Detoxifying Semi-Coke

Mushrooms could provide an answer to how to utilise the toxic byproduct of oil shale processing.

Project by Siim Karro, Joy Sindern
Supervisors: Kärt Ojavee, Annika Kaldoja, Erki Nagla
Estonian Academy of Arts, 2017

Semi-coke is one of the toxic by-products of shale oil production. Around 1 million tons are produced annually in Estonia alone. So far there isn’t a working solution on how to utilise or process semi-coke without harming the environment. 

Mycoremediation is the use of fungi to degrade or remove toxins from the environment. Fungi are adept at breaking down long-chained toxins into simpler, less toxic chemicals. The Oyster Mushroom (Pleurotus Ostreatus) can disassemble polycyclic aromatic hydrocarbons (PAHs), which are one of the toxic elements in semi-coke. During our experiments, we discovered oyster mushrooms’ ability to survive and grow on semi-coke. Regarding the fact that oyster mushrooms’ usual food is hardwood, we decided to use sawdust as the complementary element in the mycoremediation process.

The test made by Oil Shale Competence Center showed that the number of toxic sulfides had reduced in the semi-coke colonized by the mushroom.