PROCESS OPTIMIZATION OF MICROBIAL CONSORTIUM-ASSISTED WINDROW COMPOSTING FOR ENHANCED NUTRIENT RECOVERY AND SAFE ORGANIC FERTILIZER PRODUCTION

Rahul Prataprao Padwal; Milind A. Kulkarni

doi:10.29121/shodhkosh.v7.i12s.2026.8239

Authors

Rahul Prataprao Padwal Department of Production Management, Savitribai Phule Pune University, Pune, Maharashtra, India
Prof. Dr. Milind A. Kulkarni Director, RSM’s Chetan Dattaji Gaikwad Institute of Management Studies, CDGIMS, Pune, Maharashtra, India

DOI:

https://doi.org/10.29121/shodhkosh.v7.i12s.2026.8239

Keywords:

Municipal Organic Solid Waste, Windrow Composting, Microbial Consortium, Process Optimization, Organic Fertilizer Production, Nutrient Enrichment, Heavy Metal Immobilization, Pathogen Reduction

Abstract [English]

The rapid increase in municipal and agro-industrial organic waste generation, coupled with declining soil fertility, necessitates efficient and sustainable waste-to-resource conversion strategies. Conventional composting systems often exhibit limitations such as slow degradation rates, incomplete pathogen removal, and persistence of bioavailable heavy metals, thereby restricting their agronomic and environmental applicability.
This study presents a process-optimized microbial consortium-assisted windrow composting approach for the production of high-quality organic fertilizer from municipal organic solid waste under field-scale conditions. A synergistic consortium comprising bacterial strains (Bacillus subtilis, Pseudomonas fluorescens, Lactobacillus spp.) and fungal species (Trichoderma harzianum, Aspergillus niger) was applied at 2% (w/w). The novelty of this study lies in the integrated evaluation of nutrient enrichment, pathogen inactivation, and heavy metal immobilization within a single composting system under practical operational conditions. Physicochemical, microbiological, and maturity parameters were systematically monitored over a 45-day composting period.
The consortium significantly enhanced composting efficiency, reducing stabilization time from over 70 days to 45 days. Total nitrogen increased from 0.5% to 1.5%, with corresponding increases in phosphorus and potassium (200–250%). Pathogenic indicators, including Escherichia coli and coliforms, were completely eliminated within 21 days during the thermophilic phase (65–70°C). Bioavailable heavy metals (Pb, Cd, and Zn) were reduced by 55–66%, indicating effective immobilization.
The improved performance is attributed to synergistic microbial interactions, where bacterial activity enhances enzymatic degradation and nutrient mineralization, while fungal metabolism facilitates lignocellulosic breakdown and promotes the formation of humic substances that stabilize heavy metals through complexation and adsorption mechanisms. These combined processes enable simultaneous enhancement of compost quality and biosafety.
Overall, this study demonstrates that microbial consortium-assisted windrow composting provides a scalable and efficient strategy for optimized organic fertilizer production, supporting sustainable waste management and circular bioeconomy applications.

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