Summary: | A wastewater treatment plant has the task to refine the wastewater from substances that should not be released into the environment. The decomposition process can, in a simple way, be described as follows: micro-organisms breathe oxygen and eat unwanted substances. The environment in which the micro-organism lives is known as sludge and the correct amount of oxygen available in the sludge is important for the decomposition to be effective. The oxygenation of the sludge alone stands for about 30% of the plant’s energy consumption. The purpose of this thesis is to propose a controller for a new technology which oxygenates the sludge. In this project the oxygenation process is modeled. The model is then used to validate the proposed controllers by simulations. The result from this thesis is a PI controller with anti-windup. Other results are a monitoring system that can be used to detect toxic substances in the plant and an approach to, through the control of the oxygen level, minimize the plant’s power consumption.
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