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Phytoremediation potential of weeds: Imperata cylindrica and Pityrogramma calomelanos
Author
Lee, Si Hui
Supervisor
Tan, Swee Ngin
Abstract
Phytoremediation is an emerging environmentally-friendly and cost-effective technology for the remediation of heavy metal polluted soils. As it depends on a wide range of plant traits and their responses in different environments, there is a need to identify more plant species suitable for phytoremediation. Potential plant species may be identified from field observations or screening experiments, and the analysis of the pollutant accumulation pattern will determine if the plants are suitable for extracting or immobilising heavy metals in the environment. This study investigated the phytoremediation potential of two common weeds. Imperata cylindrica (L.) Raeusch. was preliminary identified from a field screening experiment for tolerance to molybdenum (Mo) pollution, while Pityrogramma calomelanos (L.) Link was found growing on soil highly polluted with copper (Cu). Each weed species was examined for its tolerance and accumulation of the above-mentioned heavy metal through spiking experiments in the greenhouse. No prior research has been done on these two plant species and the respective heavy metals. The results showed that I. cylindrica can tolerate up to 700 ppm of Mo in soil while accumulating small amounts of Mo in its leaves, and P. calomelanos was able to grow on soil with Cu levels of up to 2500 ppm while maintaining normal levels of Cu within its fronds. The metal accumulation patterns indicated that both species were excluders of the respective heavy metal. These findings were also supported by the respective physiological parameters monitored, which showed no significant differences between control and treated plants. Hence, the two common weeds would be suitable for immobilizing the respective heavy metals in polluted soils for the various applications of phytoremediation.
Date Issued
2015
Call Number
TD878.48 Lee
Date Submitted
2015