Oil Sands Flashcards
(23 cards)
What is crude oil?
animal and plant remains that sunk to the bottom of the ocean, covered by sand and sediments, and through heat and pressure became petroleum
What is conventional oil?
recovered as a liquid at atmospheric pressure
How are oil sands formed?
algae and marine life decomposed into light oil, microbes fed off of lighter hydrocarbons and left behind heavier complex hydrocarbons with sulphur and trace metals
What is the composition of oil sands?
10% bitumen (thick viscous form of petroleum), 5% water and 85% solids (clays, silica sand)
What is unconventional oil?
can’t be extracted by conventional drilling and requires some form of processing
How much of the bitumen present in the AB oil sands can actually be recovered?
10%
What is the common in situ way to collect the oil sand?
one well injected with steam and the other collects softened bitumen, no tailings pond, high water and energy use
Describe the surface mining technique to extract the oil sand
large pits dug to expose sand reserves, oil sands transported into crushers, hot water used to separate bitumen from the sand and water, bitumen then used to create synthetic oil
How many tonnes of oil sand produces 1 barrel of crude oil?
2 tonnes
What are the pollutants that are emitted from oil sands?
Co2, SO2, NOx, metals and PAHs
What was one concerning study that was brought up on the Athabasca oil sands?
Oxidized mercury in the air wre up 60% within 50km of the oil sands
What are tailings ponds?
large pools of water mixed with sand, silt, clay, metals and PAHs, cannot be released back into the environment
Why is the presence of PAHs in the oil a concern?
it produces alkylated PAHs which are more toxic, persistent and less water soluble than the unsubstituted PAHs
What are the four major mechanisms of toxicity regarding PAHs?
nonpolar narcosis—> alters membrane fluidity
activation of aryl hydrocarbon receptor
bioactivation of ultimate carcinogens
bioactivation of quinones
What were the implications from the snowpack study?
PAHs were being released into water in the spring after snowmelt which is the same time as fish breed. Leads to pericardial edema, hemorrhaging, spinal deformities and CYP1A1 induction
What was significant from the PAC studies?
They were present in the areas around the oil sands, in forage fish they were below consumption guidelines, often most toxic to larval fish
What are the side effects to being exposed to oil sand processed water?
developmental, reproductive and immunotoxic effects, but reduces as bacteria break down compounds
What endocrine glands are affected by OSPW and what occurs in the fish?
affects gene expression in hypothalamus, pituitary and gonads, and disrupts estrogen balance
Males: vitellogenin genes induced, decreased 2ary sex characteristics
Females: decreased estradiol concentrations in females, lower fecundity and decreased 2ary sex characteristics
What are the immunotoxic effects of OSPW?
reduces B and T cells in spleens
What are the properties of naphthenic acids?
organic acids, have a polar and non polar section
What is NAs mechanism of toxicity?
uncouple oxidative phosphorylation and ROS emission in mitochondria
What were the results from the fractionated tests
toxicity varied on species tested, OPSW and inorganics caused toxicity. the non polar fraction was generally non toxic
What toxicants are present in the OSPW?
high concentrations of HCO3-, vanadium, mercury, arsenic, PAHS and Napthenic acid
