Project Background
Oil sands tailings pondsOil sands tailings are semi-solid substances, which are made of sand, silt, clay, water, and bitumen residual. After the oil extraction process, tailings will be discharged into tailing ponds, which are temporary storage facilities and the reclamation target of the tailings reclamation project. During the storage process, the water will be extracted out of the ponds to extend the service life of tailings ponds. However, the remaining tailings will continuously release water in the storage and reclamation processes.
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Fig 3. Oil sands tailing ponds in northern Alberta |
Tailings and tailings water
For the oil extraction process, the hot water separation method is used to separate bitumen from oil sands. In this process, hot water, sodium hydroxide, and sodium carbonate are added to increase the extraction efficiency. At the same time, these chemicals make the byproducts of the extraction process, tailings, have alkaline properties, High concentrations of NaCl, Na2SO4, naphthenic acids, boron, fluoride, and heavy metals. Besides, the water released from tailings will also contain various salinity ions, including Na, sulfate, bicarbonate, and chloride, as well as Ca, and Mg. According to the research, the high pH and salinity environment can reduce the availability of nutrient elements, reduce the synthesis of photosynthetic pigments, and inhibit plant growth.
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Research Objective
There are two objectives in my research project:
1. Examining the potential effects and toxicity of oil sands tailing water to reclamation plants
2. Investigating the role of hypoxic environment in the land reclamation process
The ultimate goal of this research project is to provide knowledge to tailings regulators to select plant species with high resistance. These plants will increase the reclamation success rate and efficiency.
1. Examining the potential effects and toxicity of oil sands tailing water to reclamation plants
2. Investigating the role of hypoxic environment in the land reclamation process
The ultimate goal of this research project is to provide knowledge to tailings regulators to select plant species with high resistance. These plants will increase the reclamation success rate and efficiency.
Expected Results
In this research project, I expect that the addition of oil sands tailings water in the growth solution can inhibit the growth of plants. And the effects maybe reflected in the morphology of plants. For example, the plants treated with tailings water may have lower height and yellow leaves. Besides, I also expect that the tailing water can inhibit metabolite processes, like photosynthesis and respiration, of plants. Furthermore, I expect that the hypxic environment can aggravate the negative effects of tailings water on plants.