Kinetics and physics during composting of various organic wastes: Statistical approach to interpret compost application feasibility

Surge in the demand for compost applicability in enhancing the overall soil health has prioritized the need to evaluate and interpret the engineering aspect of composting and quality product. Although studies on various facets of biological and chemical properties are plenty, its interplay with waste degradation rate, and physical properties were barely investigated in terms of compost applicability. Rate of degradation varies for different wastes that dramatically affects the transformation of organics. Present research on composting of optimized mix proportions from earlier literatures for 5 different organics namely, water thyme (Drum A), water hyacinth (Drum B), vegetable waste (Drum C), sewage sludge (Drum D) and industrial sludge (Drum E) were done in 550 L rotary drum composter for 20 d in batch-mode. Compost applicability was interpreted on factors like degradation kinetics, physical (BD, FAS, etc.) and nutritional (K, Na, P, etc.) properties along with their interdependency via the statistical route (scatterplot matrix and principal component analysis). High organic matter loss (64%) in Drum B and improved bulk density (756 kg m(-3)) in Drum A inferred better suitability for soil application. Compost for all the drums (except Drum D) were observed to be well-graded in nature (coefficient of uniformity > 3 and coefficient of curvature >= 1) and could be utilized as an artificial soil in foundations or embankments to improve the physical characteristics of the soil. Present investigation through multivariate (statistical) approach are imperative to truly master the production of desired compost for both agro and engineering applications. (C) 2020 Elsevier Ltd. All rights reserved.