Title: Phytocapping: an alternative technique for landfill remediation

Authors: Nanjappa Ashwath, Kartik Venkatraman

Addresses: Centre for Plant and Water Science, CQUniversity, Rockhampton, Qld 4702, Australia. ' Centre for Plant and Water Science, CQUniversity, Rockhampton, Qld 4702, Australia

Abstract: An alternative technique of landfill remediation known as |Phytocapping| was trialled at Rockhampton, Australia. Twenty one tree species were established on two types of phytocaps (thick cap; 1400 mm soil and thin cap; 700 mm). The trial was monitored for plant growth, transpiration loss, canopy rainfall interception and methane oxidation. The results show that the tree species can intercept ca. 30% of the rainfall and they transpire 1-2 mm day−1. The phytocaps also lowered methane emission by 4-5 times compared to an adjacent non-vegetated landfill. The HYDRUS 1D simulation revealed a percolation rate of 16.7 mm yr−1 in thick phytocap and 23.8 mm yr−1 in thin phytocap. These values are significantly lower than those expected from compacted clay capping (78 mm yr−1; i.e. 10% of the rainfall). Overall, this study demonstrated that the phytocaps are effective in minimising percolation of water into buried waste. Further research is being conducted (http://www.wmaa.com.au/aacap/aacap.html), to seek approval of regulatory authorities to use phytocapping as an alternative technique of landfill remediation.

Keywords: phytocapping; sap flow; landfills; LAI; tree species; biopumps; canopy rainfall interception; methane emission; water balance; HYDRUS; landfill remediation; plant growth; transpiration loss; solid waste management.

DOI: 10.1504/IJEWM.2010.033983

International Journal of Environment and Waste Management, 2010 Vol.6 No.1/2, pp.51 - 70

Published online: 06 Jul 2010 *

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