Testing effectiveness of treating oil sands process - affected water

Client: Syncrude Canada (now Suncor)

Time: 2018 – 2022

Services: Study design, client support, mesocosm design, fabrication, and operation, field operations, lab management, data management and analysis in R and Primer7, reporting.

Syncrude Canada Ltd. (now Suncor) developed a novel technology to treat oil sand process-affected water (OSPW) using fresh fluid petroleum coke as an adsorbent, to improve its quality with an overall goal of making Treated OSPW safe for future, managed release to regional aquatic receiving environments. Relative to untreated OSPW, a pilot-scale facility operated in 2021 greatly reduced concentrations of organic constituents of OSPW and of several dissolved and total metals, and eliminated acute toxicity, with small or negligible changes in major ions and total dissolved solids..

As part of a broad assessment to test longer term ecotoxicity, a site-based mesocosm with 32 independent experimental streams was used to test a series of  dilutions of treated OSPW in Athabasca River water on epilithic algae and benthic invertebrate assemblages. Seven logarithmically separated dilutions ranging from 100% treated OSPW to a control of 0% treated OSPW plus an extra control were replicated four times and controlled using a precision pump system. Substrate and native biota from the Athabacsa River were introduced to the streams. Periphyton response was additionally tested using measurement of growth on artificial substrata. The mesocosm operated for five weeks. Dose response curves and biotic assemblages showed logarithmic patterns. The mesocosm findings coupled with sublethal toxicity testing will be used to support decisions on potential discharge of OSPW.

Collaboration with

Let’s do more like this together