Greenhouse gas (GHG) production in Swedish fiberbanks – combining GHG measurements and microbial analysis for improved assessment (FIB-GHG)

In the aquatic environment, heavily polluted fiberbanks, originating from pulp and paper industry discharges during the 19th and 20th centuries, produce large amounts of greenhouse gases (GHG). The gas is produced when microbes degrade the wood fibers under anaerobic and sulfate-free conditions.

The rate of organic matter degradation is dependent on both environmental factors (e.g. temperature and salinity) and the cooperation of different microbes, in which methanogens are responsible for the final degradation step leading to methane production.

Because of the predicted increase in temperature in the future due to climate change, GHG emissions from fiberbanks are expected to increase, with a risk of increased contaminant dispersal.

For better assessment of fiberbanks as a source of GHG more research is needed to understand which parameters affect methanogenesis in this unique type of sediment and how the GHG production differs in various aquatic environments in Sweden.

In FIB-GHG we will study fiberbanks in limnic, brackish and marine waters and investigate how methane production varies spatially and vertically within fiberbanks with different fiber types and how the production is linked to the distribution and composition of the microbial communities.

We will also determine the methane concentration in the water column above fiberbanks to explore how much of the methane released that is oxidized in the water and how much is emitted to the atmosphere.