Can phytocapping technique reduce methane emission from municipal landfills?

Abstract

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.

A comprehensive review of sectorial contribution towards greenhouse gas emissions and progress in carbon capture and storage in Pakistan

“…Landfills are the most convenient, efficient and economical method to dispose of the waste as waste is a major source of climate change and global warming. CH 4 is produced by decomposition of organic matters while handling and depositing the solid waste in the landfills . As per the Global Methane Initiative, the international anthropogenic CH 4 was accounted to be at 6.875 Gt CO 2 ‐eq in 2010, and if no efforts are made it is likely to reach up to 8.586 Gt CO 2 ‐eq in 2020 .…”

“…CH 4 is produced by decomposition of organic matters while handling and depositing the solid waste in the landfills. 91 As per the Global Methane Initiative, the international anthropogenic CH 4 was accounted to be at 6.875 Gt CO 2 -eq in 2010, and if no efforts are made it is likely to reach up to 8.586 Gt CO 2 -eq in 2020. 92 Diversified efforts are underway to minimize anthropogenic CH 4 emissions through modernization of technologies.…”

Organic carbon storage change in China's urban landfills from 1978–2014

“…Fourth, the difference in representing organic matter decomposition between our study and Churkina et al (2010) might have contributed to the discrepancy. Biodegradation of organic matter is likely to occur in the landfills despite the advancement of capping technology that could reduce the fugitive carbon release into the atmosphere after closure (Venkatraman and Ashwath 2008, Lamb et al 2014. Accumulative deduction of degraded organic matter present in the landfills from our study would result in a lower OC storage relative to the estimate that does not consider decomposition, as in the case of the United States study (Churkina et al 2010).…”

Phyto cover for Sanitary Landfill Sites: A brief review

“…In this technique, trees are established/planted on a layer of soil cap placed over the refuse. Soil cover acts as a "storage" and trees act as "bio-pump and filters" show that the planted trees can remove more water than that received via rainfall and rainfall [13]. Functions of phytocaps are to control percolation of water into waste, promotes surface runoff, minimise erosion, control odour and land fill gases oxidation [38].…”

“…Overall phycapping can reduce 80% of methane emissions from landfill compared to un-vegetated fields. Thick cover of soil has better water carrying capacity than thin cover [13]. Biocovers while offering the advantages of covering an entire landfill while also simultaneously providing good water holding capacity and porosity for vegetation and evapotranspiration.…”