Methane production from cattle waste in laboratory reactors at 40 degrees and 60 degrees C after solid-liquid...

Area of Science:

• Environmental Science
• Biotechnology
• Anaerobic Digestion

Background:

• Dairy waste presents a significant disposal challenge.
• Anaerobic digestion is a viable technology for dairy waste valorization.
• Optimizing digestion conditions is crucial for maximizing methane yields.

Purpose of the Study:

• To compare methane production from whole dairy waste and separated liquid effluent.
• To evaluate the effect of mesophilic and thermophilic temperatures on methane yield.
• To assess the impact of retention times on the efficiency of anaerobic digestion.

Main Methods:

• Dairy waste and separated effluent were subjected to anaerobic digestion.
• Fermentation was conducted in reactors operating at mesophilic (40°C) and thermophilic (60°C) temperatures.
• Volatile solids content and methane production were analyzed at different retention times.

Main Results:

• Thermophilic reactors demonstrated superior methane production compared to mesophilic reactors.
• Methane yield from whole waste (156 ml/g VS) and separated effluent (173 ml/g VS) were comparable.
• At 60°C, methane production (166 ml/g VS) was efficient at shorter retention times (3-6 days) than at 40°C (162 ml/g VS at 5-10 days).
• Thermophilic reactors achieved higher daily methane output (1.67 L/L/day) than mesophilic reactors (0.93 L/L/day).

Conclusions:

• Thermophilic anaerobic digestion is more effective for dairy waste treatment and methane generation.
• Separating solids does not significantly impact the overall efficiency of methane production.
• Optimized temperature and retention time are key factors for maximizing biogas yield from dairy waste.