Spectral characterization and Indexing methods for the quality assessment of municipal solid waste compost prepared using novel bacterial consortia

Abstract

Composting is one of the integral components in the global circular bio-economy platform. However, the traditional composting contains major limitations, including it’s longer time requirement and formation of odour. Therefore, the inoculation of efficient novel bacterial consortia for compost process modification is a global concern. Furthermore, the assessment of compost quality is crucial because the immature compost can cause for phytotoxicity, disrupting soil structure, and damaging the natural ecological balance when used in agriculture. Conversely, there is no universally applicable procedure to determine compost quality, maturity, and stability. This study focuses on assessing the quality of compost produced by novel microbial consortia using indexing and spectroscopic methods. Clean Index (CI) Fertilizing Index (FI), Germination Index (GI) and Vigor Index (VI) were used as indexing methods whereas to assess the phyto toxicity and compost quality. Scanning Electron Microscopy (SEM), X Ray Diffraction Spectroscopy (XRD) and Energy Dispersive X-ray Spectroscopy (EDAS) techniques were used for spectroscopically analysis of compost micro structure. The results revealed that, the compost made by Consortium 5 (C5) recorded a significantly greater (p<0.05) GI, VI, FI and CI compared to the control and other treatments. Further, the GI value of C5 was recorded as 110.2 ± 2.2 %, demonstrating the possible usage of C5 compost as a phytonutrient soil amendment. Importantly, SEM, XRD and EDS spectrograms also confirmed the rapid waste degradation pattern and elemental composition alteration by the inoculated consortium. Consequently, the compost by the C5 consortium was categorized into the compost quality “A” category whereas the control compost
belonged to the compost quality “D” category. In contrast, rapid greener waste management approach in sustainable economy.