Smart Wastewater Treatment Aeration for Reducing Operational Costs and Greenhouse Gas Emissions

Wastewater treatment plants (WWTP) treat most of the water that is used in households and industry before it is discharged back to the environment. One of the key treatment steps in a plant is the biological treatment which reduces nutrient concentrations in the water. This protects the recipients against eutrophication and acidification and hence WWTPs are a key infrastructure in terms of securing water quality in lakes, rivers, fiords, and seas. The main catalyst in the biological treatment step is the addition of oxygen, as this activates some specialized bacteria which in return reduce nutrient concentrations. However, the addition of air to the wastewater requires a large amount of electricity to run huge blower stations. For the utility company operating the WWTP, this can be both a heavy expense and related to large emissions of greenhouse gasses. In this study, a new control algorithm for the aeration (i.e. adding air) is developed. The algorithm plans operation with respect to data from electricity markets and production and hence it helps to reduce costs and emissions to the benefit of future smart cities.