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Title:	Phytoremediation of spiked inorganic mercury in sand using native Malaysian plants
Authors:	Huda Salem Mohamed Alrawiq (P50778)
Supervisor:	Mushrifah Idris, Dato' Prof. Dr.
Keywords:	Phytoremediation Inorganic Mercury Sand Native plant Dissertations, Academic -- Malaysia
Issue Date:	6-Oct-2016
Description:	The development of industry, mining activity, irrigation of waste water, and the application of sewage sludge to agricultural lands have increased the release of metals into our ecosystems causing serious environmental problems and posing threats to human health. Mercury (Hg) is one of the most significant environmental contaminates and health concerns. Phytoremediation is a process of using environmentally- friendly and cost effective technology, to clean up heavy metals and toxic compound from contaminated environment. This research investigated the potential use of native plant species - Paspalum vaginatum, Paspalum scrobiculatum, Eragrostis atrovirens and Ludwigia octovalvis for the phytoremediation of mercury contaminated soil. This requires plant species tolerate Hg in the soil, and accumulate it within easily harvestable tissues. The plants were exposed to concentrations of 0, 0.5, 1 and 2 mg/L of mercury for 70 days. Mercury uptake induced a significant reduction in both wet and dry biomass, also root and stem length for all plant species. Mercury concentration in shoots as well as in the roots increased with increasing Hg concentrations in the growth medium. Moreover, mercury accumulation varied within the plant tissues i.e. roots and shoots. The concentration of Hg in the root tissues of P. vaginatum, P. scrobiculatum, E. atrovirens and L. octovalvis were found in the range of 0.31–11.50, 0.79–19.12, 1.45–7.77 and 1.06–15.06 mg/kg whereas the corresponding shoot values were 0.18– 4.36, 0.16–3.94, 0.24–2.80 and 0.17–3.14 mg/kg respectively. Among the four species, P. scrobiculatum accumulated maximum Hg (19.92 mg/kg, in dry weight), L. octovalvis (16.83 mg/kg, in dry weight), followed by P. vaginatum (11.70 mg/kg, in dry weight), and E. atrovirens (8.53 mg/kg, in dry weight). The translocation factor (TF) ranged between 0.02–1.02, 0.03–3.236, 0.09–0.90, and 0.10–0.91 for P. vaginatum, P. scrobiculatum, E. atrovirens and L. octovalvis respectively. All the plants were found to have bioaccumulation factor of >1, which reflects their high metal accumulation potential. All the four plants were able to remove Hg from the contaminated soil. The average removal efficiency for the four plant species was 83.2% (P. vaginatum), 96.5% (P. scrobiculatum), 94.4% (E. atrovirens) and 93.1% (L.octovalvis) respectively. Light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to study the structural change of the plant species. Observation under the LM showed Hg exposure caused dark deposits in the endodermal cells and vascular cylinder and rupturing of the parenchyma tissue. Observation under the SEM showed cells degeneration and thickening of cell walls, increasing number of treacherous element in vascular tissue as well as accumulation of residue in the cell. Observation under TEM showed the loss of cell shape and reduction of intercellular spaces. The palisade chloroplasts exhibited decreases in their amounts as well as a loss of spindle shape. Moreover, chloroplasts contained a large number of plastoglobuli and an increase of starch grains (number and size). As a conclusion, the selected plant species can be potential candidates for phytostabilization of mercury-ontaminated soils.,Certification of Master's/Doctoral Thesis" is not available
Pages:	281
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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