Performance study of compounded biocover material for methane removal based on cattle manure compost

Area of Science:

• Environmental Science
• Microbiology
• Geochemistry

Background:

• Methane is a potent greenhouse gas, second only to carbon dioxide in significance.
• Landfill cover soils are crucial for mitigating methane emissions from landfills.
• Cattle manure compost (CMC) is explored as a potential biocover material.

Purpose of the Study:

• To construct and evaluate methane removal biocover materials based on CMC.
• To compare the methane removal efficiency of CMC with traditional materials (sand, clay soil, paddy soil).
• To investigate the performance of compounded biocover materials (CBMs) incorporating CMC.

Main Methods:

• Comparative analysis of methane (CH4) removal by sand (S), clay soil (CS), paddy soil (PS), and CMC.
• Determination of maximum removal rate (Vmax) and half saturation constant (Km) for CMC.
• Construction and testing of three CBMs (ratio 2:8 CMC to other materials).
• Optimization of moisture (80% saturated water content) and temperature (35 °C) for CBMs.
• Analysis of bacterial community diversity using terminal restriction fragment length polymorphism (T-RFLP).

Main Results:

• CMC exhibited superior CH4 removal compared to S, CS, and PS.
• CMC showed high Vmax (3451.25 ± 18.57 μg g⁻¹ h⁻¹) and Km (3.67 ± 0.02 × 10⁵ ppm).
• CBMs enhanced CH4 removal rates by 13.56 to 16.42 times compared to individual materials.
• Optimal conditions for CBMs were 80% saturated water content and 35 °C.
• CMC addition decreased diversity and evenness but enriched Type I methanotrophs in CBMs.

Conclusions:

• CMC is a highly effective biocover material for methane emission reduction.
• CBMs incorporating CMC significantly improve methane removal capacity.
• Optimized CBMs represent a viable strategy for mitigating landfill methane emissions.