30 april 2015

Generating green energy in Warsaw

Culminating a four-year effort, the city of Warsaw inaugurated its new wastewater treatment plant, bringing the city in line with European standards.

With capacity for a population equivalent of 2.1 million, the new plant is one of the largest in Eastern Europe. It treats 435,000 cubic meters per day (m3/d) of wastewater, and can handle up to 515,000 m3/d at peak flow rate — well in excess of the old plant’s capacity of around 200,000 m3/d.

Completed by Veolia, the enormous project included installation of 30 kilometers of wastewater collection systems and construction of a tunnel and siphon under Warsaw’s Vistula River to transport left bank effluent, as well a  rebuilding, modernizing, and extending the existing treatment plant and building a sludge incineration plant.

The plant’s treatment system is based on activated sludge technology, selected for its reliable treatment and service. The wastewater is settled and treated biologically to remove the carbon, phosphate, and nitrogen. Biological treatment is managed using advanced controls — enabling high-level treatment performance, while saving energy and chemical consumption. Once the wastewater has been treated the sludge is incinerated in a furnace at 850 degrees Celsius using Veolia’s Pyrofluid™ thermal treatment process, which oxidizes the organic matter and produces recoverable ash and energy. The incineration plant also uses the sludge’s inherent heat to generate green energy.

Due to the technical performance of the processes used at this plant, the incineration flue gas released into the atmosphere above the Polish capital falls well within the area’s highly stringent air quality standards -- all part of the green revolution underway in Warsaw.