Tuesday 02 Dec 2014: Multi-objective optimisation of wastewater treatment plant control to reduce greenhouse gas emissions
Christine Sweetapple -
Harrison 103 13:00-14:00
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, although trade-offs exist and a balancing act is necessary. However, conclusions drawn from previous studies regarding the reduction of GHG emissions are based on only a limited number of control scenarios and further improvements achievable by multi-objective optimisation of operational parameters have not been investigated.
In this presentation, the primary sources of GHG production in wastewater treatment will be introduced and a dynamic emissions model for an activated sludge wastewater treatment plant presented. Multi-objective optimisation is then used to derive sets of Pareto optimal operational and control parameters, with objectives including minimisation of operational costs, GHG emissions and effluent pollutant concentrations. The sets of optimal solutions enable identification of trade-offs and conflicting objectives; it is demonstrated that multi-objective optimisation of wastewater treatment plant control can facilitate a significant reduction in GHG emissions without the need for plant redesign or modification of the control strategy layout, but these are subject to trade-offs.