Plant-based remediation techniques that can address mixtures of heavy metals and organic contaminants in soil warrant investigation due to their cost effectiveness and public acceptability. The potential of phytoremediation to remediate mixtures of heavy metals and hydrocarbons in soil is presented in two papers. A hydropic screening of twenty-seven forage grasses, grown in a solution containing 100 muM Zn, 5 muM Cu and 1 muM Cd, provided six species that were exceptionally metal tolerant. These six species were examined for their growth response and root phenolic secretion at five levels of hydroponic heavy metal contamination. Phenolic secretion, an indicator of a plant's capacity to promote polycyclic aromatic hydrocarbon (PAH) degradation, increased with heavy metal contamination, however, the values were low (<30 mug/g root). Two high biomass producing, metal-tolerant grasses, Bromus riparius and Arrhenatherum elatius, were combined with M2Rhizo4, a strain of plant growth-promoting rhizobacteria. The plant-bacterial combinations were established in artificial and genuine soils contaminated with heavy metals and PAHs at a range of concentrations. In contaminant-free artificial soil, inoculation promoted B. riparius growth by 25% compared to non-inoculated plants. In artificial soil, contaminated with 495 mg/kg Zn, 263 mg/kg Cu and 23 mg/kg Cd, M2Rhizo4 promoted B. riparius growth by 22%. In chromated-copper-arsenate (CCA) and creosote contaminated soil, M2Rhizo4 inoculated A. elatius had 15% more biomass and greater survival rates than non-inoculated A. elatius. A phytoremediation system composed of metal-tolerant plants inoculated with hydrocarbon-degrading or plant growth promoting bacteria may be suitable for sites contaminated with a mixtures of hydrocarbons and heavy metals.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30816 |
| Date | January 2000 |
| Creators | Duxbury, Patrick H. |
| Contributors | Prasher, S. O. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Agricultural and Biosystems Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001810171, proquestno: MQ70418, Theses scanned by UMI/ProQuest. |
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