Simple control system in Daugavpils wastewater treatment plant
One of the technologies implemented within the IWAMA project was an investment into installing new equipment (1 valve on aeration system and 42 energy meters) in Daugavpils WWTP, which allows organizing maintenance works without harm to technological (biological) process and keeps separate electricity records by main consumer groups (return sludge pumps, aeration mixers, compressors, centrifuges). Collected real time data allows to control, analyze and in short time correct and optimize settings of equipment used, reducing energy consumption while maintaining the required quality of wastewater treatment.
Daugavpils WWTP serves 80 174 PE (2018), and about 11 613 m³ of wastewater collected from a combined sewer network is treated daily. Based on the original Soviet style design, the WWTP has been renovated and upgraded. The current treatment process consists of mechanical pre-treatment (screen, aerated grid removal), biological treatment in two lines and sludge dewatering by centrifuges. Before the investment was realized, the process control enabled the staff to monitor flows, selected concentrations and setting/configuration of equipment, but no information about the energy consumption of the total process and of specific units was available. In case of maintenance works in one of four aeration tanks, which could only be performed in empty tank, the air supply to the other tanks had to be stopped accordingly, since the pipes for air supply were interconnected without any valve.
As a result of the investment, the staff includes the monitored energy consumption to the evaluation of the treatment efficiency enabling identification of saving potentials.