Using immune cell-based bioactivity assays to compare the inflammatory activities of oil sands process-affected waters from a pilot scale demonstration pit lake

In this study,we provide evidence that oil sands process-affected waters(OSPW)contain factors that activate the antimicrobial and proinflammatory responses of immune cells.Specifically,using the murine macrophage RAW 264.7 cell line,we establish the bioactivity of two different OSPW samples and their isolated fractions.Here,we directly compared the bioactivity of two pilot scale demonstration pit lake(DPL)water samples,which included expressed water from treated tailings(termed the before water capping sample;BWC)as well as an after water capping(AWC)sample consisting of a mixture of expressed water,precipitation,upland runoff,coagulated OSPW and added freshwater.Significant inflammatory(i.e.macrophage activating)bioactivity was associated with the AWC sample and its organic fraction(OF),whereas the BWC sample had reduced bioactivity that was primarily associated with its inorganic fraction(IF).Overall,these results indicate that at non-toxic exposure doses,the RAW 264.7 cell line serves as an acute,sensitive and reliable biosensor for the screening of inflammatory constituents within and among discrete OSPW samples.

Abiotic and biotic constituents of oil sands process-affected waters

The oil sands in Northern Alberta are the largest oil sands in the world,providing an important economic resource for the Canadian energy industry.The extraction of petroleum in the oil sands begins with the addition of hot water to the bituminous sediment,generating oil sands process-affected water(OSPW),which is acutely toxic to organisms.Trillions of litres of OSPW are stored on oil sands mining leased sites in man-made reservoirs called tailings ponds.As the volume of OSPW increases,concerns arise regarding the reclamation and eventual release of this water back into the environment.OSPW is composed of a complex and heterogeneous mix of components that vary based on factors such as company extraction techniques,age of the water,location,and bitumen ore quality.Therefore,the effective remediation of OSPW requires the consideration of abiotic and biotic constituents within it to understand short and long term effects of treatments used.This review summarizes selected chemicals and organisms in these waters and their interactions to provide a holistic perspective on the physiochemical and microbial dynamics underpinning OSPW.