Biological waste-water treatment plants (ABB)

Current situation

This industry normally uses very basic control system, so the performance can be really improved through the implementation of the methods with control, based on various quality measurements of incoming waste.

Improvement potential

For waste water treatment plants using activated sludge processes it has been identified the possibility to combine algae with microorganisms and thereby eliminate the aeration demand, giving at the same time more biomass and hence biogas as well. Aeration demand constitutes 50% of the electric energy demand in current waste water treatment plants and corresponds to about 2% of the total electric energy demand in developed countries. As the total consumption of electricity in EU is around 3400TWh/year the savings potential is in the range of 60-80 TWh(el)/year. With a cost of electricity at 100€/MWh this means electricity savings in the range of 3-4B€/year. At the same time the biogas production can be increased by some 25% in those plants utilising sludge for biogas production, and much more where biogas is still not produced.