VA TECH WABAG ONAS has received orders from the Tunisian wastewater authority (Office National de l’Assainissement) for wastewater treatment plants in Hergla and Enfidha in the Sousse coastal region.
The project is worth more than € 11 million and WABAG will serve as the leader of a consortium which includes the local construction company, MTT. The work is to be co-financed by the European Investment Bank (EIB).
In addition to the municipal wastewater from the towns of Enfidha and Hergla, the plant will also deal with wastewater emanating from the new airport which commences operations next year.
The wastewater treatment plant incorporates conventional wastewater treatment technologies in the form of mechanical/biological processes. An automated screen system will be used for mechanical pre-treatment while an activated sludge system is to be employed for biological treatment. Downstream sludge treatment will then follow in the form of thickening and dewatering. The wastewater treatment plant is designed for a capacity of 10,540 m3 of wastewater and a BSB5 freight of 4,200 kg/d, which corresponds with a p.e. value of 70,000.
The cleaned wastewater will be discharged into the Mediterranean via a 1.5 km submarine duct. The two-stage plant technology employed will secure environmentally compatible wastewater disposal and represents a further contribution to water protection and the retention of the marine habitat. The wastewater plant will become operational at the end of 2010.