ABSTRACT
Conventional materials, such as compacted clay or geo-synthetic clay liners, are still used for the closure of landfills in developed countries. Moreover, conventional capping technologies are now considered to be increasingly ineffective in reducing percolation of water into waste. Hence, cost-effective alternative systems are of increasing interest, including the use of plants to control and limit the entry of water into waste, which is known as phytocapping. Phytocapping has been shown to be at least as effective as clay capping in reducing percolation through landfill cover materials, along with providing many additional benefits, such as increased cap stability, reduced erosion of capping materials, reduction of wind-blown dust, carbon sequestration, and enhanced methane oxidation from microbial communities. The most common approach is the construction of vegetation assemblages for the purposes of creating natural vegetation nodes. Appropriate selection of plant species can enhance methane oxidation in capping soils. There is considerable potential for the use of high biomass energy plants, but choosing an appropriate plant species is a Herculean task. The different aspects of phytocapping landfill sites are presented in this chapter.
