Sara Yavari

Université de Montréal
Postdoctoral fellow candidate

Supervisor: Jacques Brisson
Start: 2019-02-15
End: 2020-02-28


Nutrient-Assisted Multispecies Phytoremediation of Mixed-Contaminated Soils
The rapid industrialization has led to ever-increasing accumulation of hazardous contaminants in soils which have detrimental impacts on human health and ecosystems. The polluted sites often contain both organic and inorganic contaminants that makes their removal complicated. As an example, wood utility pole storage sites are contaminated with wood preservatives, mainly pentachlorophenol and chromated copper arsenate, which are highly toxic and carcinogenic. As a sustainable treatment strategy, plant-assisted remediation provides a possible treatment solution for individual pollutants, but its application for mixed-contaminated sites have been remained limited. Plant growing in these polluted sites often need to cope with not only the toxicity of various contaminants but also with adverse environmental factors such as compacted and mineralized soil, drought, shortage of essential nutrients and so forth. There have been many efforts that contribute to improving plants efficacy to tack this problem. The use of the power of complementarity effect of plant diversity and the select of highly adapted indigenous plants are some of those approaches. However, extremely poor fertility of soil in mixed-contaminated areas restrains the remediation potential of the mixed community of indigenous plants through hindering plant growth and soil microbial activity. Therefore, the amendment of soil with appropriate amounts of fertilizers seems to be indispensable for providing technically efficient plant-assisted remediation. However, there is the possibility of interactions between nutrients and pollutants which need to be considered. This study will attempt to evaluate the role of nutrients in multispecies-assisted remediation of mixed-contaminated soils. To achieve this objective, two mesocosm experiments will be conducted in fully controlled environment greenhouse of Institut de recherche en biologie végétale- Université de Montréal. The first experiment will assess the effect of different levels of phosphorus fertilizer on desorption and adsorption mechanisms of arsenic by multi-plant species and soil material in highly mixed-contaminated soil. The second experiment will center on the effect of three ratios of nitrogen:phosphorous with two concentration levels on remediation of wood preservatives-contaminated soil. The results of this study will allow to have a better understanding of the possible interactions between nutrients and contaminants in soil environment that can be exploited for establishing a higher efficiency plant-assisted remediation in mixed-contaminated soils.