Unlike incineration or gasification, thermolysis optimises energy production. The gas produced, which can be recycled to treat new sludge, allows the plant to meet its own energy requirements. Moreover, there is no oxidation reaction (combustion) of the matter, only decomposition, enabling a notable reduction in fumes and harmful volatile elements. Pollutants such as heavy metals, when present, are trapped then stabilised. They can then be stored without causing a nuisance for the environment.

Thermolysis, which has been tested over the past year and a half by Saur's technical department at the Voreppe wastewater treatment plant (south-eastern France), operated by Saur France, is a flexible process perfectly adapted to the changing needs of local authorities and companies. The installation allows for substantial variations in sludge quantity, since the reactor can be operated at 50% of nominal load.

In Europe, municipalities and companies are responsible for sludge treatment and for ensuring that it is recycled or eliminated under ecologically and economically viable conditions in compliance with increasingly stringent standards. Stéreau is a wholly-owned subsidiary of Saur (Bouygues group), and one of France's leading water treatment specialists. The company designs and builds drinking water/process water and wastewater treatment facilities in France and abroad. Among its recent achievements are the construction of wastewater treatment plants at Glasgow-West (Scotland), Nantes, Orléans, Annecy, Caen and Tours (France), along with drinking water treatment plants in Harbin (China), Bray (UK), Aix-les-Bains and Douarnez. It also works alongside several companies such as the Atomic Energy Commission CEA, French power utility EDF, Kodak and Renault. (December 2001)

Information & Contact:

Fabrice Nauleau
Tel. +33 1 30 78 49 00