Can phytocapping technique reduce methane emission from municipal landfills?

Landfill gases, predominantly methane and carbon dioxide, are produced by the biodegradation of organic wastes. Biodegradation occur, if the water comes in contact with the buried waste. Techniques such as clay capping are used to minimise percolation of water into the landfill, or gas collection system installed to reduce methane emission into the atmosphere. The use of clay cap has proven not effective in avoiding percolation of water and the gas extraction technique is found expensive for many landfills in Australia. Thus a new technique “Phytocapping” is being trialled at Rockhampton’s Lakes Creek Landfill. Results from this study show that Phytocaps can reduce surface methane emission 4 to 5 times more than the adjacent un-vegetated site, and the thick cap (1400 mm) reduces surface methane emission 45% more than the thin cap (700 mm). The root zone effects of 19 tree species on methane emission were also examined.