Wood biodegradation in laboratory-scale landfills

Area of Science:

• Environmental Science
• Waste Management
• Biochemistry

Background:

• Municipal solid waste contains significant wood products.
• Accurate assessment of wood biodegradability is crucial for methane production and carbon storage estimations.
• Current models often assume uniform biodegradability, which may not reflect reality.

Purpose of the Study:

• To characterize the anaerobic biodegradability of major wood products.
• To measure methane yields, decay rates, carbohydrate decomposition, carbon storage, and leachate toxicity.
• To evaluate the suitability of current waste models for wood decomposition.

Main Methods:

• Triplicate 8 L reactors were used to measure methane yields and other parameters.
• Various wood products including red oak, eucalyptus, pine, plywood, OSB, PB, and MDF were tested.
• Carbohydrate decomposition, carbon storage, and leachate toxicity were analyzed.

Main Results:

• Methane yields varied significantly across wood types, with OSB-HW showing the highest yield (84.5 mL CH(4) dry g(-1)).
• Hardwoods like red oak decomposed better than softwoods, but eucalyptus showed toxicity.
• Actual carbon conversion ranged from 0-19.9%, significantly lower than default model assumptions.

Conclusions:

• Wood species possess distinct anaerobic biodegradability and methane yields.
• The assumption of uniform wood biodegradability in waste management is inappropriate.
• Accurate characterization of wood waste is essential for reliable national methane inventories and carbon storage assessments.