Microbial diversity during Rotary Drum and Windrow Pile composting

Area of Science:

• Environmental Microbiology
• Waste Management
• Biotechnology

Background:

• Composting is a sustainable method for organic waste management.
• Understanding microbial dynamics is crucial for optimizing composting efficiency and compost quality.

Purpose of the Study:

• To investigate and compare microbial communities and physico-chemical changes during composting of vegetable waste, cattle manure, and sawdust.
• To evaluate the effectiveness of Rotary Drum and Windrow Pile composting systems.

Main Methods:

• Household-scale Rotary Drum and Windrow Pile composting systems were used.
• Physico-chemical parameters (organic matter, C/N ratio) and microbial populations (bacteria, fungi, fecal coliforms, E. coli, Salmonella) were analyzed.
• Scanning electron microscopy was employed to study mycoflora surface structures.

Main Results:

• Rotary drum composting showed greater reduction in organic matter and C/N ratio compared to windrow composting.
• Total heterotrophic bacteria decreased in both systems, while fungal load initially increased then decreased.
• Pathogenic bacteria like fecal coliforms and Streptococci significantly reduced over time.
• Rotary drum system exhibited higher microbial diversity, leading to more stable and pathogen-free compost in a shorter period.

Conclusions:

• Rotary drum composting is superior to windrow composting for rapid and effective treatment of vegetable waste, cattle manure, and sawdust.
• Microbial community shifts, driven by organic matter transformation and temperature, are key to successful composting.
• The study highlights the potential of Rotary Drum composting for producing high-quality, safe compost.