M.; Cabrera, Francisco; Diaz, M.; Jimenez, L.; Madejon, E.;
• Abstract: This paper evaluates the influence of operating conditions (pH, Kjeldahl-N losses, NO3--N, NO4+-N, C/N ratio and biodegradation) used in the vinasse/grape marc incubation on the properties of products obtained to determine the best incubation conditions (time and amount of vinasse proportion) to aid in the design of an in-vessel composting system. A second-order polynomial model consisting of two independent process variables was found to accurately describe, with 10% differences between experimental values and model prediction, the vinasse-grape marc incubation. The dependent variables measured were pH, Kjeldahl-N losses, NO3--N, NO4+-N, C/N ratio and biodegradation and the independent process variables were operation time and amount of vinasse. Results determined products with acceptable chemical properties, high biodegradation and germination index and minimum Kjeldahl-N losses entails operating at medium-to-short operation time (20-35 days) and medium-to-low vinasse percentages (0-20%).
• Publication Date: Jun 2004
• Journal: Compost Science & Utilization