Effects of air flow directions on composting process temperature profile

Area of Science:

• Environmental Science
• Waste Management
• Agricultural Science

Background:

• Composting is a vital process for managing organic waste like chicken manure and plant residues.
• Effective aeration is crucial for optimizing composting efficiency and achieving desired end-products.
• Different airflow directions can significantly impact temperature homogeneity and material degradation during composting.

Purpose of the Study:

• To compare the effectiveness of three distinct airflow directions (sucking, blowing, and mixed) in composting chicken manure and carnation wastes.
• To determine the optimal aeration strategy for achieving homogenous temperature distribution within composting reactors.
• To evaluate the impact of airflow direction on key composting parameters and dry material losses.

Main Methods:

• Composting trials were conducted using chicken manure mixed with carnation wastes in reactors with three airflow configurations: R1 (sucking/downward), R2 (blowing/upward), and R3 (mixed).
• Radial fans were employed to manage aeration in the reactors.
• Key parameters monitored included temperature, moisture content, carbon dioxide (CO2) and oxygen (O2) ratios, and dry material losses.

Main Results:

• The mixed airflow (R3) demonstrated superior performance, yielding a more homogenous temperature distribution throughout the composting process.
• R3 also resulted in significantly higher dry material losses compared to the other methods.
• Conversely, the blowing airflow (R2) exhibited the most heterogeneous temperature distribution and the lowest dry material loss, indicating lower composting efficiency.

Conclusions:

• Mixed airflow (R3) is the most effective aeration strategy for composting chicken manure and carnation wastes, promoting homogenous temperature and efficient material degradation.
• Sucking (R1) and blowing (R2) airflow methods are less efficient, with blowing airflow being particularly detrimental to temperature homogeneity and composting effectiveness.
• Optimizing airflow direction is critical for enhancing the efficiency and success of composting operations for agricultural and horticultural wastes.