Simultaneous mitigation of methane and odors in a biowindow using a pipe network

In this study, a biowindow with a piped gas collection network is proposed as an area-efficient landfill gas treatment system. A 9-m² biowindow was constructed for treating landfill gas collected from an area of 450 m² in a sanitary landfill, and its performance was evaluated for 224 days. The methane removal efficiency was 59–100% at 146.3–675.1 g-CH₄ m⁻² d⁻¹. Odorous compounds were also removed by the biowindow, with a complex odor intensity removal rate of 93–100%. In particular, the removal efficiency for hydrogen sulfide and methanethiol, major contributors to the complex odor intensity, was 97% and 91%, respectively. Metagenomic analysis showed that the dominant bacterial genera shifted from Acinetobacter and Pseudomonas to Methylobacter and Methylocaldum due to the high concentration of methane. A high bacterial diversity was maintained, which may have contributed to the robust performance of the biowindow against environmental fluctuations. At 1/50th of the size of conventional biocovers, the proposed biowindow can greatly reduce the required installation area and represents a competitive method for the simultaneous treatment of methane and odor in landfills.