Process automation in Wastewater Treatment Plants: the Finnish experience

The degree and importance of automation at municipal wastewater treatment plants (WWTPs) have increased with the development of technology and tightening of treatment requirements. The objective of this paper is to assess and document the current status of process automation at WWTPs in Finland to determine successful practices and the needs of plant operators. Renewing ammonia or organic content removal processes to total nitrogen removal processes has also increased the need of Instrumentation, Control and Automation (ICA). The survey has quantified that the reliability and accuracy of the on-line sensor measurement has improved recently, which makes the use of on-line measurements in control more applicable. The use of nutrient sensors in control is apparently still rare at Finnish WWTPs even though their use for monitoring purposes is common.