Modelling and control of the activated sludge process.

Abstract

During recent years there has been an increasing demand for better operation of wastewater treatment plants in order to guarantee satisfactory effluent quality at minimal cost. The renewed interest in instrumentation and control comes after a period of huge investments in sewer networks and treatment plants. Several factors have contributed to the potential for better operation and control, such as cheap computing power, improving sensors and better knowledge of process dynamics and control. The activated sludge process is recognized as the most common and major unit process for the reduction of municipal and industrial waste. Although its dynamics is complex the potential for control is far from exhausted. Already with commercially available instrumentation today its operation can be significantly improved. In the process heterotrophic microorganisms react with organic pollutants in the wastewater and with oxygen dissolved in the water to produce more cell mass, carbon dioxide and water. Nitrifying organisms