Tuesday 03 Dec 2013: Identifying key sources of uncertainty in the modelling of greenhouse gas emissions from wastewater treatment
Christine Sweetapple - University of Exeter
Harrison 170 14:00-15:00
Wastewater treatment processes can result in significant emissions of greenhouse gases (GHGs) and it is recognised that appropriate design and operation of wastewater treatment processes can play a significant role in mitigating the effects of global warming. It has been shown, through modelling, that automatic control can reduce GHG emissions. However, models used are typically of hypothetical plants and are not always validated with real data; as such, their results are subject to a high degree of uncertainty and careful calibration is essential if they are to be applied to plant design or control strategy development for real wastewater treatment plants. Efficient calibration of emission models can be aided by identification of the most significant sources of uncertainty, yet there has been little previous research into the effects of uncertainty in model parameters and emission factors on GHG emission estimates. In this presentation, the primary sources of GHG production in wastewater treatment will be introduced and a detailed dynamic emissions model for an activated sludge wastewater treatment plant presented. Sources of uncertainty in modelled GHG emissions, in addition to the more conventional performance indicators of effluent quality and cost, will then be investigated through the use of local and global sensitivity analysis tools; these reveal critical parameters and parameter interactions contributing to uncertainty in key model outputs, thereby providing a better understanding of wastewater treatment plant characterisation.