The environmental benefits of the art-ICA controllers lie in their ability to noticeably improve the performance of current wastewater treatment processes. This performance will become apparent in the form of:
- Lower levels of pollutants in treated effluents;
- Reductions in electricity consumption.
The environmental benefits of the art-ICA controllers mainly come from the improved performance that wastewater treatment plants (WWTPs) will experience immediately after installation. Accordingly, the environmental indicators for the art-ICA controllers will describe comparative performance figures for controlled and conventional plant operation (the latter representing the baseline for comparison). In fact, the reality in most of the urban biological nutrient removal WWTPs is that plant operators manually manipulate the set-point values for the sludge surplus pump, the internal recycling pump and the external air supply. Three indicators will be adopted to determine the environmental impact of the art-ICA controllers: nutrients, energy consumption and CO2 emissions.
We estimate that at the end of the project (2016) the replication of the art-ICA controllers in three real-world biological nutrient removal plants will give rise to reductions in CO2 emissions of around 116 t CO2/year (-20 %), to savings in electricity above 0.4 GWh/year (-20 %), and to reductions of nitrogen emissions in the treated effluents that are close to 115 t N/year (-10 %).
Considering the size that the potential market for the art-ICA controllers is expected to reach by 2018 and the dissemination and commercial activities that the partners of the artICA4nr project will carry out during the course of the project, it is realistic to estimate that the art-ICA controllers might be working in 14 additional wastewater plants by 2018. If such estimates come true, the net environmental benefits directly attributable to the art-ICA controllers will be more than 406 t CO2/year in CO2 emission reductions, approximately 1.4 GWh/year in electricity savings, and close to 403 t N/year in nitrogen emission reductions in the treated effluents.
The above performance improvements will be the result of the art-ICA controllers’ operating principle, which rests on applying feedback control to automatically adjust the plant’s actuators to values that achieve an optimum balance at all times between pollutant removal and energy use. The project will measure the performance of the art-ICA controllers in three different real-world plants to prove that this principle works in a broad sense.